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Sample records for abo3-type perovskite compounds

  1. High-throughput DFT calculations of formation energy, stability and oxygen vacancy formation energy of ABO3 perovskites

    Science.gov (United States)

    Emery, Antoine A.; Wolverton, Chris

    2017-10-01

    ABO3 perovskites are oxide materials that are used for a variety of applications such as solid oxide fuel cells, piezo-, ferro-electricity and water splitting. Due to their remarkable stability with respect to cation substitution, new compounds for such applications potentially await discovery. In this work, we present an exhaustive dataset of formation energies of 5,329 cubic and distorted perovskites that were calculated using first-principles density functional theory. In addition to formation energies, several additional properties such as oxidation states, band gap, oxygen vacancy formation energy, and thermodynamic stability with respect to all phases in the Open Quantum Materials Database are also made publicly available. This large dataset for this ubiquitous crystal structure type contains 395 perovskites that are predicted to be thermodynamically stable, of which many have not yet been experimentally reported, and therefore represent theoretical predictions. The dataset thus opens avenues for future use, including materials discovery in many research-active areas.

  2. Ceramic materials on perovskite-type structure for electronic applications

    International Nuclear Information System (INIS)

    Surowiak, Z.

    2003-01-01

    Ceramic materials exhibiting the perovskite-type structure constitute among others, resource base for many fields of widely understood electronics (i.e., piezoelectronics, accustoelectronics, optoelectronics, computer science, tele- and radioelectronics etc.). Most often they are used for fabrication of different type sensors (detectors), transducers, ferroelectric memories, limiters of the electronic current intensity, etc., and hence they are numbered among so-called intelligent materials. Prototype structure of this group of materials is the structure of the mineral called perovskite (CaTiO 3 ). By means of right choice of the chemical composition of ABO 3 and deforming the regular perovskite structure (m3m) more than 5000 different chemical compounds and solid solutions exhibiting the perovskite-type structure have been fabricated. The concept of perovskite functional ceramics among often things ferroelectric ceramics, pyroelectric ceramics, piezoelectric ceramics, electrostrictive ceramics, posistor ceramics, superconductive ceramics and ferromagnetic ceramics. New possibilities of application of the perovskite-type ceramics are opened by nanotechnology. (author)

  3. Generalized trends in the formation energies of perovskite oxides

    DEFF Research Database (Denmark)

    Zeng, Zhenhua; Calle-Vallejo, Federico; Mogensen, Mogens Bjerg

    2013-01-01

    Generalized trends in the formation energies of several families of perovskite oxides (ABO3) and plausible explanations to their existence are provided in this study through a combination of DFT calculations, solid-state physics analyses and simple physical/chemical descriptors. The studied...... elements at the A site of perovskites comprise rare-earth, alkaline-earth and alkaline metals, whereas 3d and 5d metals were studied at the B site. We also include ReO3-type compounds, which have the same crystal structure of cubic ABO3 perovskites except without A-site elements. From the observations we...... extract the following four conclusions for the perovskites studied in the present paper: for a given cation at the B site, (I) perovskites with cations of identical oxidation state at the A site possess close formation energies; and (II) perovskites with cations of different oxidation states at the A site...

  4. Ab initio Defect Energetics in LaBO3 Perovskite Solid Oxide Fuel Cell Materials

    DEFF Research Database (Denmark)

    Lee, Yueh-Lin; Morgan, Dane; Kleis, Jesper

    2009-01-01

    Perovskite materials of the form ABO3 are a promising family of compounds for use in solid oxide fuel cell (SOFC) cathodes. Study of the physics of these compounds under SOFC conditions with ab initio methods is particularly challenging due to high temperatures, exchange of oxygen with O2 gas...

  5. Interfacial coupling and polarization of perovskite ABO3 heterostructures

    Science.gov (United States)

    Wu, Lijun; Wang, Zhen; Zhang, Bangmin; Yu, Liping; Chow, G. M.; Tao, Jing; Han, Myung-Geun; Guo, Hangwen; Chen, Lina; Plummer, E. W.; Zhang, Jiandi; Zhu, Yimei

    2017-02-01

    Interfaces with subtle difference in atomic and electronic structures in perovskite ABO3 heterostructures often yield intriguingly different properties, yet their exact roles remain elusive. In this article, we report an integrated study of unusual transport, magnetic, and structural properties of Pr0.67Sr0.33MnO3 (PSMO) films and La0.67Sr0.33MnO3 (LSMO) films of various thicknesses on SrTiO3 (STO) substrate. In particular, using atomically resolved imaging and electron energy-loss spectroscopy (EELS), we measured interface related local lattice distortion, BO6 octahedral rotation and cation-anion displacement induced polarization. In the very thin PSMO film, an unexpected interface-induced ferromagnetic polaronic insulator phase was observed during the cubic-to-tetragonal phase transition of the substrate STO, due to the enhanced electron-phonon interaction and atomic disorder in the film. On the other hand, for the very thin LSMO films we observed a remarkably deep polarization in non-ferroelectric STO substrate near the interface. Combining the experimental results with first principles calculations, we propose that the observed deep polarization is induced by an electric field originating from oxygen vacancies that extend beyond a dozen unit-cells from the interface, thus providing important evidence of the role of defects in the emergent interface properties of transition metal oxides.

  6. Oxyfluoride Chemistry of Layered Perovskite Compounds

    Directory of Open Access Journals (Sweden)

    Yoshihiro Tsujimoto

    2012-03-01

    Full Text Available In this paper, we review recent progress and new challenges in the area of oxyfluoride perovskite, especially layered systems including Ruddlesden-Popper (RP, Dion-Jacobson (DJ and Aurivillius (AV type perovskite families. It is difficult to synthesize oxyfluoride perovskite using a conventional solid-state reaction because of the high chemical stability of the simple fluoride starting materials. Nevertheless, persistent efforts made by solid-state chemists have led to a major breakthrough in stabilizing such a mixed anion system. In particular, it is known that layered perovskite compounds exhibit a rich variety of O/F site occupation according to the synthesis used. We also present the synthetic strategies to further extend RP type perovskite compounds, with particular reference to newly synthesized oxyfluorides, Sr2CoO3F and Sr3Fe2O5+xF2−x (x ~ 0.44.

  7. Synthesis and characterization of Ba_0_._5Pb_0_._5TiO_3 perovskite - type thin films deposited by spin coating at low temperatures

    International Nuclear Information System (INIS)

    Wermuth, T.B.; Wiederkehr, N.A.; Alves, A.K.; Bergmann, C.P.

    2014-01-01

    In this paper we present a non-aqueous sol-gel route for the obtention of solid compounds and thin films of oxide type- perovskite ABO_3, such as Ba_0_._5 Pb_0_._5 TiO_3, synthesized by sol - gel route with subsequent heat treatment. The solid compounds were characterized by X-ray diffraction (XRD) techniques and thermal analysis (TGA / DTA). The thin film was obtained by using spin-coating techniques at low temperatures onto commercial substrates of polymethylmethacrylate (PMMA) and characterized by contact angle, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results show that the films present microstructures and roughness directly related to annealing temperatures, characterized by the formation of crystalline nanostructures with surface regularity and transparency. (author)

  8. Generalized trends in the formation energies of perovskite oxides.

    Science.gov (United States)

    Zeng, ZhenHua; Calle-Vallejo, Federico; Mogensen, Mogens B; Rossmeisl, Jan

    2013-05-28

    Generalized trends in the formation energies of several families of perovskite oxides (ABO3) and plausible explanations to their existence are provided in this study through a combination of DFT calculations, solid-state physics analyses and simple physical/chemical descriptors. The studied elements at the A site of perovskites comprise rare-earth, alkaline-earth and alkaline metals, whereas 3d and 5d metals were studied at the B site. We also include ReO3-type compounds, which have the same crystal structure of cubic ABO3 perovskites except without A-site elements. From the observations we extract the following four conclusions for the perovskites studied in the present paper: for a given cation at the B site, (I) perovskites with cations of identical oxidation state at the A site possess close formation energies; and (II) perovskites with cations of different oxidation states at the A site usually have quite different but ordered formation energies. On the other hand, for a given A-site cation, (III) the formation energies of perovskites vary linearly with respect to the atomic number of the elements at the B site within the same period of the periodic table, and the slopes depend systematically on the oxidation state of the A-site cation; and (IV) the trends in formation energies of perovskites with elements from different periods at the B site depend on the oxidation state of A-site cations. Since the energetics of perovskites is shown to be the superposition of the individual contributions of their constituent oxides, the trends can be rationalized in terms of A-O and B-O interactions in the ionic crystal. These findings reveal the existence of general systematic trends in the formation energies of perovskites and provide further insight into the role of ion-ion interactions in the properties of ternary compounds.

  9. A method for increasing the surface area of perovskite-type oxides

    Indian Academy of Sciences (India)

    ABO3-type perovskite oxides (A = rare earth element with or without its partial substitution by alkaline earth element, and B = transition element such as Co, Mn, Ni, Fe, etc., with or without its partial substitution by other transition elements) have high potential for their ... In our very recent communication 8, we have reported a ...

  10. Synthesis and Evaluation of ABO3 Perovskites (A=La and B=Mn, Co with Stoichiometric and Over-stoichiometric Ratios of B/A for Catalytic Oxidation of Trichloroethylene

    Directory of Open Access Journals (Sweden)

    Razieh Alagheband

    2018-01-01

    Full Text Available In this contribution, perovskite catalysts (ABO3 were probed that site A and site B were occupied by lanthanum and transition metals of manganese or cobalt, respectively, with stoichiometric ratios as well as 20 % over-stoichiometric ratios of B/A. The perovskite samples were synthesized using a gel-combustion method and characterized by BET, XRD, SEM and O2-TPD analyses. After mounting in a fixed bed reactor, the catalysts were examined in atmospheric pressure conditions at different temperatures for oxidation of 1000 ppm trichloroethylene in the air. Evaluation of over-stoichiometric catalysts activity showed that the increased ratio of B/A in the catalysts compared to the stoichiometric one led to BET surface area, oxygen mobility, and consequently catalytic performance improvement. The lanthanum manganite perovskite with 20 % excess manganese yielded the best catalytic performance among the probed perovskites. Copyright © 2018 BCREC Group. All rights reserved Received: 28th April 2017; Revised: 31st July 2017; Accepted: 4th August 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Alagheband, R., Maghsoodi, S., Kootenaei, A.S., Kianmanesh, H. (2018. Synthesis and Evaluation of ABO3 Perovskites (A=La and B=Mn, Co with Stoichiometric and Over-stoichiometric Ratios of B/A for Catalytic Oxidation of Trichloroethylene. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1: 47-56 (doi:10.9767/bcrec.13.1.1188.47-56

  11. Ferroic properties in bi-component perovskites: artificial superlattices and naturally forming compounds

    International Nuclear Information System (INIS)

    Saha-Dasgupta, T

    2014-01-01

    The use of four different metal cations in a bi-component perovskite ABO 3 structure with 50 : 50 substitution at A sublattice as well as B sublattice, opens up the door for materials designing, with the aim to improve ferroic properties. This can be achieved following two different routes; one using the concept of artificially grown superlattices with alternating layers of ABO 3 and A′B′O 3 perovskites in a periodic set-up and another, through synthesis of naturally grown bulk double perovskites with ordered arrangement of A and A′ cations, simultaneously with that of B and B′ cations. The tremendous progress in layered deposition techniques as well as advances in solid state chemistry methods, has made both routes equally plausible and an area of much activity. This review summarizes some of the recent progress in this field, with a special emphasis on two computational studies, (i) one on ultra-thin 1–1 superlattices built out of paraelectric and ferroelectric components, showing tunable piezoelectric properties, and (ii) another on CrOs-based double perovskites which show multiferroic behavior, achieved through layered ordering of A and A′ cations. (topical review)

  12. Structural characterization of a new vacancy ordered perovskite modification found for Ba3Fe3O7F (BaFeO2.333F0.333): Towards understanding of vacancy ordering for different perovskite-type ferrites

    International Nuclear Information System (INIS)

    Clemens, Oliver

    2015-01-01

    The new vacancy ordered perovskite-type compound Ba 3 Fe 3 O 7 F (BaFeO 2.33 F 0.33 ) was prepared by topochemical low-temperature fluorination of Ba 2 Fe 2 O 5 (BaFeO 2.5 ) using stoichiometric amounts of polyvinylidene difluoride (PVDF). The vacancy order was found to be unique so far for perovskite compounds, and the connectivity pattern can be explained by the formula Ba 3 (FeX 6/2 ) (FeX 5/2 ) (FeX 3/2 X 1/1 ), with X=O/F. Mössbauer measurements were used to confirm the structural analysis and agree with the presence of Fe 3+ in the above mentioned coordination environments. Group–subgroup relationships were used to build a starting model for the structure solution and to understand the relationship to the cubic perovskite structure. Furthermore, a comparison of a variety of vacancy-ordered iron-containing perovskite-type structures is given, highlighting the factors which favour one structure type over the other depending on the composition. - Graphical abstract: The crystal structure of Ba 3 Fe 3 O 7 F in comparison to other perovskite type ferrites. - Highlights: • The crystal structure of Ba 3 Fe 3 O 7 F in comparison to other perovskite type ferrites. • Ba 3 Fe 3 O 7 F was synthesized by low temperature fluorination of Ba 2 Fe 2 O 5 . • Ba 3 Fe 3 O 7 F shows a unique vacancy order not found for other perovskite type compounds. • The structure of Ba 3 Fe 3 O 7 F was solved using group–subgroup relationships. • A systematic comparison to other ferrite type compounds reveals structural similarities and differences. • The A-site coordination of the cation is shown to play an important role for the type of vacancy order found

  13. Crystallographic and Electronic Structure of the Sr3Sb2CoO9 Triple Perovskite

    International Nuclear Information System (INIS)

    González, W; Téllez, D A Landínez; Roa-Rojas, J; Cardona, R

    2014-01-01

    Compounds The perovskites are materials with physical and chemical characteristics that make them optimal for application in the technological and scientist. When the ideal formula of perovskite ABO 3 is modified by introducing a special structural arrangement can get to get triple perovskites, which correspond to the formula A 3 B 2 B'O 9 . In this work we report the synthesis process and the study of electronic structure and crystal Sr 3 Sb 2 CoO 9 new triple perovskite. From the experiments of X-ray Diffraction and the application of the Rietveld refinement method was revealed that the system crystallizes in a perovskite structure with a characteristic triple given by the space group Immm (#71) and lattice parameters a=9.791(9) Å, b=5.656(7) Å and c=16.957(8) Å. Ab initio calculations of density of states (DOS) and electronic structure were carried out for this perovskite-like system by using the Quantum EXPRESSO code. The exchange-correlation potential was treated using the Generalized Gradient Approximation (GGA). All calculations were carried-out using spin polarization.

  14. Identifying open-volume defects in doped and undoped perovskite-type LaCoO3, PbTiO3, and BaTiO3

    International Nuclear Information System (INIS)

    Ghosh, Vinita J.; Nielsen, Bent; Friessnegg, Thomas

    2000-01-01

    Dopants, vacancies, and impurity-vacancy clusters have a substantial impact on the properties of perovskite-type metal oxides (general formula ABO 3 ). In order to determine synthesis and processing conditions that optimize the desirable properties of these materials a careful study of these defects is required. It is essential to identify the defects and to map the defect densities. Positron annihilation spectroscopy has often been used to identify vacancy-type defects. Calculations of the positron lifetime and Doppler-broadened profiles of the positron-electron annihilation radiation in undoped and doped LaCoO 3 , PbTiO 3 , and BaTiO 3 are reported, and compared with available experimental data. The results show that these positron techniques are excellent for studying open-volume defects, vacancy-impurity complexes, and for identifying the sublattice occupied by the dopants. (c) 2000 The American Physical Society

  15. Classification of perovskites with supervised self-organizing maps

    International Nuclear Information System (INIS)

    Kuzmanovski, Igor; Dimitrovska-Lazova, Sandra; Aleksovska, Slobotka

    2007-01-01

    In this work supervised self-organizing maps were used for structural classification of perovskites. For this purpose, structural data for total number of 286 perovskites, belonging to ABO 3 and/or A 2 BB'O 6 types, were collected from literature: 130 of these are cubic, 85 orthorhombic and 71 monoclinic. For classification purposes, the effective ionic radii of the cations, electronegativities of the cations in B-position, as well as, the oxidation states of these cations, were used as input variables. The parameters of the developed models, as well as, the most suitable variables for classification purposes were selected using genetic algorithms. Two-third of all the compounds were used in the training phase. During the optimization process the performances of the models were checked using cross-validation leave-1/10-out. The performances of obtained solutions were checked using the test set composed of the remaining one-third of the compounds. The obtained models for classification of these three classes of perovskite compounds show very good results. Namely, the classification of the compounds in the test set resulted in small number of discrepancies (4.2-6.4%) between the actual crystallographic class and the one predicted by the models. All these results are strong arguments for the validity of supervised self-organizing maps for performing such types of classification. Therefore, the proposed procedure could be successfully used for crystallographic classification of perovskites in one of these three classes

  16. Formation of perovskite-type compounds La0.5Ca0.5Mn1-xTixO3 (0≤x≤0.5)

    International Nuclear Information System (INIS)

    Wang, K.-Y.; Arcas, J.; Chen, D.-X.; Hernando, A.

    1997-01-01

    A series of perovskite-type compounds La 0.5 Ca 0.5 Mn 1-x Ti x O 3 is prepared by solid-state reaction. It is found that a single-phase tetragonal structure can be obtained for x≤0.5; the lattice parameters increase and magnetization at μ 0 H=0.2. T decreases with increasing x. (orig.)

  17. NaIrO3-A pentavalent post-perovskite

    International Nuclear Information System (INIS)

    Bremholm, M.; Dutton, S.E.; Stephens, P.W.; Cava, R.J.

    2011-01-01

    Sodium iridium (V) oxide, NaIrO 3, was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO 3 , the much-studied structural analog of the high-pressure post-perovskite phase of MgSiO 3 . Among the oxide post-perovskites, NaIrO 3 is the first example with a pentavalent cation. The structure consists of layers of corner- and edge-sharing IrO 6 octahedra separated by layers of NaO 8 bicapped trigonal prisms. NaIrO 3 shows no magnetic ordering and resistivity measurements show non-metallic behavior. The crystal structure, electrical and magnetic properties are discussed and compared to known post-perovskites and pentavalent perovskite metal oxides. -- Graphical abstract: Sodium iridium(V) oxide, NaIrO 3 , synthesized by a high pressure solid state method and recovered to ambient conditions is found to crystallize as the post-perovskite structure and is the first example of a pentavalent ABO 3 post-perovskite. Research highlights: → NaIrO 3 post-perovskite stabilized by pressure. → First example of a pentavalent oxide post-perovskite. → Non-metallic and non-magnetic behavior of NaIrO 3 .

  18. Predictions of new AB O3 perovskite compounds by combining machine learning and density functional theory

    Science.gov (United States)

    Balachandran, Prasanna V.; Emery, Antoine A.; Gubernatis, James E.; Lookman, Turab; Wolverton, Chris; Zunger, Alex

    2018-04-01

    We apply machine learning (ML) methods to a database of 390 experimentally reported A B O3 compounds to construct two statistical models that predict possible new perovskite materials and possible new cubic perovskites. The first ML model classified the 390 compounds into 254 perovskites and 136 that are not perovskites with a 90% average cross-validation (CV) accuracy; the second ML model further classified the perovskites into 22 known cubic perovskites and 232 known noncubic perovskites with a 94% average CV accuracy. We find that the most effective chemical descriptors affecting our classification include largely geometric constructs such as the A and B Shannon ionic radii, the tolerance and octahedral factors, the A -O and B -O bond length, and the A and B Villars' Mendeleev numbers. We then construct an additional list of 625 A B O3 compounds assembled from charge conserving combinations of A and B atoms absent from our list of known compounds. Then, using the two ML models constructed on the known compounds, we predict that 235 of the 625 exist in a perovskite structure with a confidence greater than 50% and among them that 20 exist in the cubic structure (albeit, the latter with only ˜50 % confidence). We find that the new perovskites are most likely to occur when the A and B atoms are a lanthanide or actinide, when the A atom is an alkali, alkali earth, or late transition metal atom, or when the B atom is a p -block atom. We also compare the ML findings with the density functional theory calculations and convex hull analyses in the Open Quantum Materials Database (OQMD), which predicts the T =0 K ground-state stability of all the A B O3 compounds. We find that OQMD predicts 186 of 254 of the perovskites in the experimental database to be thermodynamically stable within 100 meV/atom of the convex hull and predicts 87 of the 235 ML-predicted perovskite compounds to be thermodynamically stable within 100 meV/atom of the convex hull, including 6 of these to

  19. Phase formation and UV luminescence of Gd{sup 3+} doped perovskite-type YScO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yuhei; Ueda, Kazushige, E-mail: kueda@che.kyutech.ac.jp

    2016-10-15

    Synthesis of pure and Gd{sup 3+}doped perovskite-type YScO{sub 3} was attempted by a polymerized complex (PC) method and solid state reaction (SSR) method. Crystalline phases and UV luminescence of samples were examined with varying heating temperatures. The perovskite-type single phase was not simply formed in the SSR method, as reported in some literatures, and two cubic C-type phases of starting oxide materials remained forming slightly mixed solid solutions. UV luminescence of Gd{sup 3+} doped samples increased with an increase in heating temperatures and volume of the perovskite-type phase. In contrast, a non-crystalline precursor was crystallized to a single C-type phase at 800 °C in the PC method forming a completely mixed solid solution. Then, the phase of perovskite-type YScO{sub 3} formed at 1200 °C and its single phase was obtained at 1400 °C. It was revealed that high homogeneousness of cations was essential to generate the single perovskite-phase of YScO{sub 3}. Because Gd{sup 3+} ions were also dissolved into the single C-type phase in Gd{sup 3+} doped samples, intense UV luminescence was observed above 800 °C in both C-type phase and perovskite-type phase. - Graphical abstract: A pure perovskite-type YScO{sub 3} phase was successfully synthesized by a polymerized complex (PC) method. The perovskite-type YScO{sub 3} was generated through a solid solution of C-type (Y{sub 0.5}Sc{sub 0.5}){sub 2}O{sub 3} with drastic change of morphology. The PC method enabled a preparation of the single phase of the perovskite-type YScO{sub 3} at lower temperature and in shorter heating time. Gd{sup 3+} doped perovskite-type YScO{sub 3} was found to show a strong sharp UV emission at 314 nm. - Highlights: • Pure YScO{sub 3} phase was successfully synthesized by polymerized complex (PC) method. • Pure perovskite-type YScO{sub 3} phase was generated from pure C-type (Y{sub 0.5}Sc{sub 0.5}){sub 2}O{sub 3} one. • YScO{sub 3} was obtained at lower temperature and

  20. Formability of ABX3 (X=F,Cl,Br,I) halide perovskites

    International Nuclear Information System (INIS)

    Li Chonghea; Lu Xionggang; Ding Weizhong; Feng Liming; Gao Yonghui; Guo Ziming

    2008-01-01

    In this study a total of 186 complex halide systems were collected; the formabilities of ABX 3 (X = F, Cl, Br and I) halide perovskites were investigated using the empirical structure map, which was constructed by Goldschmidt's tolerance factor and the octahedral factor. A model for halide perovskite formability was built up. In this model obtained, for all 186 complex halides systems, only one system (CsF-MnF 2 ) without perovskite structure and six systems (RbF-PbF 2 , CsF- BeF 2 , KCl-FeCl 2 , TlI-MnI 2 , RbI-SnI 2 , TlI-PbI 2 ) with perovskite structure were wrongly classified, so its predicting accuracy reaches 96%. It is also indicated that both the tolerance factor and the octahedral factor are a necessary but not sufficient condition for ABX 3 halide perovskite formability, and a lowest limit of the octahedral factor exists for halide perovskite formation. This result is consistent with our previous report for ABO 3 oxide perovskite, and may be helpful to design novel halide materials with the perovskite structure. (orig.)

  1. System Ba/sub 2/Gdsub(2/3)vacantsub(1/3)Usub(1-x)Wsub(x)O/sub 6/ and hexagonal perovskites of an 18-layer type

    Energy Technology Data Exchange (ETDEWEB)

    Wischert, W; Schittenhelm, H J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

    1978-04-01

    In the system Ba/sub 2/Gdsub(2/3)vacantsub(1/3)Usub(1-x)Wsub(x)O/sub 6/ the formation of a continuous solid solution series is observed. With x <= 0.9 the mixed crystals have a cubic 1:1 ordered perovskite structure. With x >= 0.95 the compounds are polymorphic: besides an cubic 1:1 ordered perovskite type for x = 0.95; 0.99 and 1.00 one hexagonal layer structure exists. This lattice is in all cases rhombohedral (space group R3m) and represents an 18 L-type. Likewise the compounds Ba/sub 2/Bsub(2/3)sup(III)vacantsub(1/3)Wsup(VI)O/sub 6/ with Bsup(III) Tb-Lu and Y belong to the 18 L-type.

  2. Scintillating Organic–Inorganic Layered Perovskite-type Compounds and the Gamma-ray Detection Capabilities

    OpenAIRE

    Kawano, Naoki; Koshimizu, Masanori; Okada, Go; Fujimoto, Yutaka; Kawaguchi, Noriaki; Yanagida, Takayuki; Asai, Keisuke

    2017-01-01

    We investigated scintillation properties of organic–inorganic layered perovskite-type compounds under gamma-ray and X-ray irradiation. A crystal of the hybrid compounds with phenethyl amine (17 × 23 × 4 mm) was successfully fabricated by the poor-solvent diffusion method. The bulk sample showed superior scintillation properties with notably high light yield (14,000 photons per MeV) under gamma-rays and very fast decay time (11 ns). The light yield was about 1.4 time higher than that of common...

  3. Electrical and Optical Properties of Nanosized Perovskite-type La ...

    African Journals Online (AJOL)

    Electrical and Optical Properties of Nanosized Perovskite-type La 0.5 Ca 0.5 MO 3 (M=Co,Ni) ... In addition, the TEM images show that the average particle size of ... of both compounds decreases exponentially by increasing the temperature.

  4. On the luminescence of perovskite type rare earth gallates

    International Nuclear Information System (INIS)

    Jianmei, Y.; Qingyuan, W.; Shuzhen, L.; Lianren, S.; Mingyu, C.

    1985-01-01

    It has been reported that perovskite type lanthanum gallates may be a good host material for laser and luminescence, but in the rare earth gallates studied, the numbers of perovskite type are less than that of the garnet type and there is less report on their spectroscopic properties in the literature. In this paper synthesis and spectroscopic properties of these compounds are studied

  5. Blood type, ABO genetic variants, and ovarian cancer survival.

    Directory of Open Access Journals (Sweden)

    Gabriella D Cozzi

    Full Text Available Blood type A and the A1 allele have been associated with increased ovarian cancer risk. With only two small studies published to date, evidence for an association between ABO blood type and ovarian cancer survival is limited.We conducted a retrospective cohort study of Tumor Registry confirmed ovarian cancer cases from the Vanderbilt University Medical Center with blood type from linked laboratory reports and ABO variants from linked Illumina Exome BeadChip data. Associations with overall survival (OS were quantified by hazard ratios (HR and confidence intervals (CI from proportional hazards regression models; covariates included age, race, stage, grade, histologic subtype, and year of diagnosis.ABO phenotype (N = 694 and/or genotype (N = 154 data were available for 713 predominantly Caucasian (89.3% cases. In multivariable models, blood type A had significantly better OS compared to either O (HR: 0.75, 95% CI: 0.60-0.93 or all non-A (HR: 0.77, 95% CI: 0.63-0.94 cases. Similarly, missense rs1053878 minor allele carriers (A2 had better OS (HR: 0.50, 95% CI: 0.25-0.99. Among Caucasians, this phenotype association was strengthened, but the genotype association was attenuated; instead, four variants sharing moderate linkage disequilibrium with the O variant were associated with better OS (HR: 0.62, 95% CI: 0.39-0.99 in unadjusted models.Blood type A was significantly associated with longer ovarian cancer survival in the largest such study to date. This finding was supported by genetic analysis, which implicated the A2 allele, although O related variants also had suggestive associations. Further research on ABO and ovarian cancer survival is warranted.

  6. Lithium intercalation in the LiLaNb{sub 2}O{sub 7} perovskite structure; Intercalation du lithium dans la structure perovskite LiLaNb{sub 2}O{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Bohnke, C.; Bohnke, O.; Fourquet, J.L. [Universite du Maine, 72 - Le Mans (France). Laboratoire des Fluorures

    1996-12-31

    ABO{sub 3} perovskite-type oxides having vacancies in the A-sites of their structure are interesting candidates for solid electrolytes when their A-sites are occupied by Li{sup +} ions having a high mobility. This is the case with the [Li{sub 3x}La{sub 2/3-x}]TiO{sub 3} solid solution compound which has a 10{sup -3} S cm{sup -1} ionic conductivity at ambient temperature. Electrochemical intercalation in this material is possible thanks to the presence of Ti{sup 4+} but the small amount of vacancies (0.33 maximum) leads to a low intercalation rate. In order to solve this problem, the LiLaNb{sub 2}O{sub 7} material which has a greater amount of vacancies has been studied and the results relative to the electrochemical intercalation of lithium in this perovskite are presented. The thermodynamical and kinetics properties of the lithium intercalation reaction have been studied by intermittent galvano-static discharges and impedance spectroscopy in LiClO{sub 4}-propylene carbonate medium. (J.S.) 7 refs.

  7. Lithium intercalation in the LiLaNb{sub 2}O{sub 7} perovskite structure; Intercalation du lithium dans la structure perovskite LiLaNb{sub 2}O{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Bohnke, C; Bohnke, O; Fourquet, J L [Universite du Maine, 72 - Le Mans (France). Laboratoire des Fluorures

    1997-12-31

    ABO{sub 3} perovskite-type oxides having vacancies in the A-sites of their structure are interesting candidates for solid electrolytes when their A-sites are occupied by Li{sup +} ions having a high mobility. This is the case with the [Li{sub 3x}La{sub 2/3-x}]TiO{sub 3} solid solution compound which has a 10{sup -3} S cm{sup -1} ionic conductivity at ambient temperature. Electrochemical intercalation in this material is possible thanks to the presence of Ti{sup 4+} but the small amount of vacancies (0.33 maximum) leads to a low intercalation rate. In order to solve this problem, the LiLaNb{sub 2}O{sub 7} material which has a greater amount of vacancies has been studied and the results relative to the electrochemical intercalation of lithium in this perovskite are presented. The thermodynamical and kinetics properties of the lithium intercalation reaction have been studied by intermittent galvano-static discharges and impedance spectroscopy in LiClO{sub 4}-propylene carbonate medium. (J.S.) 7 refs.

  8. Simple descriptors for proton-conducting perovskites from density functional theory

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Bonanos, Nikolaos; Rossmeisl, Jan

    2010-01-01

    series of (pseudo)cubic perovskites, ABO3, have been investigated using density functional theory calculations. The structures have been optimized and thermodynamic properties and activation energies for the relevant steps of the hydrogen/proton diffusion mechanism have been calculated using...... the nudged elastic band path technique. We find a strong correlation between the O-H binding energy for hydrogen/proton uptake in perovskites and the energy barriers involved in the observed Grotthuss-type diffusion process. We demonstrate the possibility of estimating diffusion rates based on O-H binding...

  9. Evaluation of covalency of ions in lead-free perovskite-type dielectric oxides

    Directory of Open Access Journals (Sweden)

    Naohisa Takesue

    2017-10-01

    Full Text Available Electronic states of ions in lead-free perovskite-type dielectric oxides have been investigated with a first-principle cluster calculation. For this calculation a double-perovskite cluster model based upon the simple cubic ABO3 was used; A and B are both the cations, and O is the oxygen anion. Systematic variations of ionic species for A and B, and lengths of the model cube edge were given to the model. Results of charge transfers of the ions show that their magnitudes depend on the edge length; the lager length leads to the higher transfer magnitude. This tendency implies spatial tolerance of the ions to the clusters, and are expected to correlate with electric polarizability and dipole reversibility of this kind of oxides. The density of states and the overlap population indicate that the higher cation valence causes the higher covalency of the anions. Considering all results together provides us an idea to obtain lead-free high-performance ferroelectrics, as high as the lead-based solid solutions.

  10. Hexagonal perovskites with cationic vacancies. 3. Structure determination on compounds of type Ba/sub 2/Bsub(1/3)sup(III)vacantsub(2/3)Resup(VII)O/sub 6/

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S; Wischert, W; Treiber, U [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

    1978-09-01

    Compounds of type Ba/sub 2/Bsub(1/3)sup(III)vacantsub(2/3)Resup(VII)O/sub 6/ with Bsup(III) = rare earth, Y, Sc. In belong to the group of hexagonal perovskite stacking polytypes. For Bsup(III) = Gd, Y structure determinations with powder data have been performed. The refined R' factors are 9.11% for Ba/sub 2/Gdsub(1/3)vacantsub(2/3)ReO/sub 6/ and 12.07% for Ba/sub 2/Ysub(1/3)vacantsub(2/3)ReO/sub 6/. The structure represents a rhombohedral 12 L type (space group R3m) with the sequence hhcchhcchhcc. The lattice contains groups of three octahedra connected by common faces which are linked together by a single octahedron via common vertices. In the block of three face-sharing octahedra the central octahedral lattice site is vacant and the two outer positions are occupied by the rhenium atoms. According to this distribution direct contact of occupied face-sharing octahedra is absent.

  11. Unreliable patient identification warrants ABO typing at admission to check existing records before transfusion.

    Science.gov (United States)

    Ferrera-Tourenc, V; Lassale, B; Chiaroni, J; Dettori, I

    2015-06-01

    This study describes patient identification errors leading to transfusional near-misses in blood issued by the Alps Mediterranean French Blood Establishment (EFSAM) to Marseille Public Hospitals (APHM) over an 18-month period. The EFSAM consolidates 14 blood banks in southeast France. It supplies 149 hospitals and maintains a centralized database on ABO types used at all area hospitals. As an added precaution against incompatible transfusion, the APHM requires ABO testing at each admission regardless of whether the patient has an ABO record. The study goal was to determine if admission testing was warranted. Discrepancies between ABO type determined by admission testing and records in the centralized database were investigated. The root cause for each discrepancy was classified as specimen collection or patient admission error. Causes of patient admission events were further subclassified as namesake (name similarity) or impersonation (identity fraud). The incidence of ABO discrepancies was 1:2334 including a 1:3329 incidence of patient admission events. Impersonation was the main cause of identity events accounting for 90.3% of cases. The APHM's ABO control policy prevented 19 incompatible transfusions. In relation to the 48,593 packed red cell units transfused, this would have corresponded to a risk of 1:2526. Collecting and storing ABO typing results in a centralized database is an essential public health tool. It allows crosschecking of current test results with past records and avoids redundant testing. However, as patient identification remains unreliable, ABO typing at each admission is still warranted to prevent transfusion errors. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. The Classroom-Friendly ABO Blood Types Kit: Blood Agglutination Simulation

    Science.gov (United States)

    Arnold, Savittree Rochanasmita; Kruatong, Tussatrin; Dahsah, Chanyah; Suwanjinda, Duongdearn

    2012-01-01

    The classroom-friendly ABO blood type kit was developed by combining advantages of modelling and a simulation laboratory to teach the topics of ABO blood types and blood transfusion. Teachers can easily simulate the agglutination reaction on a blood type testing plate in the classroom, and show the students how this reaction occurs by using the…

  13. Cerium luminescence in nd0 perovskites

    International Nuclear Information System (INIS)

    Setlur, A.A.; Happek, U.

    2010-01-01

    The luminescence of Ce 3+ in perovskite (ABO 3 ) hosts with nd 0 B-site cations, specifically Ca(Hf,Zr)O 3 and (La,Gd)ScO 3 , is investigated in this report. The energy position of the Ce 3+ excitation and emission bands in these perovskites is compared to those of typical Al 3+ perovskites; we find a Ce 3+ 5d 1 centroid shift and Stokes shift that are larger versus the corresponding values for the Al 3+ perovskites. It is also shown that Ce 3+ luminescence quenching is due to Ce 3+ photoionization. The comparison between these perovskites shows reasonable correlations between Ce 3+ luminescence quenching, the energy position of the Ce 3+ 5d 1 excited state with respect to the host conduction band, and the host composition. - Graphical abstract: Ce 3+ decay times versus temperature for perovskites with nd 0 B-site cations.

  14. Blood type, ABO genetic variants, and ovarian cancer survival

    Science.gov (United States)

    Cozzi, Gabriella D.; Levinson, Rebecca T.; Toole, Hilary; Snyder, Malcolm-Robert; Deng, Angie; Crispens, Marta A.; Khabele, Dineo; Beeghly-Fadiel, Alicia

    2017-01-01

    Objective Blood type A and the A1 allele have been associated with increased ovarian cancer risk. With only two small studies published to date, evidence for an association between ABO blood type and ovarian cancer survival is limited. Methods We conducted a retrospective cohort study of Tumor Registry confirmed ovarian cancer cases from the Vanderbilt University Medical Center with blood type from linked laboratory reports and ABO variants from linked Illumina Exome BeadChip data. Associations with overall survival (OS) were quantified by hazard ratios (HR) and confidence intervals (CI) from proportional hazards regression models; covariates included age, race, stage, grade, histologic subtype, and year of diagnosis. Results ABO phenotype (N = 694) and/or genotype (N = 154) data were available for 713 predominantly Caucasian (89.3%) cases. In multivariable models, blood type A had significantly better OS compared to either O (HR: 0.75, 95% CI: 0.60–0.93) or all non-A (HR: 0.77, 95% CI: 0.63–0.94) cases. Similarly, missense rs1053878 minor allele carriers (A2) had better OS (HR: 0.50, 95% CI: 0.25–0.99). Among Caucasians, this phenotype association was strengthened, but the genotype association was attenuated; instead, four variants sharing moderate linkage disequilibrium with the O variant were associated with better OS (HR: 0.62, 95% CI: 0.39–0.99) in unadjusted models. Conclusions Blood type A was significantly associated with longer ovarian cancer survival in the largest such study to date. This finding was supported by genetic analysis, which implicated the A2 allele, although O related variants also had suggestive associations. Further research on ABO and ovarian cancer survival is warranted. PMID:28448592

  15. Sensitive typing of reverse ABO blood groups with a waveguide-mode sensor.

    Science.gov (United States)

    Uno, Shigeyuki; Tanaka, Torahiko; Ashiba, Hiroki; Fujimaki, Makoto; Tanaka, Mutsuo; Hatta, Yoshihiro; Takei, Masami; Awazu, Koichi; Makishima, Makoto

    2018-07-01

    Portable, on-site blood typing methods will help provide life-saving blood transfusions to patients during an emergency or natural calamity, such as significant earthquakes. We have previously developed waveguide-mode (WM) sensors for forward ABO and Rh(D) blood typing and detection of antibodies against hepatitis B virus and hepatitis C virus. In this study, we evaluated a WM-sensor for reverse ABO blood typing. Since reverse ABO blood typing is a method for detection of antibodies against type A and type B oligosaccharide antigens on the surface of red blood cells (RBCs), we fixed a synthetic type A or type B trisaccharide antigen on the sensor chip of the WM sensor. We obtained significant changes in the reflectance spectra from a WM sensor on type A antigen with type B plasma and type O plasma and on type B antigen with type A plasma and type O plasma, and no spectrum changes on type A antigen or type B antigen with type AB plasma. Signal enhancement with the addition of a peroxidase reaction failed to increase the sensitivity for detection on oligosaccharide chips. By utilizing hemagglutination detection using regent type A and type B RBCs, we successfully determined reverse ABO blood groups with higher sensitivity compared to a method using oligosaccharide antigens. Thus, functionality of a portable device utilizing a WM sensor can be expanded to include reverse ABO blood typing and, in combination with forward ABO typing and antivirus antibody detection, may be useful for on-site blood testing in emergency settings. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. Development of Perovskite-Type Materials for Thermoelectric Application

    Directory of Open Access Journals (Sweden)

    Tingjun Wu

    2018-06-01

    Full Text Available Oxide perovskite materials have a long history of being investigated for thermoelectric applications. Compared to the state-of-the-art tin and lead chalcogenides, these perovskite compounds have advantages of low toxicity, eco-friendliness, and high elemental abundance. However, because of low electrical conductivity and high thermal conductivity, the total thermoelectric performance of oxide perovskites is relatively poor. Variety of methods were used to enhance the TE properties of oxide perovskite materials, such as doping, inducing oxygen vacancy, embedding crystal imperfection, and so on. Recently, hybrid perovskite materials started to draw attention for thermoelectric application. Due to the low thermal conductivity and high Seebeck coefficient feature of hybrid perovskites materials, they can be promising thermoelectric materials and hold the potential for the application of wearable energy generators and cooling devices. This mini-review will build a bridge between oxide perovskites and burgeoning hybrid halide perovskites in the research of thermoelectric properties with an aim to further enhance the relevant performance of perovskite-type materials.

  17. Ordered perovskites with cationic vacancies. 4. Compounds of type Ba/sub 6/B/sub 2/sup(III)vacantTe/sub 3/sup(VI)O/sub 18/

    Energy Technology Data Exchange (ETDEWEB)

    Schittenhelm, H J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1979-07-01

    Compounds of the composition Ba/sub 6/B(III)/sub 2/vacantTe(VI)/sub 3/O/sub 18/ equivalent to Ba/sub 2/Ba(III)sub(2/3)vacantsub(1/3)Te(VI)O/sub 6/, with B(III) = Pr, Nd, Sm-Lu, Y crystallize with a cubic perovskite lattice. The cell parameters diminish as the size of B(III) falls (B(III) = Pr: a = 8.52 A; Lu: a = 8.33 A). In contrast to the corresponding perovskites with U(VI) and W(VI) no polymorphism is observed.

  18. Methane combustion over lanthanum-based perovskite mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Arandiyan, Hamidreza [New South Wales Univ., Sydney (Australia). School of Chemical Engineering

    2015-11-01

    This book presents current research into the catalytic combustion of methane using perovskite-type oxides (ABO{sub 3}). Catalytic combustion has been developed as a method of promoting efficient combustion with minimum pollutant formation as compared to conventional catalytic combustion. Recent theoretical and experimental studies have recommended that noble metals supported on (ABO{sub 3}) with well-ordered porous networks show promising redox properties. Three-dimensionally ordered macroporous (3DOM) materials with interpenetrated and regular mesoporous systems have recently triggered enormous research activity due to their high surface areas, large pore volumes, uniform pore sizes, low cost, environmental benignity, and good chemical stability. These are all highly relevant in terms of the utilization of natural gas in light of recent catalytic innovations and technological advances. The book is of interest to all researchers active in utilization of natural gas with novel catalysts. The research covered comes from the most important industries and research centers in the field. The book serves not only as a text for researcher into catalytic combustion of methane, 3DOM perovskite mixed oxide, but also explores the field of green technologies by experts in academia and industry. This book will appeal to those interested in research on the environmental impact of combustion, materials and catalysis.

  19. ABO blood type and the risk of cancer - Findings from the Shanghai Cohort Study.

    Directory of Open Access Journals (Sweden)

    Joyce Yongxu Huang

    Full Text Available ABO blood type is an inherited characteristic. The associations between ABO blood type and risk of all cancer and specific cancers were examined in a prospective cohort study of 18,244 Chinese men enrolled in 1986. During the 25 years of follow-up, 3,973 men developed cancer including 964 lung cancers, 624 colorectal cancers, 560 gastric cancers, 353 liver cancers, and 172 urinary bladder cancers. Hazard ratios (HR for all cancer and specific cancers by ABO blood type were calculated using Cox proportional hazards models. Compared with blood type A, blood type B was associated with statistically significant reduced risk of all cancers (HR, 0.91, 95% CI:0.84, 0.99. Both blood types B and AB were associated with significantly lower risk of gastrointestinal cancer and colorectal cancer, respectively. Blood type B was also associated with significantly lower risk of stomach cancer and bladder cancer, while blood type AB was associated with significantly increased risk of liver cancer. By histological type, blood types B and AB were associated with lower risk of epidermoid carcinoma and adenocarcinoma, but were not associated with risk of sarcoma, lymphoma, leukemia or other cell types of cancer. The findings of this study support a role of genetic traits related to ABO blood type in the development of cancers in the gastrointestinal and urinary tracts.

  20. ABO blood type and the risk of cancer - Findings from the Shanghai Cohort Study.

    Science.gov (United States)

    Huang, Joyce Yongxu; Wang, Renwei; Gao, Yu-Tang; Yuan, Jian-Min

    2017-01-01

    ABO blood type is an inherited characteristic. The associations between ABO blood type and risk of all cancer and specific cancers were examined in a prospective cohort study of 18,244 Chinese men enrolled in 1986. During the 25 years of follow-up, 3,973 men developed cancer including 964 lung cancers, 624 colorectal cancers, 560 gastric cancers, 353 liver cancers, and 172 urinary bladder cancers. Hazard ratios (HR) for all cancer and specific cancers by ABO blood type were calculated using Cox proportional hazards models. Compared with blood type A, blood type B was associated with statistically significant reduced risk of all cancers (HR, 0.91, 95% CI:0.84, 0.99). Both blood types B and AB were associated with significantly lower risk of gastrointestinal cancer and colorectal cancer, respectively. Blood type B was also associated with significantly lower risk of stomach cancer and bladder cancer, while blood type AB was associated with significantly increased risk of liver cancer. By histological type, blood types B and AB were associated with lower risk of epidermoid carcinoma and adenocarcinoma, but were not associated with risk of sarcoma, lymphoma, leukemia or other cell types of cancer. The findings of this study support a role of genetic traits related to ABO blood type in the development of cancers in the gastrointestinal and urinary tracts.

  1. Preparation and characterization of a layered perovskite-type organic-inorganic hybrid compound (C8NH6-CH2CH2NH3)2CuCl4

    International Nuclear Information System (INIS)

    Zheng Yingying; Wu Gang; Deng Meng; Chen Hongzheng; Wang Mang; Tang, B.-Z.

    2006-01-01

    The organic-inorganic hybrid compound (C 8 NH 6 -CH 2 CH 2 NH 3 ) 2 CuCl 4 (AEI-CuCl 4 ) was synthesized from ethanol solution containing copper chloride and 3-2-(aminoethyl) indole hydrochloride (AEI-HCl). High order diffraction peaks corresponding to (0 0 l; l = 2, 4, 6, ...) observed in the X-ray diffraction profile of AEI-CuCl 4 indicated the formation of hybrid crystal with layered perovskite structure. The organic-inorganic hybrid crystal thin film can be easily prepared by spin-coating method from the ethanol solution of the AEI-CuCl 4 perovskite and it showed characteristic absorptions of CuCl-based layered perovskite centered at 288 and 388 nm, as well as the photoluminescence peak at around 420 nm. The unaided-eye-detectable blue fluorescence emission comes from the cooperation of AEI-HCl and AEI-CuCl 4 perovskite, in which protonized aminoethyl indole dominates the shape of the spectrum and the enhancement of emission intensity is due to the formation of the perovskite structure. The thermal analysis presented that the AEI-CuCl 4 perovskite started to melt at 182 deg. C, together with the beginning of the decomposition of the hybrids. Compared with the organic-inorganic perovskite hybrids reported previously, the AEI-CuCl 4 perovskite shows a novel stepwise decomposition behavior

  2. Low temperature synthesis and photocatalytic property of perovskite-type LaCoO3 hollow spheres

    International Nuclear Information System (INIS)

    Fu, Shasha; Niu, Helin; Tao, Zhiyin; Song, Jiming; Mao, Changjie; Zhang, Shengyi; Chen, Changle; Wang, Dong

    2013-01-01

    Highlights: •Hollow perovskite-type LaCoO 3 is fabricated by green colloidal template method. •Carbonaceous colloids acted as templates and offered internal heat source. •The calcination temperature to form perovskite-type LaCoO 3 was dropped to 550 °C. •The photocatalytic properties were studied upon UV irradiation. •Hollow perovskite-type LaCoO 3 shows excellent photocatalytic activity on dyes. -- Abstract: Hollow perovskite-type LaCoO 3 was successfully fabricated by surface-ion adsorption method utilizing the carbonaceous colloids as template under relatively low calcination temperature. Carbonaceous colloids not only acted as templates but also offered internal heat source during calcination process. The impact of calcined temperature and time on the structure and morphology of the product were studied and the possible formation process of perovskite-type LaCoO 3 hollow spheres was illustrated. The obtained product was characterized by SEM, TEM, XRD, TG-DSC, ICP-OES, BET and UV–visible absorption spectra. The photocatalytic activities for degradation of methylene blue, methyl orange and neutral red were tested. The good photocatalytic degradation activity of the three different dyes and the band gap of 2.07 eV make it a promising candidate material for photocatalytic applications

  3. 42 CFR 493.859 - Standard; ABO group and D (Rho) typing.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Standard; ABO group and D (Rho) typing. 493.859 Section 493.859 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN..., Or Any Combination of These Tests § 493.859 Standard; ABO group and D (Rho) typing. (a) Failure to...

  4. Association of ABO and Rh blood groups with type 2 diabetes mellitus.

    Science.gov (United States)

    Meo, S A; Rouq, F A; Suraya, F; Zaidi, S Z

    2016-01-01

    The phenotypic "ABO" blood groups are inherited antigenic substances which are found on the surface of red blood cells in addition to other tissues. Certain hypothesis advocates that genetic predisposition like "ABO" blood group would be associated with occurrence of diseases including type 2 diabetes. This study aimed to investigate the potential association between "ABO" and "Rhesus" blood groups with type 2 diabetes. We identified 47 research documents in a data based search including ISI-Web of Science, EMBASE and PubMed. Literature was explored using the key terms including "ABO blood groups" "type 2 diabetes". Studies in which "ABO" blood types and diabetes mellitus were discussed included without restrictions of research documents, types, status and language of the publications. Finally, 15 publications which matched our criteria were included, and remaining studies were excluded. Blood group "B" was associated with high incidence of type 2 diabetes and blood group "O" has a minimum association with type 2 diabetes. Blood group "A" and "AB" were almost equally distributed in both diabetic and non-diabetic population. However, we were unable to find an association between "Rh+ve" and "Rh-ve" blood groups with type 2 diabetes. Subjects with blood group "B" are at high risk while individuals with blood group "O" are at low peril of evolving type 2 diabetes. It is suggested that subjects with blood group "B" should be closely monitored by physicians as these subjects have an increased risk of type 2 diabetes.

  5. Oxide perovskites with tetravalent dysprosium and compounds of the type Ba/sub 3/RE/sub 4/O/sub 9/ (RE = Rare Earth Element)

    Energy Technology Data Exchange (ETDEWEB)

    Brauer, G; Kristen, H [Freiburg Univ. (Germany, F.R.)

    1980-03-01

    In analogy to our investigations concerning tetravalent Nd in oxide perovskites, we also tried to stabilize dysprosium(IV) by incorporation in host-lattices with the perovskite structure. As host-lattices we used BaCeO/sub 3/, BaTbO/sub 3/, and SrTbO/sub 3/. Only in Ba(Ce, Dy)O/sub 3/ we could trace Dy(IV) with certainty. Among the prepared mixed oxides, also the phase Ba/sub 3/Dy/sub 4/O/sub 9/ occured. The lattice parameters of several phases of this latter type were redetermined.

  6. Structures and magnetic properties of rare earth double perovskites containing antimony or bismuth Ba{sub 2}LnMO{sub 6} (Ln=rare earths; M=Sb, Bi)

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Shumpei, E-mail: m-nis-s-o@ec.hokudai.ac.jp; Hinatsu, Yukio

    2015-07-15

    A series of double perovskite-type oxides Ba{sub 2}LnMO{sub 6} (Ln=lanthanides; M=Sb, Bi) were synthesized and their structures were studied. The Ln and M are structurally ordered in the rock-salt type at the B-site of the perovskite ABO{sub 3}. For Ba{sub 2}PrBiO{sub 6} and Ba{sub 2}TbBiO{sub 6}, it has been found that the disordering between Ln ion and Bi ion occurs at the B-site of the double perovskite and both the Pr (Tb) and Bi exist in two oxidation state in the same compound from the analysis of the X-ray diffraction and magnetic susceptibility data. Magnetic susceptibility measurements show that all these compounds are paramagnetic and have no magnetic ordering down to 1.8 K. - Graphical abstract: Tolerance factor for Ba{sub 2}LnMO{sub 6} (M=Sb, Bi) plotted against the ionic radius of Ln{sup 3+}. We have found that there is a clear relation between crystal structures and tolerance factors. - Highlights: • The Ln and M ions are structurally ordered in the rock-salt type at the B-site. • The disordering between Pr (Tb) ion and Bi ion occurs at the B-site. • Ba{sub 2}LnMO{sub 6} (M=Sb, Bi) have no magnetic ordering down to 1.8 K.

  7. Hyperfine interaction studies of the perovskite oxides of the type RCrO3 (R = Gd, Tb e Dy)

    International Nuclear Information System (INIS)

    Silva, Renilson Adriano da

    2009-01-01

    ABO 3 perovskite oxides have ideal cubic structure, however, some distortions in this type of structure may induce changes from cubic to orthorhombic or rhombroedric symmetry. The larger atoms A are located at the center of a cube, the B atoms are on 8 vertices and oxygen atoms occupy 12 positions in the middle of each side of the cube. Distortions in this structure may lead to new magnetic and electrical properties, with great scientific and technological interest. In this work RCrO 3 (R = Gd, Tb, Dγ) compounds (also known as orthocromites) were studied. The samples were produced by means of sol-gel chemical procedure and analyzed by X-Ray Diffraction. The results showed a single phase with Pbnm space group. The perturbed gamma-gamma angular correlation (PAC) measurements were carried out using 181 Hf( 181 Ta) and 111 In( 111 Cd) nuclear probes, which substitute 'A' and 'B' positions respectively. The probe nuclei were introduced in the samples during the chemical procedures for preparation. One of the objectives of this work's was to study the hyperfine magnetic field and its variation as a function of temperature, crystallographic structure as well as the antiferromagnetic transition temperature (T N ). The PAC Measurements were carried out in the temperature range of 20 to 300 K for R = Gd, Tb and 20 to 800 K in the case of R = Dγ from. Electric field gradient was also measured as a function of temperature. It was possible to observe the expected transition as well as the alignment of Cr spins, as found in literature. The Neel temperatures (TN) for investigated samples are ∼170 K, ∼164 K and ∼148 K for GdCrO 3 , TbCrO 3 and DyCrO 3 respectively. (author)

  8. Effect of ABO blood type on ovarian reserve in Chinese women.

    Science.gov (United States)

    Lin, Shengli; Li, Rong; Chi, Hongbin; Huang, Shuo; Zhang, Hua; Zheng, Xiaoying; Liu, Ping; Qiao, Jie

    2014-12-01

    To explore the effect of ABO blood type on ovarian reserve in Chinese women. Retrospective analysis. University-affiliated IVF center. The retrospective analysis involved 35,479 women who underwent in vitro fertilization and embryo transfer (IVF-ET) cycles between 2006 and 2012. None. The association between ABO blood types and diminished ovarian reserve (DOR). Among 35,479 Chinese women, 11,395 (32.12%) had blood type B, 10,583 (29.83%) had blood type O, 9,861 (27.79%) had blood type A, and 3,640 (10.26%) had blood type AB. There was a statistically significantly higher percentage of blood type O among those with follicle-stimulating hormone (FSH) levels ≤10 IU/L compared with those with FSH levels >10 IU/L. Conversely, among the women with DOR, there was statistically significantly higher percentage of those with blood types B and AB. Blood type A was not associated with DOR occurrence. Multivariate logistic regression analysis showed that blood type O was statistically significantly less often associated with DOR occurrence, whereas the B antigen (blood type B or AB) was statistically significantly associated with an increased risk of DOR. Our results have shown that there is an association between ABO blood type and DOR occurrence in Chinese women. Women with blood type O were statistically significantly less likely to have DOR, whereas those with B antigen (blood type B or AB) were statistically significantly more likely to have DOR. Blood type A was not associated with ovarian reserve. Copyright © 2014. Published by Elsevier Inc.

  9. Retrospective analysis of forward and reverse ABO typing discrepancies among patients and blood donors in a tertiary care hospital.

    Science.gov (United States)

    Makroo, R N; Kakkar, B; Agrawal, S; Chowdhry, M; Prakash, B; Karna, P

    2018-01-12

    The aim of our study was to determine the incidence and causes of ABO typing discrepancies among patients and blood donors at our centre. An accurate interpretation of the ABO blood group of an individual is of utmost importance to ensure patient safety and good transfusion practices. A retrospective observational study was carried out in the Department of Transfusion Medicine in our hospital from March 2013 to December 2015. Records of all patient and blood donor samples were retrieved and analysed for ABO typing discrepancies. In total, 135 853 patient and 62 080 donor samples were analysed for ABO typing discrepancies. The incidence among patients and blood donors was found to be 0·1% (138/135853) and 0·02% (14/62080), respectively. The mean age for patients and blood donors was 48·4 and 29·2 years, respectively. The most common cause of ABO typing discrepancies was due to cold autoantibodies among the patients (50·7%) and blood donors (57%) causing discrepant results in reverse typing. The various other causes of reverse typing discrepancies among patients were weak/missing antibody (25·4%), cold-reacting alloantibody (4·3%), warm autoantibody (2·2%), anti-A1 antibody (2·2%), Bombay phenotype (1·5%), transplantation (0·7%) and rouleaux (0·7%), whereas in blood donors, the causes were cold-reacting antibody (7%) and weak antibody (7%). The major cause of forward typing discrepancies among patients (12·3%) and blood donors (29%) was ABO subgroups. The resolution of ABO typing discrepancy is essential to minimise the chance of transfusion of ABO-incompatible blood. © 2018 British Blood Transfusion Society.

  10. ABO blood type and the risk of cancer – Findings from the Shanghai Cohort Study

    Science.gov (United States)

    Wang, Renwei; Gao, Yu-Tang

    2017-01-01

    ABO blood type is an inherited characteristic. The associations between ABO blood type and risk of all cancer and specific cancers were examined in a prospective cohort study of 18,244 Chinese men enrolled in 1986. During the 25 years of follow-up, 3,973 men developed cancer including 964 lung cancers, 624 colorectal cancers, 560 gastric cancers, 353 liver cancers, and 172 urinary bladder cancers. Hazard ratios (HR) for all cancer and specific cancers by ABO blood type were calculated using Cox proportional hazards models. Compared with blood type A, blood type B was associated with statistically significant reduced risk of all cancers (HR, 0.91, 95% CI:0.84, 0.99). Both blood types B and AB were associated with significantly lower risk of gastrointestinal cancer and colorectal cancer, respectively. Blood type B was also associated with significantly lower risk of stomach cancer and bladder cancer, while blood type AB was associated with significantly increased risk of liver cancer. By histological type, blood types B and AB were associated with lower risk of epidermoid carcinoma and adenocarcinoma, but were not associated with risk of sarcoma, lymphoma, leukemia or other cell types of cancer. The findings of this study support a role of genetic traits related to ABO blood type in the development of cancers in the gastrointestinal and urinary tracts. PMID:28880901

  11. Low temperature synthesis and photocatalytic property of perovskite-type LaCoO{sub 3} hollow spheres

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Shasha [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Niu, Helin, E-mail: niuhelin@ahu.edu.cn [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Tao, Zhiyin; Song, Jiming; Mao, Changjie; Zhang, Shengyi [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Chen, Changle, E-mail: changle@ustc.edu.cn [CAS Key Laboratory of Soft Matter Chemistry and Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026 (China); Wang, Dong [Department of Bio-Health Technology, College of Biomedical Science, Kangwon National University, Chuncheon, Gangwon-Do 200-701 (Korea, Republic of)

    2013-11-05

    Highlights: •Hollow perovskite-type LaCoO{sub 3} is fabricated by green colloidal template method. •Carbonaceous colloids acted as templates and offered internal heat source. •The calcination temperature to form perovskite-type LaCoO{sub 3} was dropped to 550 °C. •The photocatalytic properties were studied upon UV irradiation. •Hollow perovskite-type LaCoO{sub 3} shows excellent photocatalytic activity on dyes. -- Abstract: Hollow perovskite-type LaCoO{sub 3} was successfully fabricated by surface-ion adsorption method utilizing the carbonaceous colloids as template under relatively low calcination temperature. Carbonaceous colloids not only acted as templates but also offered internal heat source during calcination process. The impact of calcined temperature and time on the structure and morphology of the product were studied and the possible formation process of perovskite-type LaCoO{sub 3} hollow spheres was illustrated. The obtained product was characterized by SEM, TEM, XRD, TG-DSC, ICP-OES, BET and UV–visible absorption spectra. The photocatalytic activities for degradation of methylene blue, methyl orange and neutral red were tested. The good photocatalytic degradation activity of the three different dyes and the band gap of 2.07 eV make it a promising candidate material for photocatalytic applications.

  12. Magnetic properties of rare earth oxides with perovskite structure

    International Nuclear Information System (INIS)

    Hinatsu, Yukio

    2008-01-01

    A perovskite composite oxide is represented by the general formula of ABO 3 . Cations at the B site characterize magnetic properties of the oxide. Many studies have been accumulated for transition metal elements at the B sites. In this report the studies of rare earth elements at the B sites are reviewed. In rare elements, tetravalent ions such as Ce 4+ , Pr 4+ and Tb 4+ can occupy the B sites with Ba and Sr ions at the A sites. Both the SrTbO 3 and BaTbO 3 have an orthorhombic structure and show the antiferromagnetic transition at about 33 K, which is originated from terbium ions coupled antiferromagnetically with the six neighboring terbium ions. A tetravalent praseodymium perovskite SrPrO 3 shows no existence of the magnetic ordering down to 2.0 K. This is in contrast to the result of isomorphous BaPrO 3 , which shows an antiferromagnetic transition at 11.5 K. A double perovskite structure is represented by the formula A 2 LnMO 6 (A=Ba, Sr, Ca; M=Ru, Ir). In a double perovskite compound Ba 2 PrRuO 6 , the Pr 3+ and Ru 5+ ions are arranged with regularity over the six-coordinate B sites. This compound transforms to an antiferromagnetic state below 117 K. Antiferromagnetic transition temperatures T N for isomorphous Sr and Ca show a clear tendency, T N (A=Ba)>T N (Sr)>T N (Ca), in the compounds with the same rare earth elements (Ln). The 6H-perovskite structure Ba 3 LnRu 2 O 9 consists of linkages between LnO 6 octahedra and Ru 2 O 9 dimers made from face-shared RuO 6 octahedra. The 6H-perovskite structure Ba 3 MRu 2 O 9 (M=Sc, Y, La, Nd-Gd, Dy-Lu) have the valence state of Ba 3 M 3+ Ru 2 4.5+ O 9 . The magnetic susceptibilities show a broad maximum at 135-370 K. This magnetic behavior is ascribed to the antiferromagnetic coupling between two Ru ions in a Ru 2 O 9 dimer and to the magnetic interaction between the Ru 2 O 9 dimers. (author)

  13. ABO blood type is associated with ovarian reserve in Chinese women with subfertility.

    Science.gov (United States)

    Mu, Liangshan; Jin, Wumin; Yang, Haiyan; Chen, Xia; Pan, Jiexue; Lin, Jia; Wang, Peiyu; Huang, Xuefeng

    2016-08-09

    Ovarian reserve reflects both the quantity and quality of oocytes available for procreation, and is affected by many known and unknown factors. ABO blood type is related to a number of infertility processes, but it is unclear whether and how ABO blood type affects ovarian reserve. Here, we explored the relationship between ABO blood type and ovarian reserve in Chinese women with subfertility. Day-3 serum follicle-stimulating hormone (FSH) levels and blood type were examined in 14,875 women who underwent IVF or ICSI treatment. Blood type proportions in the patient population were as follows: 30.98% type A, 24.54% type B, 7.57% type AB, and 36.91% type O. A higher percentage of women with diminished ovarian reserve (DOR) were blood type O, while a lower percentage had the B antigen (B and AB). Multiple logistic regression analysis revealed that blood type O was associated with a greater risk of DOR than blood type B and B antigen-positive types. By contrast, the B antigen (B and AB) was associated with a lower incidence of DOR than blood type O. These results suggest that blood type O is a risk factor for DOR while the B antigen (blood type B or AB) is a protective factor for ovarian reserve in Chinese women with subfertility. Further studies are needed to confirm this effect and identify the underlying mechanisms.

  14. Tilts and Ionic Shifts in Rhombohedral Perovskites

    NARCIS (Netherlands)

    Noheda, Beatriz; Duan, Ning; Cereceda, Noé; Gonzalo, Julio A.

    1998-01-01

    We make a comparative analysis of rhombohedral perovskites (ABO3) with/without oxygen rotations and ionic shifts, within the framework of a generalised effective field approach. We analyse available data on LaAlO3 and LiTaO3 and new data on Zr-rich PZT, examples of three different ways of structural

  15. New Type of 2D Perovskites with Alternating Cations in the Interlayer Space, (C(NH 2 ) 3 )(CH 3 NH 3 ) n Pb n I 3n+1 : Structure, Properties, and Photovoltaic Performance

    Energy Technology Data Exchange (ETDEWEB)

    Soe, Chan Myae Myae; Stoumpos, Constantinos C.; Kepenekian, Mikaël; Traoré, Boubacar; Tsai, Hsinhan; Nie, Wanyi; Wang, Binghao; Katan, Claudine; Seshadri, Ram; Mohite, Aditya D.; Even, Jacky; Marks, Tobin J.; Kanatzidis, Mercouri G. (UCSB); (NWU); (LANL); (CNRS-UMR)

    2017-11-01

    We present the new homologous series (C(NH2)3)(CH3NH3)nPbnI3n+1 (n = 1, 2, 3) of layered 2D perovskites. Structural characterization by single-crystal X-ray diffraction reveals that these compounds adopt an unprecedented structure type, which is stabilized by the alternating ordering of the guanidinium and methylammonium cations in the interlayer space (ACI). Compared to the more common Ruddlesden–Popper (RP) 2D perovskites, the ACI perovskites have a different stacking motif and adopt a higher crystal symmetry. The higher symmetry of the ACI perovskites is expressed in their physical properties, which show a characteristic decrease of the bandgap with respect to their RP perovskite counterparts with the same perovskite layer thickness (n). The compounds show a monotonic decrease in the optical gap as n increases: Eg = 2.27 eV for n = 1 to Eg = 1.99 eV for n = 2 and Eg = 1.73 eV for n = 3, which show slightly narrower gaps compared to the corresponding RP perovskites. First-principles theoretical electronic structure calculations confirm the experimental optical gap trends suggesting that the ACI perovskites are direct bandgap semiconductors with wide valence and conduction bandwidths. To assess the potential of the ACI perovskites toward solar cell applications, we studied the (C(NH2)3)(CH3NH3)3Pb3I10 (n = 3) compound. Compact thin films from the (C(NH2)3)(CH3NH3)3Pb3I10 compound with excellent surface coverage can be obtained from the antisolvent dripping method. Planar photovoltaic devices from optimized ACI perovskite films yield a power-conversion-efficiency of 7.26% with a high open-circuit voltage of ~1 V and a striking fill factor of ~80%.

  16. Magnetism in ordered metallic perovskite compound GdPd3BxC1-x

    International Nuclear Information System (INIS)

    Pandey, Abhishek; Mazumdar, Chandan; Ranganathan, R.; Dattagupta, S.

    2009-01-01

    We report results of dc-magnetization, ac-susceptibility and magnetoresistance measurements on crystalline metallic-perovskite compounds GdPd 3 B x C 1-x (x=0.25, 0.50, 0.75 and 1.00) and the parent cubic compound GdPd 3 . The interest in these materials stems from the observation of negative temperature coefficient of resistance and negative thermal expansion in some of the members of this series. In the present study, we show that by substitution of non-magnetic elements, boron and carbon, the nature of the magnetic interaction can be varied from dominating ferromagnetic to antiferromagnetic and finally to a canted magnetic structure without altering the crystal symmetry of the compounds. The variation of magnetic interaction by modifying the lattice parameter resembles Ruderman-Kittel-Kasuya-Yosida (RKKY) oscillations.

  17. The influence of the relative thermal expansion and electric permittivity on phase transitions in the perovskite-type bidimensional layered NH3(CH2)3NH3CdBr4 compound

    Science.gov (United States)

    Staśkiewicz, Beata; Staśkiewicz, Anna

    2017-07-01

    Hydrothermal method has been used to synthesized the layered hybrid compound NH3(CH2)3NH3CdBr4 of perovskite architecture. Structural, dielectric and dilatometric properties of the compound have been analyzed. Negative thermal expansion (NTE) effect in the direction perpendicular to the perovskite plane as well as an unusual phase sequence have been reported based on X-ray diffraction analysis. Electric permittivity measurements evidenced the phase transitions at Tc1=326/328 K and Tc2=368/369 K. Relative linear expansion measurements almost confirmed these temperatures of phase transitions. Anomalies of electric permittivity and expansion behavior connected with the phase transitions are detected at practically the same temperatures as those observed earlier in differential scanning calorimetry (DSC), infrared (IR), far infrared (FIR) and Raman spectroscopy studies. Mechanism of the phase transitions is explained. Relative linear expansion study was prototype to estimate critical exponent value β for continuous phase transition at Tc1. It has been inferred that there is a strong interplay between the distortion of the inorganic network, those hydrogen bonds and the intermolecular interactions of the organic component.

  18. Ab-initio study of the dielectric response of high-permittivity perovskites for energy storage

    International Nuclear Information System (INIS)

    Do-Amaral-De-Andrade-Sophia, Gustavo

    2014-01-01

    Many of materials based on transition metals have a wide range of applications, such as the storage of energy, due to their peculiar properties (high-dielectric constants, ferro-electricity,...). The knowledge of their bulk properties is essential in designing targeted devices with high performance. For instance, ABO 3 perovskites are peculiarly interesting for their atomic structural flexibility, allowing high number of atoms substitution and giving them specific chemical and electrical properties compared to the pure compounds. In this context, first principles calculations can be useful to understand the structural and electronic properties of these materials. The pressure-induced giant dielectric anomaly of ABO 3 perovskites has been investigated at the ab initio level. Its mechanism has been analyzed in terms of thermodynamic phase stability, structural and phonon contributions and Born effective charges. It is shown that the IR-active soft phonon is responsible for the anomaly. This mode always involves a displacement and a deformation of the oxygen octahedra, while the roles of A and B ions vary among the materials and between high- and low-pressure phase transitions. A sharp increase in the phonon amplitude near the phase transition gives rise to the dielectric anomaly. The use of hybrid functionals is required for agreement with experimental data. The calculations show that the dielectric anomaly in the pressure-induced phase transitions of these perovskites is a property of the bulk material. (author)

  19. Anomalous perovskite PbRuO3 stabilized under high pressure

    Science.gov (United States)

    Cheng, J.-G.; Kweon, K. E.; Zhou, J.-S.; Alonso, J. A.; Kong, P.-P.; Liu, Y.; Jin, Changqing; Wu, Junjie; Lin, Jung-Fu; Larregola, S. A.; Yang, Wenge; Shen, Guoyin; MacDonald, A. H.; Manthiram, Arumugam; Hwang, G. S.; Goodenough, John B.

    2013-01-01

    Perovskite oxides ABO3 are important materials used as components in electronic devices. The highly compact crystal structure consists of a framework of corner-shared BO6 octahedra enclosing the A-site cations. Because of these structural features, forming a strong bond between A and B cations is highly unlikely and has not been reported in the literature. Here we report a pressure-induced first-order transition in PbRuO3 from a common orthorhombic phase (Pbnm) to an orthorhombic phase (Pbn21) at 32 GPa by using synchrotron X-ray diffraction. This transition has been further verified with resistivity measurements and Raman spectra under high pressure. In contrast to most well-studied perovskites under high pressure, the Pbn21 phase of PbRuO3 stabilized at high pressure is a polar perovskite. More interestingly, the Pbn21 phase has the most distorted octahedra and a shortest Pb—Ru bond length relative to the average Pb—Ru bond length that has ever been reported in a perovskite structure. We have also simulated the behavior of the PbRuO3 perovskite under high pressure by first principles calculations. The calculated critical pressure for the phase transition and evolution of lattice parameters under pressure match the experimental results quantitatively. Our calculations also reveal that the hybridization between a Ru:t2g orbital and an sp hybrid on Pb increases dramatically in the Pbnm phase under pressure. This pressure-induced change destabilizes the Pbnm phase to give a phase transition to the Pbn21 phase where electrons in the overlapping orbitals form bonding and antibonding states along the shortest Ru—Pb direction at P > Pc. PMID:24277807

  20. Hyperfine interactions studies in perovskite oxides of the type LaMO3 (M = Fe, Cr, Mn and Co)

    International Nuclear Information System (INIS)

    Junqueira, Astrogildo de Carvalho

    2004-01-01

    ABO 3 -type perovskite oxides have ideal cubic structure and usually show distortions to the orthorhombic or rombohedric symmetry. The A and B siteshave 12-fold and 6-fold oxygen coordination, respectively. Distortions of thecubic structure give rise to new electric, structural and magnetic propertieswhich have great technological and scientific interests. Magnetic dipole and electric quadrupole hyperfine interaction measurements were obtained using 111 In -> 111 Cd , 181 Hf -> 181 Ta e 140 La -> 140 Ceradioactive nuclei substituting for the A or B sites via Perturbed Angulargamma-gamma Correlation technique (1-4) . LaMO 3 (M = Fe, Cr, Mn and Co)samples were prepared through the chemical route known as Sol-Gel techniqueand analyzed with x-ray diffraction. Both 111 In and 181 Hf nuclei wereintroduced in to the sample during the chemical procedure and the 140 Lawas obtained by irradiating with neutrons in the IPEN reactor the natural Lapresent in the samples. One of the aims of this work was the analysis of theElectric Field Gradient (EFG) in the A and B sites as function oftemperature, crystal structure or the electronic characteristic of thetransition metal in the B site. The temperature range of the measurements wasabout from 4 K to 1400 K. The experimental EFG showed to be dependent of thesite occupation and the nuclear probe used in the measurements. Spintransition phenomena were also observed in LaCoO 3 samples, which confirmed amodel used to interpret the spin properties in such compound.Crystallographic phase transition effects on the hyperfine parameters inperovskites where M = Fe, Cr and K4n were also analyzed. An additional aim ofthis work was to carry out measurements in the antiferromagnetic region ofthe systems with M = Fe, Cr and Mn using the three radioactive nuclei. Theresults for the magnetic interaction measurements showed a strong influenceof the substitutional sites in the supertransferred magnetic hyperfine fieldfor all the three probe nuclei

  1. Magnetic structure of post-perovskite compound CaIrO3

    International Nuclear Information System (INIS)

    Ohgushi, Kenya; Ohsumi, Hiroyuki; Yamaura, Jun-ichi; Arima, Taka-hisa

    2014-01-01

    We have performed resonant X-ray diffraction experiments at the Ir L absorption edges for a post-perovskite compound CaIrO 3 with a Ir 4+ : (t 2g ) 5 electronic configuration. By observing the magnetic signals, we could clearly see that the magnetic structure was a striped ordering with antiferromagnetic moments along the c axis and that the wave function of a t 2g hole is strongly spin-orbit entangled, the J eff = 1/2 state. The observed spin arrangement is consistent with a theoretical work predicting a unique superexchange interaction called the quantum compass model. Our studies stimulate further studies for developing novel quantum states in iridium oxides. (author)

  2. Simplification of genotyping techniques of the ABO blood type experiment and exploration of population genetics.

    Science.gov (United States)

    Hu, Jian; Zhou, Yi-ren; Ding, Jia-lin; Wang, Zhi-yuan; Liu, Ling; Wang, Ye-kai; Lou, Hui-ling; Qiao, Shou-yi; Wu, Yan-hua

    2017-05-20

    The ABO blood type is one of the most common and widely used genetic traits in humans. Three glycosyltransferase-encoding gene alleles, I A , I B and i, produce three red blood cell surface antigens, by which the ABO blood type is classified. By using the ABO blood type experiment as an ideal case for genetics teaching, we can easily introduce to the students several genetic concepts, including multiple alleles, gene interaction, single nucleotide polymorphism (SNP) and gene evolution. Herein we have innovated and integrated our ABO blood type genetics experiments. First, in the section of Molecular Genetics, a new method of ABO blood genotyping was established: specific primers based on SNP sites were designed to distinguish three alleles through quantitative real-time PCR. Next, the experimental teaching method of Gene Evolution was innovated in the Population Genetics section: a gene-evolution software was developed to simulate the evolutionary tendency of the ABO genotype encoding alleles under diverse conditions. Our reform aims to extend the contents of genetics experiments, to provide additional teaching approaches, and to improve the learning efficiency of our students eventually.

  3. Study of ABO blood types by combining membrane electrophoresis with surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Wang, Jing; Lin, Juqiang; Huang, Zufang; Sun, Liqing; Shao, Yonghong; Lu, Peng; Shi, Wei; Lin, Jinyong; Chen, Rong

    2012-12-01

    The molecular characterization of ABO blood types, which is clinically significant in blood transfusion, has clinical and anthropological importance. Polymerase chain reaction sequence-based typing (PCR-SBT) is one of the most commonly used methods for the analysis of genetic bases of ABO blood types. However, such methods as PCR-SBT are time-consuming and are high in demand of equipments and manipulative skill. Here we showed that membrane electrophoresis based SERS method employed for studying the molecular bases of ABO blood types can provide rapidand easy-operation with high sensitivity and specificity. The plasma proteins were firstly purified by membrane electrophoresis and then mixed with silver nanoparticles to perform SERS detection. We use this method to classify different blood types, including blood type A (n=13), blood type B (n=9) and blood type O (n=10). Combination of principal component analysis (PCA) and liner discriminant analysis (LDA) was then performed on the SERS spectra of purified albumin, showing good classification results among different blood types. Our experimental outcomes represent a critical step towards the rapid, convenient and accurate identification of ABO blood types.

  4. Aging and ABO blood type influence von Willebrand factor and factor VIII levels through interrelated mechanisms.

    Science.gov (United States)

    Albánez, S; Ogiwara, K; Michels, A; Hopman, W; Grabell, J; James, P; Lillicrap, D

    2016-05-01

    Essentials von Willebrand factor (VWF) and factor VIII (FVIII) levels are modulated by age and ABO status. The effect of aging and ABO blood type on VWF and FVIII was assessed in 207 normal individuals. Aging and ABO blood type showed combined and bidirectional influences on VWF and FVIII levels. Aging and ABO blood type influence VWF levels through both secretion and clearance mechanisms. Background The effect of aging and ABO blood type on plasma levels of von Willebrand factor (VWF) and factor VIII (FVIII) have been widely reported; however, a comprehensive analysis of their combined effect has not been performed and the mechanisms responsible for the age-related changes have not been determined. Objectives To assess the influence of aging and ABO blood type on VWF and FVIII levels, and to evaluate the contribution of VWF secretion and clearance to the age-related changes. Methods A cross-sectional observational study was performed in a cohort of 207 normal individuals, whose levels of VWF, FVIII, VWF propeptide (VWFpp), VWFpp/VWF:Ag ratio and blood type A antigen content on VWF (A-VWF) were quantified. Results Aging and ABO blood type exerted interrelated effects on VWF and FVIII plasma levels, because the age-related increase in both proteins was significantly higher in type non-O individuals (β = 0.011 vs. 0.005). This increase with age in non-O subjects drove the differences between blood types in VWF levels, as the mean difference increased from 0.13 U/mL in the young to 0.57 U/mL in the old. Moreover, A-VWF was associated with both VWF antigen (β = 0.29; 95% confidence interval [CI], 0.09, 0.50) and VWF clearance (β = -0.15; 95% CI, -0.25, -0.06). We also documented an effect of ABO blood type on VWF secretion with aging, as old individuals with blood type non-O showed higher levels of VWFpp (mean difference 0.29 U/mL). Conclusions Aging and ABO blood type have an interrelated effect on VWF and FVIII levels, where the effect of one is significantly

  5. Sensing properties of perovskite oxide La0.5SR0.5Co0-3-d obtained by using pulsed laser deposition

    NARCIS (Netherlands)

    Dam, T.V.A.; Olthuis, Wouter; Bergveld, Piet

    2004-01-01

    La1−xSrxCoO3−δ belongs to the group of perovskite oxides of the ABO3 structure, with a trivalent rare earth in the A position (La) and a trivalent metal ion in the B position (Co). Doping with divalent Sr-ions at the trivalent La-positions creates oxygen vacancies which give the oxide catalytic

  6. Comparative Analysis of Clinical Samples Showing Weak Serum Reaction on AutoVue System Causing ABO Blood Typing Discrepancies.

    Science.gov (United States)

    Jo, Su Yeon; Lee, Ju Mi; Kim, Hye Lim; Sin, Kyeong Hwa; Lee, Hyeon Ji; Chang, Chulhun Ludgerus; Kim, Hyung Hoi

    2017-03-01

    ABO blood typing in pre-transfusion testing is a major component of the high workload in blood banks that therefore requires automation. We often experienced discrepant results from an automated system, especially weak serum reactions. We evaluated the discrepant results by the reference manual method to confirm ABO blood typing. In total, 13,113 blood samples were tested with the AutoVue system; all samples were run in parallel with the reference manual method according to the laboratory protocol. The AutoVue system confirmed ABO blood typing of 12,816 samples (97.7%), and these results were concordant with those of the manual method. The remaining 297 samples (2.3%) showed discrepant results in the AutoVue system and were confirmed by the manual method. The discrepant results involved weak serum reactions (serum reactions, samples from patients who had received stem cell transplants, ABO subgroups, and specific system error messages. Among the 98 samples showing ≤1+ reaction grade in the AutoVue system, 70 samples (71.4%) showed a normal serum reaction (≥2+ reaction grade) with the manual method, and 28 samples (28.6%) showed weak serum reaction in both methods. ABO blood tying of 97.7% samples could be confirmed by the AutoVue system and a small proportion (2.3%) needed to be re-evaluated by the manual method. Samples with a 2+ reaction grade in serum typing do not need to be evaluated manually, while those with ≤1+ reaction grade do.

  7. Fabrication and characterization of perovskite solar cells added with MnCl2, YCl3 or poly(methyl methacrylate)

    Science.gov (United States)

    Taguchi, Masaya; Suzuki, Atsushi; Tanaka, Hiroki; Oku, Takeo

    2018-01-01

    Perovskite-type CH3NH3PbI3-based photovoltaic devices were fabricated and characterized. Effects of manganese (Mn), yttrium (Y) compounds addition into the perovskite crystal on the photovoltaic properties were investigated. Also, the effects of poly(methyl methacrylate) (PMMA) addition on perovskite layer on the photovoltaic properties were investigated. When 3 % MnCl2 was added, the short circuit current density and conversion efficiency were improved by promoting the crystal growth of perovskite phase. The photoelectric conversion efficiency for 0.9 mg mL-1 PMMA added was 7.36 %. Open circuit voltage and fill factor were improved by 5 % YCl3 addition.

  8. New vanadium oxides with perovskite type structure: AThV/sub 2/O/sub 6/ (A=Ca,Sr)

    Energy Technology Data Exchange (ETDEWEB)

    Vidyasagar, K; Gopalakrishnan, J

    1982-07-01

    New perovskite oxides of the formula AThV/sub 2/O/sub 6/ (A=Ca,Sr) have been prepared by reduction of the corresponding AThV/sub 2/O/sub 8/ under hydrogen atmosphere. CaThV/sub 2/O/sub 6/ crystallizes in an orthorhombic LaVO/sub 3/ type structure, while the strontium compound exhibiting cation-deficient nonstoichiometry. SrThsub(1-x)V/sub 2/O/sub 6/ (x approx. 0.4), is cubic. The magnetic susceptibility behaviour of the calcium compound is similar to that of V/sup 3 +/ perovskites, while the strontium compound exhibits a large increase in susceptibility below 130K, the behaviour being likely to be associated with the mixed-valence character of vanadium.

  9. Prognostic role of ABO blood type in patients with extranodal natural killer/T cell lymphoma, nasal type: a triple-center study.

    Science.gov (United States)

    Li, Ya-Jun; Yi, Ping-Yong; Li, Ji-Wei; Liu, Xian-Ling; Tang, Tian; Zhang, Pei-Ying; Jiang, Wen-Qi

    2017-07-31

    The prognostic significance of ABO blood type for lymphoma is largely unknown. We evaluated the prognostic role of ABO blood type in patients with extranodal natural killer (NK)/T-cell lymphoma (ENKTL). We retrospectively analyzed clinical data of 697 patients with newly diagnosed ENKTL from three cancer centers. The prognostic value of ABO blood type was evaluated using Kaplan-Meier curves and Cox proportional hazard models. The prognostic values of the International Prognostic Index (IPI) and the Korean Prognostic Index (KPI) were also evaluated. Compared with patients with blood type O, those with blood type non-O tended to display elevated baseline serum C-reactive protein levels (P = 0.038), lower rate of complete remission (P = 0.005), shorter progression-free survival (PFS, P 60 years (P KPI in distinguishing between the intermediate-to-low- and high-to-intermediate-risk groups. ABO blood type was an independent predictor of clinical outcome for patients with ENKTL.

  10. High performance photodetector based on 2D CH3NH3PbI3 perovskite nanosheets

    International Nuclear Information System (INIS)

    Li, Pengfei; Shivananju, B N; Li, Shaojuan; Bao, Qiaoliang; Zhang, Yupeng

    2017-01-01

    In this work, a high performance vertical-type photodetector based on two-dimensional (2D) CH 3 NH 3 PbI 3 perovskite nanosheets was fabricated. The low trap density of the perovskite nanosheets and their short carrier diffusion distance result in a significant performance enhancement of the perovskite-based photodetector. The photoresponsivity of this vertical-type photodetector is as high as 36 mA W −1 at visible wavelength, which is much better than traditional perovskite photodetectors (0.34 mA W −1 ). Compared with traditional planar-type perovskite-based photodetectors, this vertical-type photodetector also shows the advantages of low-voltage operation and large responsivity. These results may pave the way for exploiting high performance perovskite-based photodetectors with an ingenious device design. (paper)

  11. Activity and stability trends of perovskite oxides for oxygen evolution catalysis at neutral pH

    OpenAIRE

    Ling, Chen; Jia, Hongfei; Han, Binghong; Risch, Marcel; Lee, Yueh Lin; Shao-Horn, Yang

    2015-01-01

    Perovskite oxides (ABO[subscript 3]) have been studied extensively to promote the kinetics of the oxygen evolution reaction (OER) in alkaline electrolytes. However, developing highly active catalysts for OER at near-neutral pH is desirable for many photoelectrochemical/electrochemical devices. In this paper, we systematically studied the activity and stability of well-known perovskite oxides for OER at pH 7. Previous activity descriptors established for perovskite oxides at pH 13, such as hav...

  12. Application of Electron Structure Calculations to the Migration of Oxygen through a Perovskite Membrane

    Science.gov (United States)

    Wood, Douglas A.

    The focus of this thesis is the application of electron structure calculations, particularly density functional theory, to the analysis of the process by which oxygen is able to migrate through a perovskite crystal. This property creates the possibility of using perovskite membranes to separate oxygen from air. This could be applied to the generation of syngas directly from natural gas without the need for a separate air separation unit. A perovskite has the nominal formula ABO3 where A is a rare earth type cation and B is a transition type cation. The structure consists of the B cations arranged in a cube with the A cation in the center. The oxygen ions are located at the midpoint of each B-B cube edge and form an octahedron centered on each B cation. Any real perovskite crystal will contain a certain fraction of vacancies at the oxygen sites. Oxygen migrates through the crystal by jumping from a neighboring site to the vacancy. The permeability of the crystal is thus a function of the concentration of vacancies and the activation energy of the jump from a neighboring site to the vacancy. These properties can be modified by adding dopants for the A and B cations. The literature contains a substantial amount of experimental work on the effect of such dopants. The overall migration process can be divided into components (i) the concentration of oxygen vacancies, (ii) the activation energy for a neighboring on-site oxygen atom to jump to the vacant site, (iii) the concentration of surface vacancies, and (iv) the processes by which oxygen ions transfer back and forth between the perovskite surface and the contiguous vapor space. Using SrTiO3 and LaCoO3 as model compounds, DFT calculations have been used to (i) calculate various properties of the perovskite crystal, (ii) estimate the activation energy of a jump between an occupied oxygen site and an adjacent vacant oxygen site, (iii) predict the effects of various dopants at the A and B site and (iv) analyze the

  13. CO2 absorption of perovskites as seen by positron lifetime spectroscopy

    International Nuclear Information System (INIS)

    Suevegh, K.; Nomura, K.; Juhasz, G.; Homonnay, Z.; Vertes, A.

    2000-01-01

    The CO 2 absorption of several ABO 3 type perovskites was studied by positron lifetime spectroscopy. The longer positron lifetime was associated with positrons trapped by A site vacancies. The evaluated positron lifetime data indicated the relative stability of the crystal structure of Sr(Co 0.5 Fe 0.5 )O 3-δ against Ca doping at low Ca concentrations. Oxygen desorption and CO 2 absorption/desorption could also be followed by positron lifetime spectroscopy. It was shown that the concentration of oxygen vacancies has a large effect on positron lifetime data through the electron density of A site vacancies.

  14. Genetic and mechanistic evaluation for the mixed-field agglutination in B3 blood type with IVS3+5G>A ABO gene mutation.

    Directory of Open Access Journals (Sweden)

    Ding-Ping Chen

    Full Text Available BACKGROUND: The ABO blood type B(3 is the most common B subtype in the Chinese population with a frequency of 1/900. Although IVS3+5G>A (rs55852701 mutation of B gene has been shown to associate with the development of B(3 blood type, genetic and mechanistic evaluation for the unique mixed-field agglutination phenotype has not yet been completely addressed. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we analyzed 16 cases of confirmed B(3 individuals and found that IVS3+5G>A attributes to all cases of B(3. RT-PCR analyses revealed the presence of at least 7 types of aberrant B(3 splicing transcripts with most of the transcripts causing early termination and producing non-functional protein during translation. The splicing transcript without exon 3 that was predicted to generate functional B(3 glycosyltransferase lacking 19 amino acids at the N-terminal segment constituted only 0.9% of the splicing transcripts. Expression of the B(3 cDNA with exon 3 deletion in the K562 erythroleukemia cells revealed that the B(3 glycosyltransferase had only 40% of B(1 activity in converting H antigen to B antigen. Notably, the typical mixed-field agglutination of B(3-RBCs can be mimicked by adding anti-B antibody to the K562-B(3 cells. CONCLUSIONS/SIGNIFICANCE: This study thereby demonstrates that both aberrant splicing of B transcripts and the reduced B(3 glycosyltransferase activity contribute to weak B expression and the mixed-field agglutination of B(3, adding to the complexity for the regulatory mechanisms of ABO gene expression.

  15. Phase transition in metastable perovskite Pb(AlNb)0,5O3

    International Nuclear Information System (INIS)

    Zhabko, T.E.; Olekhnovich, N.M.; Shilin, A.D.

    1987-01-01

    Dielectric properties of metastable perovskite Pb(AlNb) 0.5 O 3 and X-ray temperature investigations of both perovskite and pyrochlore modifications of the given compound are studied. Samples with the perovskite structure are prepared from the pyrochlorephase at 4-5 GPa pressure and 1170-1270 K. Ferroelectric phase transition is shown to occur in the metastable perovskite phase Pb(AlNb) 0.5 O 3 at 170 K

  16. Magnetic properties of Pr ions in perovskite-type oxides

    International Nuclear Information System (INIS)

    Sekizawa, K.; Kitagawa, M.; Takano, Y.

    1998-01-01

    Magnetic properties of Pr ions with the controlled valence on the A and B sites of perovskite-type oxides (ABO 3 ) were investigated for two systems. PrSc 1-x Mg x O 3 and BaPr 1-x Bi x O 3 . From the magnetic susceptibility χ versus temperature T curves of PrSc 1-x Mg x O 3 , the χ-T curve for molar Pr 3+ ions on the A site and that of Pr 4+ ions were obtained. The 1/χ-T curves for both ions exhibit the crystalline electric field (CEF) effect and the effective magneticmoment μ eff above 100 K is 3.41 μ B for Pr 3- and 2.58 μ B for Pr 4+ , respectively. The χ-T curve of PrSc 0.8 Mg 0.2 O 3 is similar to that of PrBa 2 Cu 3 O y . In the BaPr 1-x Bi x O 3 system, only one intermediate phase BaPr 0.5 Bi 0.5 O 3 exists, in which Pr and Bi take an ordered arrangement on the B site. The magnetic susceptibility χ for Pr 4+ and that of Pr 3+ in the ordered arrangement with Bi 5- on the B site are much smaller than those for the A site, reflecting the strong CEF effect on the B site. Experimental χ-T curves can be well reproducedby the numerical calculation for Pr 3+ or Pr 4+ ions in the molecular field and the CEF with proper respective parameters. (orig.)

  17. Fabrication and Characterization of CH3NH3PbI3−x−yBrxCly Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Atsushi Suzuki

    2016-05-01

    Full Text Available Fabrication and characterization of CH3NH3PbI3−x−yBrxCly perovskite solar cells using mesoporous TiO2 as electron transporting layer and 2,2′,7,7′-tetrakis-(N,N-di-4-methoxyphenylamino-9,9′-spirobifluorene as a hole-transporting layer (HTL were performed. The purpose of the present study is to investigate role of halogen doping using iodine (I, bromine (Br and chlorine (Cl compounds as dopant on the photovoltaic performance and microstructures of CH3NH3PbI3−x−yBrxCly perovskite solar cells. The X-ray diffraction identified a slight decrease of crystal spacing in the perovskite crystal structure doped with a small amount of I, Br, and Cl in the perovskite compounds. Scanning electron microscopy (SEM and energy dispersive X-ray spectroscopy (EDX showed the perovskite crystal behavior depended on molar ratio of halogen of Pb, I, Br and Cl. Incorporation of the halogen doping into the perovskite crystal structure improved photo generation, carrier diffusion without carrier recombination in the perovskite layer and optimization of electronic structure related with the photovoltaic parameters of open-circuit voltage, short-circuit current density and conversion efficiency. The energy diagram and photovoltaic mechanisms of the perovskite solar cells were discussed in the context of the experimental results.

  18. CaMn(1-x)Nb(x)O3 (x < or = 0.08) perovskite-type phases as promising new high-temperature n-type thermoelectric materials.

    Science.gov (United States)

    Bocher, L; Aguirre, M H; Logvinovich, D; Shkabko, A; Robert, R; Trottmann, M; Weidenkaff, A

    2008-09-15

    Perovskite-type CaMn(1-x)Nb(x)O(3+/-delta) (x = 0.02, 0.05, and 0.08) compounds were synthesized by applying both a "chimie douce" (SC) synthesis and a classical solid state reaction (SSR) method. The crystallographic parameters of the resulting phases were determined from X-ray, electron, and neutron diffraction data. The manganese oxidations states (Mn(4+)/Mn(3+)) were investigated by X-ray photoemission spectroscopy. The orthorhombic CaMn(1-x)Nb(x)O(3+/-delta) (x = 0.02, 0.05, and 0.08) phases were studied in terms of their high-temperature thermoelectric properties (Seebeck coefficient, electrical resistivity, and thermal conductivity). Differences in electrical transport and thermal properties can be correlated with different microstructures obtained by the two synthesis methods. In the high-temperature range, the electron-doped manganate phases exhibit large absolute Seebeck coefficient and low electrical resistivity values, resulting in a high power factor, PF (e.g., for x = 0.05, S(1000K) = -180 microV K(-1), rho(1000K) = 16.8 mohms cm, and PF > 1.90 x 10(-4) W m(-1) K(-2) for 450 K 0.3) make these phases the best perovskitic candidates as n-type polycrystalline thermoelectric materials operating in air at high temperatures.

  19. Pseudo Jahn–Teller origin of ferroelectric instability in BaTiO{sub 3} type perovskites: The Green's function approach and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Polinger, V., E-mail: polinv@uw.edu [Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States); Garcia-Fernandez, P. [Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Avenida de los Castros s/n, E-39005 Santander (Spain); Bersuker, I.B. [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712-0165 (United States)

    2015-01-15

    The local origin of dipolar distortions in ABO{sub 3} perovskite crystals is reexamined by means of a novel approach, the Green's function method augmented by DFT computations. The ferroelectric distortions are shown to be induced by the pseudo Jahn–Teller effect (PJTE). The latter involves vibronic hybridization (admixture) of the ground state to same-spin opposite-parity excited electronic bands. Similar to numerous molecular calculations, the PJT approach provides a deeper insight into the nature of chemical bonding in the octahedral cluster [BO{sub 6}] and, in particular, reveals the local origin of its polar instability. This allows predicting directly which transition ions can create ferroelectricity. In particular, the necessary conditions are established when an ABO{sub 3} perovskite crystal with an electronic d{sup n} configuration of the complex ion [BO{sub 6}] can possess both proper ferroelectric and magnetic properties. Distinguished from the variety of cluster approaches to local properties, the Green's function method includes the influence of the local vibronic-coupling perturbation on the whole crystal via the inter-cell interaction responsible for creation of electronic and vibrational bands. Calculated Green's functions combined with the corresponding numeric estimates for the nine electronic bands, their density of states, and the local adiabatic potential energy surface (APES) confirm the eight-minimum form of this surface and feasibility of the PJT origin of the polar instability in BaTiO{sub 3}. We show also that multicenter long-range dipole–dipole interactions critically depend on the PJTE largely determining the magnitude of the local dipoles. DFT calculations for the bulk crystal and its clusters confirm that the dipolar distortions are of local origin, but become possible only when their influence on (relaxation of) the whole lattice is taken into account. The results are shown to be in full qualitative and

  20. Study of transport properties of bodies with a perovskite structure: application to the MgSiO3 perovskite

    International Nuclear Information System (INIS)

    Kapusta, Benedicte

    1990-01-01

    After some recalls on transport in ionic solids (Nernst-Einstein relationship, variation of ionic conductivity, hybrid conduction, fast ionic conduction), this research thesis presents the physical properties of perovskites and more particularly the structure and stability of the MgSiO 3 perovskite: structure and elastic properties, electric conductivity and transport properties in compounds with a perovskite structure. Then, the author reports the experimental study of the KZnF 3 perovskite (a structural analogous of MgSiO 3 ): measurements of electric conductivity under pressure, measurements under atmospheric pressure, result discussion. The next part addresses the numerical simulation of MgSiO 3 : simulation techniques (generalities on molecular dynamics, model description), investigation of structural, elastic and thermodynamic properties, diffusion properties in quadratic phase [fr

  1. Overuse of preoperative laboratory coagulation testing and ABO blood typing: a French national study.

    Science.gov (United States)

    Beloeil, H; Ruchard, D; Drewniak, N; Molliex, S

    2017-12-01

    Following publication of guidelines on routine preoperative tests, the French Society of Anaesthesiology and Intensive Care (SFAR), in association with French national public health insurance, conducted a survey to evaluate adherence to guidelines and the economic consequences. Using the French Hospital Discharge Database and National Health Insurance Information system, tests performed during the 30 days before surgery were analysed for two situations: (1) standard laboratory coagulation tests and ABO blood typing in children able to walk and scheduled for tonsillectomy/adenoidectomy; and (2) ABO blood typing in adults before laparoscopic cholecystectomy, thyroidectomy, lumbar discectomy or breast surgery. Guidelines do not recommend any preoperative tests in these settings. Between 2013 and 2015, a coagulation test was performed in 49% of the 241 017 children who underwent tonsillectomy and 39% of the 133 790 children who underwent adenoidectomy. A similar pattern was observed for ABO blood typing although re-operation rates for bleeding on the first postoperative day were very low (0.12-0.31% for tonsillectomy and 0.01-0.02% for adenoidectomy). Between 2012 and 2015, ABO blood typing was performed in 32-45% of the 1 114 082 patients who underwent one of the four selected procedures. The transfusion rate was very low (0.02-0.31%). The mean cost for the four procedures over the 4 yr period was €5 310 000 (sd €325 000). Standard laboratory coagulation tests and ABO blood typing are still routinely prescribed before surgery and anaesthesia despite current guidelines. This over-prescription represents a high and unnecessary cost, and should therefore be addressed. © The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  2. Crystal structures and some physical properties of perovskite type vanadites of lanthanide-series elements

    Energy Technology Data Exchange (ETDEWEB)

    Shinike, T [Osaka Dental Coll., Hirakata (Japan); Adachi, G; Shiokawa, J

    1980-04-01

    Crystal structures and some physical properties of the perovskite type vanadites of the lanthanide-series elements were studied. LaVO/sub 3/ and CeVO/sub 3/ had a tetragonal unit cell and other compounds studied were isostructural with orthorhombic GdFeO/sub 3/. The conductivity of all compounds showed semiconductive behavior with an activation energy about 0.1 eV. Electrical conductivity at room temperature decreased along the series from LaVO/sub 3/ to GdVO/sub 3/, and quasiconstant values were observed from TbVO/sub 3/ to LuVO/sub 3/. All the compounds studied, with the exception of LaVO/sub 3/, SmVO/sub 3/ and GdVO/sub 3/, were antiferromagnets with a weak ferromagnetism because of antisymmetric exchange interaction at low temperatures. At high temperature, all the compounds showed paragnetism.

  3. Transport, Optical, and Magnetic Properties of the Conducting Halide Perovskite CH 3NH 3SnI 3

    Science.gov (United States)

    Mitzi, D. B.; Feild, C. A.; Schlesinger, Z.; Laibowitz, R. B.

    1995-01-01

    A low-temperature ( T ≤ 100°C) solution technique is described for the preparation of polycrystalline and single crystal samples of the conducting halide perovskite, CH 3NH 3SnI 3. Transport, Hall effect, magnetic, and optical properties are examined over the temperature range 1.8-300 K, confirming that this unusual conducting halide perovskite is a low carrier density p-type metal with a Hall hole density, 1/ RHe ≃ 2 × 10 19 cm -3. The resistivity of pressed pellet samples decreases with decreasing temperature with resistivity ratio ρ(300 K)/ρ(2 K) ≃ 3 and room temperature resistivity ρ(300 K) ≃ 7 mΩ-cm. A free-carrier infrared reflectivity spectrum with a plasma edge observed at approximately 1600 cm -1 further attests to the metallic nature of this compound and suggests a small optical effective mass, m* ≃ 0.2.

  4. Influence of ABO blood type on the outcome after non-aneurysmal subarachnoid hemorrhage.

    Science.gov (United States)

    Dubinski, Daniel; Won, Sae-Yeon; Behmanesh, Bedjan; Kashefiolasl, Sepide; Geisen, Christof; Seifert, Volker; Senft, Christian; Konczalla, Juergen

    2018-04-01

    In patients with non-aneurysmal subarachnoid hemorrhage (NA-SAH), the etiology is unknown and the bleeding source remains unidentified. However, the ABO blood type system has a profound role in patient's hemostasis and thrombosis. To date, the aspect of ABO blood type in incidence, clinical course, and outcome after NA-SAH has not been investigated. In this retrospective analysis, 81 patients with non-traumatic and non-aneurysmal subarachnoid hemorrhage treated between 2010 and 2014 at the author's institution were included. WFNS admission status, cerebral vasospasm, delayed infarction, ventriculoperitoneal shunt necessity, the Fisher grade, and the modified Rankin Scale were analyzed for their association with ABO blood type. Four hundred seventy patients with aneurysmal subarachnoid hemorrhage served as a control group. The AB blood type is more frequent in NA-SAH compared to aneurysmal patients and the German population (OR 2.45, p ≤ 0.05). Furthermore, NA-SAH with AB blood type showed a similar sequelae compared to aneurysmal patients in terms of shunt necessity (OR 2.00, p ≥ 0.05), cerebral vasospasm (OR 1.66, p ≥ 0.05), and delayed infarctions (OR 1.07, p ≥ 0.05). The clinical course of NA-SAH AB blood type patients shows similar severity as of aneurysmal subarachnoid hemorrhage. Therefore, patients with AB blood type should be under intensified observation.

  5. Magnetism in ordered metallic perovskite compound GdPd{sub 3}B{sub x}C{sub 1-x}

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Abhishek [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: abhishek.phy@gmail.com; Mazumdar, Chandan [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: chandan.mazumdar@saha.ac.in; Ranganathan, R. [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Dattagupta, S. [Indian Institute of Science Education and Research, Block-HC, Sector-III, Salt Lake, Kolkata 700106 (India)

    2009-08-15

    We report results of dc-magnetization, ac-susceptibility and magnetoresistance measurements on crystalline metallic-perovskite compounds GdPd{sub 3}B{sub x}C{sub 1-x} (x=0.25, 0.50, 0.75 and 1.00) and the parent cubic compound GdPd{sub 3}. The interest in these materials stems from the observation of negative temperature coefficient of resistance and negative thermal expansion in some of the members of this series. In the present study, we show that by substitution of non-magnetic elements, boron and carbon, the nature of the magnetic interaction can be varied from dominating ferromagnetic to antiferromagnetic and finally to a canted magnetic structure without altering the crystal symmetry of the compounds. The variation of magnetic interaction by modifying the lattice parameter resembles Ruderman-Kittel-Kasuya-Yosida (RKKY) oscillations.

  6. Charge compensation and magnetic properties in Sr and Cu doped La-Fe perovskites

    Directory of Open Access Journals (Sweden)

    de Julián Fernández C.

    2013-01-01

    Full Text Available Orthorhombic lanthanum orthoferrites La0.8Sr0.2Fe1-yCuyO3-w (y = 0 and 0.10 have been studied using X-rays and neutron powder diffraction (XRPD and NPD, magnetization measurements and 57Fe Mössbauer spectroscopy. Rietveld refinements on XRPD and NPD data show that they adopt an orthorhombic ABO3 perovskite symmetry with La/Sr and Fe/Cu atoms randomly distributed on crystal A and B sites, respectively. The magnetic structure at room temperature is antiferromagnetic, with the Fe/Cu magnetic moments aligned along the a axis. Magnetization curves versus temperature show that the compounds exhibit an overall antiferromagnetic and a weak ferromagnetic behaviour in the range 5-298 K. 57Fe Mössbauer spectroscopy measurements indicate that Fe3+ and Fe5+ ions coexist in both compounds, and the relative percentage of Fe5+ is almost the same at 77 and 170 K, rejecting a charge disproportion mechanism.

  7. Local-site cation ordering of Eu{sup 3+} ion in doped PbTiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Mendez-González, Y. [Departamento de Física Aplicada, Instituto de Cibernética, Matemática y Física, ICIMAF, 15 No. 551, Vedado, La Habana 10400 (Cuba); Pentón-Madrigal, A., E-mail: arbelio@fisica.uh.cu [Facultad de Física-Instituto de Ciencia y Tecnología de Materiales, Universidad de La Habana, San Lázaro y L, Vedado, La Habana 10400 (Cuba); Peláiz-Barranco, A. [Facultad de Física-Instituto de Ciencia y Tecnología de Materiales, Universidad de La Habana, San Lázaro y L, Vedado, La Habana 10400 (Cuba); Figueroa, Santiago J.A. [Brazilian Synchrotron Light Laboratory (LNLS)/Brazilian Center of Energy and Materials (CNPEM), CP 6192, 13083-970, Campinas, SP (Brazil); Oliveira, L.A.S. de [Polo Xerém, Universidade Federal do Rio de Janeiro, Estrada de Xerém, 27 Xerém, Duque de Caxias, RJ (Brazil); Concepción-Rosabal, B. [Facultad de Física-Instituto de Ciencia y Tecnología de Materiales, Universidad de La Habana, San Lázaro y L, Vedado, La Habana 10400 (Cuba)

    2014-02-01

    X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), and scanning electron microscopy experiments were carried out in the (Pb{sub 0.88}Eu{sub 0.08})TiO{sub 3} ferroelectric compound with a perovskite type structure. Qualitative EXAFS analysis has shown that Eu{sup 3+} ions substitute to Pb{sup 2+} and Ti{sup 4+} ions at A and B sites of the ABO{sub 3} structure, respectively. The XRD pattern refinement was consistent with the Eu{sup 3+} substitution at both A and B sites, which provides the formation of donor and acceptor-type defects. The shape of the observed X-ray lines profiles has shown features, which are known for this kind of ferroelectric material to be typical of the ferroelectric domains microstructure. A phenomenological model has been used for fitting the diffraction profiles by the Rietveld method.

  8. Perovskite type nanopowders and thin films obtained by chemical methods

    Directory of Open Access Journals (Sweden)

    Viktor Fruth

    2010-09-01

    Full Text Available The review presents the contribution of the authors, to the preparation of two types of perovskites, namely BiFeO3 and LaCoO3, by innovative methods. The studied perovskites were obtained as powders, films and sintered bodies. Their complex structural and morphological characterization is also presented. The obtained results have underlined the important influence of the method of preparation on the properties of the synthesized perovskites.

  9. Heat capacity anomalies associated with structural transformations in. beta. -W and perovskite compounds

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, R [Brookhaven National Lab., Upton, NY; Ho, J C

    1977-01-01

    The similarity of the heat capacity anomalies, often observed with structural transformations driven by soft phonons, in both ..beta..-W and perovskite compounds is discussed referring to our recent work on V/sub 3/Si and RbCaF/sub 3/.

  10. CO sub 2 absorption of perovskites as seen by positron lifetime spectroscopy

    CERN Document Server

    Suevegh, K; Juhasz, G; Homonnay, Z; Vertes, A

    2000-01-01

    The CO sub 2 absorption of several ABO sub 3 type perovskites was studied by positron lifetime spectroscopy. The longer positron lifetime was associated with positrons trapped by A site vacancies. The evaluated positron lifetime data indicated the relative stability of the crystal structure of Sr(Co sub 0 sub . sub 5 Fe sub 0 sub . sub 5)O sub 3 sub - subdelta against Ca doping at low Ca concentrations. Oxygen desorption and CO sub 2 absorption/desorption could also be followed by positron lifetime spectroscopy. It was shown that the concentration of oxygen vacancies has a large effect on positron lifetime data through the electron density of A site vacancies.

  11. Self-propagating high-temperature synthesis of LaMO{sub 3} perovskite-type oxide using heteronuclearcyano metal complex precursors

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Rodríguez, Daniel, E-mail: daniel.sanchez@udg.edu [GRMT, Department of Physics, University of Girona, Campus Montilivi, Edif.PII, E17071 Girona, Catalonia (Spain); Wada, Hiroki; Yamaguchi, Syuhei [Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Farjas, Jordi [GRMT, Department of Physics, University of Girona, Campus Montilivi, Edif.PII, E17071 Girona, Catalonia (Spain); Yahiro, Hidenori, E-mail: yahiro.hidenori.me@ehime-u.ac.jp [Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan)

    2015-11-15

    The decomposition of La[Fe(CN){sub 6}]·5H{sub 2}O and La[Co(CN){sub 6}]·5H{sub 2}O under different atmospheres has been analyzed by thermogravimetry (TG) and differential thermal analysis (DTA). In addition, the decomposition temperature at different sample locations was monitored for sample masses around 2 g of La[Fe(CN){sub 6}]·5H{sub 2}O and La[Co(CN){sub 6}]·5H{sub 2}O, when they were calcined for 1 h at temperatures ranging from 200 to 400 °C in a controlled gas-flow system. Results showed that, the large enough of the cyano complex precursors undergo combustion when they are decomposed under oxygen atmosphere. X-ray diffraction results revealed that perovskite-type oxides crystallize due to the overheating of the process. As a result, it has been possible to produce LaFeO{sub 3} and LaCoO{sub 3} perovskite-type oxide powders by SHS under oxygen atmosphere using La[Fe(CN){sub 6}]·5H{sub 2}O and La[Co(CN){sub 6}]·5H{sub 2}O as a precursor. The effect of the ignition temperature has been investigated. The specific surface area of the perovskite-type oxides produced via SHS using heteronuclearcyano metal complex as a precursor is significantly higher than that of other LaMO{sub 3} produced using the same technique but obtained from other type of precursors. - Highlights: • The decomposition of La[Fe(CN){sub 6}] and La[Co(CN){sub 6}] precursors was analyzed. • The combustion process proceeded under oxygen when sample was large enough. • Perovskite oxides via SHS from the cyano complex precursors were synthesized. • LaMO{sub 3} perovskite oxides via SHS was obtained with high specific surface area.

  12. Superconductivity in Ti3P-type compounds

    International Nuclear Information System (INIS)

    Wills, J.O.; Hein, R.A.; Waterstrat, R.M.

    1978-01-01

    A study of 12 intermetallic A 3 B compounds which crsytallize in the tetragonal Ti 3 P-type structure has revealed five new superconductors with transition temperatures below 1 K: Zr 3 Si, Zr 3 Ge, Zr 3 P, V 3 P, and Nb 3 Ge (extrapolated from the alloy series Nb-Ge-As). In addition, two compounds, Zr 3 Sb and Ta 3 Ge, having the Ni 3 P structure type are found to be superconducting below 1 K. Within the Ti 3 P-type compounds, those with the lighter ''B'' elements in a given column of the Periodic Table have the higher transition temperatures. Critical-magnetic-field and electrical-resistivity data are reported for the superconducting Ti 2 P-type compound Nb 3 P, which permit one to estimate the Ginzburg-Landau kappa parameter and the electronic-specific-heat coefficient γ. The kappa value of 8.4 indicates that this material is type II, and the γ value of 1.3 mJ/mole K 2 for Nb 3 P is probably related to its low transition temperature relative to many A15 compounds

  13. Temperature-independent sensors based on perovskite-type oxides

    International Nuclear Information System (INIS)

    Zaza, F.; Frangini, S.; Masci, A.; Leoncini, J.; Pasquali, M.; Luisetto, I.; Tuti, S.

    2013-01-01

    The need of energy security and environment sustainability drives toward the development of energy technology in order to enhance the performance of internal combustion engines. Gas sensors play a key role for controlling the fuel oxygen ratio and monitoring the pollution emissions. The perovskite-type oxides can be synthesized for an extremely wide variety of combinations of chemical elements, allowing to design materials with suitable properties for sensing application. Lanthanum strontium ferrites, such as La 0.7 Sr 0.3 FeO 3 , are suitable oxygen sensing materials with temperature-independence conductivity, but they have low chemical stability under reducing conditions. The addition of aluminum into the perovskite structure improves the material properties in order to develop suitable oxygen sensing probes for lean burn engine control systems. Perovskite-type oxides with formula (La 0.7 Sr 0.3 )(Al x Fe 1−x )O 3 was synthesized by the citrate-nitrate combustion synthesis method. XRD analyses, show that it was synthesized a phase-pure powder belonging to the perovskite structure. Aluminum affects both the unit cell parameters, by shrinking the unit cell, and the powder morphology, by promoting the synthesis of particles with small crystallite size and large specific surface area. The partial substitution of iron with aluminum improves the chemical stability under reducing gas conditions and modulates the oxygen sensitivity by affecting the relative amount of Fe 4+ and Fe 3+ , as confirmed from TPR profiles. In the same time, the addition of aluminum does not affects the temperature-independent properties of lanthanum strontium ferrites. Indeed, the electrical measurements show that (La 0.7 Sr 0.3 )(Al x Fe 1−x )O 3 perovskites have temperature-independence conductivity from 900 K

  14. Temperature-independent sensors based on perovskite-type oxides

    Energy Technology Data Exchange (ETDEWEB)

    Zaza, F.; Frangini, S.; Masci, A. [ENEA-Casaccia R.C., Via Anguillarese 301, 00123 S.Maria di Galeria, Rome (Italy); Leoncini, J.; Pasquali, M. [University La Sapienza, Piazza Via del Castro Laurenziano 7, 00161 Rome (Italy); Luisetto, I.; Tuti, S. [University RomaTre, Rome 00146 (Italy)

    2014-06-19

    The need of energy security and environment sustainability drives toward the development of energy technology in order to enhance the performance of internal combustion engines. Gas sensors play a key role for controlling the fuel oxygen ratio and monitoring the pollution emissions. The perovskite-type oxides can be synthesized for an extremely wide variety of combinations of chemical elements, allowing to design materials with suitable properties for sensing application. Lanthanum strontium ferrites, such as La{sub 0.7}Sr{sub 0.3}FeO{sub 3}, are suitable oxygen sensing materials with temperature-independence conductivity, but they have low chemical stability under reducing conditions. The addition of aluminum into the perovskite structure improves the material properties in order to develop suitable oxygen sensing probes for lean burn engine control systems. Perovskite-type oxides with formula (La{sub 0.7}Sr{sub 0.3})(Al{sub x}Fe{sub 1−x})O{sub 3} was synthesized by the citrate-nitrate combustion synthesis method. XRD analyses, show that it was synthesized a phase-pure powder belonging to the perovskite structure. Aluminum affects both the unit cell parameters, by shrinking the unit cell, and the powder morphology, by promoting the synthesis of particles with small crystallite size and large specific surface area. The partial substitution of iron with aluminum improves the chemical stability under reducing gas conditions and modulates the oxygen sensitivity by affecting the relative amount of Fe{sup 4+} and Fe{sup 3+}, as confirmed from TPR profiles. In the same time, the addition of aluminum does not affects the temperature-independent properties of lanthanum strontium ferrites. Indeed, the electrical measurements show that (La{sub 0.7}Sr{sub 0.3})(Al{sub x}Fe{sub 1−x})O{sub 3} perovskites have temperature-independence conductivity from 900 K.

  15. Electronic and Structural Properties of ABO3: Role of the B-O Coulomb Repulsions for Ferroelectricity.

    Science.gov (United States)

    Miura, Kaoru; Azuma, Masaki; Funakubo, Hiroshi

    2011-01-17

    We have investigated the role of the Ti-O Coulomb repulsions in the appearance of the ferroelectric state in BaTiO3 as well as the role of the Zn-O Coulomb repulsions in BiZn0.5Ti0.5O3, using a first-principles calculation with optimized structures. In tetragonal BaTiO3, it is found that the Coulomb repulsions between Ti 3s and 3p states and O 2s and 2p states have an important role for the appearance of Ti ion displacement. In BiZn0.5Ti0.5O3, on the other hand, the stronger Zn-O Coulomb repulsions, which are due to the 3s, 3p, and 3d (d10) states of the Zn ion, have more important role than the Ti-O Coulomb repulsions for the appearance of the tetragonal structure. Our suggestion is consistent with the other ferroelectric perovskite oxides ABO3 in the appearance of tetragonal structures as well as rhombohedral structures.

  16. Estimating the Risk of ABO Hemolytic Disease of the Newborn in Lagos

    Science.gov (United States)

    Akanmu, Alani Sulaimon; Oyedeji, Olufemi Abiola; Adeyemo, Titilope Adenike; Ogbenna, Ann Abiola

    2015-01-01

    Background. ABO hemolytic disease of the newborn is the most common hemolytic consequence of maternofetal blood group incompatibility restricted mostly to non-group-O babies of group O mothers with immune anti-A or anti-B antibodies. Aim. We estimated the risk of ABO HDN with view to determining need for routine screening for ABO incompatibility between mother and fetus. Materials and Methods. Prevalence of ABO blood group phenotypes in blood donors at the donor clinic of the Lagos University Teaching Hospital and arithmetic methods were used to determine population prevalence of ABO genes. We then estimated proportion of pregnancies of group O mothers carrying a non-group-O baby and the risk that maternofetal ABO incompatibility will cause clinical ABO HDN. Results. Blood from 9138 donors was ABO typed. 54.3%, 23%, 19.4%, and 3.3% were blood groups O, A, B, and AB, respectively. Calculated gene frequencies were 0.1416, 0.1209, and 0.7375 for A, B, and O genes, respectively. It was estimated that 14.3% of deliveries will result in a blood group O woman giving birth to a child who is non-group-O. Approximately 4.3% of deliveries are likely to suffer ABO HDN with 2.7% prone to suffer from moderately severe to severe hemolysis. PMID:26491605

  17. Comparative DFT+U and HSE Study of the Oxygen Evolution Electrocatalysis on Perovskite Oxides

    DEFF Research Database (Denmark)

    Tripkovic, Vladimir; Hansen, Heine Anton; García Lastra, Juan Maria

    2018-01-01

    +U functional and the amount of exact exchange, α, in the hybrid HSE functional on the structural stability, catalytic activity and electronic conductivity of pure and doped perovskite oxides, ABO3, (A = La, Ca, Sr and Ba, B = Cr, Mn, Fe, Co, Ni and Cu) for oxygen evolution electrocatalysis. We find a strong...

  18. Postoperative rebound of antiblood type antibodies and antibody-mediated rejection after ABO-incompatible living-related kidney transplantation.

    Science.gov (United States)

    Ishida, Hideki; Kondo, Tsunenori; Shimizu, Tomokazu; Nozaki, Taiji; Tanabe, Kazunari

    2015-03-01

    The purpose of this study is to examine whether postoperative antiblood type antibody rebound is attributed to kidney allograft rejection in ABO blood type-incompatible (ABO-I) living-related kidney transplantation (KTx). A total of 191 ABO-I recipients who received ABO-I living-related KTx between 2001 and 2013 were divided into two groups: Group 1 consisted of low rebound [(≦1:32), N = 170] and Group 2 consisted of high rebound [(≧1:64), N = 21], according to the levels of the rebounded antiblood type antibodies within 1 year after transplantation. No prophylactic treatment for rejection was administered for elevated antiblood type antibodies, regardless of the levels of the rebounded antibodies. Within 1 year after transplantation, T-cell-mediated rejection was observed in 13 of 170 recipients (13/170, 8%) in Group 1 and in 2 of 21 recipients (2/21, 10%) in Group 2 (Groups 1 vs. 2, P = 0.432). Antibody-mediated rejection was observed in 15 of 170 recipients (15/170, 9%) and 2 of 21 recipients (2/21, 10%) in Groups 1 and 2, respectively (P = 0.898). In this study, we found no correlation between the postoperative antiblood type antibody rebound and the incidence of acute rejection. We concluded that no treatment is necessary for rebounded antiblood type antibodies. © 2014 Steunstichting ESOT.

  19. Frequency of ABO, subgroup ABO and Rh(D) blood groups in major sudanese ethnic groups

    International Nuclear Information System (INIS)

    Hassan, F.M.

    2010-01-01

    Background: There are differences in the distribution of ABO, sub group A BO and Rh(D) blood groups in different populations of the world. Relatively little information is available about blood group distributions in Sudanese population. To see the frequency of ABO, subgroup ABO and Rh(D) blood groups in major Sudanese ethnic groups(Danagla Shaygia and Gaaleen). Blood testing for ABO, subgroup ABO and Rh(D) typing was done over six months, in 300 unrelated individuals, from both genders. Blood samples were collected from students of the college of medical laboratory science - Sudan University of Science and Technology using finger prick method and following routine slide method. Blood group 'O' was the most predominant ( 52.7%) in both Rh positive and negative subjects followed by blood group A, B and AB. Majority (98.0%)o f the subjects were Rh(D) positive and only 2% were Rh negative. The predominant subgroup of ABO was A2 (14.1% ). The frequency of ABO blood groups in both Rh positive and negative subjects among the major Sudanese ethnic group was similar to that reported from neighbouring regions. (author)

  20. Synthesis, structural and semiconducting properties of Ba(Cu1/3 Sb2/3)O3-PbTiO3 solid solutions

    Science.gov (United States)

    Singh, Chandra Bhal; Kumar, Dinesh; Prashant, Verma, Narendra Kumar; Singh, Akhilesh Kumar

    2018-05-01

    We report the synthesis and properties of a new solid solution 0.05Ba(Cu1/3Sb2/3)O3-0.95PbTiO3 (BCS-PT) which shows the semiconducting properties. In this study, we have designed new perovskite-type (ABO3) solid solution of BCS-PT that have tunable optical band gap. BCS-PT compounds were prepared by conventional solid-state reaction method and their structural, micro-structural and optical properties were analyzed. The calcination temperature for BCS-PT solid solutions has been optimized to obtain a phase pure system. The Reitveld analysis of X-ray data show that all samples crystallize in tetragonal crystal structure with space group P4mm. X-ray investigation revealed that increase in calcination temperature led to increase of lattice parameter `a' while `c' parameter value lowered. The band gap of PbTiO3 is reduced from 3.2 eV to 2.8 eV with BCS doping and with increasing calcination temperature it further reduces to 2.56 eV. The reduced band gap indicated that the compounds are semiconducting and can be used for photovoltaic device applications.

  1. Crystal structure and magnetism of layered perovskites compound EuBaCuFeO5

    Science.gov (United States)

    Lal, Surender; Mukherjee, K.; Yadav, C. S.

    2018-04-01

    Layered perovskite compounds have interesting multiferroic properties.YBaCuFeO5 is one of the layered perovskite compounds which have magnetic and dielectric transition above 200 K. The multiferroic properties can be tuned with the replacement of Y with some other rare earth ions. In this manuscript, structural and magnetic properties of layered perovskite compound EuBaCuFeO5 have been investigated. This compound crystallizes in the tetragonal structure with P4mm space group and is iso-structural with YBaCuFeO5. The magnetic transition has been found to shift to 120 K as compared to YBaCuFeO5 which has the transition at 200 K. This shift in the magnetic transition has been ascribed to the decrease in the chemical pressure that relaxes the magnetic moments.

  2. ABO blood groups of residents and the ABO host choice of malaria vectors in southern Iran.

    Science.gov (United States)

    Anjomruz, Mehdi; Oshaghi, Mohammad A; Sedaghat, Mohammad M; Pourfatollah, Ali A; Raeisi, Ahmad; Vatandoost, Hassan; Mohtarami, Fatemeh; Yeryan, Mohammad; Bakhshi, Hassan; Nikpoor, Fatemeh

    2014-01-01

    Recent epidemiological evidences revealed the higher prevalence of 'O' blood group in the residents of malaria-endemic areas. Also some data indicated preference of mosquitoes to 'O' group. The aim of this study was to determine ABO group ratio in the residents as well as ABO group preference of Anopheles in two malaria endemic areas in south of Iran. Agglutination method was used for ABO typing of residents. Field blood fed Anopheles specimens were tested against vertebrate DNA using mtDNA-cytB PCR-RFLP and then the human fed specimens were tested for ABO groups using multiplex allele-specific PCR. A total of 409 human blood samples were identified, of which 150(36.7%) were 'O' group followed by 113(27.6%), 109(26.7%), and 37(9.0%) of A, B, and AB groups respectively. Analyzing of 95 blood fed mosquitoes revealed that only four Anopheles stephensi had fed human blood with A(1), B(1), and AB(2) groups. Result of this study revealed high prevalence of O group in south of Iran. To our knowledge, it is the first ABO molecular typing of blood meal in mosquitoes; however, due to low number of human blood fed specimens, ABO host choice of the mosquitoes remains unknown. This study revealed that ABO blood preference of malaria vectors and other arthropod vectors deserves future research. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Effect of mechanical milling on barium titanate (BaTiO3) perovskite

    Science.gov (United States)

    Singh, Rajan Kumar; Sanodia, Sagar; Jain, Neha; Kumar, Ranveer

    2018-05-01

    Commercial Barium Titanate BaTiO3 (BT) is milled by planetary ball mill in acetone medium using stainless steel bowl & ball for different hours. BT is an important perovskite oxide with structure ABO3. BT has applications in electro-optic devices, energy storing devices such as photovoltaic cells, thermistors, multiceramic capacitors & DRAMs etc. BT is non-toxic & environment friendly ceramic with high dielectric and piezoelectric property so it can be used as the substitute of PZT & PbTiO3. Here, we have investigated the effect of milling time and temperature on particle size and phase transition of BT powder. We used use Raman spectroscopy for studying the spectra of BT; XRD is used for structural study. Intensity (height) of Raman spectra and XRD spectra continuously decrease with increasing the milling hours and width if these spectra increases which indicates, decrease in BT size.

  4. Synthesis of LaNiO3 perovskite type by chelating precursor method using EDTA: optimization of chelating content

    International Nuclear Information System (INIS)

    Santos, Jose Carlos dos; Pedrosa, Anne Michelle Garrido; Mesquita, Maria Eliane; Souza, Marcelo Jose Barros de

    2011-01-01

    The perovskites are strategic materials due their catalytic, electronic and magnetic properties. These properties are influenced by the calcination and synthesis conditions. In this work was carried out the synthesis of LaNiO 3 perovskite type by chelating precursor method using EDTA and also was studied the optimization of the EDTA content in the synthesis. The synthesized materials were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TG) and Infrared Spectroscopy (FTIR). In the optimization of the EDTA content the lowest ratio of metal / EDTA used was 1.0 / 0.1, where it was possible to obtain monophasic perovskite. (author)

  5. Influence of ABO blood group on sports performance.

    Science.gov (United States)

    Lippi, Giuseppe; Gandini, Giorgio; Salvagno, Gian Luca; Skafidas, Spyros; Festa, Luca; Danese, Elisa; Montagnana, Martina; Sanchis-Gomar, Fabian; Tarperi, Cantor; Schena, Federico

    2017-06-01

    Despite being a recessive trait, the O blood group is the most frequent worldwide among the ABO blood types. Since running performance has been recognized as a major driver of evolutionary advantage in humans, we planned a study to investigate whether the ABO blood group may have an influence on endurance running performance in middle-aged recreational athletes. The study population consisted of 52 recreational, middle-aged, Caucasian athletes (mean age: 49±13 years, body mass index, 23.4±2.3 kg/m 2 ), regularly engaged in endurance activity. The athletes participated to a scientific event called "Run for Science" (R4S), entailing the completion of a 21.1 km (half-marathon) run under competing conditions. The ABO blood type status of the participants was provided by the local Service of Transfusion Medicine. In univariate analysis, running performance was significantly associated with age and weekly training, but not with body mass index. In multiple linear regression analysis, age and weekly training remained significantly associated with running performance. The ABO blood group status was also found to be independently associated with running time, with O blood type athletes performing better than those with non-O blood groups. Overall, age, weekly training and O blood group type explained 62.2% of the total variance of running performance (age, 41.6%; training regimen, 10.5%; ABO blood group, 10.1%). The results of our study show that recreational athletes with O blood group have better endurance performance compared to those with non-O blood group types. This finding may provide additional support to the putative evolutionary advantages of carrying the O blood group.

  6. Synthesis and characterization of perovskites type La(Fe_xV_1_-_x)O_3

    International Nuclear Information System (INIS)

    Tupan, Lilian Felipe da Silva

    2014-01-01

    Perovskites of the La(Fe_xV_1_-_x)O_3 type were synthesized by solid state reaction and by arc-melting. The samples prepared were structurally characterized by X-ray diffraction and regarding the magnetic and hyperfine properties by "5"7Fe Mössbauer spectroscopy. The results revealed that the samples crystallized mostly with orthorhombic structure, in the Pbnm space group. The lattice parameters of the pseudo-ternary compounds decreased linearly with the progressive substitution of iron by vanadium, in agreement with the Vegard's law. It was also observed the reduction of the hyperfine magnetic field which changes from a well defined sextet of 51,8 T, obtained for LaFeO_3, to a magnetic field distribution and, further, to a paramagnetic component for the richest vanadium samples. Low temperature Mössbauer spectroscopy measurements were additionally performed for the La(Fe_0_,_2V_0_,_8)O_3 sample. It was shown that the sample recovers the magnetic order with decreasing temperature. These results reveal that the coexistence of iron-vanadium results in an even more complicated magnetic behavior, decreasing the magnetic transition temperature, as replacement of iron by vanadium in orthoferrite increases. (author)

  7. CH3NH3Pb1-xMgxI3 perovskites as environmentally friendly photovoltaic materials

    Science.gov (United States)

    Zhang, Y. D.; Feng, J.

    2018-01-01

    In an effort to reduce the toxicity of Pb in perovskite solar cells, the band structures, electron and hole effective masses, and electronic and optical properties of the novel perovskites CH3NH3Pb1-xMgxI3 were predicted using density functional theory with the scalar relativistic generalized gradient approximation. The calculation results indicated that the introduction of the Mg component caused the band gaps of the CH3NH3Pb1-xMgxI3 compounds to exceed that of CH3NH3PbI3. The calculated absorption coefficients of the CH3NH3PbI3 and CH3NH3Pb1-xMgxI3 perovskites revealed that substituting 12.5 mol % of the Pb in CH3NH3PbI3 with Mg had little effect on the absorption ability. Surprisingly, it was also found that CH3NH3Pb0.75Mg0.25I3 retained up to 83% of the absorption performance relative to CH3NH3PbI3. This indicates that the amount of toxic Pb used in perovskite solar cells could be reduced by a quarter while retaining over 80% of the light-absorbing ability. In general, these novel CH3NH3Pb1-xMgxI3 (x ≤ 0.25) perovskites represent promising candidates for environmentally friendly light-harvesting materials for use in solar cells.

  8. ABO blood groups and rheumatic diseases.

    Science.gov (United States)

    Çildağ, Songül; Kara, Yasemin; Şentürk, Taşkın

    2017-12-01

    Various genetic and environmental risk factors have been shown to be associated with the incidence of rheumatic diseases. However, the pathogenesis of rheumatic diseases poorly understood. Several studies have shown associations of ABO blood groups with various diseases. Our study aimed to determine whether there is an association between the types of rheumatic diseases and ABO and Rh blood groups. The study included the patients, followed up at the Immunology-Rheumatology clinic between January 2016 and December 2016 for diagnosis of rheumatic disease, who had an ABO Rh blood data. Age, gender, type of rheumatic disease, ABO Rh blood groups were recorded. When 823 patients were assessed for blood types, 42.5% patients had A type, 33.2% had O type, 15.4% had B type, and 8.9% had AB type. There was significant difference in the distribution of blood types in rheumatic diseases. While SpA, vasculitis, UCTD, Behçet's and RA were more common in the patients with A blood type; FMF, SLE, SSc and SjS were more common in the patients with O blood type. In addition, the blood type where all the diseases are observed the least commonly was AB. There was significant difference in the distribution of Rh factor in rheumatic diseases. 92.2% patients were Rh positive and 7.8% patients were Rh negative. In our study, we thought that the higher incidence of different rheumatic diseases in different blood types was associated with different genetic predisposition.

  9. On the Defect Chemistry, Electrical Properties and Electrochemical Performances As Solid Oxide Fuel Cell Cathode Materials of New La-(Sr/Vac)-Co-Ti-O Perovskites

    DEFF Research Database (Denmark)

    García-Alvarado, Flaviano; Gómez-Pérez, Alejandro; Pérez-Flores, Juan Carlos

    2015-01-01

    Perovskite-type oxides are well known materials that have been proposed as electrodes and electrolytes for solid oxide fuel cells (SOFCs). The structure, which is referred to the ABO3 stoichiometry, can accommodate many different transition metal ions in the B-site; its electronic conductivity...... materials with valuable properties for SOFCs. We have analysed the effect of La3+ by Sr2+ substitution and vacancies creation in several double perovskites, La2MTiO6 (M = Co, Ni, Cu). Defect chemistry and electrical behavior have been investigated in order to unveil the nature of charge carriers....... Electrochemical performances have been assessed through polarization resistance measurements. In this communication we present the results regarding La2SrTiO6 perovskites. La/Sr substitution in La2-xSrxCoTiO6-δ produces Co2+ to Co3+ oxidation while vacancies in La2-xCoTiO6-δ yield Co2+ oxidation for low A...

  10. [Association of abo blood groups with gestational diabetes mellitus].

    Science.gov (United States)

    Huidobro M, Andrea; Torres C, Demetrio; Paredes, Fabio

    2017-04-01

    ABO and Rhesus blood systems are associated with type 2 Diabetes Mellitus (DM2). Gestational Diabetes (GDM) is a model to study DM. To study the association between GDM and ABO and Rhesus groups. A retrospective cohort study was performed in 1,078 women who gave birth to a singleton in Talca Regional Hospital, Chile, during 2008. We analyzed personal, obstetric, medical data and ABO and Rh blood groups. GDM was diagnosed in 6.6% of women. Age and body mass index were significantly associated with GDM. There were no differences in Rh blood groups (p = 0.604), while ABO groups were different between GDM and controls. B antigen was present in 3% of GDM women and in 10.8% of controls (p = 0.037), with an odds ratio of 0.25 after adjusting for other associated risk factors (p = 0.06). ABO group is suggested as a possible protector marker for GDM.

  11. Role of bromine doping on the photovoltaic properties and microstructures of CH3NH3PbI3 perovskite solar cells

    International Nuclear Information System (INIS)

    Suzuki, Atsushi; Okada, Hiroshi; Oku, Takeo

    2016-01-01

    Organic-inorganic hybrid heterojunction solar cells containing CH 3 NH 3 PbI 3 perovskite compound were fabricated using mesoporous TiO 2 as the electronic transporting layer and spirobifluorence as the hole-transporting layer. The purpose of the present study is to investigate role of bromine (Br) doping on the photovoltaic properties and microstructure of CH 3 NH 3 PbI 3 perovskite solar cells. Photovoltaic, optical properties and microstructures of perovskite-based solar cells were investigated. The X-ray diffraction identified crystal structure of the perovskite layer doped with Br in the solar cell. Scanning electron microscopy observation showed a different behavior of surface morphology and the perovskite crystal structure on the TiO 2 mesoporous structure depending on extent amount of hydrogen doping of Br. The role of bromide halogen doping on the perovskite crystal structure and photovoltaic properties was due to improvement of carrier mobility, optimization of electron structure, band gap related with the photovoltaic parameters of V oc , J sc and η. Energy diagram and photovoltaic mechanism of the perovskite solar cells varied with halogen doping was discussed by experimental results

  12. X-ray absorption spectroscopy and neutron diffraction study of the perovskite-type rare-earth cobaltites

    Science.gov (United States)

    Sikolenko, V.; Efimova, E.; Franz, A.; Ritter, C.; Troyanchuk, I. O.; Karpinsky, D.; Zubavichus, Y.; Veligzhanin, A.; Tiutiunnikov, S. I.; Sazonov, A.; Efimov, V.

    2018-05-01

    Correlations between local and long-range structure distortions in the perovskite-type RE1-xSrxCoO3-δ (RE = La, Pr, Nd; x = 0.0 and 0.5) compounds have been studied at room temperature by extended X-ray absorption fine structure (EXAFS) at the Co K-edge and high-resolution neutron powder diffraction (NPD). The use of two complementary experimental techniques allowed us to explore the influence of the type of rare-earth element and strontium substitution on unusual behavior of static and dynamic features of both the Co-O bond lengths.

  13. ABO Blood Group and Endometrial Carcinoma: A Preliminary Single-Center Experience from Saudi Arabia.

    Science.gov (United States)

    Abu-Zaid, Ahmed; Alsabban, Mohannad; Abuzaid, Mohammed; Alomar, Osama; Al-Badawi, Ismail A; Salem, Hany

    2017-12-18

    Inherited ABO blood groups have been shown to play possible contributions in the pathogenesis of various gynecologic and non-gynecologic carcinomas. With regard to gynecologic carcinomas, there is a confined number of studies that explored the relationship between ABO blood group and endometrial carcinoma (EC) in the PubMed-indexed literature. To the best of our knowledge, no such study has ever been conducted in Saudi Arabia. Our study has two objectives: (I) to determine the prevalence of ABO blood groups among Saudi patients with EC, and (II) to explore the relationship between ABO blood group and several clinico-pathological prognostic parameters (namely: menopausal status [age], body mass index [BMI], tumor grade, FIGO [Fédération Internationale de Gynécologie et d'Obstétrique] stage and recurrence) in Saudi patients with EC. A retrospective cross-sectional study from 01-January-2010 to 31-July-2014 was conducted at King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia - a referral tertiary healthcare institute. One-hundred and fourteen patients (n=114) were included in the study. Clinico-pathological data were extrapolated from medical records, and their association with ABO blood groups were evaluated. Categorical data were presented as number of cases (n) and percentages (%). Two-tailed Chi-square test was used for univariate analysis. For all purposes, p values 28 kg/m 2 (84.2%), diagnosed with early FIGO stage I-II (76.3%) and developed no recurrence (86.8%). The frequencies of ABO blood group types A, B, AB, and O were 28.1%, 12.3%, 3.5% and 56.1%, respectively. When ABO blood groups were analyzed as four different types (A, B, AB and O), O-type was the most common ABO blood group in pre- and post-menopausal EC patients (43.8% and 58.2%, respectively; p=0.14). There were no statistically significant correlations between ABO blood groups and all the examined clinico-pathological factors. Moreover, when ABO blood groups were

  14. Magnetic properties of compounds Ba/sub 3/Fesub(2-x)Msub(x)UO/sub 9/ with M=Y, Sc, In and rare earth

    Energy Technology Data Exchange (ETDEWEB)

    Grenet, J C; Berthon, J [Paris-11 Univ., 91 - Orsay (France); Poix, P [Ecole Nationale Superieure de Chimie, 67 - Strasbourg (France)

    1979-01-01

    The compounds Ba/sub 3/Fesub(2-x)Msub(x)UO/sub 9/ crystallize in the perovskite type system. The magnetic behavior of these compounds is different when M/sup 3 +/ is dia- or paramagnetic. When M/sup 3 +/ is diamagnetic, the magnetic exchange interaction between A and B sublattices is strongly antiferromagnetic, the (UO/sub 6/)/sup 6 -/ clusters having a special effect. When M/sup 3 +/ is paramagnetic, the perovskite compounds have three magnetic sublattices. In the third one are placed rare earth ions M/sup 3 +/; in this case the A-B exchange interactions are antiferromagnetic but the interactions with the third sublattice are probably slightly ferromagnetic. This special feature and the fact that a temperature of compensation is missing differentiate these perovskites from the garnets.

  15. Hexagonal perovskites with cationic vacancies. 15. Ba/sub 9/Nb/sub 6/Wvacant/sub 2/O/sub 27/ - the first perovskite stacking polytype of rhombohedral 27 L-type

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1980-02-01

    The perovskite stacking polytype Ba/sub 9/Nb/sub 6/sup(V)Wsup(VI)vacant/sub 2/O/sub 27/ (white) is the first representative of a rhombohedral 27 L-type. The lattice parameters (trigonal setting) are: a = 5.79/sub 3/ A; c = 63.4/sub 1/ A; Z = 3 (rhosub(exp) = 6.4/sub 6/ g/cm/sup 3/; rhosub(calc) = 6.51/sub 2/ g/cm/sup 3/). The corresponding Tasup(V)-compound is isotypic; it tends to develop stacking faults.

  16. CH3NH3Pb1−xMgxI3 perovskites as environmentally friendly photovoltaic materials

    Directory of Open Access Journals (Sweden)

    Y. D. Zhang

    2018-01-01

    Full Text Available In an effort to reduce the toxicity of Pb in perovskite solar cells, the band structures, electron and hole effective masses, and electronic and optical properties of the novel perovskites CH3NH3Pb1−xMgxI3 were predicted using density functional theory with the scalar relativistic generalized gradient approximation. The calculation results indicated that the introduction of the Mg component caused the band gaps of the CH3NH3Pb1−xMgxI3 compounds to exceed that of CH3NH3PbI3. The calculated absorption coefficients of the CH3NH3PbI3 and CH3NH3Pb1−xMgxI3 perovskites revealed that substituting 12.5 mol % of the Pb in CH3NH3PbI3 with Mg had little effect on the absorption ability. Surprisingly, it was also found that CH3NH3Pb0.75Mg0.25I3 retained up to 83% of the absorption performance relative to CH3NH3PbI3. This indicates that the amount of toxic Pb used in perovskite solar cells could be reduced by a quarter while retaining over 80% of the light-absorbing ability. In general, these novel CH3NH3Pb1−xMgxI3 (x ≤ 0.25 perovskites represent promising candidates for environmentally friendly light-harvesting materials for use in solar cells.

  17. Association between ABO blood type and live-birth outcomes in single-embryo transfer cycles.

    Science.gov (United States)

    Pereira, Nigel; Patel, Hency H; Stone, Logan D; Christos, Paul J; Elias, Rony T; Spandorfer, Steven D; Rosenwaks, Zev

    2017-11-01

    To investigate the association between ABO blood type and live-birth outcomes in patients undergoing IVF with day 5 single-embryo transfer (SET). Retrospective cohort study. University-affiliated center. Normal responders, blood type and live birth, while controlling for confounders. Odds ratios (OR) with 95% confidence intervals (CI) for live birth were estimated. A total of 2,329 patients were included. The mean age of the study cohort was 34.6 ± 4.78 years. The distribution of blood types was as follows: A = 897 (38.5%); B = 397 (17.0%); AB = 120 (5.2%); and, O = 1,915 (39.3%) patients. There was no difference in the baseline demographics, ovarian stimulation, or embryo quality parameters between the blood types. The unadjusted ORs for live birth when comparing blood type A (referent) with blood types B, AB, and O were 0.96 (95% CI, 0.6-1.7), 0.72 (95% CI, 0.4-1.2), and 0.96 (95% CI. 0.6-1.7), respectively. The adjusted ORs for live birth remained not significant when comparing blood type A to blood types B, AB, and O individually. No difference in birth weight or gestational age at delivery was noted among the four blood types. Our findings suggest that ABO blood type is not associated with live-birth rate, birth weight, or gestational age at delivery in patients undergoing IVF with day 5 SET. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  18. Comparative Analysis of Clinical Samples Showing Weak Serum Reaction on AutoVue System Causing ABO Blood Typing Discrepancies

    OpenAIRE

    Jo, Su Yeon; Lee, Ju Mi; Kim, Hye Lim; Sin, Kyeong Hwa; Lee, Hyeon Ji; Chang, Chulhun Ludgerus; Kim, Hyung-Hoi

    2016-01-01

    Background ABO blood typing in pre-transfusion testing is a major component of the high workload in blood banks that therefore requires automation. We often experienced discrepant results from an automated system, especially weak serum reactions. We evaluated the discrepant results by the reference manual method to confirm ABO blood typing. Methods In total, 13,113 blood samples were tested with the AutoVue system; all samples were run in parallel with the reference manual method according to...

  19. ABO and D typing and alloantibody screening in marrow samples: relevance to intraosseous blood transfusion.

    Science.gov (United States)

    Bäckman, Sari; Ångerman-Haasmaa, Susanne; Jousi, Milla; Siitonen, Sanna; Salmela, Katja

    2018-03-01

    Blood transfusion through the intraosseous route is gaining popularity in emergency medicine. Pretransfusion peripheral blood (PB) samples are usually not available in these patients, leading to discrepancies in blood group typing and a possible delay in transferring to group-specific blood products. The aim of this study was to assess the feasibility of ABO and D typing and red blood cell alloantibody screening in marrow (BM) samples. Direct and reverse ABO typing, D typing, and a two-cell alloantibody screen were performed in EDTA-anticoagulated BM samples with standard manual column agglutination techniques. EDTA-anticoagulated PB samples were used as controls. The mean age of the study subjects (n = 71) was 47 years (range, 1-82 years). All ABO groups and both D+ and D- types were represented. In all subjects, concordant results were observed for all analyses in BM and PB samples. In 15 (21%) of the samples, a discrepancy of one reaction strength step (1+) was observed in at least one of the analyses (Cohen's weighted κ = 0.993); this did not affect interpretation of the results. Blood group typing and alloantibody screening are feasible in BM samples, providing proof-of-concept that intraosseous samples for blood group serologic analyses can be collected from emergency patients before intraosseous blood transfusion. This will enable a timely transfer to group-specific blood products and enable conservation of the valuable universal-donor blood products. © 2018 AABB.

  20. Associations between ABO blood groups and biochemical recurrence after radical prostatectomy.

    Science.gov (United States)

    Ohno, Yoshio; Ohori, Makoto; Nakashima, Jun; Okubo, Hidenori; Satake, Naoya; Takizawa, Issei; Hashimoto, Takeshi; Hamada, Riu; Nakagami, Yoshihiro; Yoshioka, Kunihiko; Tachibana, Masaaki

    2015-01-01

    Recent studies have demonstrated associations between ABO blood groups and prognosis in various types of cancers. The aim of this study was to investigate the association between ABO blood groups and biochemical recurrence (BCR) after radical prostatectomy (RP). A total of 555 patients with prostate cancer who underwent RP were included in the study. No patients received neoadjuvant and/or adjuvant therapy. The effect of ABO blood groups on BCR was examined using univariate and multivariate analyses. During the follow-up period (mean, 52.0 months), 166 patients (29.9%) experienced BCR, with a 5-year BCR-free rate of 67.3%. Although the ABO blood group was not a significantly associated with BCR in the univariate analysis, it was an independent predictor of BCR in the multivariate analysis: blood type O patients had a significantly lower risk of BCR compared to type A patients (Hazard ratio, 0.608; 95% confidence interval, 0.410-0.902; P = 0.014). Further analyses revealed that surgical margin status confounded the assessment of the association between the ABO blood group and BCR. In the analyses of patients with a negative surgical margin, the 5-year BCR-free rate in blood type O patients was a significantly higher than that in type A patients (91.2% vs. 71.0%; P = 0.026). Blood type O is significantly associated with a decreased risk of biochemical recurrence after radical prostatectomy. Further studies are needed to clarify the nature of this association.

  1. Synthesis and structural study of the transition metal doped rhodium perovskites

    International Nuclear Information System (INIS)

    Ting, J.; Kennedy, B.; Zhang, Z.

    2009-01-01

    Full text: One of the most common structures encountered in solid state chemistry is the perovskite structure. With a general formula of AB0 3, the A-type cations are 12-coordinate within a cubo-octahedral environment, while the B-type cations are 6-coordinate, forming an interconnecting three-dimensional octahedral network with neighbouring oxygen anions. While the ideal perovskite structure is cubic in Pm 3 m, many perovskites exhibit symmetry lowering tilting of the corner-sharing B0 6o ctahedral units as a result of A- and B-type cation size disparity. This is also evident in substituted perovskites, where two cations occupy the smaller octahedral site, AB 1- xB' x0 3' Electronic effects can also lower the symmetry. The two most commonly observed effects are the polarisation of the B-cation with a d 0 electronic configuration and Jahn-Teller distortion where the B-cation has a d 4 or d 9 electronic configuration, such as Mn 3+ or Cu 2+ respectively. Manganese containing perovskites have been shown in some compounds to exhibit long-range orbital ordering, giving rise to interesting properties. Heavier transition metals such as ruthenium and iridium have been previously incorporated into these perovskites as an avenue to regulate the properties of these materials. Two orthorhombic rhodium perovskite structures are presented, LaMn 0 . 5 Rh 0 . 5 O 3 and LaCu 05 Rh 0 . 5 O 3 ' A combination of synchrotron x-ray and neutron powder diffraction has been used to elucidate their structures, and have shown both B- and B'-type cations to be disordered across the same crystallographic site for both compounds. x-ray absorption spectroscopy measurements have been used to provide an insight into the valence states of the cations, which show a valency of +3.5 for rhodium due to an extensive charge delocalisation between copper and rhodium.

  2. A Laboratory Exercise to Determine Human ABO Blood Type by Noninvasive Methods

    Science.gov (United States)

    Martin, Michael P.; Detzel, Stephen M.

    2008-01-01

    Analysis of single-nucleotide polymorphisms and their association with diseases and nondisease phenotypes is of growing importance in human biology studies. In this laboratory exercise, students determine the genetic basis for their ABO blood type; however, no blood is drawn. Students isolate genomic DNA from buccal mucosa cells that are present…

  3. Annealing Effect on (FAPbI31−x(MAPbBr3x Perovskite Films in Inverted-Type Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Lung-Chien Chen

    2016-09-01

    Full Text Available This study determines the effects of annealing treatment on the structure and the optical and electronic behaviors of the mixed (FAPbI31−x(MAPbBr3x perovskite system. The experimental results reveal that (FAPbI31−x(MAPbBr3x (x ~ 0.2 is an effective light-absorbing material for use in inverted planar perovskite solar cells owing to its large absorbance and tunable band gap. Therefore, good band-matching between the (FAPbI31−x(MAPbBr3x and C60 in photovoltaic devices can be controlled by annealing at various temperatures. Accordingly, an inverted mixed perovskite solar cell with a record efficiency of 12.0% under AM1.5G irradiation is realized.

  4. Timing of blood transfusion and not ABO blood type is associated with survival in patients treated with radical cystectomy for nonmetastatic bladder cancer: Results from a single high-volume institution.

    Science.gov (United States)

    Moschini, Marco; Bianchi, Marco; Rossi, Martina Sofia; Dell׳Oglio, Paolo; Gandaglia, Giorgio; Fossati, Nicola; Mattei, Agostino; Damiano, Rocco; Shariat, Shahrokh F; Salonia, Andrea; Montorsi, Francesco; Briganti, Alberto; Colombo, Renzo; Gallina, Andrea

    2016-06-01

    Perioperative transfusions have been recently associated to poor outcomes as an indirect consequence of immune-hematological changes related to transfusion itself and blood type. We tested the role of blood transfusion on cancer-specific mortality (CSM) and overall mortality (OM), considering the effect of ABO system, Rh factor, and timing of transfusions. The study focused on 728 patients with bladder cancer treated with radical cystectomy at a single tertiary care referral center between January 1995 and August 2013 with complete ABO blood type information. Kaplan-Meier analysis was used to assess the effect of transfusions, stratified according to ABO type and Rh factor, on CSM and OM. The same endpoints were tested in Cox regression models, after adjusting for all available confounders. A total of 341 (46.8%), 277 (38.0%), 83 (11.4%), and 27 (3.7%) patients had blood type O, A, B and AB, respectively. Overall, 630 (86.5%) and 98 (13.5%) patients were Rh-and Rh+, respectively. At a median follow-up time of 65 months, 225 (30.9%) and 282 (38.7%) patients recorded CSM and OM, respectively. At univariable analyses, ABO blood type and Rh status were not associated to either CSM or OM (all P>0.2). Similar results were observed when ABO blood type and Rh factor were tested in multivariable models (all P>0.3). Conversely, Charlson score, preoperative hemoglobin, number of nodes removed, pathological T stage, and number of positive nodes were associated to both CSM and OM (all Pblood units in the postoperative period (P>0.05) was associated with an increase of CSM and OM. Although ABO type or Rh factor or both were associated with several adverse outcomes in many cancers, we were not able to confirm this association in bladder cancer. Based on our results, the effect of transfusion on survival is independent by ABO type but is associated to the timing of blood supply administration. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. ABO blood type correlates with survival on prostate cancer vaccine therapy.

    Science.gov (United States)

    Muthana, Saddam M; Gulley, James L; Hodge, James W; Schlom, Jeffrey; Gildersleeve, Jeffrey C

    2015-10-13

    Immunotherapies for cancer are transforming patient care, but clinical responses vary considerably from patient to patient. Simple, inexpensive strategies to target treatment to likely responders could substantially improve efficacy while simultaneously reducing health care costs, but identification of reliable biomarkers has proven challenging. Previously, we found that pre-treatment serum IgM to blood group A (BG-A) correlated with survival for patients treated with PROSTVAC-VF, a therapeutic cancer vaccine in phase III clinical trials for the treatment of prostate cancer. These results suggested that ABO blood type might influence efficacy. Unfortunately, blood types were not available in the clinical records for all but 8 patients and insufficient amounts of sera were left for standard blood typing methods. To test the hypothesis, therefore, we developed a new glycan microarray-based method for determining ABO blood type. The method requires only 4 μL of serum, provides 97% accuracy, and allows simultaneous profiling of many other serum anti-glycan antibodies. After validation with 220 healthy subjects of known blood type, the method was then applied to 74 PROSTVAC-VF patients and 37 control patients from a phase II trial. In this retrospective study, we found that type B and O PROSTVAC-VF patients demonstrated markedly improved clinical outcomes relative to A and AB patients, including longer median survival, longer median survival relative to Halabi predicted survival, and improved overall survival via Kaplan-Meier survival analysis (p = 0.006). Consequently, blood type may provide an inexpensive screen to pre-select patients likely to benefit from PROSTVAC-VF therapy.

  6. Association Between ABO Blood Type and Postoperative Cognitive Dysfunction in Elderly Patients Undergoing Unilateral Total Hip Arthroplasty Surgery in China.

    Science.gov (United States)

    Li, Jie; Zhou, Jun; Wan, Yunqiang; Liu, Li; Ou, Cehua

    2017-05-28

    BACKGROUND Postoperative cognitive dysfunction (POCD) is a postoperative complication after surgery and anesthesia. Whether ABO blood types are associated with POCD in elderly patients undergoing unilateral total hip arthroplasty surgery in China is unclear. MATERIAL AND METHODS Firstly, 142 elderly patients were divided into a POCD group and a non-POCD group according to the Mini Mental State Examination (MMSE) scores and ABO blood types were analyzed. Secondly, according to ABO blood type, the selected 226 patients were divided into 4 groups: type A group, type B group, type AB group, and type O group. Then, all patients completed the MMSE before and after surgery. Finally, the occurrence of POCD was recorded and related data were analyzed. RESULTS Firstly, there was a significant difference in both groups in terms of distribution of ABO blood types, and elderly patients who developed POCD were more likely to have type A blood and less likely to have type O blood. Secondly, compared with elderly patients with type A blood, those with type O had higher MMSE scores on the first day and the seventh day after surgery. Finally, the risk of developing POCD was significantly higher in patients with type A blood and on the first day and the seventh day after surgery the risk of developing POCD was significantly lower in patients with type O blood. CONCLUSIONS Elderly patients with type A blood have higher risk of developing early POCD and those with type O blood have less risk of developing early POCD.

  7. Phonon model of perovskite thermal capacity

    International Nuclear Information System (INIS)

    Kesler, Ya.A.; Poloznikova, M.Eh.; Petrov, K.I.

    1983-01-01

    A model for calculating the temperature curve of thermal capacity of perovskite family crystals on the basis of vibrational spectra is proposed. Different representatives of the perovskite family: cubic SrTiO 3 , tetragonal BaTiO 3 and orthorbombic CaTiO 3 and LaCrO 3 are considered. The total frequency set is used in thermal capacity calcUlations. Comparison of the thermal capacity values of compounds calculated on the basis of the proposed model with the experimental values shows their good agreement. The method is also recommended for other compounds with the perovskite-like structure

  8. The influence of charge transfers effects in monazite-type LaVO{sub 4} and perovskite-type LaVO{sub 3} prepared by sol-gel acrylamide polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Herrera-Pérez, G., E-mail: guillermo.herrera@cimav.edu.mx [CONACYT Research Fellow. Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua 31136, Chihuahua (Mexico); Jiménez-Mier, J. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, 04510 Mexico D. F (Mexico); Yang, W.-L. [The Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Reyes-Rojas, A.; Fuentes-Cobas, L.E. [Department of Physics of Materials Department. Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua 31136, Chihuahua (Mexico)

    2016-08-15

    Highlights: • We elucidate the electronic structure through the vanadium L{sub 2,3} edge in LaVO{sub 4} by XAS. • The interpretation of XAS spectrum was performed by the multiplet calculation. • Our results suggest that LaVO{sub 4} can be considered in the charge transfer regime. - Abstract: Core-hole spectroscopy such as X-ray absorption spectroscopy (XAS) is useful to determine the electronic structure of strongly correlated and strongly hybridized compounds such as vanadates. Monazite-type LaVO{sub 4} and perovskite-type LaVO{sub 3} are good candidates to elucidate the electronic structure through the vanadium L{sub 2,3} edge. LaVO{sub 4} was prepared by sol-gel acrylamide polymerization and solid-state reaction. LaVO{sub 3} was obtained by reduction of LaVO{sub 4} using Zr as gatherer. Monoclinic crystal phase for LaVO{sub 4} and orthorhombic crystal phase for LaVO{sub 3} were confirmed by the Rietveld refinement of X-ray diffraction patterns. XAS comparison between Vanadium L{sub 2,3} edge confirms the presence of V{sup 5+} for the monazite and V{sup 3+} for the orthorhombic perovskite. Multiplet calculations including crystal field and charge transfer effects (CTM) were performed in order to elucidate the tetragonal (D{sub 4h} symmetry) parameters Dq, Ds and Dt, the charge transfer energy Δ, and d-d Coulomb repulsion energy U parameters. CTM confirms for LaVO{sub 3} the strong V 3d–O 2p hybridization with a significant contribution of covalent character due to the delocalization of 3d electrons. For LaVO{sub 4} this work suggest the reclassification of this band insulator as charge transfer insulator that shows a significant contribution of ionic character.

  9. Solid-state synthesis in the system Na0.8NbyW1-yO3 with 0≤y≤0.4: A new phase, Na0.5NbO2.75, with perovskite-type structure

    International Nuclear Information System (INIS)

    Debnath, Tapas; Ruescher, Claus H.; Gesing, Thorsten M.; Koepke, Juergen; Hussain, Altaf

    2008-01-01

    Series of compounds in the system Na x Nb y W 1-y O 3 were prepared according to the appropriate molar ratio of Na 2 WO 4 , WO 3 , WO 2 and Nb 2 O 5 with x=0.80 and 0.0≤y≤0.4 at 600 deg. C in evacuated silica glass tubes. These compounds were investigated by X-ray powder diffraction, optical microscopy, microprobe analysis, Raman and optical microspectroscopy. A y-dependent separation into three distinct coloured crystallites with cubic perovskite-type structures is observed: (i) red-orange crystallites with composition Na x WO 3 with slightly decreasing x (i.e. 0.8-0.72) with increasing nominal y, (ii) bluish solid solution of composition Na x Nb y W 1-y O 3 and (iii) white crystallites of a new phase having defect perovskite-type structure with composition Na 0.5 NbO 2.75 . - Graphical abstract: Optical micrograph of a polished sample of nominal composition Na 0.8 Nb 0.4 W 0.6 O 3 showing a mixture of three different coloured crystals: red, light blue and white. The scale bar is 30 μm

  10. Role of bromine doping on the photovoltaic properties and microstructures of CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsushi; Okada, Hiroshi; Oku, Takeo [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga, 522-8533 (Japan)

    2016-02-01

    Organic-inorganic hybrid heterojunction solar cells containing CH{sub 3}NH{sub 3}PbI{sub 3} perovskite compound were fabricated using mesoporous TiO{sub 2} as the electronic transporting layer and spirobifluorence as the hole-transporting layer. The purpose of the present study is to investigate role of bromine (Br) doping on the photovoltaic properties and microstructure of CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cells. Photovoltaic, optical properties and microstructures of perovskite-based solar cells were investigated. The X-ray diffraction identified crystal structure of the perovskite layer doped with Br in the solar cell. Scanning electron microscopy observation showed a different behavior of surface morphology and the perovskite crystal structure on the TiO{sub 2} mesoporous structure depending on extent amount of hydrogen doping of Br. The role of bromide halogen doping on the perovskite crystal structure and photovoltaic properties was due to improvement of carrier mobility, optimization of electron structure, band gap related with the photovoltaic parameters of V{sub oc}, J{sub sc} and η. Energy diagram and photovoltaic mechanism of the perovskite solar cells varied with halogen doping was discussed by experimental results.

  11. Initial Experience with ABO-incompatible Live Donor Renal Transplantation

    Directory of Open Access Journals (Sweden)

    Meng-Kun Tsai

    2006-01-01

    Full Text Available The serious shortage of cadaveric organs has prompted the development of ABO-incompatible live donor renal transplantation. We report our experience of the initial two live donor ABO incompatible renal transplants at our hospital. The first patient was a 55-year-old type A female who received a kidney from her AB type husband. The second patient was a 27-year-old type O male who received renal transplantation from his type A father. Preconditioning immunosuppressive therapy in the two patients with tacrolimus, mycophenolate mofetil and methylprednisolone was started 7 days before transplantation. During the period of preconditioning, double filtration plasmapheresis (DFPP was employed to remove anti-A and -B antibodies. Laparoscopic splenectomy and renal transplantation were performed after the anti-donor ABO antibodies were reduced to a titer of 1:4. Rituximab, a humanized monoclonal anti-CD20 antibody, was administered to the second patient due to a rebound in the anti-A antibody titer during the preconditioning period. Under a tacrolimus-based immunosuppressive regimen, both patients recovered very well without any evidence of rejection. Serum creatinine levels were 1.0 and 1.4 mg/dL at 6 and 3 months after transplantation, respectively. These cases illustrate that with new immunosuppressive agents, DFPP and splenectomy, ABO-incompatible renal transplantation can be successfully conducted in end-stage renal disease patients whose only available live donors are blood group incompatible.

  12. p-type Mesoscopic nickel oxide/organometallic perovskite heterojunction solar cells.

    Science.gov (United States)

    Wang, Kuo-Chin; Jeng, Jun-Yuan; Shen, Po-Shen; Chang, Yu-Cheng; Diau, Eric Wei-Guang; Tsai, Cheng-Hung; Chao, Tzu-Yang; Hsu, Hsu-Cheng; Lin, Pei-Ying; Chen, Peter; Guo, Tzung-Fang; Wen, Ten-Chin

    2014-04-23

    In this article, we present a new paradigm for organometallic hybrid perovskite solar cell using NiO inorganic metal oxide nanocrystalline as p-type electrode material and realized the first mesoscopic NiO/perovskite/[6,6]-phenyl C61-butyric acid methyl ester (PC61BM) heterojunction photovoltaic device. The photo-induced transient absorption spectroscopy results verified that the architecture is an effective p-type sensitized junction, which is the first inorganic p-type, metal oxide contact material for perovskite-based solar cell. Power conversion efficiency of 9.51% was achieved under AM 1.5 G illumination, which significantly surpassed the reported conventional p-type dye-sensitized solar cells. The replacement of the organic hole transport materials by a p-type metal oxide has the advantages to provide robust device architecture for further development of all-inorganic perovskite-based thin-film solar cells and tandem photovoltaics.

  13. High-temperature compressive creep behaviour of perovskite-type oxides SrTi1-xFexO3

    NARCIS (Netherlands)

    ten Donkelaar, S.F.P.; Stournari, V.; Malzbender, J.; Nijmeijer, Arian; Bouwmeester, Henricus J.M.

    2015-01-01

    Compressive creep tests have been performed on mixed ionic-electronic conducting perovskite-type oxides SrTi1-xFexO3- (STF, x = 0.3, 0.5 and 0.7). Observed activation energies and stress exponents, at 800–1000 ◦C and in the stress range 10 100 MPa, indicate that the steady-state creep rate of STF

  14. Persistent semi-metal-like nature of epitaxial perovskite CaIrO3 thin films

    International Nuclear Information System (INIS)

    Biswas, Abhijit; Jeong, Yoon Hee

    2015-01-01

    Strong spin-orbit coupled 5d transition metal based ABO 3 oxides, especially iridates, allow tuning parameters in the phase diagram and may demonstrate important functionalities, for example, by means of strain effects and symmetry-breaking, because of the interplay between the Coulomb interactions and strong spin-orbit coupling. Here, we have epitaxially stabilized high quality thin films of perovskite (Pv) CaIrO 3 . Film on the best lattice-matched substrate shows semi-metal-like characteristics. Intriguingly, imposing tensile or compressive strain on the film by altering the underlying lattice-mismatched substrates still maintains semi-metallicity with minute modification of the effective correlation as tensile (compressive) strain results in tiny increases (decreases) of the electronic bandwidth. In addition, magnetoresistance remains positive with a quadratic field dependence. This persistent semi-metal-like nature of Pv-CaIrO 3 thin films with minute changes in the effective correlation by strain may provide new wisdom into strong spin-orbit coupled 5d based oxide physics

  15. Electron Transfer from Triplet State of TIPS-Pentacene Generated by Singlet Fission Processes to CH3NH3PbI3 Perovskite.

    Science.gov (United States)

    Lee, Sangsu; Hwang, Daesub; Jung, Seok Il; Kim, Dongho

    2017-02-16

    To reveal the applicability of singlet fission processes in perovskite solar cell, we investigated electron transfer from TIPS-pentacene to CH 3 NH 3 PbI 3 (MAPbI 3 ) perovskite in film phase. Through the observation of the shorter fluorescence lifetime in TIPS-pentacene/MAPbI 3 perovskite bilayer film (5 ns) compared with pristine MAPbI 3 perovskite film (20 ns), we verified electron-transfer processes between TIPS-pentacene and MAPbI 3 perovskite. Furthermore, the observation of singlet fission processes, a faster decay rate, TIPS-pentacene cations, and the analysis of kinetic profiles of the intensity ratio between 500 and 525 nm in the TA spectra of the TIPS-pentacene/MAPbI 3 perovskite bilayer film indicate that electron transfer occurs from triplet state of TIPS-pentacene generated by singlet fission processes to MAPbI 3 perovskite conduction band. We believe that our results can provide useful information on the design of solar cells sensitized by singlet fission processes and pave the way for new types of perovskite solar cells.

  16. Synthesis and magnetic characterization of LaMnO{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, E.; Sagredo, V. [Universidad de Los Andes, Facultad de Ciencias, Laboratorio de Magnetismo, 5101 Merida (Venezuela, Bolivarian Republic of); Delgado, G. E. [Universidad de Los Andes, Facultad de Ciencias, Laboratorio de Cristalografia, 5101 Merida (Venezuela, Bolivarian Republic of)

    2015-07-01

    LaMnO{sub 3} nanoparticles system were prepared by the sol-gel auto-combustion method, in order to analyze the structure and magnetic behavior presented by the compound prepared following a new alternative route of synthesis. Structural characterization, morphology and crystallite size was performed by X-ray diffraction (XRD), infrared spectroscopy (IR) and electron microscopy. The XRD study together with a Rietveld analysis showed that the LaMnO{sub 3} compound crystallized in a perovskite hexagonal structure. The IR spectra showed that the compound has tensile energy bands in the Mn-O-Mn bonds related with the octahedron MnO{sub 6}; which are attributed to a characteristic vibration of the ABO{sub 3} perovskite. An estimated size and morphological analysis was carried out by applying the Scherrer formula and using transmission electron microscopy, revealing non-spherical shape and particle sizes between 13 nm and 18 nm. The magnetic measurements M(T) were performed by using zero field-cooled and field-cooled protocols which revealed a positive Weiss temperature indicating the presence of ferromagnetic interactions with a Curie temperature, T{sub C} = 150 K. (Author)

  17. Our first experiences in applying an original method for removal of ABO-isoagglutinins in ABO-incompatible kidney recipients

    Directory of Open Access Journals (Sweden)

    Ignjatović Ljiljana

    2009-01-01

    Full Text Available Background/Aim. Due to improved methods for removal of ABO isoagglutinins and novel immunosuppressive protocols, short and long term outcome in blood group incompatible is similar to blood group compatible kidney transplantation. The aim of this study was to determine the efficacy of our original method for removal of ABO isoagglutinins from the blood in ABO-incompatible kidney allograft recipients. Method. Between 2006 and 2008 twelve patients were transplanted from ABO incompatible living donors. Titers of ABO isoagglutinins were 4-128 (IgG. Immunosuppressive therapy started 14 days before kidney transplantation with rituximab, followed by a triple therapy (prednisone + tacrolimus + mycophenolate mofetil and the first plasma exchange (PE procedure, in which one plasma volume was substituted with albumin and saline on day 7 before transplantation. For selective extracorporeal immunoadsorption, the removed plasma was mixed with donor blood type filtered red blood cells, centrifuged and the supernatant separated and preserved. In the next PE procedure, the removed plasma was replaced with immunoadsorbed plasma, and so on. Titers of ABO agglutinins, renal allograft function and survival were followed-up. Results. The pre-transplant treatment consisting of 1-5 PE procedures and immunosuppressive therapy resulted in target ABO agglutinins titers below 4. During a 10-24 month follow-up three patients had an early acute rejection, one patient acute rejection and hemolytic anemia, two patients surgical complications and one of them lost his graft. In the post-transplant period, the titers of ABO antibodies remained below 4. All the patients had stable kidney allograft function with mean serum creatinine ±SD of 129 ± 45 μmol/l at the end of the study. Conclusion. Our method for removal of ABO antibodies was effective in a limited series of patients and short-term follow-up.

  18. ABO-incompatible kidney transplantation: first cases in Turkey.

    Science.gov (United States)

    Tuncer, M; Yücetin, L; Tekin, S; Demirbas, A

    2012-01-01

    ABO compatibility has been believed to be necessary in kidney transplantation (Ktx) to prevent acute antibody-mediated rejection. However, developments in immunosuppression and immunoadsorption techniques have overcome acute antibody-mediated rejection caused by ABO incompatibility. Herein, we have presented the first ABO-incompatible Ktx cases in Turkey. All recipients did not have an ABO-compatible donor but presented significant dialysis inadequacy due to vascular access problems. Five dialysis patients with blood groups O or B underwent kidney transplantation from living related donors of blood group type A1 or AB between march 23, 2007 and August 16, 2007. All patients received Rituximab (375 mg/m(2)) at 3-4 weeks before the Ktx. Additionally, we started tacrolimus (0.15 mg/kg), mycophenolate mofetil (2 × 1 g), and simvastatin (1 × 20 mg) 1 week before the operation. Immunoadsorption therapy employing a specific filter (Glycosorbs) to remove anti-A or anti-B antibodies was continued until the titers were 1/8 during the first postoperative week and >1/16 at the second postoperative week. We used 2 standard hemodialysis machines with a connection line to perform immunoabsorption and dialysis during the same session. Acute humoral and cellular rejection was not detected. During the follow-up 1 patient was lost due to a cardiovascular complication. Mean creatinine level was 1.1 ± 0.3 mg/dL. These first ABO-incompatible transplantation cases in Turkey suggest that this source may represent an effective approach to overcome the organ shortage. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Sn2+—Stabilization in MASnI3 perovskites by superhalide incorporation

    Science.gov (United States)

    Xiang, Junxiang; Wang, Kan; Xiang, Bin; Cui, Xudong

    2018-03-01

    Sn-based hybrid halide perovskites are a potential solution to replace Pb and thereby reduce Pb toxicity in MAPbI3 perovskite-based solar cells. However, the instability of Sn2+ in air atmosphere causes a poor reproducibility of MASnI3, hindering steps towards this goal. In this paper, we propose a new type of organic metal-superhalide perovskite of MASnI2BH4 and MASnI2AlH4. Through first-principles calculations, our results reveal that the incorporation of BH4 and AlH4 superhalides can realize an impressive enhancement of oxidation resistance of Sn2+ in MASnI3 perovskites because of the large electron transfer between Sn2+ and [BH4]-/[AlH4]-. Meanwhile, the high carrier mobility is preserved in these superhalide perovskites and only a slight decrease is observed in the optical absorption strength. Our studies provide a new path to attain highly stable performance and reproducibility of Sn-based perovskite solar cells.

  20. Correlation of ABO blood groups with spontaneous recanalization in acute myocardial infarction.

    Science.gov (United States)

    Lin, Xian-Liang; Zhou, Bing-Yang; Li, Sha; Li, Xiao-Lin; Luo, Zhu-Rong; Li, Jian-Jun

    2017-08-01

    Although previous studies have demonstrated the relationship between ABO blood groups and cardiovascular disease, the association of ABO blood type with spontaneous recanalization (SR) in patients with acute myocardial infarction (AMI) has not been previously investigated. We performed an initial exploratory study on the association of ABO blood groups with the presence of SR in 1209 patients with AMI. They were divided into two groups according to the thrombolysis in myocardial infarction (TIMI) grades: no-SR group (TIMI 0-1, n = 442) and SR group (TIMI 2-3, n = 767). To confirm our primary findings, data from a second AMI population (n = 200) was analyzed. In the initial data, SR group had a significantly higher percentage of blood type O and a lower percentage of blood type A compared to the no-SR group. Multivariate logistic regression analysis showed that blood type O was positively associated with SR (odds ratio: 1.40, 95% confidence interval: 1.05-1.87, p = .02), and this finding was confirmed in our second population. The present study demonstrates that blood type O was independently and positively associated with an open culprit artery in patients with AMI, suggesting that the ABO blood type is not only associated with the susceptibility to coronary artery disease but also to spontaneous reperfusion in AMI patients.

  1. Synergic nature of dielectric relaxation process in the layered perovskite halide salts: The case of 1,3- diammoniumpropylenetetrabromocadmate compound

    Science.gov (United States)

    Staśkiewicz, Beata

    2018-06-01

    The negative thermal expansion (NTE) property was a prototype to discuss the origin of difference between classical Debye relaxation process and the non-Debye behavior in the layered perovskite halide salt of chemical formula NH3(CH2)3NH3CdBr4. The analysis has been taken by dielectric relaxation spectroscopy measurements in almost six decades in frequency 5 × 102 ≤ f(ω) ≤ 1.2 × 108 and in the temperature range 315 ≤ T(K) ≤ 390. It was shown that the investigated sample exhibit an antiferrodistortive nature of phase transition between two orthorhombic structural modifications i.e. Pnma (phase I) and Ima2 (phase II) at Tc1(I → II) = 326 K, leading from an antiferroelectric to a paraelectric phase. The involvement of an odd number of carbon atoms in the alkylammonium chains in dielectric properties of examined sample is proved. Higher structural modifications, i.e. Ima2 (phase II) and P21/m (phase III), have shown significant deviations from a regular circle on the Cole-Cole diagram. Presented experimental observations are essentially important for the theoretical explanation of relaxation processes in analyzed organic - inorganic compound crystallizing in a perovskite-like topology and may provide new perspective on the fundamental aspect of relaxation response in "diammonium" series.

  2. Mechanical properties of hybrid organic-inorganic CH3NH3BX3 (B = Sn, Pb; X = Br, I perovskites for solar cell absorbers

    Directory of Open Access Journals (Sweden)

    Jing Feng

    2014-08-01

    Full Text Available The crystal structures, elastic and anisotropic properties of CH3NH3BX3 (B = Sn, Pb; X = Br, I compounds as solar cell absorber layers are investigated by the first-principles calculations. The type and strength of chemical bond B-X are found to determine the elastic properties. B-X bonds and the organic cations are therefore crucial to the functionalities of such absorbers. The bulk, shear, Young's modulus ranges from 12 to 30 GPa, 3 to 12 GPa, and 15 to 37 GPa, respectively. Moreover, the interaction among organic and inorganic ions would have negligible effect for elastic properties. The B/G and Poisson's ratio show it would have a good ductile ability for extensive deformation as a flexible/stretchable layer on the polymer substrate. The main reason is attributed to the low shear modulus of such perovskites. The anisotropic indices AU, AB AG, A1, A2, and A3 show ABX3 perovskite have very strong anisotropy derived from the elastic constants, chemical bonds, and symmetry.

  3. Distribution of ABO Blood Groups and Coronary Artery Calcium.

    Science.gov (United States)

    Wang, Yao; Zhou, Bing-Yang; Zhu, Cheng-Gang; Guo, Yuan-Lin; Wu, Na-Qiong; Qing, Ping; Gao, Ying; Liu, Geng; Dong, Qian; Li, Jian-Jun

    2017-06-01

    ABO blood groups have been confirmed to be associated with cardiovascular diseases such as coronary artery disease. However, whether ABO blood group is correlated with coronary artery calcium (CAC) is still unknown. 301 patients with coronary artery calcium score (CACS) assessed by computed tomography were consecutively enrolled and divided into two groups: with calcium group (CACS>0, n=104) and without calcium group (CACS=0, n=197). Distribution of ABO blood groups was evaluated between the two groups. The percentage of A blood type was significantly higher (p=0.008) and O blood type was significantly lower (p=0.037) in the calcium group. Univariate regression analysis showed that age, total cholesterol, low density lipoprotein cholesterol, high-sensitivity C-reactive protein, A blood type were positively correlated with CAC, and O blood type was inversely associated with CAC. Multivariate regression analysis showed that A blood type was independently associated with CAC (odds ratio: 2.217, 95% confidence interval: 1.260-3.900, p=0.006) even after further adjustment for variables that were clearly different between the two groups. Our data has suggested for the first time that A blood type was an independent risk marker for CAC. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  4. Persistent semi-metal-like nature of epitaxial perovskite CaIrO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Abhijit; Jeong, Yoon Hee, E-mail: yhj@postech.ac.kr [Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of)

    2015-05-21

    Strong spin-orbit coupled 5d transition metal based ABO{sub 3} oxides, especially iridates, allow tuning parameters in the phase diagram and may demonstrate important functionalities, for example, by means of strain effects and symmetry-breaking, because of the interplay between the Coulomb interactions and strong spin-orbit coupling. Here, we have epitaxially stabilized high quality thin films of perovskite (Pv) CaIrO{sub 3}. Film on the best lattice-matched substrate shows semi-metal-like characteristics. Intriguingly, imposing tensile or compressive strain on the film by altering the underlying lattice-mismatched substrates still maintains semi-metallicity with minute modification of the effective correlation as tensile (compressive) strain results in tiny increases (decreases) of the electronic bandwidth. In addition, magnetoresistance remains positive with a quadratic field dependence. This persistent semi-metal-like nature of Pv-CaIrO{sub 3} thin films with minute changes in the effective correlation by strain may provide new wisdom into strong spin-orbit coupled 5d based oxide physics.

  5. Copper-Substituted Lead Perovskite Materials Constructed with Different Halides for Working (CH3NH3)2CuX4-Based Perovskite Solar Cells from Experimental and Theoretical View.

    Science.gov (United States)

    Elseman, Ahmed Mourtada; Shalan, Ahmed Esmail; Sajid, Sajid; Rashad, Mohamed Mohamed; Hassan, Ali Mostafa; Li, Meicheng

    2018-04-11

    Toxicity and chemical instability issues of halide perovskites based on organic-inorganic lead-containing materials still remain as the main drawbacks for perovskite solar cells (PSCs). Herein, we discuss the preparation of copper (Cu)-based hybrid materials, where we replace lead (Pb) with nontoxic Cu metal for lead-free PSCs, and investigate their potential toward solar cell applications based on experimental and theoretical studies. The formation of (CH 3 NH 3 ) 2 CuX 4 [(CH 3 NH 3 ) 2 CuCl 4 , (CH 3 NH 3 ) 2 CuCl 2 I 2 , and (CH 3 NH 3 ) 2 CuCl 2 Br 2 ] was discussed in details. Furthermore, it was found that chlorine (Cl - ) in the structure is critical for the stabilization of the formed compounds. Cu-based perovskite-like materials showed attractive absorbance features extended to the near-infrared range, with appropriate band gaps. Green photoluminescence of these materials was obtained because of Cu + ions. The power conversion efficiency was measured experimentally and estimated theoretically for different architectures of solar cell devices.

  6. Spontaneous and continuous anti-virus disinfection from nonstoichiometric perovskite-type lanthanum manganese oxide

    Directory of Open Access Journals (Sweden)

    Ding Weng

    2015-06-01

    Full Text Available Viral pathogens have threatened human being׳s health for a long time, from periodically breakout flu epidemics to recent rising Ebola virus disease. Herein, we report a new application of nonstoichiometric Perovskite-type LaxMnO3 (x=1, 0.95, and 0.9 compounds in spontaneous and continuous disinfection of viruses. Perovskite-type LaxMnO3 (x=1, 0.95, and 0.9 is well-known for their catalytic properties involving oxidization reactions, which are usually utilized as electrodes in fuel cells. By utilizing superb oxidative ability of LaxMnO3 (x=1, 0.95, and 0.9, amino acid residues in viral envelope proteins are oxidized, thus envelope proteins are denatured and infectivity of the virus is neutralized. It is of great importance that this process does not require external energy sources like light or heat. The A/PR/8/34H1N1 influenza A virus (PR8 was employed as the sample virus in our demonstration, and high-throughput disinfections were observed. The efficiency of disinfection was correlated to oxidative ability of LaxMnO3 (x=1, 0.95, and 0.9 by EPR and H2-TPR results that La0.9MnO3 had the highest oxidative ability and correspondingly gave out the best disinfecting results within three nonstoichiometric compounds. Moreover, denaturation of hemagglutinin and neuraminidase, the two key envelope proteins of influenza A viruses, was demonstrated by HA unit assay with chicken red blood cells and NA fluorescence assay, respectively. This unique disinfecting application of La0.9MnO3 is considered as a great make up to current sterilizing methods especially to photocatalyst based disinfectants and can be widely applied to cut-off spread routes of viruses, either viral aerosol or contaminated fluid, and help in controlling the possibly upcoming epidemics like flus and hemorrhagic fever.

  7. ABO-incompatible kidney transplantation

    DEFF Research Database (Denmark)

    Schousboe, Karoline; Titlestad, Kjell; Baudier, Francois

    2010-01-01

    INTRODUCTION: Kidney transplantation is the optimal treatment for many patients with end-stage renal disease (ESRD). Due to shortage of donor kidneys in Denmark, there is a need to expand the possibilities for donation. At the Odense University Hospital (OUH), we have introduced ABO......-incompatible kidney transplantation. We used antigenspecific immunoadsorptions to remove blood group antibodies and anti-CD20 antibody (rituximab) to inhibit the antibody production. The aim of introducing the ABO-incompatible kidney transplantation at the OUH was to increase the rate of living donor kidney...... transplantation without increasing rejection or mortality rates. MATERIAL AND METHODS: Retrospective evaluation. Eleven patients received ABO-incompatible kidney transplantation. The patients were followed for 3-26 months. RESULTS: One patient had an antibody-mediated rejection, one patient suffered T...

  8. Gene frequencies of ABO and Rh blood groups in Nigeria: A review

    African Journals Online (AJOL)

    Abass Toba Anifowoshe

    2016-12-05

    Dec 5, 2016 ... d Department of Science Technology, The Federal Polytechnic Ado-Ekiti, Nigeria .... germane discoveries lead to reduced mortality due to blood trans- fusion. Human ABO ... the current frequencies of ABO types among populations based ... ABO blood group system extends beyond transfusion medicine/.

  9. Manganites in Perovskite Superlattices: Structural and Electronic Properties

    KAUST Repository

    Jilili, Jiwuer

    2016-07-13

    Perovskite oxides have the general chemical formula ABO3, where A is a rare-earth or alkali-metal cation and B is a transition metal cation. Perovskite oxides can be formed with a variety of constituent elements and exhibit a wide range of properties ranging from insulators, metals to even superconductors. With the development of growth and characterization techniques, more information on their physical and chemical properties has been revealed, which diversified their technological applications. Perovskite manganites are widely investigated compounds due to the discovery of the colossal magnetoresistance effect in 1994. They have a broad range of structural, electronic, magnetic properties and potential device applications in sensors and spintronics. There is not only the technological importance but also the need to understand the fundamental mechanisms of the unusual magnetic and transport properties that drive enormous attention. Manganites combined with other perovskite oxides are gaining interest due to novel properties especially at the interface, such as interfacial ferromagnetism, exchange bias, interfacial conductivity. Doped manganites exhibit diverse electrical properties as compared to the parent compounds. For instance, hole doped La0.7Sr0.3MnO3 is a ferromagnetic metal, whereas LaMnO3 is an antiferromagnetic insulator. Since manganites are strongly correlated systems, heterojunctions composed of manganites and other perovskite oxides are sunject to complex coupling of the spin, orbit, charge, and lattice degrees of freedom and exhibit unique electronic, magnetic, and transport properties. Electronic reconstructions, O defects, doping, intersite disorder, magnetic proximity, magnetic exchange, and polar catastrophe are some effects to explain these interfacial phenomena. In our work we use first-principles calculations to study the structural, electronic, and magnetic properties of manganite based superlattices. Firstly, we investigate the electronic

  10. Perovskite phases in the systems Asup(II)O-UO/sub 3/. 1. Tetragonal perovskite Ba/sub 2/Basub(7/8)vacantsub(1/8)UO/sub 5/sub(7/8)

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, A J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.)

    1979-10-01

    The new tetragonal compound Ba/sub 2/Basub(7/8)vacantsub(1/8)UO/sub 5/sub(7/8) (a = 2 x 6.31/sub 2/ A; c = 2 x 8.76/sub 7/ A) has been found besides Ba/sub 3/UO/sub 6/ (triclinic) in the BaO-UO/sub 3/ system. It crystallizes with a superstructure of perovskite type. The differences in properties between Ba/sub 3/UO/sub 6/ and Ba/sub 2/Basub(7/8)vacantsub(1/8) UO/sub 5/sub(7/8) are discussed.

  11. High-pressure synthesis, crystal chemistry and physics of perovskites with small cations at the A site

    International Nuclear Information System (INIS)

    Belik, Alexei A; Yi, Wei

    2014-01-01

    ABO 3 perovskites with small cations at the A site (A = Sc 3+ , In 3+ and Mn 2+ and B = Al 3+ and transition metals) are reviewed. They extend the corresponding families of perovskites with A 3+ = Y, La–Lu, and Bi and A 2+ = Cd, Ca, Sr and Ba and exhibit the largest structural distortions. As a result of these large distortions, they show, in many cases, distinct structural and magnetic properties. These are manifested in: B-site-ordered monoclinic structures of ScMnO 3 and ‘InMnO 3 ’; an unusual superstructure of ScRhO 3 and InRhO 3 ; antiferromagnetic ground states and multiferroic properties of Sc 2 NiMnO 6 and In 2 NiMnO 6 ; two magnetic transitions in ScCrO 3 and InCrO 3 with very close transition temperatures; a Pnma-to-P-1 structural transition and k = (½, 0, ½) magnetic ordering in ScVO 3 ; and incommensurate magnetic ordering of Mn 2+ spins in metallic MnVO 3 . A large number of simple ScBO 3 , InBO 3 and MnBO 3 perovskites has not been synthesized yet, and the number of experimental and theoretical works on each known ScBO 3 , InBO 3 and MnBO 3 perovskites counts to only one or two (except for ScAlO 3 ). The synthesis, crystal chemistry and physics of perovskites with small cations at the A site is an emerging field in perovskite science. (topical review)

  12. Evidence for a different electronic configuration as a primary effect during compression of orthorhombic perovskites: The case of Nd M3 +O3 (M =Cr ,Ga )

    Science.gov (United States)

    Ardit, M.; Dondi, M.; Merli, M.; Cruciani, G.

    2018-02-01

    (Mg ,Fe ) Si O3 perovskite is the most abundant mineral of the Earth's lower mantle, and compounds with the perovskite structure are perhaps the most widely employed ceramics. Hence, they attract both geophysicists and material scientists. Several investigations attempted to predict their structural evolution at high pressure, and recent advancements highlighted that perovskites having ions with the same formal valence at both polyhedral sites (i.e., 3 +:3 + ) define different compressional patterns when transition metal ions (TMI) are involved. In this study, in situ high-pressure synchrotron XRD measurements coupled with ab initio simulations of the electronic population of NdCr O3 perovskite are compared with the compressional feature of NdGa O3 . Almost identical from a steric point of view (C r3 + and G a3 + have almost the same ionic radius), the different electronic configuration of octahedrally coordinated ions - which leads to a redistribution of electrons at the 3 d orbitals for C r3 + - allows the crystal field stabilization energy (CFSE) to act as a vehicle of octahedral softening in NdCr O3 or it turns octahedra into rigid units when CFSE is null as in NdGa O3 . Besides to highlight that different electronic configurations can act as a primary effect during compression of perovskite compounds, our findings have a deep repercussion on the way the compressibility of perovskites have to be modeled.

  13. Magnetism and transport studies in off-stoichiometric metallic perovskite compounds GdPd{sub 3}B{sub x} (x=0.25, 0.50 and 0.75)

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Abhishek, E-mail: abhishek.phy@gmail.co [S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Mazumdar, Chandan, E-mail: chandan.mazumdar@saha.ac.i [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Ranganathan, R. [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)

    2010-12-15

    We report the magnetic and transport properties of the off-stoichiometric metallic perovskite like compounds GdPd{sub 3}B{sub x} (x=0.25, 0.50 and 0.75). Our results show that doping with boron in the lattice of parent binary-compound GdPd{sub 3} leads to lattice expansion. Which in turn manifests in contrasting magnetic and transport behaviors of the doped compounds in comparison with the undoped GdPd{sub 3}. An attempt has been made to compare and correlate the results of magnetic and transport measurements of GdPd{sub 3}B{sub x} with that of stoichiometric compositions GdPd{sub 3}B{sub x}C{sub 1-x}. The comparative study of GdPd{sub 3}B{sub x} and GdPd{sub 3}B{sub x}C{sub 1-x} confirms that there is a strong correlations between the structural, magnetic and transport properties of these compounds.

  14. [(CH3)3NCH2CH2NH3]SnI4: a layered perovskite with quaternary/primary ammonium dications and short interlayer iodine-iodine contacts.

    Science.gov (United States)

    Xu, Zhengtao; Mitzi, David B; Medeiros, David R

    2003-03-10

    The organic-inorganic hybrid [(CH(3))(3)NCH(2)CH(2)NH(3)]SnI(4) presents a layered perovskite structure, templated by an organic dication containing both a primary and a quaternary ammonium group. Due to the high charge density and small size of the organic cation, the separation of the perovskite layers is small and short iodine-iodine contacts of 4.19 A are formed between the layers. Optical thin-film measurements on this compound indicate a significant red shift of the exciton peak (630 nm) associated with the band gap, as compared with other SnI(4)(2)(-)-based layered perovskite structures.

  15. Cation vacancies in ferroelectric PbTiO3 and Pb(Zr,Ti)O3 : A positron annihilation lifetime spectroscopy study

    Science.gov (United States)

    Keeble, D. J.; Singh, S.; Mackie, R. A.; Morozov, M.; McGuire, S.; Damjanovic, D.

    2007-10-01

    Positron annihilation lifetime spectroscopy measurements identify A - and B -site cation vacancies in ferroelectric perovskite oxides (ABO3) . Crystal PbTiO3 and ceramic lead zirconium titanate (PZT) were studied and gave consistent values for the lifetime resulting from positron localization at lead vacancies VPb . Positron trapping to B -site vacancies was inferred in PZT. Temperature dependent studies showed that the defect specific trapping rate was higher for VB compared to VPb , consistent with the larger negative charge. Doping PZT with Fe increased the fraction positron trapping to VB compared to VPb -type defects.

  16. Sulfide perovskites for solar energy conversion applications: computational screening and synthesis of the selected compound LaYS3

    DEFF Research Database (Denmark)

    Kuhar, Korina; Crovetto, Andrea; Pandey, Mohnish

    2017-01-01

    of ternary sulfides followed by synthesis and confirmation of the properties of one of the most promising materials. The screening focusses on materials with ABS3 composition taking both perovskite and non-perovskite structures into consideration, and the material selection is based on descriptors...

  17. Effects of Fe-Enrichment on the Equation of State and Stability of (Mg,Fe)SiO3 Perovskite and Post-Perovskite

    Science.gov (United States)

    Dorfman, S. M.; Holl, C. M.; Meng, Y.; Prakapenka, V.; Duffy, T. S.

    2010-12-01

    Fe-enrichment in the deep lower mantle has been proposed as an explanation for seismic anomalies such as large low shear velocity provinces (LLSVPs) and ultralow velocity zones (ULVZs). In order to resolve the effect of Fe on the stability and equation of state of the lower mantle’s dominant constituent, (Mg,Fe)SiO3 perovskite, we have studied Fe-rich natural orthopyroxenes, (Mg0.61Fe0.37Ca0.02)SiO3 and (Mg0.25Fe0.70Ca0.05)SiO3 (compositions determined by microprobe analysis), at lower mantle P-T conditions. Pyroxene starting materials were mixed with Au (pressure calibrant and laser absorber) and loaded with NaCl or Ne (pressure medium and thermal insulator) in a symmetric diamond anvil cell. X-ray diffraction experiments at pressures up to 122 GPa with in-situ laser heating were performed at the GSECARS (13-ID-D) and HPCAT (16-ID-B) sectors of the Advanced Photon Source. Heating samples to 2000 K produced single-phase orthorhombic GdFeO3-type perovskite at 63 GPa for the Mg# 61 composition and at 72 GPa for the Mg# 25 composition. At lower pressures (56 GPa for Mg# 61, 67 GPa for Mg# 25), heating both compositions resulted in a mixture of perovskite, SiO2 and (Mg,Fe)O. These measurements provide new constraints on the dependence of (Mg,Fe)SiO3 perovskite stability on pressure and composition. Upon further compression to 93 GPa and higher pressures with laser heating, Mg# 25 perovskite transformed to a two-phase mixture of perovskite and post-perovskite. This is consistent with previous findings that Fe substitution destabilizes (Mg,Fe)SiO3 perovskite relative to (Mg,Fe)SiO3 post-perovskite (Mao et al. 2004, Caracas and Cohen 2005). The bulk modulus at 80 GPa (K80) is ~550 GPa for both Fe-rich perovskites, comparable to values measured for MgSiO3 perovskite (Lundin et al. 2008). However, the volume of Fe-rich perovskites increases linearly with Fe-content. The (Mg0.25Fe0.70Ca0.05)SiO3 perovskite is 3% greater at 80 GPa than V80 for the Mg end

  18. On the structural phase transitions of the perovskite-type layer structures (Csub(n)Hsub(2n+1)NH3)2MeCl4

    International Nuclear Information System (INIS)

    Heger, G.

    1978-01-01

    The perovskite-type layer compounds (Csub(n)Hsub(2n+1)NH 3 ) 2 MeCl 4 show a variety of different structural modifications. They differ from oneanother by the order and dynamical behaviour of the CH 3 -CH 2 -...-CH 2 -NH 3 chain molecules and the [MeCl 6 ] octahedra layers. These two structural members are coupled together by N-H...Cl hydrogen bonds. According to group theoretical relations the modifications of (Csub(n)Hsub(2n+1)NH 3 ) 2 MeCl 4 were ordered in the scheme of a 'family tree'. Taking (CH 3 NH 3 ) 2 MnCl 4 as an example, various experimental investigations incorporated neutron diffraction are reported. They lead to a sequence of phase transitions. For these phase transitions a model is developed based on the orientations of the CH 3 NH 3 dump-bell molecules and their interactions with the [MnCl 6 ] layers. (orig./HPOE) [de

  19. A Direct Bandgap Copper-Antimony Halide Perovskite.

    Science.gov (United States)

    Vargas, Brenda; Ramos, Estrella; Pérez-Gutiérrez, Enrique; Alonso, Juan Carlos; Solis-Ibarra, Diego

    2017-07-12

    Since the establishment of perovskite solar cells (PSCs), there has been an intense search for alternative materials to replace lead and improve their stability toward moisture and light. As single-metal perovskite structures have yielded unsatisfactory performances, an alternative is the use of double perovskites that incorporate a combination of metals. To this day, only a handful of these compounds have been synthesized, but most of them have indirect bandgaps and/or do not have bandgaps energies well-suited for photovoltaic applications. Here we report the synthesis and characterization of a unique mixed metal ⟨111⟩-oriented layered perovskite, Cs 4 CuSb 2 Cl 12 (1), that incorporates Cu 2+ and Sb 3+ into layers that are three octahedra thick (n = 3). In addition to being made of abundant and nontoxic elements, we show that this material behaves as a semiconductor with a direct bandgap of 1.0 eV and its conductivity is 1 order of magnitude greater than that of MAPbI 3 (MA = methylammonium). Furthermore, 1 has high photo- and thermal-stability and is tolerant to humidity. We conclude that 1 is a promising material for photovoltaic applications and represents a new type of layered perovskite structure that incorporates metals in 2+ and 3+ oxidation states, thus significantly widening the possible combinations of metals to replace lead in PSCs.

  20. High-pressure stability relations, crystal structures, and physical properties of perovskite and post-perovskite of NaNiF3

    International Nuclear Information System (INIS)

    Shirako, Y.; Shi, Y.G.; Aimi, A.; Mori, D.; Kojitani, H.; Yamaura, K.; Inaguma, Y.; Akaogi, M.

    2012-01-01

    NaNiF 3 perovskite was found to transform to post-perovskite at 16–18 GPa and 1273–1473 K. The equilibrium transition boundary is expressed as P (GPa)=−2.0+0.014×T (K). Structure refinements indicated that NaNiF 3 perovskite and post-perovskite have almost regular NiF 6 octahedra consistent with absence of the first-order Jahn–Teller active ions. Both NaNiF 3 perovskite and post-perovskite are insulators. The perovskite underwent a canted antiferromagnetic transition at 156 K, and the post-perovskite antiferromagnetic transition at 22 K. Magnetic exchange interaction of NaNiF 3 post-perovskite is smaller than that of perovskite, reflecting larger distortion of Ni–F–Ni network and lower dimension of octahedral arrangement in post-perovskite than those in perovskite. - Graphical abstract: Perovskite–post-perovskite transition in NaNiF 3 at high pressure Highlights: ► NaNiF 3 perovskite (Pv) transforms to post-perovskite (pPv) at 16 GPa and 1300 K. ► The equilibrium transition boundary is expressed as P (GPa)=−2.0+0.014 T (K). ► Antiferromagnetic transition occurs at 156 K in Pv and 22 K in pPv.

  1. Optically stimulated luminescence properties of Tm3+ doped KMgF3 fluoro perovskite

    International Nuclear Information System (INIS)

    Camargo, L.; Marcazzo, J.; Perez C, L.; Cruz Zaragoza, E.; Martinez O, S. A.

    2017-10-01

    In this work the optically stimulated luminescence (OSL) properties of undoped and Tm 3+ doped KMgF 3 fluoro perovskite have been investigated for the first time. OSL efficiency for stimulation with different wavelengths has been analyzed for each compound. The maximum OSL emission was found with blue light stimulation. The radioluminescence (Rl) spectra have shown two emission peaks at 455 and 360 nm, which can be ascribed to the 1 D 2 - 3 F 4 and 1 D 2 - 3 H 6 transitions of the Tm 3+ cations. It has been found that doping with Thulium 0.5 mol % renders the most intense OSL emission. Furthermore, several dosimetric properties such as OSL response as a function of dose, reproducibility of the OSL signal after several cycles of irradiation readout and the minimum detectable dose have been investigated. Finally, the OSL response of KMgF 3 : Tm 3+ has been compared to that of commercial Al 2 O 3 :C and the possible application of this fluoro perovskite to OSL dosimetry has been evaluated. (Author)

  2. Displacement-type ferroelectric transition with magnetic Mn ions in perovskite Sr1-xBaxMnO3

    Science.gov (United States)

    Sakai, Hideaki; Fujioka, Jun; Fukuda, Tatsuo; Okuyama, Daisuke; Hashizume, Daisuke; Kagawa, Fumitaka; Nakao, Hironori; Murakami, Youich; Arima, Takahisa; Baron, Alfred Q. R.; Taguchi, Yasujiro; Tokura, Yoshinori

    2012-02-01

    Almost all the proper ferroelectrics with a perovskite structure discovered so far have no d-electrons in the off-center transition metal site, as exemplified by BaTiO3 and Pb(Zr,Ti)O3. This empirical d^0 rule is incompatible with the emergence of magnetism and has significantly restricted the variety of multiferroic materials. In this work, we have discovered a displacement-type ferroelectric transition originating from off-center Mn^4+ ions in antiferromagnetic Mott insulators Sr1-xBaxMnO3. As Ba concentration increases, the perovskite lattice shows the typical soft mode dynamics, and the ferroelectricity shows up for x .45. In addition to the large polarization and high transition temperature comparable to BaTiO3, we demonstrate that the magnetic order suppresses the ferroelectric lattice dilation by ˜70% and increases the soft-phonon energy by ˜50%, indicating gigantic magnetoelectric effects [1]. This work was supported by the FIRST program on ``Quantum Science on Strong Correlation''. [4pt] [1] H. Sakai et al., Phys. Rev. Lett. 107, 137601 (2011).

  3. Antiferroelectric Nature of CH3NH3PbI3-xClx Perovskite and Its Implication for Charge Separation in Perovskite Solar Cells

    Science.gov (United States)

    Sewvandi, Galhenage A.; Kodera, Kei; Ma, Hao; Nakanishi, Shunsuke; Feng, Qi

    2016-07-01

    Perovskite solar cells (PSCs) have been attracted scientific interest due to high performance. Some researchers have suggested anomalous behavior of PSCs to the polarizations due to the ion migration or ferroelectric behavior. Experimental results and theoretical calculations have suggested the possibility of ferroelectricity in organic-inorganic perovskite. However, still no studies have been concretely discarded the ferroelectric nature of perovskite absorbers in PSCs. Hysteresis of P-E (polarization-electric field) loops is an important evidence to confirm the ferroelectricity. In this study, P-E loop measurements, in-depth structural study, analyses of dielectric behavior and the phase transitions of CH3NH3PbI3-xClx perovskite were carried out and investigated. The results suggest that CH3NH3PbI3-xClx perovskite is in an antiferroelectric phase at room temperature. The antiferroelectric phase can be switched to ferroelectric phase by the poling treatment and exhibits ferroelectric-like hysteresis P-E loops and dielectric behavior around room temperature; namely, the perovskite can generate a ferroelectric polarization under PSCs operating conditions. Furthermore, we also discuss the implications of ferroelectric polarization on PSCs charge separation.

  4. New lithium-ion conducting perovskite oxides related to (Li, La)TiO3

    Indian Academy of Sciences (India)

    Unknown

    We describe the synthesis and lithium-ion conductivity of new perovskite-related oxides ... work on lithium-ion conducting perovskite oxides containing d0 cations. Keywords. ..... On the other hand, Nb/Ta compounds show a higher conductivity.

  5. Hexagonal perovskites with cationic vacancies. 4. Ba/sub 8/Re/sub 3/Msup(V)Wvacant/sub 3/O/sub 24/ with Msup(V) = Nb, Ta - perovskite stacking polytypes of 24 L type

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

    1978-11-01

    The yellow perovskite stacking polytypes Ba/sub 8/Re/sub 3/NbWvacant/sub 3/O/sub 24/ and Ba/sub 8/Re/sub 3/TaWvacant/sub 3/O/sub 24/ have a rhombohedral layer structure of 24 L type with 3 formula units in the trigonal setting (Ba/sub 8/Re/sub 3/NbWvacant/sub 3/O/sub 24/: a = 5,82 A; c = 55.6 A; Ba/sub 8/Re/sub 3/TaWvacant/sub 3/O/sub 24/; a = 5,81 A; c = 55.6 A).

  6. Direct Vapor Growth of Perovskite CsPbBr3 Nanoplate Electroluminescence Devices.

    Science.gov (United States)

    Hu, Xuelu; Zhou, Hong; Jiang, Zhenyu; Wang, Xiao; Yuan, Shuangping; Lan, Jianyue; Fu, Yongping; Zhang, Xuehong; Zheng, Weihao; Wang, Xiaoxia; Zhu, Xiaoli; Liao, Lei; Xu, Gengzhao; Jin, Song; Pan, Anlian

    2017-10-24

    Metal halide perovskite nanostructures hold great promises as nanoscale light sources for integrated photonics due to their excellent optoelectronic properties. However, it remains a great challenge to fabricate halide perovskite nanodevices using traditional lithographic methods because the halide perovskites can be dissolved in polar solvents that are required in the traditional device fabrication process. Herein, we report single CsPbBr 3 nanoplate electroluminescence (EL) devices fabricated by directly growing CsPbBr 3 nanoplates on prepatterned indium tin oxide (ITO) electrodes via a vapor-phase deposition. Bright EL occurs in the region near the negatively biased contact, with a turn-on voltage of ∼3 V, a narrow full width at half-maximum of 22 nm, and an external quantum efficiency of ∼0.2%. Moreover, through scanning photocurrent microscopy and surface electrostatic potential measurements, we found that the formation of ITO/p-type CsPbBr 3 Schottky barriers with highly efficient carrier injection is essential in realizing the EL. The formation of the ITO/p-type CsPbBr 3 Schottky diode is also confirmed by the corresponding transistor characteristics. The achievement of EL nanodevices enabled by directly grown perovskite nanostructures could find applications in on-chip integrated photonics circuits and systems.

  7. Perovskite-Perovskite Homojunctions via Compositional Doping.

    Science.gov (United States)

    Dänekamp, Benedikt; Müller, Christian; Sendner, Michael; Boix, Pablo P; Sessolo, Michele; Lovrincic, Robert; Bolink, Henk J

    2018-05-11

    One of the most important properties of semiconductors is the possibility of controlling their electronic behavior via intentional doping. Despite the unprecedented progress in the understanding of hybrid metal halide perovskites, extrinsic doping of perovskite remains nearly unexplored and perovskite-perovskite homojunctions have not been reported. Here we present a perovskite-perovskite homojunction obtained by vacuum deposition of stoichiometrically tuned methylammonium lead iodide (MAPI) films. Doping is realized by adjusting the relative deposition rates of MAI and PbI 2 , obtaining p-type (MAI excess) and n-type (MAI defect) MAPI. The successful stoichiometry change in the thin films is confirmed by infrared spectroscopy, which allows us to determine the MA content in the films. We analyzed the resulting thin-film junction by cross-sectional scanning Kelvin probe microscopy (SKPM) and found a contact potential difference (CPD) of 250 mV between the two differently doped perovskite layers. Planar diodes built with the perovskite-perovskite homojunction show the feasibility of our approach for implementation in devices.

  8. Fundamental and excited states of F-type centres in MgSiO3 perovskite

    International Nuclear Information System (INIS)

    Stashans, Arvids; Piedra, Lorena; Briceno, Tamara

    2010-01-01

    Quantum-chemical modelling based on the Hartree-Fock methodology and a periodic supercell model is done to study oxygen vacancy and F-type centres in the perovskite-type MgSiO 3 crystal. The equilibrium geometry of defects is obtained, confirming the importance of electrostatic interaction in determination of atomic shifts. The calculated relaxation energies due to the defect formation are between 8 and 10 eV, thus evidencing favourability in the occurrence of such defects. The wave functions describing both F + and F centres are rather diffuse and the point defects are not well localised within the oxygen vacancy region. The Δ SCF computed absorption energies due to the F-type centres fall well within the ultraviolet spectrum, between 136 and 254 nm for the F + centre and between 163 and 248 nm for the F centre.

  9. ABO blood groups and psychiatric disorders: a Croatian study.

    Science.gov (United States)

    Pisk, Sandra Vuk; Vuk, Tomislav; Ivezić, Ena; Jukić, Irena; Bingulac-Popović, Jasna; Filipčić, Igor

    2018-02-15

    The prevalence of ABO alleles is different in different populations, and many studies have shown a correlation between the occurrences of some diseases and different genotypes of ABO blood groups. The aim of this study was to determine whether there is a significant association between psychiatric syndromes and ABO blood groups. This case-control study involved 156 psychiatric patients and 303 healthy, unrelated, voluntary blood donors. Genomic DNA was isolated from blood on a QIAcube device using a QIAamp DNA Blood mini QIAcube kit. ABO genotyping on five basic ABO alleles was performed using allele-specific polymerase chain reaction analysis. Compared with healthy subjects, a significantly higher proportion of psychiatric patients had AB blood group (χ 2 =9.359, df=3, p=0.025) and, accordingly, a significantly higher incidence of A1B genotype (χ 2 =8.226, df=3, p=0.042). The odds ratio showed that psychiatric disorders occur almost three times more frequently in carriers of AB group compared to other blood groups. However, no statistically significant difference was found in the distribution of ABO blood groups among patients with different psychiatric diagnoses. Likewise, no correlations were found between ABO blood groups and other characteristics of the psychiatric patients (sex, psychiatric heredity, somatic comorbidity, suicidality). The results of this study support the hypothesis of an association between psychiatric disorders and ABO blood groups. The probability is that psychiatric disorders will occur almost three times more frequently in carriers of AB group compared to other ABO blood groups in the Croatian population.

  10. Synthesis, Resistivity, and Thermal Properties of the Cubic Perovskite NH 2CH=NH 2SnI 3and Related Systems

    Science.gov (United States)

    Mitzi, D. B.; Liang, K.

    1997-12-01

    Combining concentrated hydriodic acid solutions of tin(II) iodide and formamidine acetate in an inert atmosphere results in the precipitation of a new conducting organic-inorganic compound, NH 2CH=NH 2SnI 3, which at room temperature adopts a cubic perovskite structure. The lattice constant for NH 2CH=NH 2SnI 3is found to be a=6.316(1) Å, which is approximately 1.2% larger than that for the isostructural compound CH 3NH 3SnI 3. The electrical resistivity of a pressed pellet of the new compound exhibits semimetallic temperature dependence from 10 to 300 K, with evidence of a structural transition at approximately 75 K. NH 2CH=NH 2SnI 3begins to slowly decompose in an inert atmosphere at temperatures as low as 200°C, with bulk decomposition/melting occurring above 300°C. The properties of the formamidinium-based perovskite are compared with those of the related cubic (at room temperature) perovskite CH 3NH 3SnI 3and the mixed-cation system (CH 3NH 3) 1- x(NH 2CH=NH 2) xSnI 3.

  11. Frequency and temperature dependence of the electrical conductivity of KTaO3; Li and PbTiO3; La, Cu: Indication of a low temperature polaron mechanism

    International Nuclear Information System (INIS)

    Levstik, A.; Filipic, C.; Bidault, O.; Maglione, M.

    2008-01-01

    Recently, the concept of polarons has again been at the focus of solid-state research, as it can constitute the basis for understanding the high-temperature superconductivity or the colossal magnetoresistance of materials. More than a decade ago there were some indications that polarons play an important role in explaining low temperature maxima in imaginary part of the dielectric constant ε '' (T) in ABO 3 perovskites. In the present work we report the ac electrical conductivities of KTaO 3 ; Li and PbTiO 3 ; La, Cu and their frequency and temperature dependence. The real part of the complex ac conductivity was found to follow the universal dielectric response σ ' ∝ν s . A detailed theoretical analysis of the temperature dependence of the parameter s revealed that, at low temperatures, the tunnelling of small polarons is the dominating charge transport mechanism in ABO 3 perovskites

  12. Atomic layer deposition of perovskite oxides and their epitaxial integration with Si, Ge, and other semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, Martin D.; Ngo, Thong Q.; Hu, Shen; Ekerdt, John G., E-mail: ekerdt@utexas.edu [Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Posadas, Agham; Demkov, Alexander A. [Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-12-15

    Atomic layer deposition (ALD) is a proven technique for the conformal deposition of oxide thin films with nanoscale thickness control. Most successful industrial applications have been with binary oxides, such as Al{sub 2}O{sub 3} and HfO{sub 2}. However, there has been much effort to deposit ternary oxides, such as perovskites (ABO{sub 3}), with desirable properties for advanced thin film applications. Distinct challenges are presented by the deposition of multi-component oxides using ALD. This review is intended to highlight the research of the many groups that have deposited perovskite oxides by ALD methods. Several commonalities between the studies are discussed. Special emphasis is put on precursor selection, deposition temperatures, and specific property performance (high-k, ferroelectric, ferromagnetic, etc.). Finally, the monolithic integration of perovskite oxides with semiconductors by ALD is reviewed. High-quality epitaxial growth of oxide thin films has traditionally been limited to physical vapor deposition techniques (e.g., molecular beam epitaxy). However, recent studies have demonstrated that epitaxial oxide thin films may be deposited on semiconductor substrates using ALD. This presents an exciting opportunity to integrate functional perovskite oxides for advanced semiconductor applications in a process that is economical and scalable.

  13. Atomic layer deposition of perovskite oxides and their epitaxial integration with Si, Ge, and other semiconductors

    International Nuclear Information System (INIS)

    McDaniel, Martin D.; Ngo, Thong Q.; Hu, Shen; Ekerdt, John G.; Posadas, Agham; Demkov, Alexander A.

    2015-01-01

    Atomic layer deposition (ALD) is a proven technique for the conformal deposition of oxide thin films with nanoscale thickness control. Most successful industrial applications have been with binary oxides, such as Al 2 O 3 and HfO 2 . However, there has been much effort to deposit ternary oxides, such as perovskites (ABO 3 ), with desirable properties for advanced thin film applications. Distinct challenges are presented by the deposition of multi-component oxides using ALD. This review is intended to highlight the research of the many groups that have deposited perovskite oxides by ALD methods. Several commonalities between the studies are discussed. Special emphasis is put on precursor selection, deposition temperatures, and specific property performance (high-k, ferroelectric, ferromagnetic, etc.). Finally, the monolithic integration of perovskite oxides with semiconductors by ALD is reviewed. High-quality epitaxial growth of oxide thin films has traditionally been limited to physical vapor deposition techniques (e.g., molecular beam epitaxy). However, recent studies have demonstrated that epitaxial oxide thin films may be deposited on semiconductor substrates using ALD. This presents an exciting opportunity to integrate functional perovskite oxides for advanced semiconductor applications in a process that is economical and scalable

  14. [CH(3)(CH(2))(11)NH(3)]SnI(3): a hybrid semiconductor with MoO(3)-type tin(II) iodide layers.

    Science.gov (United States)

    Xu, Zhengtao; Mitzi, David B

    2003-10-20

    The organic-inorganic hybrid [CH(3)(CH(2))(11)NH(3)]SnI(3) presents a lamellar structure with a Sn-I framework isotypic to that of MoO(3). The SnI(3)(-) layer consists of edge and corner-sharing SnI(6) octahedra in which one of the six Sn-I bonds is distinctly elongated (e.g., 3.62 A), indicating lone-pair stereoactivity for the Sn(II) atom. The overall electronic character remains comparable with that of the well-studied SnI(4)(2)(-)-based perovskite semiconductors, such as [CH(3)(CH(2))(11)NH(3)](2)SnI(4), with a red-shifted and broadened exciton peak associated with the band gap, apparently due to the increased dimensionality of the Sn-I framework. The title compound offers, aside from the hybrid perovskites, a new type of solution-processable Sn-I network for potential applications in semiconductive devices.

  15. Enhancing Optically Pumped Organic-Inorganic Hybrid Perovskite Amplified Spontaneous Emission via Compound Surface Plasmon Resonance

    Directory of Open Access Journals (Sweden)

    Xiaoyan Wu

    2018-03-01

    Full Text Available Organic-inorganic hybrid perovskite has attracted intensive attention from researchers as the gain medium in lasing devices. However, achieving electrically driven lasing remains a significant challenge. Modifying the devices’ structure to enhance the optically pumped amplified spontaneous emission (ASE is the key issue. In this work, gold nanoparticles (Au NPs are first doped into PEDOT: PSS buffer layer in a slab waveguide device structure: Quartz/PEDOT: PSS (with or w/o Au NPs/CH3NH3PbBr3. As a result, the facile device shows a significantly enhanced ASE intensity and a narrowed full width at half maximum. Based on experiments and theoretical simulation data, the improvement is mainly a result of the compound surface plasmon resonance, including simultaneous near- and far-field effects, both of which could increase the density of excitons excited state and accelerate the radiative decay process. This method is highly significant for the design and development and fabrication of high-performance organic-inorganic hybrid perovskite lasing diodes.

  16. Perovskite oxides: Oxygen electrocatalysis and bulk structure

    Science.gov (United States)

    Carbonio, R. E.; Fierro, C.; Tryk, D.; Scherson, D.; Yeager, Ernest

    1987-01-01

    Perovskite type oxides were considered for use as oxygen reduction and generation electrocatalysts in alkaline electrolytes. Perovskite stability and electrocatalytic activity are studied along with possible relationships of the latter with the bulk solid state properties. A series of compounds of the type LaFe(x)Ni1(-x)O3 was used as a model system to gain information on the possible relationships between surface catalytic activity and bulk structure. Hydrogen peroxide decomposition rate constants were measured for these compounds. Ex situ Mossbauer effect spectroscopy (MES), and magnetic susceptibility measurements were used to study the solid state properties. X ray photoelectron spectroscopy (XPS) was used to examine the surface. MES has indicated the presence of a paramagnetic to magnetically ordered phase transition for values of x between 0.4 and 0.5. A correlation was found between the values of the MES isomer shift and the catalytic activity for peroxide decomposition. Thus, the catalytic activity can be correlated to the d-electron density for the transition metal cations.

  17. Phase Stability and Electronic Structure of Prospective Sb-Based Mixed Sulfide and Iodide 3D Perovskite (CH3NH3)SbSI2.

    Science.gov (United States)

    Li, Tianyang; Wang, Xiaoming; Yan, Yanfa; Mitzi, David B

    2018-06-29

    Lead-free antimony-based mixed sulfide and iodide perovskite phases have recently been reported to be synthesized experimentally and to exhibit reasonable photovoltaic performance. Through a combination of experimental validation and computational analysis, we show no evidence of the formation of the mixed sulfide and iodide perovskite phase, MASbSI 2 (MA = CH 3 NH 3 + ), and instead that the main products are a mixture of the binary and ternary compounds (Sb 2 S 3 and MA 3 Sb 2 I 9 ). Density functional theory calculations also indicate that such a mixed sulfide and iodide perovskite phase should be thermodynamically less stable compared with binary/ternary anion-segregated secondary phases and less likely to be synthesized under equilibrium conditions. Additionally, band structure calculations show that this mixed sulfide and iodide phase, if possible to synthesize (e.g., under nonequilibrium conditions), should have a suitable direct band gap for photovoltaic application.

  18. Simulation design of P–I–N-type all-perovskite solar cells with high efficiency

    International Nuclear Information System (INIS)

    Du Hui-Jing; Wang Wei-Chao; Gu Yi-Fan

    2017-01-01

    According to the good charge transporting property of perovskite, we design and simulate a p–i–n-type all-perovskite solar cell by using one-dimensional device simulator. The perovskite charge transporting layers and the perovskite absorber constitute the all-perovskite cell. By modulating the cell parameters, such as layer thickness values, doping concentrations and energy bands of n-, i-, and p-type perovskite layers, the all-perovskite solar cell obtains a high power conversion efficiency of 25.84%. The band matched cell shows appreciably improved performance with widen absorption spectrum and lowered recombination rate, so weobtain a high J sc of 32.47 mA/cm 2 . The small series resistance of the all-perovskite solar cell also benefits the high J sc . The simulation provides a novel thought of designing perovskite solar cells with simple producing process, low production cost and high efficient structure to solve the energy problem. (paper)

  19. Frequency of ABO/Rhesus Blood Groups in Patients with Diabetes Mellitus.

    Science.gov (United States)

    Oner, Can; Dogan, Burcu; Telatar, Berrin; Celik Yagan, Canan Fidan; Oguz, Aytekin

    2016-01-01

    The correlation between ABO/Rh blood groups and diabetes mellitus is still controversial. The aim of this study was to determine the relationship between ABO/Rhesus blood groups and diabetes in Turkish population. This cross-sectional study was conducted in Istanbul Medeniyet University Göztepe Education and Training Hospital's Diabetes Units. The study group was composed of 421 patients with type-1 diabetes, 484 patients with type-2 diabetes and 432 controls. Blood samples were collected and tested for ABO/Rhesus blood groups. Data was analyzed by SPSS version 17.0. A significant association was found between blood groups and diabetes mellitus. The frequency of AB blood group was significantly higher in type-1 diabetics; and A blood group was significantly higher in type-2 diabetics. Furthermore, Rh negativity were significantly more frequent in type-2 diabetics.

  20. Post-perovskite transitions in CaB4+O3 at high pressure

    International Nuclear Information System (INIS)

    Akaogi, M; Shirako, Y; Kojitani, H; Takamori, S; Yamaura, K; Takayama-Muromachi, E

    2010-01-01

    High-pressure phase transitions in CaRhO 3 were examined using a multianvil apparatus up to 27 GPa and 1930 o C. CaRhO 3 perovskite transforms to post-perovskite via a monoclinic intermediate phase with increasing pressure. Volume changes for the transitions of perovskite - intermediate phase and of intermediate phase - post-perovskite are -1.1 and -0.7 %, respectively. CaRhO 3 post-perovskite is the fourth quenchable post-perovskite oxide found so far. By high-temperature calorimetric experiments, enthalpy of the perovskite - post-perovskite transition in CaRuO 3 was measured as 15.2±3.3 kJ/mol. Combining the datum with those of CaIrO 3 , it is shown that CaIrO 3 perovskite is energetically less stable than CaRuO 3 perovskite. This is consistent with the fact that orthorhombic distortion of CaIrO 3 perovskite is larger than CaRuO 3 , as indicated with the tilt-angle of octahedral framework of perovskite structure. The transition pressure from perovskite to post-perovskite in CaBO 3 (B = Ru, Rh, Ir) increases almost linearly with decreasing the tilt-angle, suggesting that the perovskite - post-perovskite transition may result from instability of the perovskite structure with pressure.

  1. Highly Controlled Codeposition Rate of Organolead Halide Perovskite by Laser Evaporation Method.

    Science.gov (United States)

    Miyadera, Tetsuhiko; Sugita, Takeshi; Tampo, Hitoshi; Matsubara, Koji; Chikamatsu, Masayuki

    2016-10-05

    Organolead-halide perovskites can be promising materials for next-generation solar cells because of its high power conversion efficiency. The method of precise fabrication is required because both solution-process and vacuum-process fabrication of the perovskite have problems of controllability and reproducibility. Vacuum deposition process was expected to achieve precise control; however, vaporization of amine compound significantly degrades the controllability of deposition rate. Here we achieved the reduction of the vaporization by implementing the laser evaporation system for the codeposition of perovskite. Locally irradiated continuous-wave lasers on the source materials realized the reduced vaporization of CH 3 NH 3 I. The deposition rate was stabilized for several hours by adjusting the duty ratio of modulated laser based on proportional-integral control. Organic-photovoltaic-type perovskite solar cells were fabricated by codeposition of PbI 2 and CH 3 NH 3 I. A power-conversion efficiency of 16.0% with reduced hysteresis was achieved.

  2. Frequency of abo blood groups among the diabetes mellitus type 2 patients

    International Nuclear Information System (INIS)

    Qureshi, M.A.; Bhatti, R.

    2003-01-01

    Objective: To study the frequency of ABO blood groups among diabetes mellitus type 2. Results: Comparison of blood groups frequency between the general population and diabetes type 2 patients was carried out in term of percentage. It was noticed that the values were 4.36, 17.15 and 7.34% higher for A, B and AB blood groups respectively in the diabetic patients. On the contrary, the value was 28.94% lower for the blood group O. Conclusion: Present study has supported the hypothesis that diabetes mellitus type 2 and blood groups are interrelated because of the broad genetic immunologic basis in both. It is concluded that the frequency of blood groups B and O is significantly higher and lower respectively in the diabetes mellitus type 2 patients as compared to the general population. (author)

  3. Hexagonal perovskites with cationic vacancies. 1. Compounds of the type Ba/sub 2/Bsub(1/3)sup(III) vacantsub(2/3) Resup(VII)O/sub 6/

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S; Jooss, I [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

    1978-04-01

    Compounds of type Ba/sub 2/Bsub(1/3)sup(III)vacantsub(2/3)Resup(VII)O/sub 6/ are formed with Bsup(III) = Sm-Gd, Ho-Lu, Y, Sc, In (yellow); Tb (black-brown); Dy (yellow-orange). They crystallize with Bsup(III) = Sm-Lu, Y and Sc in a rhombohedral layer structure of 12 L-type (space group R3m; sequence: cchhcchhcchh) with 6 formula units in the unit cell.

  4. Synthesis, structure and phase separation of a new 12R-type perovskite-related oxide Ba3NdMn2O9

    International Nuclear Information System (INIS)

    Yang, H.; Tang, Y.K.; Yao, L.D.; Zhang, W.; Li, Q.A.; Li, F.Y.; Jin, C.Q.; Yu, R.C.

    2007-01-01

    A new 12R-type perovskite-related oxide, Ba 3 NdMn 2 O 9 , has been prepared by traditional solid-state reaction method and the presence of chemical phase separation phenomenon has been revealed by transmission electron microscopy. The perfect grains of the compound have an average chemical composition of Ba 4 NdMn 3 O 12 (mainly for cationic ratio) according to the characterization by TEM-EDX. In this perfect 12R-type structure with composition Ba 4 NdMn 3 O 12 , the Nd cations are located in the corner-sharing octahedra, whereas the Mn cations are located in the face-sharing octahedra, leading to a remarkable cation ordering. Superstructure modulation was found to be a common phenomenon in the 12R polytype and the modulated areas were revealed by both EDX and EELS to be Nd rich compared to the perfect areas. This result together with the previous work [A.F. Fuentes, K. Boulahya, U. Amador, J. Solid State Chem. 177 (2004) 714] has shown that, for the rare-earth-containing Ba-RE-Mn-O systems (RE being rare-earth elements), the composition Ba 4 REMn 3 O 12 (mainly for cationic ratio) is required for the formation of perfect 12R polytype

  5. ABO blood groups, Rhesus factor, and Behçet's disease.

    Science.gov (United States)

    Ozyurt, Kemal; Oztürk, Perihan; Gül, Mustafa; Benderli, Yasemin Cihan; Cölgeçen, Emine; Inci, Rahime

    2013-09-01

    Recently, numerous studies have been carried out to explain the genetics and immunopathogenesis of Behçet's disease (BD). There is still insufficient understanding of its etiopathogenesis, but substantial genetic and immune system abnormalities have been suggested. Several studies have shown remarkable associations of ABO blood groups with various diseases. This study investigated the relationship between ABO and Rhesus (D) blood groups and Behçet's disease in Turkish patients. Clinical data on gender, ABO, and Rhesus blood type of patients with BD were collected at the Kayseri Education and Research Hospital from 2005 to 2012. A total of 115 patients with BD were assessed for their association with ABO or Rhesus (D) blood groups and compared with the distribution of the blood groups of 25,701 healthy donors admitted to the Kayseri Education and Research Hospital Blood Center in 2010 and 2011. The distribution of ABO and Rhesus blood groups in patients with BD was similar to the healthy donors. No relationship was found between ABO or Rhesus blood groups and BD at our hospital. Further studies with a larger series and in different centers may be valuable for identifying the association between ABO or Rhesus (D) blood groups and BD.

  6. Discontinuation of steroids in ABO-incompatible renal transplantation

    DEFF Research Database (Denmark)

    Novosel, Marija Kristina; Bistrup, C.

    2016-01-01

    A steroid-free protocol for ABO-compatible renal transplantation has been used at our center since 1983. To minimize the adverse effects of steroids, we also developed a steroid sparing protocol for ABO-incompatible renal transplantation in 2008. The present study is a report of our results....... A retrospective review of the first 50 ABO-incompatible renal transplantations performed at a single university center. If no immunological events occurred in the post-transplant period, prednisolone tapering was initiated approximately 3 months after transplantation. Forty-three patients completed prednisolone...... to antirejection treatment. Overall, 1-year rejection rate was 19%. One- and 3-year graft survival was 94% and 91%, respectively. One-year post-transplant median serum creatinine was 123 mol/L. We found acceptable rejection rates, graft survival, and creatinine levels in patients undergoing ABO-incompatible renal...

  7. ABO Blood Group And Reproductive Performance | Gharoro ...

    African Journals Online (AJOL)

    ABO Blood Group And Reproductive Performance. ... Blood group A phenotype constituted 22.48%, while AB, B, and O blood groups made up 1.94, 15.28 and 60.3 percent respectively. The mean age of the ... Keywords: ABO Blood Group, Reproductive performance, population mapping, gene frequency. Journal of Mining ...

  8. Preparation and Performance Validation of Nano-Perovskite Type for Carbon Dioxide Reforming of Methane.

    Science.gov (United States)

    Kim, Taegyu; Park, Daeil

    2018-02-01

    This paper describes the La0.8Sr0.2NiO3 perovskite-type catalysts supported on α-Al2O3 that were prepared by polyol method and used as a catalyst for the carbon dioxide reforming of methane. The effect of the molar concentration of polyvinyl-pyrrolidone (PVP) on the reducibility, structural properties and carbon deposition was characterized by XRD, and TGA. The carbon dioxide reforming of methane on the catalyst was performed at the different concentration of PVP. At the 1 M PVP, main characteristic peaks of perovskite structure were established without impurities, thus showing the highest catalytic activity; 87.7% and 92.1% in CH4 and CO2 conversion, respectively. After the reaction, carbon deposition was 0.4-0.6%, while 6.2% on the existing Ni catalyst, indicating the perovskite-type catalyst has a superior characteristic preventing it from the carbon deposition at the carbon dioxide reforming of methane.

  9. Highly Luminescent Phase-Stable CsPbI3 Perovskite Quantum Dots Achieving Near 100% Absolute Photoluminescence Quantum Yield.

    Science.gov (United States)

    Liu, Feng; Zhang, Yaohong; Ding, Chao; Kobayashi, Syuusuke; Izuishi, Takuya; Nakazawa, Naoki; Toyoda, Taro; Ohta, Tsuyoshi; Hayase, Shuzi; Minemoto, Takashi; Yoshino, Kenji; Dai, Songyuan; Shen, Qing

    2017-10-24

    Perovskite quantum dots (QDs) as a new type of colloidal nanocrystals have gained significant attention for both fundamental research and commercial applications owing to their appealing optoelectronic properties and excellent chemical processability. For their wide range of potential applications, synthesizing colloidal QDs with high crystal quality is of crucial importance. However, like most common QD systems such as CdSe and PbS, those reported perovskite QDs still suffer from a certain density of trapping defects, giving rise to detrimental nonradiative recombination centers and thus quenching luminescence. In this paper, we show that a high room-temperature photoluminescence quantum yield of up to 100% can be obtained in CsPbI 3 perovskite QDs, signifying the achievement of almost complete elimination of the trapping defects. This is realized with our improved synthetic protocol that involves introducing organolead compound trioctylphosphine-PbI 2 (TOP-PbI 2 ) as the reactive precursor, which also leads to a significantly improved stability for the resulting CsPbI 3 QD solutions. Ultrafast kinetic analysis with time-resolved transient absorption spectroscopy evidence the negligible electron or hole-trapping pathways in our QDs, which explains such a high quantum efficiency. We expect the successful synthesis of the "ideal" perovskite QDs will exert profound influence on their applications to both QD-based light-harvesting and -emitting devices.

  10. ABO blood groups and risk for obesity in Arar, Northern Saudi Arabia.

    Science.gov (United States)

    Aboel-Fetoh, Nagah M; Alanazi, Arwa R; Alanazi, Abdullah S; Alruwili, Asma N

    2016-12-01

    ABO blood groups are associated with some important chronic diseases. Previous studies have observed an association between ABO blood group and risk for obesity. This study aimed to determine whether there is an association between ABO blood groups and obesity in apparently healthy attendees of primary healthcare (PHC) centers in Arar city, Northern Saudi Arabia. This cross-sectional study included 401 participants aged 15 years and older attending three randomly selected PHC centers in Arar city. Data were collected by means of personal interview using a predesigned questionnaire. Anthropometric examination included height and weight measurements with calculation of BMI. ABO and Rh blood groups were determined. The majority of the participants were female (70.8%). The mean±SD age was 28.6±9.1 years. Only 5.7% were underweight. Both normal and overweight participants were equal in number and constituted 28.4%, whereas obese individuals constituted 37.4% with a mean BMI of 28.56±8.0. Blood group O was the most common (44.1%), followed by A (30.9%), B (18.7%), and AB (6.2%). Rh-positive cases constituted 87.0%. Blood group O was the most common type among the obese individuals (44.7%), followed by A, B, and AB groups (30, 20, and 5.3%, respectively). BMI was highest (28.8±9.2) in blood group O. There were no statistically significant differences between different ABO blood groups as regards BMI, Rh, and sex. Moreover, there was no statistically significant difference between Rh type and BMI. The prevalence of obesity and overweight is high in the population attending PHC centers of Arar city, Northern Saudi Arabia. There is no association between overweight, obesity, and ABO blood groups or Rh.

  11. Crystal Structure Formation of CH3NH3PbI3-xClx Perovskite

    Directory of Open Access Journals (Sweden)

    Shiqiang Luo

    2016-02-01

    Full Text Available Inorganic-organic hydride perovskites bring the hope for fabricating low-cost and large-scale solar cells. At the beginning of the research, two open questions were raised: the hysteresis effect and the role of chloride. The presence of chloride significantly improves the crystallization and charge transfer property of the perovskite. However, though the long held debate over of the existence of chloride in the perovskite seems to have now come to a conclusion, no prior work has been carried out focusing on the role of chloride on the electronic performance and the crystallization of the perovskite. Furthermore, current reports on the crystal structure of the perovskite are rather confusing. This article analyzes the role of chloride in CH3NH3PbI3-xClx on the crystal orientation and provides a new explanation about the (110-oriented growth of CH3NH3PbI3 and CH3NH3PbI3-xClx.

  12. Ruthenium perovskites of type Ba/sub 2/BRuO/sub 6/ and Ba/sub 3/BRu/sub 2/O/sub 9/ with B = indium, rhodium

    Energy Technology Data Exchange (ETDEWEB)

    Schaller, H U; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1981-02-01

    The black perovskites Ba/sub 2/InRu/sup 5 +/O/sub 6/ and Ba/sub 3/InRu/sub 2/O/sub 9/ (mean oxydation state of ruthenium: +4.5) adopt the hexagonal BaTiO/sub 3/ structure and form a continuous series of mixed crystals. According to the intensity calculations and analysis of the vibrational spectroscopic data an ordered distribution between indium and ruthenium is present: 1:1 order in Ba/sub 2/RuO/sub 6/ (space group P-3m1 respective Dsub(3d)/sup 3/; R' = 5.3%); 1:2 order in Ba/sub 3/InRu/sub 2/O/sub 9/ (space group P6/sub 3//mmc respective Dsub(6h)/sup 4/; R' = 4.6%). The corresponding black Rh compounds, Ba/sub 2/RhRuO/sub 6/ and Ba/sub 3/RhRu/sub 2/O/sub 9/, crystallize in the rhombohedral 9 L type of BaRuO/sub 3/ (author).

  13. Prediction of compounds with electric and magnetic ordering

    Energy Technology Data Exchange (ETDEWEB)

    Nikiforov, L G [Rybinskij Aviatsionnyj Tekhnologicheskij Inst. (USSR)

    1979-03-01

    The possibility of polymorphic transformations from the structure of the pyrochlore type into that of the perovskite type for nine lead-containing compounds has been forecast. Some of them (PbTaO/sub 3/, Pb/sub 2/NiTaO/sub 6/, Pb/sub 2/MnTaO/sub 6/, Pb/sub 2/SmTaO/sub 6/) are expected to have, in addition to common for all lead-containing perovskites ferro-or antiferro-electric properties, specific magnetic properties. The periods of elementary cells of new perovskites are forecast. The possibility of considerable reduction of the number of errors when searching thermodynamical parameters of transformation has been shown.

  14. PbBr3 Perovskite Crystals

    KAUST Repository

    Wei, Tzu-Chiao

    2018-01-31

    Researchers have recently revealed that hybrid lead halide perovskites exhibit ferroelectricity, which is often associated with other physical characteristics, such as a large nonlinear optical response. In this work, the nonlinear optical properties of single crystal inorganic–organic hybrid perovskite CH3NH3PbBr3 are studied. By exciting the material with a 1044 nm laser, strong two-photon absorption-induced photoluminescence in the green spectral region is observed. Using the transmission open-aperture Z-scan technique, the values of the two-photon absorption coefficient are observed to be 8.5 cm GW−1, which is much higher than that of standard two-photon absorbing materials that are industrially used in nonlinear optical applications, such as lithium niobate (LiNbO3), LiTaO3, KTiOPO4, and KH2PO4. Such a strong two-photon absorption effect in CH3NH3PbBr3 can be used to modulate the spectral and spatial profiles of laser pulses, as well as to reduce noise, and can be used to strongly control the intensity of incident light. In this study, the superior optical limiting, pulse reshaping, and stabilization properties of CH3NH3PbBr3 are demonstrated, opening new applications for perovskites in nonlinear optics.

  15. Conducting Layered Organic-inorganic Halides Containing -Oriented Perovskite Sheets.

    Science.gov (United States)

    Mitzi, D B; Wang, S; Feild, C A; Chess, C A; Guloy, A M

    1995-03-10

    Single crystals of the layered organic-inorganic perovskites, [NH(2)C(I=NH(2)](2)(CH(3)NH(3))m SnmI3m+2, were prepared by an aqueous solution growth technique. In contrast to the recently discovered family, (C(4)H(9)NH(3))(2)(CH(3)NH(3))n-1SnnI3n+1, which consists of (100)-terminated perovskite layers, structure determination reveals an unusual structural class with sets of m -oriented CH(3)NH(3)SnI(3) perovskite sheets separated by iodoformamidinium cations. Whereas the m = 2 compound is semiconducting with a band gap of 0.33 +/- 0.05 electron volt, increasing m leads to more metallic character. The ability to control perovskite sheet orientation through the choice of organic cation demonstrates the flexibility provided by organic-inorganic perovskites and adds an important handle for tailoring and understanding lower dimensional transport in layered perovskites.

  16. The efficiency limit of CH3NH3PbI3 perovskite solar cells

    International Nuclear Information System (INIS)

    Sha, Wei E. I.; Ren, Xingang; Chen, Luzhou; Choy, Wallace C. H.

    2015-01-01

    With the consideration of photon recycling effect, the efficiency limit of methylammonium lead iodide (CH 3 NH 3 PbI 3 ) perovskite solar cells is predicted by a detailed balance model. To obtain convincing predictions, both AM 1.5 spectrum of Sun and experimentally measured complex refractive index of perovskite material are employed in the detailed balance model. The roles of light trapping and angular restriction in improving the maximal output power of thin-film perovskite solar cells are also clarified. The efficiency limit of perovskite cells (without the angular restriction) is about 31%, which approaches to Shockley-Queisser limit (33%) achievable by gallium arsenide (GaAs) cells. Moreover, the Shockley-Queisser limit could be reached with a 200 nm-thick perovskite solar cell, through integrating a wavelength-dependent angular-restriction design with a textured light-trapping structure. Additionally, the influence of the trap-assisted nonradiative recombination on the device efficiency is investigated. The work is fundamentally important to high-performance perovskite photovoltaics

  17. Fundamental and excited states of F-type centres in MgSiO{sub 3} perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Stashans, Arvids, E-mail: arvids@utpl.edu.e [Grupo de Fisicoquimica de Materiales, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Piedra, Lorena; Briceno, Tamara [Grupo de Fisicoquimica de Materiales, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Escuela de Geologia y Minas, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador)

    2010-10-15

    Quantum-chemical modelling based on the Hartree-Fock methodology and a periodic supercell model is done to study oxygen vacancy and F-type centres in the perovskite-type MgSiO{sub 3} crystal. The equilibrium geometry of defects is obtained, confirming the importance of electrostatic interaction in determination of atomic shifts. The calculated relaxation energies due to the defect formation are between 8 and 10 eV, thus evidencing favourability in the occurrence of such defects. The wave functions describing both F{sup +} and F centres are rather diffuse and the point defects are not well localised within the oxygen vacancy region. The {Delta} SCF computed absorption energies due to the F-type centres fall well within the ultraviolet spectrum, between 136 and 254 nm for the F{sup +} centre and between 163 and 248 nm for the F centre.

  18. ABO incompatibility hemolytic disease following exchange transfusion 96 newborn

    OpenAIRE

    Khatami S.F; Behjati SH.

    2007-01-01

    Background: ABO incompatibility hemolytic disease of the newborn is a common cause of clinical jaundice and causes two-thirds of the hemolytic disease in newborns. This study was undertaken to determine the frequency of ABO incompatibility hemolytic disease and its complications in newborns undergoing exchange transfusion.Methods: This prospective and descriptive study was performed in jaundiced newborn infants during a three-year period. Inclusion criteria were: maternal blood type O, newbor...

  19. Correlation of ABO and Rh blood groups with transfusion administration and fever onset after hip surgery in children.

    Science.gov (United States)

    Brdar, Radivoj; Petronic, Ivana; Nikolic, Dejan; Golubovic, Zoran; Bukva, Bojan; Radlovic, Vladimir; Abramovic, Dusan; Ducic, Sinisa; Colovic, Hristina

    2012-01-01

    Aim of our study was to evaluate distribution of ABO and Rh blood type groups in children after hip surgery regarding transfusion administration and fever presence. Four types of ABO blood groups (A; B; AB; O) and 2 types of Rh blood groups (Rh+; Rh-) were evaluated in group with administered transfusion (tr+) and without given transfusion (tr-); and in group with fever (fev+) and without fever (fev-), in 146 children after hip surgery. Tr+ and fev+ groups were divided into 3 groups (0-24h; 25-48h; 49-72h): for tr+ group (Group 1, Group 2, Group 3), and for fev+ group (Group A, Group B, Group C). AB blood group significantly decreased in Group 1 (χ2= 6.44; pblood group in Group 3 in tr+ group (χ2= 7.68; pblood group significantly increased in Group 3 in tr+ group (χ2= 9.96; pblood group significantly decreased in Groups B (χ2= 12.2; pblood group significantly increased in Group C (χ2= 34.4; pgroup. Administration of transfusion and fever onset in pediatric patients undergoing surgical correction of the hip is not influenced by the ABO and Rh blood groups system in humans. There is correlation between distribution of ABO blood groups with the time of transfusion administration and fever onset in children after hip surgery.

  20. Application of Long-Range Surface Plasmon Resonance for ABO Blood Typing

    Directory of Open Access Journals (Sweden)

    Wanida Tangkawsakul

    2016-01-01

    Full Text Available In this study, we demonstrate a long-range surface plasmon resonance (LR-SPR biosensor for the detection of whole cell by captured antigens A and B on the surface of red blood cells (RBCs as a model. The LR-SPR sensor chip consists of high-refractive index glass, a Cytop film layer, and a thin gold (Au film, which makes the evanescent field intensity and the penetration depth longer than conventional SPR. Therefore, the LR-SPR biosensor has improved capability for detecting large analytes, such as RBCs. The antibodies specific to blood group A and group B (Anti-A and Anti-B are covalently immobilized on a grafting self-assembled monolayer (SAM/Au surface on the biosensor. For blood typing, RBC samples can be detected by the LR-SPR biosensor through a change in the refractive index. We determined that the results of blood typing using the LR-SPR biosensor are consistent with the results obtained from the agglutination test. We obtained the lowest detection limits of 1.58 × 105 cells/ml for RBC-A and 3.83 × 105 cells/ml for RBC-B, indicating that the LR-SPR chip has a higher sensitivity than conventional SPR biosensors (3.3 × 108 cells/ml. The surface of the biosensor can be efficiently regenerated using 20 mM NaOH. In summary, as the LR-SPR technique is sensitive and has a simple experimental setup, it can easily be applied for ABO blood group typing.

  1. Parity-Forbidden Transitions and Their Impact on the Optical Absorption Properties of Lead-Free Metal Halide Perovskites and Double Perovskites.

    Science.gov (United States)

    Meng, Weiwei; Wang, Xiaoming; Xiao, Zewen; Wang, Jianbo; Mitzi, David B; Yan, Yanfa

    2017-07-06

    Using density functional theory calculations, we analyze the optical absorption properties of lead (Pb)-free metal halide perovskites (AB 2+ X 3 ) and double perovskites (A 2 B + B 3+ X 6 ) (A = Cs or monovalent organic ion, B 2+ = non-Pb divalent metal, B + = monovalent metal, B 3+ = trivalent metal, X = halogen). We show that if B 2+ is not Sn or Ge, Pb-free metal halide perovskites exhibit poor optical absorptions because of their indirect band gap nature. Among the nine possible types of Pb-free metal halide double perovskites, six have direct band gaps. Of these six types, four show inversion symmetry-induced parity-forbidden or weak transitions between band edges, making them not ideal for thin-film solar cell applications. Only one type of Pb-free double perovskite shows optical absorption and electronic properties suitable for solar cell applications, namely, those with B + = In, Tl and B 3+ = Sb, Bi. Our results provide important insights for designing new metal halide perovskites and double perovskites for optoelectronic applications.

  2. High-pressure crystal growth and electromagnetic properties of 5d double-perovskite Ca3OsO6

    Science.gov (United States)

    Feng, Hai Luke; Shi, Youguo; Guo, Yanfeng; Li, Jun; Sato, Akira; Sun, Ying; Wang, Xia; Yu, Shan; Sathish, Clastin I.; Yamaura, Kazunari

    2013-05-01

    Single crystals of the osmium-containing compound Ca3OsO6 have been successfully grown under high-pressure conditions, for the first time. The crystal structure of Ca3OsO6 were characterized as an ordered double-perovskite structure of space group P21/n with the Ca and Os atoms being fully ordered at the perovskite B-site. The electromagnetic analysis shows that the crystal exhibits a semiconductor-like behavior below 300 K and undergoes an antiferromagnetic transition at 50 K.

  3. ABO Blood Group Genotyping by Real-time PCR in Kazakh Population

    Directory of Open Access Journals (Sweden)

    Pavel Tarlykov

    2014-12-01

    Full Text Available Introduction. ABO blood group genotyping is a new technology in hematology that helps prevent adverse transfusion reactions in patients. Identification of antigens on the surface of red blood cells is based on serology; however, genotyping employs a different strategy and is aimed directly at genes that determine the surface proteins. ABO blood group genotyping by real-time PCR has several crucial advantages over other PCR-based techniques, such as high rapidity and reliability of analysis. The purpose of this study was to examine nucleotide substitutions differences by blood types using a PCR-based method on Kazakh blood donors.Methods. The study was approved by the Ethics Committee of the National Center for Biotechnology. Venous blood samples from 369 healthy Kazakh blood donors, whose blood types had been determined by serological methods, were collected after obtaining informed consent. The phenotypes of the samples included blood group A (n = 99, B (n = 93, O (n = 132, and AB (n = 45. Genomic DNA was extracted using a salting-out method. PCR products of ABO gene were sequenced on an ABI 3730xl DNA analyzer (Applied Biosystems. The resulting nucleotide sequences were compared and aligned against reference sequence NM_020469.2. Real-time PCR analysis was performed on CFX96 Touch™ Real-Time PCR Detection System (BioRad.Results. Direct sequencing of ABO gene in 369 samples revealed that the vast majority of nucleotide substitutions that change the ABO phenotype were limited to exons 6 and 7 of the ABO gene at positions 261, 467, 657, 796, 803, 930 and 1,060. However, genotyping of only three of them (261, 796 and 803 resulted in identification of major ABO genotypes in the Kazakh population. As a result, TaqMan probe based real-time PCR assay for the specific detection of genotypes 261, 796 and 803 was developed. The assay did not take into account several other mutations that may affect the determination of blood group, because they have a

  4. A DFT+U investigation of hydrogen adsorption on the LaFeO3(010) surface

    NARCIS (Netherlands)

    Boateng, Isaac W.; Tia, Richard; Adei, Evans; Dzade, N.Y.; Catlow, C. Richard A.; de Leeuw, Nora H.

    2017-01-01

    The ABO3 perovskite lanthanum ferrite (LaFeO3) is a technologically important electrode material for nickel–metal hydride batteries, energy storage and catalysis. However, the electrochemical hydrogen adsorption mechanism on LaFeO3 surfaces remains under debate. In the present study, we have

  5. Perovskite oxide SrTiO3 as an efficient electron transporter for hybrid perovskite solar cells

    KAUST Repository

    Bera, Ashok

    2014-12-11

    In this work, we explored perovskite oxide SrTiO3 (STO) for the first time as the electron-transporting layer in organolead trihalide perovskite solar cells. The steady-state photoluminescence (PL) quenching and transient absorption experiments revealed efficient photoelectron transfer from CH3NH3PbI3-xClx to STO. Perovskite solar cells with meso-STO exhibit an open circuit voltage of 1.01 V, which is 25% higher than the value of 0.81 V achieved in the control device with the conventional meso-TiO2. In addition, an increase of 17% in the fill factor was achieved by tailoring the thickness of the meso-STO layer. We found that the application of STO leads to uniform perovskite layers with large grains and complete surface coverage, leading to a high shunt resistance and improved performance. These findings suggest STO as a competitive candidate as electron transport material in organometal perovskite solar cells.

  6. Perovskite oxide SrTiO3 as an efficient electron transporter for hybrid perovskite solar cells

    KAUST Repository

    Bera, Ashok; Wu, Kewei; Sheikh, Arif D.; Alarousu, Erkki; Mohammed, Omar F.; Wu, Tao

    2014-01-01

    In this work, we explored perovskite oxide SrTiO3 (STO) for the first time as the electron-transporting layer in organolead trihalide perovskite solar cells. The steady-state photoluminescence (PL) quenching and transient absorption experiments revealed efficient photoelectron transfer from CH3NH3PbI3-xClx to STO. Perovskite solar cells with meso-STO exhibit an open circuit voltage of 1.01 V, which is 25% higher than the value of 0.81 V achieved in the control device with the conventional meso-TiO2. In addition, an increase of 17% in the fill factor was achieved by tailoring the thickness of the meso-STO layer. We found that the application of STO leads to uniform perovskite layers with large grains and complete surface coverage, leading to a high shunt resistance and improved performance. These findings suggest STO as a competitive candidate as electron transport material in organometal perovskite solar cells.

  7. Association of ABO blood groups with diabetes mellitus

    African Journals Online (AJOL)

    2010-02-08

    Feb 8, 2010 ... We studied the association of ABO blood groups with DM type 2. Patients and methodology: It was ... dent diabetes mellitus (NIDDM or type 2), characterized by elevated insulin levels ... diabetic ketoacidosis. Sample size was ...

  8. Structural, magnetic and transport properties of Mn3.1Sn0.9 and Mn3.1Sn0.9N compounds

    International Nuclear Information System (INIS)

    Feng, W.J.; Li, D.; Ren, W.J.; Li, Y.B.; Li, W.F.; Li, J.; Zhang, Y.Q.; Zhang, Z.D.

    2007-01-01

    The cubic anti-perovskite Mn 3.1 Sn 0.9 N compound is prepared via nitrogenation of the hexagonal Mn 3.1 Sn 0.9 compound. A magnetic phase diagram of Mn 3.1 Sn 0.9 compound is constructed by analysis of data of its magnetic properties. For Mn 3.1 Sn 0.9 N compound, parasitic ferromagnetism exists in the temperature range of 5-370 K, besides a spin-reorientation at about 280 K. Mn 3.1 Sn 0.9 compound exhibits a metallic conducting behavior, while Mn 3.1 Sn 0.9 N displays a metal-nonmetal transition due to the electron localization caused by the static disorder. The differences of the physical properties between the both compounds, are discussed, in terms of the correlation of the hexagonal DO 19 and the cubic anti-perovskite structures, the reduction of the distances between Mn atoms, and the spin-pairing or charge transfer effect due to the electron donation by N 2p to Mn 3d states after introduction of N atoms into the interstitial sites of Mn 3.1 Sn 0.9 compound

  9. Compounds of the type Ba/sub 3/Bsup(II)M/sub 2/sup(V)O/sub 9/ with Bsup(II) = Mg, Ca, Sr, Ba, and Msup(V) = Nb, Ta

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S; Thumm, I; Herrmann, M [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1981-08-01

    The hexagonal perovskites Ba/sub 3/Bsup(II)M/sub 2/sup(V)O/sub 9/ (Msup(V) = Nb, Ta) crystallize with Bsup(II) = Mg, Ca in a 3 L structure (sequence (c)/sub 3/) and Bsup(II) = Sr in the hexagonal BaTiO/sub 3/ type (6 L; sequence (hcc)/sub 2/) with an 1:2 order for the B and M ions. Intensity calculations for Ba/sub 3/SrNb/sub 2/O/sub 9/ and Ba/sub 3/SrTa/sub 2/O/sub 9/ gave in the space group P6/sub 3//mmc a refined, intensity related R' value of 8.4% (Nb) and 9.0% (Ta) respectively. For Bsup(II) = Ba the perovskite Ba/sub 3/BaTa/sub 2/O/sub 9/ has an orthorhombic distorted 6 L structure and forms with Ba/sub 3/SrTa/sub 2/O/sub 9/ a continuous series of mixed crystals (Ba/sub 3/Srsub(1-x)Basub(x)Ta/sub 2/O/sub 9/). In the system Ba/sub 3/Srsub(1-x)Basub(x)Nb/sub 2/O/sub 9/ the range of existence of the hexagonal BaTiO/sub 3/ type is confined to the Sr richer end. The pure Ba compound posesses a proper structure type (5 L: Ba/sub 5/BaNb/sub 3/vacantOsub(13.5)vacantsub(1.5)).

  10. LSFM perovskites as cathodes for the electrochemical reduction of NO

    DEFF Research Database (Denmark)

    Kammer Hansen, K.; Skou, E.M.

    2005-01-01

    Six La0.6Sr0.4Fe1-xMnO3-delta (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0) perovskite compounds have been synthesised by the citric-acid route. The perovskites have been characterised by powder XRD and are shown to belong to the hexagonal crystal system. The perovskites are also evaluated by TG...... degrees C on a ceria based electrolyte. Only La0.6Sr0.4Fe0.8Mn0.2O3-delta (LSFM020) and La0.6Sr0.4FeO3-delta (LSFM000) show significant activity for the reduction of NO. This can probably be related to the high redox capacity of these compounds. The activity of the perovskites for the reduction of oxygen...... increases systematically with increasing iron content. The selectivity of the perovskites towards the reduction of NO with regard to the reduction of O-2 is highest at the lowest temperatures. (c) 2004 Published by Elsevier B.V....

  11. Polarized emission from CsPbX3 perovskite quantum dots

    Science.gov (United States)

    Wang, Dan; Wu, Dan; Dong, Di; Chen, Wei; Hao, Junjie; Qin, Jing; Xu, Bing; Wang, Kai; Sun, Xiaowei

    2016-06-01

    Compared to organic/inorganic hybrid perovskites, full inorganic perovskite quantum dots (QDs) exhibit higher stability. In this study, full inorganic CsPbX3 (X = Br, I and mixed halide systems Br/I) perovskite QDs have been synthesized and interestingly, these QDs showed highly polarized photoluminescence which is systematically studied for the first time. Furthermore, the polarization of CsPbI3 was as high as 0.36 in hexane and 0.40 as a film. The CsPbX3 perovskite QDs with high polarization properties indicate that they possess great potential for application in new generation displays with wide colour gamut and low power consumption.Compared to organic/inorganic hybrid perovskites, full inorganic perovskite quantum dots (QDs) exhibit higher stability. In this study, full inorganic CsPbX3 (X = Br, I and mixed halide systems Br/I) perovskite QDs have been synthesized and interestingly, these QDs showed highly polarized photoluminescence which is systematically studied for the first time. Furthermore, the polarization of CsPbI3 was as high as 0.36 in hexane and 0.40 as a film. The CsPbX3 perovskite QDs with high polarization properties indicate that they possess great potential for application in new generation displays with wide colour gamut and low power consumption. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01915c

  12. Mixed valent noble metal perovskites Ba/sub 3/B/sup 3 +/Pt/sub x/Ru/sub 2-x//sup 4. 5+/O/sub 9/

    Energy Technology Data Exchange (ETDEWEB)

    Moessner, B; Kemmler-Sack, S; Ehmann, A [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1982-04-01

    In perovskites of type Ba/sub 3/B/sup 3 +/Pt/sub x/Ru/sub 2-x//sup 4.5+/O/sub 9/ the ruthenium can be substituted by platinum up to x = 1. The compounds crystallize in a 1:2 ordered hexagonal BaTiO/sub 3/ structure (sequence (hcc)/sub 2/) with face connected Pt/sub x/Ru/sub 2-x/O/sub 9/ double octahedra. Intensity calculations on powder data of Ba/sub 3/YPt/sub 1/2/Ru/sub 3/2/O/sub 9/ (space group P6/sub 3//mmc) gave a refined, intensity related R' value of 8.6%. The vibrational spectroscopic and catalytic properties are reported.

  13. Complex-oxide multilayers by design: a treasure trove of unusual ferroic functionalities

    Science.gov (United States)

    Nakhmanson, Serge

    2015-03-01

    While inheriting most of the traits of their parents, layered variations of ABO3 perovskites allow for a number of additional channels for property manipulation and fine-tuning. Their remarkable flexibility toward structural and chemical modification can be exploited for the design of new and advanced functionalities not originally present in the parent ABO3 compounds. With the help of first-principles-based computational techniques, we have predicted intriguing electroactive behavior in layered-perovskite compounds of the Ruddlesden-Popper (RP) type. Specifically, we showed that Goldstone-like states (collective, close to zero frequency excitations, requiring practically no consumption of energy) can be induced in a PbSr2Ti2O7 RP superlattice, manifesting themselves as easy rotations of the in-plane polarization vector. Examination of a fictitious epitaxial Ba2TiO4 RP compound demonstrated that it exhibits an assortment of competing incommensurate distortions, including ones that promote in-plane polarization. In this presentation we highlight the unusual behavior of a RP Ba2ZrO4 structure, which has already been synthesized as a bulk ceramic. An investigation of the properties of a (fictitious) epitaxial thin-film variant of this material reveals that under compression it undergoes a transition into an incommensurate state, while under tension it shows hints of a Goldstone-like polar instability, which surprisingly occurs without the presence of a lone-pair active ions like Pb or Sn. In both cases, we observe anomalies in the planar static dielectric susceptibility of the system, with large dielectric response predicted for the phase displaying the Goldstone-like instability.

  14. Photovoltaic Effect of 2D Homologous Perovskites

    International Nuclear Information System (INIS)

    Jung, Mi-Hee

    2017-01-01

    Highlights: • The mixed perovskite was prepared by exposure of MAI gas on the BAPbI_4 film. • The increased dimensional perovskite shows a smaller band gap than 2D perovskite. • The mixed perovskite system shows the vertical crystal orientation. • The mixed perovskite cell exhibits the higher Jsc and FF than 2D perovskite cell. - Abstract: The controlled growth of mixed dimensional perovskite structures, (C_6H_5CH_2NH_2)(CH_3NH_3)_n_-_1Pb_nI_3_n_+_1, through the introduction of CH_3NH_3I molecule vapor into the two-dimensional perovskite C_6H_5CH_2NH_3PbI_4 structure and its application in photovoltaic devices is reported. The dimensionality of (C_6H_5CH_2NH_2)(CH_3NH_3)_n_-_1Pb_nI_3_n_+_1 is controlled using the exposure time to the CH_3NH_3I vapor on the C_6H_5CH_2NH_3PbI_4 perovskite film. As the stacking of the lead iodide lattice increases, the crystallographic planes of the inorganic perovskite compound exhibit vertical growth in order to facilitate efficient charge transport. Furthermore, the devices have a smaller band gap, which offers broader absorption and the potential to increase the photocurrent density in the solar cell. As a result, the photovoltaic device based on the (C_6H_5CH_2NH_2)(CH_3NH_3)_n_-_1Pb_nI_3_n_+_1 perovskite exhibits a power conversion efficiency of 5.43% with a short circuit current density of 14.49 mA cm"−"2, an open circuit voltage of 0.85 V, and a fill factor of 44.30 for the best power conversion efficiency under AM 1.5G solar irradiation (100 mW cm"−"2), which is significantly higher than the 0.34% of the pure two-dimensional BAPbI_4 perovskite-based solar cell.

  15. Nature of potential barrier in (Ca 1/4,Cu 3/4)TiO 3 polycrystalline perovskite

    Science.gov (United States)

    Marques, V. P. B.; Bueno, P. R.; Simões, A. Z.; Cilense, M.; Varela, J. A.; Longo, E.; Leite, E. R.

    2006-04-01

    The nonohmic electrical features of (Ca 1/4,Cu 3/4)TiO 3 perovskite ceramics, which have very strong gigantic dielectric is believed originate from potential barriers at the grain boundaries. In the present study, we used the admittance and impedance spectroscopy technique to investigate (Ca 1/4,Cu 3/4)TiO 3 perovskite ceramics with low nonohmic electrical properties. The study was conducted under two different conditions: on as-sintered ceramics and on ceramics thermally treated in an oxygen-rich atmosphere. The results confirm that thermal treatment in oxygen-rich atmospheres influence the nonohmic properties. Annealing at oxygen-rich atmospheres improve the nonohmic behavior and annealing at oxygen-poor atmospheres decrease the nonohmic properties, a behavior already reported for common metal oxide nonohmic devices and here firstly evidenced for the (Ca 1/4,Cu 3/4)TiO 3 perovskite related materials. The results show that oxygen also influences the capacitance values at low frequencies, a behavior that is indicative of the Schottky-type nature of the potential barrier.

  16. Optically stimulated luminescence properties of Tm{sup 3+} doped KMgF{sub 3} fluoro perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, L.; Marcazzo, J. [UNCPBA, Facultad de Ciencias Exactas, Instituto de Fisica Arroyo Seco, Gral. Pinto 399, B7000GHG Tandil, Buenos Aires (Argentina); Perez C, L.; Cruz Zaragoza, E. [UNAM, Instituto de Ciencias Nucleares, Apdo. Postal 70543, 04510 Ciudad de Mexico (Mexico); Martinez O, S. A., E-mail: jmarcass@exa.unicen.edu.ar [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, Av. Central del Norte 39-115, 150003 Tunja, Bocaya (Colombia)

    2017-10-15

    In this work the optically stimulated luminescence (OSL) properties of undoped and Tm{sup 3+} doped KMgF{sub 3} fluoro perovskite have been investigated for the first time. OSL efficiency for stimulation with different wavelengths has been analyzed for each compound. The maximum OSL emission was found with blue light stimulation. The radioluminescence (Rl) spectra have shown two emission peaks at 455 and 360 nm, which can be ascribed to the {sup 1}D{sub 2}-{sup 3}F{sub 4} and {sup 1}D{sub 2}-{sup 3}H{sub 6} transitions of the Tm{sup 3+} cations. It has been found that doping with Thulium 0.5 mol % renders the most intense OSL emission. Furthermore, several dosimetric properties such as OSL response as a function of dose, reproducibility of the OSL signal after several cycles of irradiation readout and the minimum detectable dose have been investigated. Finally, the OSL response of KMgF{sub 3}: Tm{sup 3+} has been compared to that of commercial Al{sub 2}O{sub 3}:C and the possible application of this fluoro perovskite to OSL dosimetry has been evaluated. (Author)

  17. Temperature dependent XAFS studies of local atomic structure of the perovskite-type zirconates

    International Nuclear Information System (INIS)

    Vedrinskii, R. V.; Lemeshko, M. P.; Novakovich, A. A.; Nazarenko, E. S.; Nassif, V.; Proux, O.; Joly, Y.

    2006-01-01

    Temperature dependent preedge and extended x-ray absorption fine structure measurements at the Zr K edge for the perovskite-type zirconates PbZr 0.515 Ti 0.485 O 3 (PZT), PbZrO 3 (PZ), and BaZrO 3 are performed. To carry out a more accurate study of the weak reconstruction of the local atomic structure we employed a combination of two techniques: (i) analysis of the preedge fine structure, and (ii) analysis of the Fourier transform of the difference between χ(k) functions obtained at different temperatures. A detailed investigation of local atomic structure in the cubic phase for all the crystals is also performed. It is shown that neither the displacive nor the order-disorder model can describe correctly the changes of local atomic structure during phase transitions in PZ and PZT. A spherical model describing the local atomic structure of perovskite-type crystals suffering structural phase transitions is proposed

  18. Low-Temperature Synthesis and Gas Sensitivity of Perovskite-Type LaCoO3 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Lorenzo Gildo Ortiz

    2014-01-01

    Full Text Available LaCoO3 nanoparticles with perovskite-type structure were prepared by a microwave-assisted colloidal method. Lanthanum nitrate, cobalt nitrate, and ethylenediamine were used as precursors and ethyl alcohol as solvent. The thermal decomposition of the precursors leads to the formation of LaCoO3 from a temperature of 500°C. The structural, morphological, and compositional properties of LaCoO3 nanoparticles were studied in this work by X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and atomic force microscopy (AFM. Pellets were manufactured in order to test the gas sensing properties of LaCoO3 powders in carbon monoxide (CO and propane (C3H8 atmospheres. Agglomerates of nanoparticles with high connectivity, forming a porous structure, were observed from SEM and TEM analysis. LaCoO3 pellets presented a high sensitivity in both CO and C3H8 at different concentrations and operating temperatures. As was expected, sensitivity increased with the gas concentration and operation temperature increase.

  19. Hexagonal perovskites with cationic vacancies. 5. Structure determination on H-Ba/sub 2/Lusub(2/3)vacantsub(1/3)WO/sub 6/ - a novel rhombohedral stacking polytype with 18 layers

    Energy Technology Data Exchange (ETDEWEB)

    Wischert, W; Schittenhelm, H J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

    1979-01-01

    Compounds of type Ba/sub 2/Bsub(2/3)sup(III)vacantsub(1/3)Wsup(VI)O/sub 6/ with Bsup(III) = Gd-Lu, Y are polymorphic. They crystallize in a cubic 1:1 ordered perovskite structure and in a new rhombohedral perovskite stacking polytype of 18 L respectively. By intensity calculations out of the three possible stacking sequences (4)(2), (5)(1) and (3)1(1)1 (all space group R3m) the sequence (5)(1) can be selected. For H-Ba/sub 2/Lusub(2/3)vacant sub(1/3)WO/sub 6/ the refined R' factor is 14.1%. The structure contains groups of three octahedra connected with another by common faces which are linked with each other by three corner sharing octahedra. In the block of three face sharing octahedra the central octahedral lattice site is vacant, the two outer positions are occupied by tungsten atoms. According to this distribution a direct contact of occupied face sharing octahedra is absent.

  20. A Study of Inverted-Type Perovskite Solar Cells with Various Composition Ratios of (FAPbI31−x(MAPbBr3x

    Directory of Open Access Journals (Sweden)

    Lung-Chien Chen

    2016-10-01

    Full Text Available This work presents mixed (FAPbI31−x(MAPbBr3x perovskite films with various composition ratios, x (x = 0–1, which are formed using the spin coating method. The structural, optical, and electronic behaviors of the mixed (FAPbI31−x(MAPbBr3x perovskite films are discussed. A device with structure glass/indium tin oxide (ITO/poly(3,4-ethylenedioxythiophene polystyrene sulfonate (PEDOT:PSS/mixed perovskite/C60/BCP/Ag was fabricated. The mixed perovskite film was an active light-harvesting layer. PEDOT:PSS was a hole transporting layer between the ITO and perovskite. Both C60 and bathocuproine (BCP were electron transporting layers. MAPbBr3 was added to FAPbI3 with a composition ratio of x = 0.2, stabilizing the perovskite phase, which exhibited a uniform and dense morphology. The optimal device exhibited band matching with C60, resulting in a low series resistance (Rsh and a high fill factor (FF. Therefore, the device with composition (FAPbI31−x(MAPbBr3x and x = 0.2 exhibited outstanding performance.

  1. Characterization of cathode materials SrCoO3 and La0,2Sr0,8CoO3 for use in solid oxide fuel cells (SOFC); Caracterizacao de materiais catodicos SrCoO3 e La0,2Sr0,8CoO3 para aplicacao em celulas a combustivel de oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, G.O.; Aquino, F.M; Silva, R.M.; Medeiros, I.D.M. de, E-mail: gabriela.galvao@cear.ufpb.br [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil)

    2016-07-01

    Mixed oxide ceramics with chemical structure of ABO{sub 3} type are promising candidates for cathodes of solid oxide fuel cells (SOFC) for performing well on the electrical conductivity and thermal stability. Various methods of preparation have been studied and used for the synthesis of these materials. In this study, SrCoO{sub 3} and La{sub 0,2}Sr{sub 0,8}CoO{sub 3} perovskites were synthesized using gelatin as directing agent with the purpose of producing homogeneous and porous particles. The powders obtained at 350 ° C / 2 h were calcined at 600, 800 and 1000 ° C for 4 hours and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that gelatin is a good polymerizing agent for metal ions as the material showed characteristic peaks of perovskite, with good porosity and uniformity. Furthermore, the method of synthesis employed has advantages related to cost and toxicity, which are very low. (author)

  2. Patterning and photoluminescent properties of perovskite-type organic/inorganic hybrid luminescent films by soft lithography

    Science.gov (United States)

    Cheng, Z. Y.; Wang, Z.; Xing, R. B.; Han, Y. C.; Lin, J.

    2003-07-01

    Perovskite-type organic/inorganic hybrid layered compound (C 6H 5C 2H 4NH 3) 2PbI 4 was synthesized. The patterning of (C 6H 5C 2H 4NH 3) 2PbI 4 thin films on silicon substrate was realized by the micromolding in capillaries (MIMIC) process, a kind of soft lithography. Bright green luminescent stripes with different widths (50, 15, 0.8 μm) have been obtained. The structure and optical properties of (C 6H 5C 2H 4NH 3) 2PbI 4 films were characterized by X-ray diffraction (XRD), UV/Vis absorption and photoluminescence excitation and emission spectra, respectively. It is shown that the organic-inorganic layered (C 6H 5C 2H 4NH 3) 2PbI 4 film was c-axis oriented, paralleling to the substrate plane. Green exciton emission at 525 nm was observed in the film, and the explanations for it were given.

  3. Early humoral-mediated graft injuries in ABO-incompatible kidney transplantation in human beings.

    Science.gov (United States)

    Sekijima, M; Shimizu, A; Ishii, Y; Kudo, S; Horita, S; Nakajima, I; Fuchinoue, S; Teraoka, S

    2010-04-01

    Acute humoral rejection is the most important risk factor for early graft loss in ABO-incompatible (ABO-i) renal transplantation (RTx) and is present from the early period after RTx. However, the characteristics of early humoral-mediated graft injury are pathologically uncertain. To analyze tissue from 10 protocol graft biopsies performed in 10 patients within 30 days post-RTx to clarify the pathologic features of early humoral-mediated graft injuries in ABO-i RTx. Pathologic findings were examined using light and electron microscopy and immunofluorescence studies for C4d. Protocol biopsies were performed within 30 days after RTx in the absence of an episode of dysfunction (creatinine concentration 1.21-1.81 mg/dL). The immunofluorescence study demonstrated C4d deposition in peritubular and glomerular capillaries. Acute glomerulitis with infiltration of mononuclear cells and neutrophils was observed in 3 patients. Furthermore, glomerulitis was accompanied by endothelial cell injuries, widening of subendothelial spaces with a double-contoured glomerular basement membrane, and mesangiolysis. In ABO-i RTx, early humoral-mediated graft injuries were observed in approximately 30% of patients despite normal graft function. They were characterized by C4d deposition and glomerular capillary injury. These findings suggest that renal glomeruli are the first site of graft injury by anti-A or anti-B blood type antibody with complement activation in ABO-i RTx.

  4. Room temperature three-photon pumped CH3NH3PbBr3 perovskite microlasers

    Science.gov (United States)

    Gao, Yisheng; Wang, Shuai; Huang, Can; Yi, Ningbo; Wang, Kaiyang; Xiao, Shumin; Song, Qinghai

    2017-03-01

    Hybrid lead halide perovskites have made great strides in next-generation light-harvesting and light emitting devices. Recently, they have also shown great potentials in nonlinear optical materials. Two-photon absorption and two-photon light emission have been thoroughly studied in past two years. However, the three-photon processes are rarely explored, especially for the laser emissions. Here we synthesized high quality CH3NH3PbBr3 perovskite microstructures with solution processed precipitation method and studied their optical properties. When the microstructures are pumped with intense 1240 nm lasers, we have observed clear optical limit effect and the band-to-band photoluminescence at 540 nm. By increasing the pumping density, whispering-gallery-mode based microlasers have been achieved from CH3NH3PbBr3 perovskite microplate and microrod for the first time. This work demonstrates the potentials of hybrid lead halide perovskites in nonlinear photonic devices.

  5. Making and Breaking of Lead Halide Perovskites

    KAUST Repository

    Manser, Joseph S.

    2016-02-16

    kinetics can be tailored to yield improved thin film homogeneity. Because degradation of the as-formed perovskite film is in many ways analogous to its initial formation, the same suite of monitoring techniques reveals the moisture-induced transformation of low band gap methylammonium lead iodide (CH3NH3PbI3) to wide band gap hydrate compounds. The rate of degradation is increased upon exposure to light. Interestingly, the hydration process is reversible under certain conditions. This facile formation and subsequent chemical lability raises the question of whether CH3NH3PbI3 and its analogues are thermodynamically stable phases, thus posing a significant challenge to the development of transformative perovskite photovoltaics. Adequately addressing issues of structural and chemical stability under real-world operating conditions is paramount if perovskite solar cells are to make an impact beyond the benchtop. Expanding our fundamental knowledge of lead halide perovskite formation and degradation pathways can facilitate fabrication of stable, high-quality perovskite thin films for the next generation of photovoltaic and light emitting devices.

  6. Gene frequencies of ABO and Rh blood groups in Nigeria: A review ...

    African Journals Online (AJOL)

    Background: ABO and Rhesus factor (Rh) blood type are germane in human life in genetics and clinical studies. Aim of the study: The review was undertaken with the objective to provide data on the ABO and Rh(D) blood group distribution and gene frequency across Nigeria which is vital for blood transfusion and ...

  7. ABO incompatibility hemolytic disease following exchange transfusion 96 newborn

    Directory of Open Access Journals (Sweden)

    Khatami S.F

    2007-09-01

    Full Text Available Background: ABO incompatibility hemolytic disease of the newborn is a common cause of clinical jaundice and causes two-thirds of the hemolytic disease in newborns. This study was undertaken to determine the frequency of ABO incompatibility hemolytic disease and its complications in newborns undergoing exchange transfusion.Methods: This prospective and descriptive study was performed in jaundiced newborn infants during a three-year period. Inclusion criteria were: maternal blood type O, newborn blood type A or B, rising indirect hyperbilirubinemia in the first two days of life, positive immunohematologic test for newborns and exchange transfusion. Exclusion criteria were: incomplete information, other accompanying diseases that induce hyperbilirubinemia. All newborn infants received phototherapy before and after exchange transfusion. We did not use intravenous immunoglobulin, hemoxygenase inhibitor drugs and blood products before exchange transfusion.Results: Double-volume exchange transfusion via umbilical cord catheter was performed in 96 patients, 19 (20% of whom suffered from ABO incompatibility. Of these 19 newborns, two-thirds (13 were preterm infants. The minimum level of serum bilirubin was 10 mg/dl and the maximum serum bilirubin level was 35 mg/dl. In six patients (32% serum bilirubin levels were >25mg/dl. The most common blood group was type A for newborns. Immunohematologic tests were positive in 84% of the mothers. ABO incompatibility hemolytic disease was the fourth and second most common reasons for blood exchange transfusion in preterm and term infants, respectively. Laboratory complications were more common than clinical complications. The etiology of 48% of the alloimmunization and 42% of the hemolytic disease in these newborns was ABO incompatibility.Conclusions: Mothers with blood group O and newborns with blood group A or B with positive immunohematologic tests in first hours of life are at high risk for hemolytic disease

  8. General working principles of CH3NH3PbX3 perovskite solar cells.

    Science.gov (United States)

    Gonzalez-Pedro, Victoria; Juarez-Perez, Emilio J; Arsyad, Waode-Sukmawati; Barea, Eva M; Fabregat-Santiago, Francisco; Mora-Sero, Ivan; Bisquert, Juan

    2014-02-12

    Organometal halide perovskite-based solar cells have recently realized large conversion efficiency over 15% showing great promise for a new large scale cost-competitive photovoltaic technology. Using impedance spectroscopy measurements we are able to separate the physical parameters of carrier transport and recombination in working devices of the two principal morphologies and compositions of perovskite solar cells, viz. compact thin films of CH3NH3PbI(3-x)Clx and CH3NH3PbI3 infiltrated on nanostructured TiO2. The results show nearly identical spectral characteristics indicating a unique photovoltaic operating mechanism that provides long diffusion lengths (1 μm). Carrier conductivity in both devices is closely matched, so that the most significant differences in performance are attributed to recombination rates. These results highlight the central role of the CH3NH3PbX3 semiconductor absorber in carrier collection and provide a new tool for improved optimization of perovskite solar cells. We report for the first time a measurement of the diffusion length in a nanostructured perovskite solar cell.

  9. Thermoelectric Properties of the Perovskite-Type Oxide SrTi1-xNbxO3 Synthesized by Solid-State Reaction Method

    Science.gov (United States)

    Khan, Tamal Tahsin; Ur, Soon-Chul

    2018-05-01

    The perovskite-type oxide materials SrTi1-xNbxO3 (X = .02, 0.03, 0.04, 0.05 and 0.06) were synthesized by the conventional solid-state reaction method and the thermoelectric properties in terms of Nb doping at the B-site in the oxides were investigated in this study. The formation of single phase cubic perovskite structure was confirmed by the powder X-ray diffraction analysis. Negative conduction is shown in this materials system. The absolute value of Seebeck coefficient increased with increasing temperature over the measured temperature. The electrical conductivity decreased monotonically with increasing temperature, showing degenerating conduction behavior. The thermal conductivity, k, generally decreased with increasing temperature. The power factor increased with increasing Nb-doping level up to 5.0 mol% and hence the dimensionless figure of merit ZT, increased up to 5.0 mol%. The maximum ZT value was observed for SrTi0.95Nb0.05O3 at 873 K.

  10. Enhanced Crystalline Phase Purity of CH3NH3PbI3-xClx Film for High-Efficiency Hysteresis-Free Perovskite Solar Cells.

    Science.gov (United States)

    Yang, Yingguo; Feng, Shanglei; Xu, Weidong; Li, Meng; Li, Li; Zhang, Xingmin; Ji, Gengwu; Zhang, Xiaonan; Wang, Zhaokui; Xiong, Yimin; Cao, Liang; Sun, Baoquan; Gao, Xingyu

    2017-07-12

    Despite rapid successful developments toward promising perovskite solar cells (PSCs) efficiency, they often suffer significant hysteresis effects. Using synchrotron-based grazing incidence X-ray diffraction (GIXRD) with different probing depths by varying the incident angle, we found that the perovskite films consist of dual phases with a parent phase dominant in the interior and a child phase with a smaller (110) interplanar space (d (110) ) after rapid thermal annealing (RTA), which is a widely used post treatment to improve the crystallization of solution-processed perovskite films for high-performance planar PSCs. In particular, the child phase composition gradually increases with decreasing depth till it becomes the majority on the surface, which might be one of the key factors related to hysteresis in fabricated PSCs. We further improve the crystalline phase purity of the solution-processed CH 3 NH 3 PbI 3-x Cl x perovskite film (referred as g-perovskite) by using a facile gradient thermal annealing (GTA), which shows a uniformly distributed phase structure in pinhole-free morphology with less undercoordinated Pb and I ions determined by synchrotron-based GIXRD, grazing incidence small-angle X-ray scattering, scanning electron microscopy, and X-ray photoelectron spectroscopy. Regardless of device structures (conventional and inverted types), the planar heterojunction PSCs employing CH 3 NH 3 PbI 3-x Cl x g-perovskite films exhibit negligible hysteresis with a champion power conversion efficiency of 17.04% for TiO 2 -based conventional planar PSCs and 14.83% for poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS)-based inverted planar PSCs. Our results indicate that the crystalline phase purity in CH 3 NH 3 PbI 3-x Cl x perovskite film, especially in the surface region, plays a crucial role in determining the hysteresis effect and device performance.

  11. Characterization of cathode materials SrCoO3 and La0,2Sr0,8CoO3 for use in solid oxide fuel cells (SOFC)

    International Nuclear Information System (INIS)

    Galvao, G.O.; Aquino, F.M; Silva, R.M.; Medeiros, I.D.M. de

    2016-01-01

    Mixed oxide ceramics with chemical structure of ABO_3 type are promising candidates for cathodes of solid oxide fuel cells (SOFC) for performing well on the electrical conductivity and thermal stability. Various methods of preparation have been studied and used for the synthesis of these materials. In this study, SrCoO_3 and La_0_,_2Sr_0_,_8CoO_3 perovskites were synthesized using gelatin as directing agent with the purpose of producing homogeneous and porous particles. The powders obtained at 350 ° C / 2 h were calcined at 600, 800 and 1000 ° C for 4 hours and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that gelatin is a good polymerizing agent for metal ions as the material showed characteristic peaks of perovskite, with good porosity and uniformity. Furthermore, the method of synthesis employed has advantages related to cost and toxicity, which are very low. (author)

  12. Computational study on oxynitride perovskites for CO_2 photoreduction

    International Nuclear Information System (INIS)

    Hafez, Ahmed M.; Zedan, Abdallah F.; AlQaradawi, Siham Y.; Salem, Noha M.; Allam, Nageh K.

    2016-01-01

    Highlights: • Oxynitride perovskites are investigated for photoelectrochemical CO_2 reduction. • They have small electron and hole effective masses, rendering higher mobility. • The effect of cation size on the band gap is investigated and discussed. • W-doping allowed the selection of specific CO_2 reduction products. - Abstract: The photocatalytic conversion of CO_2 into chemical fuels is an attractive route for recycling this greenhouse gas. However, the large scale application of such approach is limited by the low selectivity and activity of the currently used photocatalysts. Using first principles calculations, we report on the selection of optimum oxynitride perovskites as photocatalysts for photoelectrochemical CO_2 reduction. The results revealed six perovskites that perfectly straddle the carbon dioxide redox potential; namely, BaTaO_2N, SrTaO_2N, CaTaO_2N, LaTiO_2N, BaNbO_2N, and SrNbO_2N. The electronic structure and the effective mass of the selected candidates are discussed in details, the partial and total density of states illustrated the orbital hybridization and the contribution of each element in the valence and conduction band minima. The effect of cation size in the ABO_2N perovskites on the band gap is investigated and discussed. The optical properties of the selected perovskites are calculated to account for their photoactivity. Moreover, the effect of W doping on improving the selectivity of perovskites toward specific hydrocarbon product (methane) is discussed in details. This study reveals the promising optical and structural properties of oxynitride perovskite candidates for CO_2 photoreduction.

  13. Oxygen perovskites of type Ba/sub 3/Bsup(III)RuIrO/sub 9/

    Energy Technology Data Exchange (ETDEWEB)

    Duerrschmidt, E; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1980-11-01

    The black perovskites Ba/sub 3/Bsup(III)RuIrO/sub 9/ with Bsup(III) = La, Nd, Sm, Gd, Dy, Er, Yb, In, Sc are isotypic. They crystallize in a hexagonal BaTiO/sub 3/ structure (sequence (hcc)/sub 2/). The mean oxydation state of the noble metal ions is +4.5.

  14. Raman spectra of MgSiO3 . 10% Al2O3-perovskite at various pressures and temperatures

    International Nuclear Information System (INIS)

    Liu Lingun; Irifune, T.

    1995-01-01

    Variations of Raman spectra of MgSiO 3 . 10% Al 2 O 3 -perovskite were investigated up to about 270 kbar at room temperature and in the range 108-425 K at atmospheric pressure. Like MgSiO 3 -perovskite, the Raman frequencies of MgSiO 3 . 10% Al 2 O 3 -perovskite increase nonlinearly with increasing pressure and decrease linearly with increasing temperature within the experimental uncertainties and the range investigated. A comparison of these data with those of MgSiO 3 -perovskite suggests that MgSiO 3 . 10% Al 2 O 3 -perovskite is slightly more compressible than MgSiO 3 -perovskite, and that the volume thermal expansion for MgSiO 3 . 10% Al 2 O 3 -perovskite is also slightly greater than that for MgSiO 3 -perovskite. (orig.)

  15. Performance Improvement of CH3NH3PbI3 Perovskite Solar Cell by CH3SH Doping

    Directory of Open Access Journals (Sweden)

    Hong Li

    2016-03-01

    Full Text Available Organometal halide perovskites have recently emerged as an appealing candidate in photovoltaic devices due to their excellent properties. Therefore, intense efforts have been devoted to find the ideal organics for perovskite solar cells. In response, we investigate the doping effect of CH3SH organic on the structure and related performance of a CH3NH3PbI3 perovskite solar cell, via in situ synchrotron- based grazing incidence X-ray diffraction (GIXRD, together with scanning electron microscopy (SEM. In situ GIXRD investigations clearly illustrated the transformation and modification of the perovskite structure induced by the organic dopant, which subsequently led to the enhance‐ ment of the power conversion efficiency of fabricated solar cells. Notably, nanoporous morphology and nanocrystal‐ line structures were discovered in the perovskite film by SEM; they were also confirmed by the increase in broad‐ ening peaks/features in the GIXRD measurements. Overall, our study may ultimately result in an attractive strategy for the fabrication of high performance perovskite solar cells.

  16. The relationship between ABO/rhesus blood groups and type 2 ...

    African Journals Online (AJOL)

    Blood samples were collected from the patients after consent had been obtained. The samples were tested for ABO and Rh blood groups, using the Beth-Vincent and Simonin-Michon methods. The allele frequencies were calculated according to the Bernstein formulas. Results: The χ2 test results showed that there was no ...

  17. Electrochemical performance of the rare-earth perovskite-type oxide La0.6Sr0.4Co0.2Fe0.8O3 as negative electrode material for Ni/oxide rechargeable batteries

    Directory of Open Access Journals (Sweden)

    John Henao

    2017-08-01

    Full Text Available Abstract In this paper, the perovskite-type oxide La0.6Sr0.4Co0.2Fe0.8O3 was evaluated as a novel negative electrode material for Ni/oxide rechargeable batteries. The structure and morphology of the as-prepared powder was studied by scanning electron microscopy and X-ray diffraction. The electrochemical performance of the perovskite-type oxide was investigated using chronopotentiometric, chronoamperometric and potentiodynamic polarization techniques. The maximum discharge capacity values of the perovskite-type electrodes were obtained during the first three cycles (51, 172 and 462 mAh g−1 at 298, 313 and 333 K, respectively. The maximum adsorption capability of hydrogen in the perovskite-type electrode was 1.72% wt. hydrogen at a current rate of 125 mA g−1, 333 K and 6 M KOH. The cycling ability was fairly good with 64% capacity conservation after 20 cycles at 333 K. The electrochemical evaluation was also performed using different electrolyte concentrations; interestingly, the maximum discharge capacity of the perovskite-type electrodes increased in a linear-like manner with the incremental changes in electrolyte concentration. The hydrogen diffusion coefficient and exchange current density were also estimated to discuss the kinetics of the process.

  18. O3 perovskite ceramic

    Indian Academy of Sciences (India)

    The prepared sample remains as double phases with the perovskite struc- ture. The structure ... Ferroelectric oxides with perovskite structure are the subject of many investigations. ... in optical devices and heterojunction solar cells. 1765 ...

  19. Magnetisation and AC susceptibility studies of La1-xSrxFe0.8Cr0.2O3-δ (0.0perovskites

    International Nuclear Information System (INIS)

    Ferreira, L.P.; Cruz, M.M.; Ramos, T.; Sa, M.A.; Carvalho, M.D.; Godinho, M.

    2007-01-01

    Magnetisation and AC magnetic susceptibility measurements have been performed in the perovskite-type compounds La 1-x Sr x Fe 0.8 Cr 0.2 O 3-δ (x=0.2, 0.4, 0.6 and 0.8). All compounds show an overall antiferromagnetic behaviour mainly attributed to predominant Fe 3+ -O-Fe 3+ interactions. For 0.2 ord . The coexistence of AFM and FM interactions leads to reentrant magnetic behaviour for the x=0.4 compound and to spin-glass like behaviour for x=0.8. Between x=0.6 and 0.8, the similar magnetic moments found in the paramagnetic region indicate that the Fe/Cr valences do not change significantly, pointing towards an increased role for oxygen vacancy formation in the charge compensation mechanism

  20. Gd0.6Sr0.4Fe0.8Co0.2O3-δ: A novel type of SOFC cathode

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent; Søgaard, Martin; Mogensen, Mogens Bjerg

    2007-01-01

    The fabrication and electrochemical activity of a type of solid oxide fuel cell (SOFC) cathode is described in this paper. In search of new cathodes a Gd0.6Sr0.4Fe0.8Co0.2O3-delta compound was synthesized using the glycine-nitrate method. It turned out that this was a two-phase compound consisting...... of two perovskite phases, a cubic and an orthorhombic phase, as shown by Rietveld refinements. These two phases were synthesized and a cone-shaped electrode study was undertaken. It was shown that the composite cathode had an electrochemical activity superior to that of the two single-phase perovskites......, indicating that the unique microstructure of this type of cathode is essential for achieving high electrochemical activity toward the reduction of oxygen in a SOFC....

  1. Desensitization for ABO incompatible kidney transplantation: Experience of a single center in Brazil. ABO incompatible kidney transplantation

    Directory of Open Access Journals (Sweden)

    Maria Cristina Ribeiro Castro

    2017-12-01

    Objective: To analyze the patient and the graft survival of the first cohort of Brazilian patients receiving ABO-incompatible transplants. Patients and Methods: From October 2012 to June 2016, we performed 10 ABO incompatible kidney transplantation (KT procedures from a living donor. The desensitization protocol was based on rituximab and PP. All patients received induction with Thymoglobulin and long-term steroids. Tacrolimus and mycophenolate sodium were initiated at the time of desensitization and continued after the transplant. Pre-transplant agglutinin titers varied from 1/32 to 1/512. Five patients also presented anti-HLA specific antibodies, being three T and B positive FCXM at baseline. Results: After a mean follow-up of 30 ( ± 13 months, all patients are alive. One patient lost the graft due to cellular rejection that occurred after reduction of immunosuppressive therapy for an aggressive HPV-related vulvar cancer. The mean serum creatinine concentration is 1.4 ± 0.5 mg/dl. Three episodes of rejection occurred in 3 patients: two cellular and one anti-HLA mediated. Conclusion: Desensitization with Rituximab and PP allowed us to perform transplants from living donors to ABO incompatible recipients in a Brazilian population with good results, even in highly-sensitized patients and in those presenting high anti-ABO agglutinin titers.

  2. Structural properties, electric response and electronic feature of BaSnO3 perovskite

    International Nuclear Information System (INIS)

    Cuervo Farfan, J.; Arbey Rodriguez, J.; Fajardo, F.; Vera Lopez, E.; Landinez Tellez, D.A.; Roa-Rojas, J.

    2009-01-01

    It has been observed that the semiconducting compound SnO 2 presents very good results as gas sensor. One important development has been performed to study perovskite oxides for this relevant application. One oxide material which constitutes an excellent candidate for this technological application is BaSnO 3 . Polycrystalline samples with single phase of BaSnO 3 were synthesized by using the solid state reaction method. Samples were characterized structurally by means of X-ray diffraction (XRD) technique. Rietveld refinement, by using the GSAS code, reveals that this material synthesizes in a cubic perovskite, space group Pm3m (no. 221), with lattice parameter 4.1190(3)A. Electric response was examined through the impedance spectroscopy technique. Results of Bode diagram, from an equivalent circuit, evidence the semiconductor character of material. We carried out a theoretical study by means of the calculation of the bands diagram and the density of states of the BaSnO 3 . Calculation was performed by employing the density functional theory (DFT), with the generalized gradient approach (GGA). DFT theory permitted to establish that BaSnO 3 material has an indirect semiconducting behavior. The calculated gap for this perovskite-like stagnate is at least 0.4 eV. Bulk modulus for material was also determined to be 132 GPa.

  3. Clinical evaluation of the endothelial tie-2 crossmatch in ABO compatible and ABO incompatible renal transplants.

    Science.gov (United States)

    Kafetzi, Maria L; Boletis, John N; Melexopoulou, Christine A; Tsakris, Athanassios; Iniotaki, Aliki G; Doxiadis, Ilias I N

    2013-11-01

    The necessity of detection of other than the classical major histocompatibility complex (MHC) and MHC class I-related chain A (MICA) directed antibodies prior to organ transplantation has already been repeatedly reported. A commercial flow cytometric endothelial crossmatch (CM) using isolated peripheral blood tie-2 positive cells provides a tool to detect non-MHC antibodies in addition to antibodies directed to MHC class I and II. The vast majority of circulating tie-2 positive cells expresses HLA-DR but not the A, B blood group antigens. Tie-2 cells are circulating surrogate endothelial cells. In this retrospective study we evaluated the endothelial CM in 51 renal transplantations, 30 with ABO compatible grafts and 21 with ABO incompatible grafts. Fifteen of the ABO compatible recipients (group A) developed unexplained rejection episodes (RE) while the remaining 15 had no RE (group B). Five cases of group A and none of group B had a positive tie-2 CM before transplantation (p=0.042). A positive tie-2 CM was also correlated with graft failure in ABO compatible transplants (p=0.02). No significant correlation was found between a positive pre-transplant tie-2 CM and RE in the ABO incompatible group. This study strongly suggest that a positive tie-2 CM may predict post-transplantation complications in ABO compatible grafts while negative reactions are not predictive. The test is not significantly correlated with RE in ABO incompatible grafts possibly due to applied desensitization. Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  4. High-pressure crystal growth and electromagnetic properties of 5d double-perovskite Ca3OsO6

    International Nuclear Information System (INIS)

    Feng, Hai Luke; Shi, Youguo; Guo, Yanfeng; Li, Jun; Sato, Akira; Sun, Ying; Wang, Xia; Yu, Shan; Sathish, Clastin I.; Yamaura, Kazunari

    2013-01-01

    Single crystals of the osmium-containing compound Ca 3 OsO 6 have been successfully grown under high-pressure conditions, for the first time. The crystal structure of Ca 3 OsO 6 were characterized as an ordered double-perovskite structure of space group P2 1 /n with the Ca and Os atoms being fully ordered at the perovskite B-site. The electromagnetic analysis shows that the crystal exhibits a semiconductor-like behavior below 300 K and undergoes an antiferromagnetic transition at 50 K. - Graphical Abstract: Schematic image of crystal structure of Ca 3 OsO 6 as determined by X-ray diffraction, where the gray and black octahedrons are occupied by Ca and Os, respectively. Top inset reveals an optic image of a typical Ca 3 OsO 6 single crystal. Highlights: ► Single crystals of Ca 3 OsO 6 have been successfully grown under high-pressure. ► Ca 3 OsO 6 crystalizes into an ordered double-perovskite structure. ► The Ca 3 OsO 6 undergoes an antiferromagnetic transition at 50 K

  5. Interrelationship of crystal structure, infrared spectra and physicochemical properties of perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Bazuev, G V; Shveikin, G P [AN SSSR, Sverdlovsk. Inst. Khimii

    1975-12-01

    In the range 400-800 cm/sup -1/ a study has been made of infrared absorption spectra of perowskites ABO/sub 3/, where A is a rare-earth element or yttrium, B is Ti or V. A common feature of the infrared absorption spectra of perowskites ABO/sub 3/ is the presence of two intensive wide bands in the range 400-700 cm/sup -1/ one of which (low-frequency) is splitted into two or three components. The spectrum of LaTiO/sub 3/ is distinguished from spectra of other compounds. In the range measured this compound is non-transparent for electromagnetic radiation. On the basis of determination of temperature dependences of the electric resistance it is found that LaTiO/sub 3/ has metallic conductivity unlike other perowskites studied which are semiconductors. The spectrum of EuTiO/sub 3/ also differs from other spectra. It is close in its structure and position of bands to the spectrum of cubic perowskite, SrTiO/sub 3/. The splitting of the low-frequency band into two and in the case of TbVO/sub 3/ into three components is caused by deformation of crystal structures of these compounds. A direct dependence between the value of splitting and the deformation degree is observed.

  6. ABO-Rh blood groups distribution in cardiac syndrome X patients.

    Science.gov (United States)

    Kheradmand, Fatemeh; Rasmi, Yousef; Nemati, Mohaddeseh; Mohammadzad, Mir Hossein Seyed

    2012-07-01

    Data on frequency distribution of ABO-Rh blood groups in cardiac syndrome X (CSX) patients are not available. We aimed to investigate the distribution of ABO-Rh blood groups in these patients. A total of 247 CSX patients' records were reviewed in a cross-sectional study from 2006 to 2010. One hundred forty six patients (59.1%) were female, and the mean patient age was 52 ± 11 years. The frequency of ABO-Rh blood groups was compared to the frequency of these blood groups in the West-Azerbaijan province, Iran; general population. Blood groups distribution among CSX patients showed phenotypes A, B, AB, O and Rh negative as 33.1%, 21.9%, 9.3%, 35.8%, and 7.9%, respectively. According to our results, there were no differences in ABO-Rh blood groups distribution between CSX patients and normal population. These data suggest that ABO-Rh blood groups might be unassociated with CSX.

  7. Formation enthalpies of LaLn'O{sub 3} (Ln'=Ho, Er, Tm and Yb) interlanthanide perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Jianqi [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Key Laboratory of Radiation Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Key Laboratory of High Energy Density Physics of Ministry of Education, Sichuan University, Chengdu 610064 (China); Guo, Xiaofeng [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); Mielewczyk-Gryn, Aleksandra [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States); Faculty of Applied Physics and Mathematics, Department of Solid State Physics, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Navrotsky, Alexandra, E-mail: anavrotsky@ucdavis.edu [Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California, Davis, CA 95616 (United States)

    2015-07-15

    High-temperature oxide melt solution calorimetry using 3Na{sub 2}O·MoO{sub 3} at 802 °C was performed for interlanthanide perovskites LaLn'O{sub 3} (Ln'=Ho, Er, Tm and Yb) and lanthanide oxides (La{sub 2}O{sub 3}, Ho{sub 2}O{sub 3}, Er{sub 2}O{sub 3}, Tm{sub 2}O{sub 3} and Yb{sub 2}O{sub 3}). The enthalpies of formation of these interlanthanide perovskites from binary lanthanide oxides at room temperature (25 °C) were determined to be −8.3±3.4 kJ/mol for LaHoO{sub 3}, −9.9±3.0 kJ/mol for LaErO{sub 3}, −10.8±2.7 kJ/mol for LaTmO{sub 3} and −12.3±2.9 kJ/mol for LaYbO{sub 3}. There is a roughly linear relationships between these enthalpy values and the tolerance factor for these and for other LaM{sup 3+}O{sub 3} (M=In, Sc, Ga, Al, Fe and Cr) perovskites, confirming that the distortion of the perovskites as results from ionic radius difference of A-site and B-site cations, is the main factor determining the stability of these compounds. - Graphical abstract: A linear relationship between the enthalpy of formation and the tolerance factor for interlanthanide LaLn'O{sub 3} (Ln'=Ho, Er, Tm, and Yb) and other LaM{sup 3+}O{sub 3} (M=In, Sc, Ga, Al, Fe and Cr) perovskites. - Highlights: • Interlanthanide perovskites were synthesized by solid state reactions. • Their enthalpies of formation were measured by oxide melt solution calorimetry. • ΔH{sub f,ox} shows a linear relationship with tolerance factor.

  8. Frequency distribution of ABO and Rh (D) blood group alleles in Silte Zone, Ethiopia

    OpenAIRE

    Kassahun Tesfaye; Yohannes Petros; Mebeaselassie Andargie

    2015-01-01

    Background: Frequency distribution of blood groups is important as it is used in modern medicine, genetic research, anthropology, and tracing ancestral relations of humans. The ABO and Rh blood groups are the most important blood groups despite the long list of several other blood groups discovered so far. Aim of the study: To study and document the frequency of ABO and Rh (D) blood groups in three ethnic groups of Silte Zone, Ethiopia. Subjects and methods: ABO and Rh (D) typing was ca...

  9. Plasmodium falciparum malaria associated with ABO blood ...

    African Journals Online (AJOL)

    The present study was carried out to investigate the relationship between blood group types and P. falciparum malaria, as well as malaria preventive measures. The venous blood specimens were collected, processed, Giemsa-stained and examined microscopically. ABO groups were determined by agglutination test using ...

  10. DFT analysis and FDTD simulation of CH3NH3PbI3-x Cl x mixed halide perovskite solar cells: role of halide mixing and light trapping technique

    Science.gov (United States)

    Saffari, Mohaddeseh; Mohebpour, Mohammad Ali; Rahimpour Soleimani, H.; Bagheri Tagani, Meysam

    2017-10-01

    Since perovskite solar cells have attracted a great deal of attention over the past few years, the enhancement of their optical absorption and current density are among the basic upcoming challenges. For this reason, first, we have studied the structural and optical properties of organic-inorganic hybrid halide perovskite CH3NH3PbI3 and the compounds doped by chlorine halogen CH3NH3PbI3-x Cl x in the cubic phase by using a density functional theory (DFT). Then, we model a single-junction perovskite solar cell based on a full solution to Maxwell’s equations, using a finite difference time domain (FDTD) technique, which helps us to investigate the light absorption efficiency and optical current density of the cell with CH3NH3PbI3-x Cl x (x  =  0, 1, 2, 3) as the active layer. The results suggest that increasing the amount of chlorine in CH3NH3PbI3-x Cl x compound leads to an increase in the bandgap energy, as well as a decrease in the lattice constants and optical properties, like the refractive index and extinction coefficient of the structure. Also, the results obtained by the simulation express that by taking advantage of the light trapping techniques of SiO2, a remarkable increase of light absorption will be achieved to the magnitude of 83.13%, which is noticeable.

  11. Effect of Different CH3NH3PbI3 Morphologies on Photovoltaic Properties of Perovskite Solar Cells

    Science.gov (United States)

    Chen, Lung-Chien; Lee, Kuan-Lin; Wu, Wen-Ti; Hsu, Chien-Feng; Tseng, Zong-Liang; Sun, Xiao Hong; Kao, Yu-Ting

    2018-05-01

    In this study, the perovskite layers were prepared by two-step wet process with different CH3NH3I (MAI) concentrations. The cell structure was glass/FTO/TiO2-mesoporous/CH3NH3PbI3 (MAPbI3)/spiro-OMeTAD/Ag. The MAPbI3 perovskite films were prepared using high and low MAI concentrations in a two-step process. The perovskite films were optimized at different spin coating speed and different annealing temperatures to enhance the power conversion efficiency (PCE) of perovskite solar cells. The PCE of the resulting device based on the different perovskite morphologies was discussed. The PCE of the best cell was up to 17.42%, open circuit voltage of 0.97 V, short current density of 24.06 mA/cm2, and fill factor of 0.747.

  12. Ordered perovskites with cationic vacancies. 9. Compounds of the type Sr/sub 2/Srsub(1/4)Bsub(1/2)sup(III)vacantsub(1/4)WO/sub 6/ equivalent to Sr/sub 8/SrB/sub 2/sup(III)vacantW/sub 4/O/sub 24/ (Bsup(III) = La, Pr, Nd, Sm - Tm, Y)

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S; Ehmann, A [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1981-08-01

    The compounds Sr/sub 2/Srsub(1/4)Bsub(1/2)sup(III)vacantsub(1/4)WO/sub 6/ equivalent to Sr/sub 8/SrB/sub 2/sup(III)vacantW/sub 4/O/sub 24/ belong to the group of perovskites with octahedral cationic vacancies (cation/vacancy ratio (CN 6) = 7:1). For the larger Bsup(III) ions (La, Pr, Nd, Sm-Dy) different ordering effects are observed. The perovskites with Bsup(III) = Sm, Eu, Gd are polymorphic too (HT modification: higher ordered cubic perovskite (Bsup(III) = Gd: a = 2 x 8.23/sub 4/ A); LT modification: hexagonal perovskite stacking polytype (Bsup(III) = Gd: a = 9.95/sub 4/ A; c = 19.0/sub 4/ A)). With the smaller Bsup(III) ions (Ho, Er, Tm and Y) a cubic, 1:1 ordered perovskite type is observed.

  13. Towards Lead-Free Piezoceramics: Facing a Synthesis Challenge

    Directory of Open Access Journals (Sweden)

    María Elena Villafuerte-Castrejón

    2016-01-01

    Full Text Available The search for electroceramic materials with enhanced ferro-pyro-piezoelectric properties and revealing the perovskite type structure has been the objective of a significant number of manuscripts reported in the literature. This has been usually carried out by proposing the synthesis and processing of new compounds and solid solution series. In this work, several methods to obtain ferro-pyro-piezoelectric families of materials featuring the well-known ABO3 perovskite structure (or related such as BaTiO3, Ba1–xCaxTi1–yZryO3, (Bi0.5Na0.5TiO3, (K0.5Na0.5NbO3 and their solid solutions with different cations either in the A or B positions, are presented. For this kind of materials, the challenge for obtaining a single phase compound with a specific grain size and morphology and, most importantly, with the adequate stoichiometry, will also be discussed. The results reviewed herein will be discussed in terms of the tendency of working with softer conditions, i.e., lower temperature and shorter reaction times, also referred to as soft-chemistry.

  14. Transparent and flexible photodetectors based on CH3NH3PbI3 perovskite nanoparticles

    Science.gov (United States)

    Jeon, Young Pyo; Woo, Sung Jun; Kim, Tae Whan

    2018-03-01

    Transparent and flexible photodetectors (PDs) based on CH3NH3PbI3 perovskite nanoparticles (NPs) were fabricated by using co-evaporation of methyl ammonium iodide and lead iodide. X-ray diffraction patterns and high-resolution transmission electron microscopy images demonstrated the formation of perovskite NPs. The optical transmittance of the perovskite NPs/glass was above 80% over the entire range of visible wavelengths, indicative of high transparency. The PDs based on CH3NH3PbI3 perovskite NPs were sensitive to a broad range of visible light from 450 to 650 nm. The currents in the PDs under exposure to red, green, and blue light-emitting diodes were enhanced to 5, 10, and 20 times that of the PD in the dark, respectively. The rise and the decay times of the PDs were 50 and 120 μs. The current in the perovskite NP PD on a polyethylene terephthalate substrate was enhanced by approximately 69% when the NP PD was exposed to a blue LED emitting at a wavelength of 459 nm. Despite multiple bending, the transparent and flexible PDs based on methyl ammonium iodide and lead iodide NPs showed reproducibility and high stability in performance.

  15. Growth of MAPbBr3 perovskite crystals and its interfacial properties with Al and Ag contacts for perovskite solar cells

    Science.gov (United States)

    Najeeb, Mansoor Ani; Ahmad, Zubair; Shakoor, R. A.; Alashraf, Abdulla; Bhadra, Jolly; Al-Thani, N. J.; Al-Muhtaseb, Shaheen A.; Mohamed, A. M. A.

    2017-11-01

    In this work, the MAPbBr3 perovskite crystals were grown and the interfacial properties of the poly-crystalline MAPbBr3 with Aluminum (Al) and Silver (Ag) contacts has been investigated. MAPbBr3 crystals are turned into the poly-crystalline pellets (PCP) using compaction technique and the Al/PCP, Al/interface layer/PCP, Ag/PCP, and Ag/interface layer/PCP contacts were investigated. Scanning Electron Microscopic (SEM), Energy-dispersive X-ray spectroscopy (EDX) and current-voltage (I-V) characteristic technique were used to have an insight of the degradation mechanism happening at the Metal/perovskite interface. The Ag/PCP contact appears to be stable, whereas Al is found to be highly reactive with the MAPbBr3 perovskite crystals due to the infiltration setback of Al in to the perovskite crystals. The interface layer showed a slight effect on the penetration of Al in to the perovskite crystals however it does not seem to be an appropriate solution. It is noteworthy that the stability of the underlying metal/perovskite contact is very crucial towards the perovskite solar cells with extended device lifetime.

  16. Engineering Interfacial Charge Transfer in CsPbBr3 Perovskite Nanocrystals by Heterovalent Doping.

    Science.gov (United States)

    Begum, Raihana; Parida, Manas R; Abdelhady, Ahmed L; Murali, Banavoth; Alyami, Noktan M; Ahmed, Ghada H; Hedhili, Mohamed Nejib; Bakr, Osman M; Mohammed, Omar F

    2017-01-18

    Since compelling device efficiencies of perovskite solar cells have been achieved, investigative efforts have turned to understand other key challenges in these systems, such as engineering interfacial energy-level alignment and charge transfer (CT). However, these types of studies on perovskite thin-film devices are impeded by the morphological and compositional heterogeneity of the films and their ill-defined surfaces. Here, we use well-defined ligand-protected perovskite nanocrystals (NCs) as model systems to elucidate the role of heterovalent doping on charge-carrier dynamics and energy level alignment at the interface of perovskite NCs with molecular acceptors. More specifically, we develop an in situ doping approach for colloidal CsPbBr 3 perovskite NCs with heterovalent Bi 3+ ions by hot injection to precisely tune their band structure and excited-state dynamics. This synthetic method allowed us to map the impact of doping on CT from the NCs to different molecular acceptors. Using time-resolved spectroscopy with broadband capability, we clearly demonstrate that CT at the interface of NCs can be tuned and promoted by metal ion doping. We found that doping increases the energy difference between states of the molecular acceptor and the donor moieties, subsequently facilitating the interfacial CT process. This work highlights the key variable components not only for promoting interfacial CT in perovskites, but also for establishing a higher degree of precision and control over the surface and the interface of perovskite molecular acceptors.

  17. Engineering Interfacial Charge Transfer in CsPbBr3 Perovskite Nanocrystals by Heterovalent Doping

    KAUST Repository

    Begum, Raihana

    2016-12-17

    Since compelling device efficiencies of perovskite solar cells have been achieved, investigative efforts have turned to understand other key challenges in these systems, such as engineering interfacial energy-level alignment and charge transfer (CT). However, these types of studies on perovskite thin-film devices are impeded by the morphological and compositional heterogeneity of the films and their ill-defined surfaces. Here, we use well-defined ligand-protected perovskite nanocrystals (NCs) as model systems to elucidate the role of heterovalent doping on charge-carrier dynamics and energy level alignment at the interface of perovskite NCs with molecular acceptors. More specifically, we develop an in situ doping approach for colloidal CsPbBr3 perovskite NCs with heterovalent Bi3+ ions by hot injection to precisely tune their band structure and excited-state dynamics. This synthetic method allowed us to map the impact of doping on CT from the NCs to different molecular acceptors. Using time-resolved spectroscopy with broadband capability, we clearly demonstrate that CT at the interface of NCs can be tuned and promoted by metal ion doping. We found that doping increases the energy difference between states of the molecular acceptor and the donor moieties, subsequently facilitating the interfacial CT process. This work highlights the key variable components not only for promoting interfacial CT in perovskites, but also for establishing a higher degree of precision and control over the surface and the interface of perovskite molecular acceptors.

  18. Ionic conductivity in new perovskite type oxides: NaAZrMO6 (A = Ca or Sr; M = Nb or Ta)

    International Nuclear Information System (INIS)

    Rajendran, Deepthi N.; Ravindran Nair, K.; Prabhakar Rao, P.; Sibi, K.S.; Koshy, Peter; Vaidyan, V.K.

    2008-01-01

    New oxides of the type, NaAZrMO 6 (M = Ca or Sr; M = Nb or Ta), have been prepared by the solid-state reaction technique. Phase identification by powder X-ray diffraction (XRD) shows that NaCaZrMO 6 has orthorhombic perovskite type structure (Pnma) and NaSrZrMO 6 has cubic perovskite type structure (Pm3m). The grain morphology observation by scanning electron microscope (SEM) shows well-sintered grains. ac impedance spectra and electrical conductivity measurements in air, oxygen and nitrogen atmospheres indicate that they are probable oxide ion conductors with ionic conductivities of the order of 10 -3 S cm -1 at 750 deg. C

  19. ABO incompatibility

    Science.gov (United States)

    ... before transfusion or transplant can prevent this problem. Alternative Names Transfusion reaction - hemolytic; Acute hemolytic transfusion reaction; AHTR; Blood incompatibility - ABO Images Jaundiced infant Antibodies References Bellone ...

  20. Mechanism of formation of perovskite phase and dielectric properties of Pb(Zn,Mg)1/3Nb2/3O3 ceramics prepared by columbite precursor routes

    International Nuclear Information System (INIS)

    Jang, H.M.; Cho, S.R.; Lee, K.M.

    1995-01-01

    The mechanism of formation of the perovskite phase and the dielectric properties of Pb(Zn,Mg) 1/3 Nb 2/3 O 3 (PZMN) ceramics were examined using two different types of columbite precursors, (Mg,Zn)Nb 2 O 6 (MZN) and MgNb 2 O 6 + ZnNb 2 O 6 (MN + ZN). The formation of perovskite phase in the PbO + MN + ZN system is characterized by an initial rapid formation of Mg-rich perovskite phase, followed by a sluggish formation of Zn-rich perovskite phase. On the other hand, due to the formation of pyrochlore phase of mixed divalent cations Pb 2-x (Zn,Mg) y Nb 2-y O 7-x-3y/2 , the pyrochlore/perovskite transformation in the PbO + MZN system proceeded uniformly with a spatial homogeneity. Further analysis suggested that the formation of perovskite phase is a diffusion-controlled process. The degree of diffuseness of the rhombohedral/cubic phase transition (DPT) is higher in the PbO + MN + ZN system than in the PbO + MZN specimen for T > T max (temperature of the dielectric permittivity maximum), indicating a broadened compositional distribution of the B-site cations in the PbO + MN + ZN system

  1. Pure phase LaFeO3 perovskite with improved surface area synthesized using different routes and its characterization

    International Nuclear Information System (INIS)

    Gosavi, Priti V.; Biniwale, Rajesh B.

    2010-01-01

    Three different wet chemistry routes, namely co-precipitation, combustion and sol-gel methods were used to synthesize LaFeO 3 perovskite with improved surface area. The synthesized perovskite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), Brunauer-Emmett-Teller (BET) nitrogen adsorption, ultraviolet diffused reflectance spectroscopy (UVDRS) and Fourier transform infrared (FTIR) spectroscopy techniques. Improved surface area was observed for all three methods as compared to the previously reported values. The perovskite synthesized using sol-gel method yields comparatively pure, crystalline phase of LaFeO 3 and relatively higher surface area of 16.5 m 2 g -1 and porosity. The material synthesized using co-precipitation method yielded other phases in addition to the targeted phase. The morphology of perovskite synthesized using co-precipitation method was uniform agglomerates. Combustion method yields flakes type morphology and that of sol-gel method was open pore type morphology. The selection of method for perovskite synthesis largely depends on the targeted application and the desired properties of perovskites. The results reported in this study are useful for establishing a simple scalable method for preparation of high surface area LaFeO 3 as compared to solid-oxide method. Further, the typical heating cycle followed for calcinations resulted in relatively high surface area in the case of all three methods.

  2. First-principles prediction of structural, elastic, electronic and thermodynamic properties of the cubic SrUO{sub 3}-Perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Sahli, B. [Laboratoire de Génie Physique, Université Ibn Khaldoun, Tiaret, 14000 (Algeria); Laboratoire des Matériaux Magnétiques, Université Djillali Liabés, Sidi Bel-Abbes 22000 (Algeria); Bouafia, H., E-mail: hamza.tssm@gmail.com [Laboratoire de Génie Physique, Université Ibn Khaldoun, Tiaret, 14000 (Algeria); Abidri, B.; Abdellaoui, A. [Laboratoire des Matériaux Magnétiques, Université Djillali Liabés, Sidi Bel-Abbes 22000 (Algeria); Hiadsi, S.; Akriche, A. [Laboratoire de Microscope Electronique et Sciences des Matériaux, Université des Sciences et de la Technologie Mohamed Boudiaf, département de Génie Physique, BP1505 El m’naouar, Oran (Algeria); Benkhettou, N.; Rached, D. [Laboratoire des Matériaux Magnétiques, Université Djillali Liabés, Sidi Bel-Abbes 22000 (Algeria)

    2015-06-25

    Highlights: • The ground state properties of SrUO{sub 3}-Perovskite were investigated. • Elastic constants and their related parameters were calculated. • Electronic properties are treated using GGA-PBEsol + U approach. - Abstract: In this paper, we investigate bulk properties of the cubic SrUO{sub 3}-Perovskite in their nonmagnetic (NM), antiferromagnetic (AFM) and ferromagnetic (FM) states using all-electron self consistent Full Potential Augmented Plane Waves plus local orbital (FP-(L)APW + lo) method within PBEsol Generalized Gradiant density approximations. Our calculation allowed us to predict that the more stable magnetic state of the cubic SrUO{sub 3}-Perovskite is that of the ferromagnetic (FM). This work is the first prediction of elastic constants and their related parameters (Young modulus, shear modulus, Poisson ratio, Zener anisotropy and the Debye temperature) for this cubic compound using Mehl method. We have employed the GGA(PBEsol) and GGA(PBEsol) + U to investigate the electronic band structure, density of states and electronic charge density of SrUO{sub 3}-Perovskite. The electronic band structure calculations revealed that SrUO{sub 3} exhibits metallic behavior. On the other hand the charge density plots for [1 1 0] direction indicates a strong ionic character along the Sr–O bond while the U–O bond has strong covalent character. Finally, we have analyzed the thermodynamic properties using the quasi-harmonic Debye model to complete the fundamental characterization of cubic SrUO{sub 3}-Perovskite.

  3. Origins of n -type doping difficulties in perovskite stannates

    Science.gov (United States)

    Weston, L.; Bjaalie, L.; Krishnaswamy, K.; Van de Walle, C. G.

    2018-02-01

    The perovskite stannates (A SnO3 ; A = Ba, Sr, Ca) are promising for oxide electronics, but control of n -type doping has proved challenging. Using first-principles hybrid density functional calculations, we investigate La dopants and explore the formation of compensating acceptor defects. We find that La on the A site always behaves as a shallow donor, but incorporation of La on the Sn site can lead to self-compensation. At low La concentrations and in O-poor conditions, oxygen vacancies form in BaSnO3. A -site cation vacancies are found to be dominant among the native compensating centers. Compared to BaSnO3, charge compensation is a larger problem for the wider-band-gap stannates, SrSnO3 and CaSnO3, a trend we can explain based on conduction-band alignments. The formation of compensating acceptor defects can be inhibited by choosing oxygen-poor (cation-rich) growth or annealing conditions, thus providing a pathway for improved n -type doping.

  4. Genetic of the ABO blood system and its link with the immune system A genética do sistema ABO e sua relação com o sistema imune

    Directory of Open Access Journals (Sweden)

    Luiz C. de Mattos

    2004-03-01

    Full Text Available In the book "Eat Right For Your Type" the author Peter J. D'Adamo writes that the O blood type was the first blood type to appear in humans and affirms that the blood groups are the key to the immune system. Some recent phylogenetic network studies in humans and non-human primates implies that the A gene represents an ancient form of the ABO genes. Relationships between blood groups and infectious and noninfectious diseases and immunodeficiency abnormalities have also been reported in the literature. As D'Adamo's propositions seem to be in opposition with the current knowledge, we present in this paper some comments about the genetics and the evolution of the ABO blood group genes and some links between this blood system and the functioning of the immune system.Peter J. D'Adamo, autor do livro "Eat Right For Your Type", escreve que o grupo O representa o primeiro tipo sangüíneo que surgiu nos humanos e também afirma que os grupos sangüíneos constituem as bases do sistema imune. Recentes estudos filogenéticos realizados em primatas humanos e não humanos estabeleceram que o gene A representa a forma ancestral dos genes que ocupam o locus ABO. Associações entre os grupos sangüíneos ABO, doenças infecciosas, não infecciosas e imunodeficiências também foram relatadas. Diante das proposições do autor, as quais se opõem às informações resultantes de recentes estudos moleculares e filogenéticos, nossa intenção é apresentar algumas reflexões sobre a genética e a evolução dos genes do sistema ABO e as conexões deste sistema com o sistema imune.

  5. Relation of ABO Blood Groups to the Plaque Characteristic of Coronary Atherosclerosis.

    Science.gov (United States)

    Huang, Xingtao; Zou, Yongpeng; Li, Lulu; Chen, Shuyuan; Hou, Jingbo; Yu, Bo

    2017-01-01

    The ABO blood types related to morphological characteristics of atherosclerosis plaque are not clear. We aimed to evaluate the relationship between ABO blood groups and the coronary plaque characteristic. We retrospectively identified the target lesions in 392 acute coronary syndrome patients who underwent optical coherence tomography examination before stenting. Subjects were divided into different groups according to different blood types. The fibrous cap thickness was significantly thicker in O type compared with non-O type (0.075 ± 0.033 mm versus 0.061 ± 0.024, p blood type groups even between O type and non-O type group ( p > 0.05). The plaques of O type blood group were exhibited more stably compared with non-O type blood group. Moreover, the non-O type blood group have more serious coronary artery stenosis than O type blood group.

  6. Thermal evolution of the crystal structure of the orthorhombic perovskite LaFeO3

    International Nuclear Information System (INIS)

    Dixon, Charlotte A.L.; Kavanagh, Christopher M.; Knight, Kevin S.; Kockelmann, Winfried; Morrison, Finlay D.; Lightfoot, Philip

    2015-01-01

    The thermal evolution of the crystal structure of the prototypical orthorhombic perovskite LaFeO 3 has been studied in detail by powder neutron diffraction in the temperature range 253 . However, an unexpected behavior is seen in the nature of the intra-octahedral distortion, which is used to rationalize the unique occurrence of a temperature dependent crossover of the a and c unit cell metrics in this compound. - Graphical abstract: The unusual thermal evolution of lattice metrics in the perovskite LaFeO 3 is rationalized from a detailed powder neutron diffraction study. - Highlights: • Crystal structure of the perovskite LaFeO 3 studied in detail by powder neutron diffraction. • Unusual thermal evolution of lattice metrics rationalized. • Contrasting behavior to Bi-doped LaFeO 3 . • Octahedral distortion/tilt parameters explain unusual a and c lattice parameter behavior

  7. Optical characterization of voltage-accelerated degradation in CH3NH3PbI3 perovskite solar cells.

    Science.gov (United States)

    Handa, Taketo; Tex, David M; Shimazaki, Ai; Aharen, Tomoko; Wakamiya, Atsushi; Kanemitsu, Yoshihiko

    2016-05-16

    We investigate the performance degradation mechanism of CH3NH3PbI3 perovskite solar cells under bias voltage in air and nitrogen atmospheres using photoluminescence and electroluminescence techniques. When applying forward bias, the power conversion efficiency of the solar cells decreased significantly in air, but showed no degradation in nitrogen atmosphere. Time-resolved photoluminescence measurements on these devices revealed that the application of forward bias in air accelerates the generation of non-radiative recombination centers in the perovskite layer buried in the device. We found a negative correlation between the electroluminescence intensity and the injected current intensity in air. The irreversible change of the perovskite grain surface in air initiates the degradation of the perovskite solar cells.

  8. Influence of hydration water on CH3NH3PbI3 perovskite films prepared through one-step procedure.

    Science.gov (United States)

    Wang, Ziyi; Yuan, Sijian; Li, Dahai; Jin, Feng; Zhang, Rongjun; Zhan, Yiqiang; Lu, Ming; Wang, Songyou; Zheng, Yuxiang; Guo, Junpeng; Fan, Zhiyong; Chen, Liangyao

    2016-10-31

    Organic-inorganic perovskites were fabricated through a one-step procedure with different levels of hydration water in precursor solutions. The optical properties of CH3NH3PbI3 films were investigated through spectroscopic ellipsometry and photoluminescence measurements. With the measured optical constants, the efficiency limit of perovskite solar cells is predicted with a detailed balance model. By comparing the optical measurement to that of planar heterojunction solar cells, we conclude that the radiative efficiency and porosity of the perovskite film significantly influence the performance of perovskite solar cells. An optimized hydration-water concentration is obtained for the 3CH3NH3I:1PbAc2•xH2O precursor solution. The results can provide guidance for further optimization of the device performance of perovskite solar cells by utilizing hydration water.

  9. Relationships between skin cancers and blood groups--link between non-melanomas and ABO/Rh factors.

    Science.gov (United States)

    Cihan, Yasemin Benderli; Baykan, Halit; Kavuncuoglu, Erhan; Mutlu, Hasan; Kucukoglu, Mehmet Burhan; Ozyurt, Kemal; Oguz, Arzu

    2013-01-01

    This investigation focused on possible relationships between skin cancers and ABO/Rh blood groups. Between January 2005 and December 2012, medical data of 255 patients with skin cancers who were admitted to Kayseri Training and Research Hospital, Radiation Oncology and Plastic Surgery Outpatient Clinics were retrospectively analyzed. Blood groups of these patients were recorded. The control group consisted of 25701 healthy volunteers who were admitted to Kayseri Training and Research Hospital, Blood Donation Center between January 2010 and December 2011. The distribution of the blood groups of the patients with skin cancers was compared to the distribution of ABO/Rh blood groups of healthy controls. The association of the histopathological subtypes of skin cancer with the blood groups was also investigated. Of the patients, 50.2% had A type, 26.3% had O type, 16.1% had B type, and 7.5% had AB blood group with a positive Rh (+) in 77.3%. Of the controls, 44.3% had A type, 31.5% had 0 type, 16.1% had B type, and 8.1% had AB blood group with a positive Rh (+) in 87.8%. There was a statistically significant difference in the distribution of blood groups and Rh factors (A Rh (-) and 0 Rh positive) between the patients and controls. A total of 36.8% and 20.4% of the patients with basal cell carcinoma (BCC) had A Rh (+) and B Rh (+), respectively, while 39.2% and 27.6% of the controls had A Rh (+) and B Rh (+), respectively. A significant relationship was observed between the patients with BCC and controls in terms of A Rh (-) (p=0.001). Our study results demonstrated that there is a significant relationship between non-melanoma skin cancer and ABO/Rh factors.

  10. High temperature-induced phase transitions in Sr2GdRuO6 complex perovskite

    International Nuclear Information System (INIS)

    Triana, C.A.; Corredor, L.T.; Landínez Téllez, D.A.; Roa-Rojas, J.

    2011-01-01

    Highlights: ► Crystal structure, thermal expansion and phase transitions at high-temperature of Sr 2 GdRuO 6 perovskite has been investigated. ► X-ray diffraction pattern at 298 K of Sr 2 GdRuO 6 corresponds to monoclinic perovskite-type structure with P2 1 /n space group. ► Evolution of X-ray diffraction patterns at high-temperature shows that the Sr 2 GdRuO 6 perovskite suffers two-phase transitions. ► At 573 K the X-ray diffraction pattern of Sr 2 GdRuO 6 corresponds to monoclinic perovskite-type structure with I2/m space group. ► At 1273 K the Sr 2 GdRuO 6 perovskite suffers a complete phase-transition from monoclinic I2/m (no. 12) to tetragonal I4/m (no. 87). -- Abstract: The crystal structure behavior of the Sr 2 GdRuO 6 complex perovskite at high-temperature has been investigated over a wide temperature range between 298 K ≤ T ≤ 1273 K. Measurements of X-ray diffraction at room-temperature and Rietveld analysis of the experimental patterns show that this compound crystallizes in a monoclinic perovskite-like structure, which belongs to the P2 1 /n (no. 14) space group and 1:1 ordered arrangement of Ru 5+ and Gd 3+ cations over the six-coordinate M sites. Experimental lattice parameters were obtained to be a =5.8103(5) Å, b =5.8234(1) Å, c =8.2193(9) Å, V = 278.11(2) Å 3 and angle β = 90.310(5)°. The high-temperature analysis shows the occurrence of two-phase transitions on this material. First, at 573 K it adopts a monoclinic perovskite-type structure with I2/m (no. 12) space group with lattice parameters a = 5.8275(6) Å, b = 5.8326(3) Å, c = 8.2449(2) Å, V = 280.31(3) Å 3 and angle β = 90.251(3)°. Close to 1273 K it undergoes a complete phase-transition from monoclinic I2/m (no. 12) to tetragonal I4/m (no. 87), with lattice parameters a = 5.8726(1) Å, c = 8.3051(4) Å, V = 286.39(8) Å 3 and angle β = 90.0°. The high-temperature phase transition from monoclinic I2/m (no. 12) to tetragonal I4/m (no. 87) is characterized

  11. New perovskite-based manganite Pb2Mn2O5

    International Nuclear Information System (INIS)

    Hadermann, Joke; Abakumov, Artem M.; Perkisas, Tyche; D'Hondt, Hans; Tan Haiyan; Verbeeck, Johan; Filonenko, Vladimir P.; Antipov, Evgeny V.; Van Tendeloo, Gustaaf

    2010-01-01

    A new perovskite based compound Pb 2 Mn 2 O 5 has been synthesized using a high pressure high temperature technique. The structure model of Pb 2 Mn 2 O 5 is proposed based on electron diffraction, high angle annular dark field scanning transmission electron microscopy and high resolution transmission electron microscopy. The compound crystallizes in an orthorhombic unit cell with parameters a=5.736(1) A∼√2a p , b=3.800(1) A∼a p , c=21.562(6) A∼4√2a p (a p -the parameter of the perovskite subcell) and space group Pnma. The Pb 2 Mn 2 O 5 structure consists of quasi two-dimensional perovskite blocks separated by 1/2[110] p (101) p crystallographic shear planes. The blocks are connected to each other by chains of edge-sharing MnO 5 distorted tetragonal pyramids. The chains of MnO 5 pyramids and the MnO 6 octahedra of the perovskite blocks delimit six-sided tunnels accommodating double chains of Pb atoms. The tunnels and pyramidal chains adopt two mirror-related configurations ('left' L and 'right' R) and layers consisting of chains and tunnels of the same configuration alternate in the structure according to an -L-R-L-R-sequence. The sequence is sometimes locally violated by the appearance of -L-L- or -R-R-fragments. A scheme is proposed with a Jahn-Teller distortion of the MnO 6 octahedra with two long and two short bonds lying in the a-c plane, along two perpendicular orientations within this plane, forming a d-type pattern. - Graphical abstract: Order of the Jahn-Teller distorted MnO 6 octahedra in Pb 2 Mn 2 O 5 . Two long and two short bonds lie in the a-c plane, along two perpendicular orientations within this plane, forming a d-type pattern.

  12. Comparison of Lip Print Patterns in Two Indian Subpopulations and Its Correlation in ABO Blood Groups.

    Science.gov (United States)

    Sr, Ashwinirani; Suragimath, Girish; Sande, Abhijeet R; Kulkarni, Prasad; Nimbal, Anand; Shankar, T; Gowd, T Snigdha; Shetty, Prajwal K

    2014-10-01

    The study of lip-print pattern (cheiloscopy) is a scientific method for personal identification and plays a major role in forensic and criminal investigations. To compare the lip print patterns in Kerala and Maharashtra population and correlate between ABO blood groups. Two hundred subjects, 100 from Maharashtra and 100 from Kerala were considered for the study. Lip prints were recorded, analyzed according to Tsuchihashi classification. The lip print patterns were compared in the two populations, correlated in ABO blood groups. The data obtained was statistically analyzed with SPSS software using chi-square test. In our study, predominant lip print pattern observed in Kerala population was type IV (53%) and Maharashtra population was type II (42%). The difference between the two population was statistically significant (pblood groups had type II lip print predominance. Subjects with B+, AB+ and O+ blood groups had type IV predominance. The lip print patterns do not show any correlation in ABO blood groups. Lip prints are unique to each individual and are different even in two persons. Lip print patterns were different in the two sub populations studied, and they showed no correlation in ABO blood groups.

  13. Plasma exchange in small intestinal transplantation between ABO-incompatible individuals: A case report

    OpenAIRE

    ZHANG, QIUHUI; HU, XINGBIN; XIA, AIJUN; YI, JING; AN, QUNXING; ZHANG, XIANQING

    2013-01-01

    The aim of this study was to investigate the application of plasma exchange in small intestinal transplantation between ABO blood type-incompatible patients. A small intestinal transplantation case between ABO-incompatible individuals is hereby presented and analyzed. The main treatment included plasma exchange, splenectomy and immunosuppression. The patient undergoing small intestinal transplantation exhibited stable vital signs. A mild acute rejection reaction developed ~2 weeks after the s...

  14. Chemical vapor deposition and electric characterization of perovskite oxides LaMO3 (M=Co, Fe, Cr and Mn) thin films

    International Nuclear Information System (INIS)

    Ngamou, Patrick Herve Tchoua; Bahlawane, Naoufal

    2009-01-01

    Oxides with a perovskite structure are important functional materials often used for the development of modern devices. In view of extending their applicability, it is necessary to efficiently control their growth as thin films using technologically relevant synthesis methods. Pulsed spray evaporation CVD was used to grow several perovskite-type oxides on planar silicon substrates at temperatures ranging from 500 to 700 deg. C. The optimization of the process control parameters allows the attainment of the perovskite structure as a single phase. The electrical characterization using the temperature-dependent conductivity and thermopower indicates the p-type conduction of the grown films and shows a decreasing concentration of the charge carrier, mobility and band gap energy in the sequence LaCoO 3 >LaMnO 3 >LaCrO 3 >LaFeO 3 . The investigation of the electric properties of the obtained perovskite thin films shows the versatility of CVD as a method for the development of innovative devices. - Graphical abstract: We report a single step deposition of perovskite thin films LaMO 3 (M: Co, Mn, Cr, Fe) using pulsed spray evaporation chemical vapor deposition. Electrical and thermopower properties, similar to these of bulk materials, could promote the development of modern thermoelectric devices based on thin films technology.

  15. Electrical Stress Influences the Efficiency of CH3 NH3 PbI3 Perovskite Light Emitting Devices.

    Science.gov (United States)

    Zhao, Lianfeng; Gao, Jia; Lin, YunHui L; Yeh, Yao-Wen; Lee, Kyung Min; Yao, Nan; Loo, Yueh-Lin; Rand, Barry P

    2017-06-01

    Organic-inorganic hybrid perovskite materials are emerging as semiconductors with potential application in optoelectronic devices. In particular, perovskites are very promising for light-emitting devices (LEDs) due to their high color purity, low nonradiative recombination rates, and tunable bandgap. Here, using pure CH 3 NH 3 PbI 3 perovskite LEDs with an external quantum efficiency (EQE) of 5.9% as a platform, it is shown that electrical stress can influence device performance significantly, increasing the EQE from an initial 5.9% to as high as 7.4%. Consistent with the enhanced device performance, both the steady-state photoluminescence (PL) intensity and the time-resolved PL decay lifetime increase after electrical stress, indicating a reduction in nonradiative recombination in the perovskite film. By investigating the temperature-dependent characteristics of the perovskite LEDs and the cross-sectional elemental depth profile, it is proposed that trap reduction and resulting device-performance enhancement is due to local ionic motion of excess ions, likely excess mobile iodide, in the perovskite film that fills vacancies and reduces interstitial defects. On the other hand, it is found that overstressed LEDs show irreversibly degraded device performance, possibly because ions initially on the perovskite lattice are displaced during extended electrical stress and create defects such as vacancies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Oxygen permeability of perovskite-type BaBi1-xLaxO3

    International Nuclear Information System (INIS)

    Yaremchenko, A.A.; Kharton, V.V.; Viskup, A.P.; Naumovich, E.N.; Samokhval, V.V.

    1998-01-01

    Oxygen permeability, electrical conductivity, and thermal expansion of BaBi 1-x La x O 3-δ (x = 0, 0.2, and 0.4) perovskite-like solid solutions have been found to decrease with lanthanum content. Thermal expansion coefficients of the ceramics are (11.9--12.8) x 10 -6 K -1 . Oxygen transport through the BaBi(La)O 3-δ dense ceramic membranes within the membrane thickness range of 0.6 < d < 1.2 mm has been shown to be limited by both bulk ionic conductivity and surface exchange rate

  17. Acute humoral rejection and C4d immunostaining in ABO blood type-incompatible liver transplantation.

    Science.gov (United States)

    Haga, Hironori; Egawa, Hiroto; Fujimoto, Yasuhiro; Ueda, Mikiko; Miyagawa-Hayashino, Aya; Sakurai, Takaki; Okuno, Tomoko; Koyanagi, Itsuko; Takada, Yasutsugu; Manabe, Toshiaki

    2006-03-01

    Complement C4d deposition in graft capillaries has been reported to be associated with antibody-mediated rejection in kidney and other solid organ transplantation. The correlation of C4d deposits and humoral rejection in liver transplants, however, is not well understood. We investigated the C4d immunostaining pattern in 34 patients whose liver biopsy was taken within the first 3 postoperative weeks for suspected acute rejection after ABO blood type-incompatible liver transplantation. The staining pattern was classified as positive (portal stromal staining), indeterminate (endothelial staining only), and negative (no staining). Positive C4d immunostaining was seen in 17 (50%) patients and was significantly associated with high (x64 or more) postoperative antidonor A/B antibody (immunoglobulin M (IgM)) titers (88 vs. 35%, P = 0.002) and poorer overall survival rate (41 vs. 88%, P = 0.007). Ten of 11 (91%) cases with histological acute humoral rejection (periportal edema and necrosis (PEN) or portal hemorrhagic edema) were positive for C4d, all of which showed high postoperative antibody titers. The other histologies associated with C4d positivity was purulent cholangitis (n = 4), coagulative hepatocyte necrosis (n = 1), acute cellular rejection (n = 1), and hepatocanalicular cholestasis (n = 1). Full clinical recovery was observed in only 6 of 17 (35%) C4d-positive patients, and tended to be associated with a lower rejection activity index (RAI). In conclusion, our study indicates that C4d deposits in the portal stroma can be a hallmark of acute humoral rejection in ABO-incompatible liver transplantation, and allograft damage can be reversible in a minority of cases. Copyright 2006 AASLD

  18. Polar octahedral rotations: A path to new multifunctional materials

    International Nuclear Information System (INIS)

    Benedek, Nicole A.; Mulder, Andrew T.; Fennie, Craig J.

    2012-01-01

    Perovskite ABO 3 oxides display an amazing variety of phenomena that can be altered by subtle changes in the chemistry and internal structure, making them a favorite class of materials to explore the rational design of novel properties. Here we highlight a recent advance in which rotations of the BO 6 octahedra give rise to a novel form of ferroelectricity – hybrid improper ferroelectricity. Octahedral rotations also strongly influence other structural, magnetic, orbital, and electronic degrees of freedom in perovskites and related materials. Octahedral rotation-driven ferroelectricity consequently has the potential to robustly control emergent phenomena with an applied electric field. The concept of ‘functional’ octahedral rotations is introduced and the challenges for materials chemistry and the possibilities for new rotation-driven phenomena in multifunctional materials are explored. - Graphical abstract: A 3 B 2 O 7 and (A/A′)B 2 O 6 are two types of layered perovskites in which octahedral rotations induce ferroelectricity. Highlights: ► Recent progress on achieving ferroelectricity from rotations of the BO 6 octahedra in ABO 3 perovskite oxides is reviewed. ► The atomic scale layering of Pnma perovskites in two different ways leads to alternative structure realizations. ► The concept of ‘functional’ octahedral rotations is introduced as a path to electric-field control of emergent phenomena.

  19. Electrically conducting perovskites for SOFC and catalysis. Preparation characterization and testing

    Energy Technology Data Exchange (ETDEWEB)

    Gordes, P

    1998-12-31

    Solid oxide fuel cells offer the possibility of high efficiency and low pollution energy source. A fuel cell converts chemical energy directly to electricity without combustion as an intermediate step. H{sub 2}, CO or hydrocarbons can be used as fuel gas. At present the main problems in developing a commercial SOFC are related to the air electrode and interconnect. Commercial air electrode and interconnect materials are still not on the market. This dissertation concerns the following main tasks: 1. A theoretical part on the co-optimization of electronic and catalytic properties of perovskites (ABO{sub 3}) where the A position is occupied by mixed rare earth or alkaline earth metal (Ca, Sr, Ba, La, etc) and the B position is occupied by a mixture of transition metals (Mn, Fe, Co, Ni, Cr, etc). 2. Optimization of the drip pyrolysis method and fabrication of high quality perovskite powders of selected compositions for further studies. This work involves a detailed characterization of powders prepared in terms of phase homogeneity, crystallite size, agglomeration, chemical composition etc. 3. Development of the necessary processing technology for fabrication of shaped samples with a closely controlled porosity and pore size distribution. This work involves development of a suitable shaping process (uniaxial pressing, extrusion, tape casting), and a detailed study of the phase evolution and densification properties of the powders as a function of temperature. 4. Characterization of the prepared perovskite components in terms of phase homogeneity, microstructure, as well as electrical and catalytic properties. 5. Recommendations for future work. (EG) 151 refs.

  20. Electrically conducting perovskites for SOFC and catalysis. Preparation characterization and testing

    Energy Technology Data Exchange (ETDEWEB)

    Gordes, P.

    1997-12-31

    Solid oxide fuel cells offer the possibility of high efficiency and low pollution energy source. A fuel cell converts chemical energy directly to electricity without combustion as an intermediate step. H{sub 2}, CO or hydrocarbons can be used as fuel gas. At present the main problems in developing a commercial SOFC are related to the air electrode and interconnect. Commercial air electrode and interconnect materials are still not on the market. This dissertation concerns the following main tasks: 1. A theoretical part on the co-optimization of electronic and catalytic properties of perovskites (ABO{sub 3}) where the A position is occupied by mixed rare earth or alkaline earth metal (Ca, Sr, Ba, La, etc) and the B position is occupied by a mixture of transition metals (Mn, Fe, Co, Ni, Cr, etc). 2. Optimization of the drip pyrolysis method and fabrication of high quality perovskite powders of selected compositions for further studies. This work involves a detailed characterization of powders prepared in terms of phase homogeneity, crystallite size, agglomeration, chemical composition etc. 3. Development of the necessary processing technology for fabrication of shaped samples with a closely controlled porosity and pore size distribution. This work involves development of a suitable shaping process (uniaxial pressing, extrusion, tape casting), and a detailed study of the phase evolution and densification properties of the powders as a function of temperature. 4. Characterization of the prepared perovskite components in terms of phase homogeneity, microstructure, as well as electrical and catalytic properties. 5. Recommendations for future work. (EG) 151 refs.

  1. Electronic structures near surfaces of perovskite type oxides

    International Nuclear Information System (INIS)

    Hara, Toru

    2005-01-01

    This work is intended to draw attention to the origin of the electronic structures near surfaces of perovskite type oxides. Deep states were observed by ultraviolet photoelectron spectroscopic measurements. The film thickness dependent electronic structures near surfaces of (Ba 0.5 Sr 0.5 )TiO 3 thin films were observed. As for the 117-308 nm thick (Ba 0.5 Sr 0.5 )TiO 3 films, deep states were lying at 0.20, 0.55, and 0.85 eV below the quasi-fermi level, respectively. However, as for the 40 nm thick (Ba 0.5 Sr 0.5 )TiO 3 film, the states were overlapped. The A-site doping affected electronic structures near surfaces of SrTiO 3 single crystals. No evolution of deep states in non-doped SrTiO 3 single crystal was observed. However, the evolution of deep states in La-doped SrTiO 3 single crystal was observed

  2. 2:1 Charge disproportionation in perovskite-structure oxide La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+}

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Haichuan; Hosaka, Yoshiteru; Seki, Hayato; Saito, Takashi; Ichikawa, Noriya [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Shimakawa, Yuichi, E-mail: shimak@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Integrated Research Consortium on Chemical Sciences, Uji, Kyoto 611-0011 (Japan)

    2017-02-15

    La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} was synthesized at a high pressure and high temperature. The compound crystallizes in a √2a×2a×√2a perovskite cell in which the La and Ca ions at the A site are disordered. At 217 K the Fe{sup 3.67+} shows charge disproportionation to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1, and this disproportionation is accompanied by transitions in magnetic and transport properties. The charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. The local electronic and magnetic environments of Fe in La{sub 1/3}Ca{sub 2/3}FeO{sub 3} are quite similar to those of Fe in La{sub 1/3}Sr{sub 2/3}FeO{sub 3}, and the 2:1 charge disproportionation pattern of Fe{sup 3+} and Fe{sup 5+} in La{sub 1/3}Ca{sub 2/3}FeO{sub 3} is also the same as that in La{sub 1/3}Sr{sub 2/3}FeO{sub 3}. - Graphical abstract: The perovskite-structure oxide La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} shows charge disproportionation to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1, and the charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. - Highlights: • La{sub 1/3}Ca{sub 2/3}FeO{sub 3} with unusually-high-valence Fe{sup 3.67+} was synthesized at a high pressure and high temperature. • At 217 K the Fe{sup 3.67+} shows charge disproportionation (CD) to Fe{sup 3+} and Fe{sup 5+} in a ratio of 2:1. • The charge-disproportionated Fe{sup 3+} and Fe{sup 5+} are arranged along the <111> direction of the cubic perovskite cell. • The disproportionation is accompanied by transitions in magnetic and transport properties.

  3. Ionic conductivity in new perovskite type oxides: NaAZrMO{sub 6} (A = Ca or Sr; M = Nb or Ta)

    Energy Technology Data Exchange (ETDEWEB)

    Rajendran, Deepthi N.; Ravindran Nair, K. [Regional Research Laboratory (CSIR), Trivandrum 695019 (India); Prabhakar Rao, P. [Regional Research Laboratory (CSIR), Trivandrum 695019 (India)], E-mail: padala_rao@yahoo.com; Sibi, K.S.; Koshy, Peter [Regional Research Laboratory (CSIR), Trivandrum 695019 (India); Vaidyan, V.K. [Department of Physics, University of Kerala, Trivandrum 695581 (India)

    2008-06-15

    New oxides of the type, NaAZrMO{sub 6} (M = Ca or Sr; M = Nb or Ta), have been prepared by the solid-state reaction technique. Phase identification by powder X-ray diffraction (XRD) shows that NaCaZrMO{sub 6} has orthorhombic perovskite type structure (Pnma) and NaSrZrMO{sub 6} has cubic perovskite type structure (Pm3m). The grain morphology observation by scanning electron microscope (SEM) shows well-sintered grains. ac impedance spectra and electrical conductivity measurements in air, oxygen and nitrogen atmospheres indicate that they are probable oxide ion conductors with ionic conductivities of the order of 10{sup -3} S cm{sup -1} at 750 deg. C.

  4. Lead Halide Perovskite Nanocrystals in the Research Spotlight: Stability and Defect Tolerance

    Science.gov (United States)

    2017-01-01

    This Perspective outlines basic structural and optical properties of lead halide perovskite colloidal nanocrystals, highlighting differences and similarities between them and conventional II–VI and III–V semiconductor quantum dots. A detailed insight into two important issues inherent to lead halide perovskite nanocrystals then follows, namely, the advantages of defect tolerance and the necessity to improve their stability in environmental conditions. The defect tolerance of lead halide perovskites offers an impetus to search for similar attributes in other related heavy metal-free compounds. We discuss the origins of the significantly blue-shifted emission from CsPbBr3 nanocrystals and the synthetic strategies toward fabrication of stable perovskite nanocrystal materials with emission in the red and infrared parts of the optical spectrum, which are related to fabrication of mixed cation compounds guided by Goldschmidt tolerance factor considerations. We conclude with the view on perspectives of use of the colloidal perovskite nanocrystals for applications in backlighting of liquid-crystal TV displays. PMID:28920080

  5. Tolerance factor rules for Sr1-x-yCaxBayMnO3 perovskites

    International Nuclear Information System (INIS)

    Dabrowski, B.; Chmaissem, O.; Mais, J.; Kolesnik, S.; Jorgensen, J.D.; Short, S.

    2003-01-01

    Synthesis of new perovskite Sr 1-x-y Ca x Ba y MnO 3compounds is described in detail and dependence of their phase stability and structural distortions on the tolerance factor is discussed. Oxygen contents have been measured over extended temperature and composition ranges. Neutron powder diffraction was used to precisely measure the A-O and Mn-O bond lengths and derive accurate interatomic distances [Ca-O], [Sr-O], [Ba-O], and [Mn-O]. By using these parameters instead of tabulated ionic radii we have derived the functional dependence of the tolerance factor t=t(x,y,T,δ) on composition, temperature, and oxygen content. At a fixed oxygen content, the tolerance factor is an increasing function of temperature as a result of greater thermal expansion of the average bond relative to the bond. We find that the stability of the perovskite phase at high temperature is governed, as expected, by the magnitude of tolerance factor (t≤1) which can be adjusted by controlling the oxygen content 3-δ. This dependence of the tolerance factor on oxygen content and temperature can be utilized to design synthesis conditions for the controlled formation of the new, kinetically stable, perovskite phases

  6. New W-and Mo-containing perovskites sythesized at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sevast' yanova, L G; Burdina, K P; Zubova, E V; Venevtsev, Yu N [Moskovskij Gosudarstvennyj Univ. (USSR); Nauchno-Issledovatel' skij Fiziko-Khimicheskij Inst., Moscow (USSR))

    1979-11-01

    The possibility of synthesizing complex oxide W and Mo-containing compounds having a perovskite structure is shown. The optimum synthesis conditions have been defined. Critical pressure Psub(cr) has been found to equal 70 kbar, above which the perovskite structure can still exist at room temperature. The ''pressure-temperature'' diagram was used to define the stability region of perovskite of Pb(HgMo)sub(1/2)Osub(3)composition, bound by pressure p=35 to 50 kbar and a temperature of 700 deg C.

  7. Lead Halide Perovskite Photovoltaic as a Model p-i-n Diode.

    Science.gov (United States)

    Miyano, Kenjiro; Tripathi, Neeti; Yanagida, Masatoshi; Shirai, Yasuhiro

    2016-02-16

    The lead halide perovskite photovoltaic cells, especially the iodide compound CH3NH3PbI3 family, exhibited enormous progress in the energy conversion efficiency in the past few years. Although the first attempt to use the perovskite was as a sensitizer in a dye-sensitized solar cell, it has been recognized at the early stage of the development that the working of the perovskite photovoltaics is akin to that of the inorganic thin film solar cells. In fact, theoretically perovskite is always treated as an ordinary direct band gap semiconductor and hence the perovskite photovoltaics as a p-i-n diode. Despite this recognition, research effort along this line of thought is still in pieces and incomplete. Different measurements have been applied to different types of devices (different not only in the materials but also in the cell structures), making it difficult to have a coherent picture. To make the situation worse, the perovskite photovoltaics have been plagued by the irreproducible optoelectronic properties, most notably the sweep direction dependent current-voltage relationship, the hysteresis problem. Under such circumstances, it is naturally very difficult to analyze the data. Therefore, we set out to make hysteresis-free samples and apply time-tested models and numerical tools developed in the field of inorganic semiconductors. A series of electrical measurements have been performed on one type of CH3NH3PbI3 photovoltaic cells, in which a special attention was paid to ensure that their electronic reproducibility was better than the fitting error in the numerical analysis. The data can be quantitatively explained in terms of the established models of inorganic semiconductors: current/voltage relationship can be very well described by a two-diode model, while impedance spectroscopy revealed the presence of a thick intrinsic layer with the help of a numerical solver, SCAPS, developed for thin film solar cell analysis. These results point to that CH3NH3PbI3 is an

  8. Comparison of different advanced oxidation processes (AOPs) in the presence of perovskites

    International Nuclear Information System (INIS)

    Rivas, F.J.; Carbajo, M.; Beltran, F.; Gimeno, O.; Frades, J.

    2008-01-01

    The efficacy of the oxidation systems: O 3 , UV radiation, O 3 /UV radiation, O 3 /perovskite, UV radiation/perovskite, O 3 /UV radiation/perovskite, H 2 O 2 /UV radiation, H 2 O 2 /UV radiation/perovskite, has been investigated by using pyruvic acid as probe compound. Under the operating conditions used, the combination of UV radiation and hydrogen peroxide (with or without perovskites) leads to the fastest pyruvic acid removal while the best results in terms of mineralization degree are obtained when combining O 3 /UV radiation/perovskite. The effect of the variables: inlet ozone (15-75 mg L -1 ) and initial pyruvic acid (10 -3 to 10 -2 M) concentrations, catalyst load (0.01-1.5 g L -1 ) and pH (2-9) was investigated for the photocatalytic ozonation. The most influencing parameter was the ozone concentration fed to the photoreactor. A zero order was observed for pyruvic acid concentration and close to zero for catalyst load. Some deactivation is observed after reusing the catalyst, likely due to leaching of the active phase

  9. [The kidney transplantation from the ABO-incompatible donors].

    Science.gov (United States)

    Goriaĭnov, V A; Kaabak, M M; Babenko, N N; Shishlo, L A; Morozova, M M; Ragimov, A A; Dashkova, N G; Salimov, É L

    2012-01-01

    The experience of 28 allotransplantations of ABO-incompatible kidneys was compared with the treatment results of 38 ABO-compatible renal transplantations. The transplanted kidney function, morphological changes of the transplanted kidney and the comparative analysis of actuary survival in both groups showed no significant difference. The results of the study prove the validity of the kidney transplantation from the ABO-incompatible donors.

  10. [Detection and analysis of ABO Hemolytic disease in newborn].

    Science.gov (United States)

    Lin, Zhao-Xia; Dong, Qing-Song

    2014-10-01

    This study was purposed to investigate the incidence and the model of ABO hemolytic disease in newborn (ABO-HDN) and the results of the three hemolysis test, so as to provide the evidences for clinical diagnosis and therapy. A total of 227 cases of maternal-fetal ABO incompatibility from January 2013 to October 2013 in the First Affiliated Hospital of Xiamen University were enrolled in the study. The ABO blood group of newborn and mother was detemined and three hemolysis tests (direct antiglobulin test, free antibody test, RBC antibody release test) were performed. The results indicated that in 227 cases of ABO incompatible pregnancies,186 cases were ABO-HDN (81.94%). There was no significant difference in the incidence between O-A and O-B incompatible pregnancies (P > 0.05). The positive ratio of direct antiglobulin test, free antibody test and RBC antibody release test were 59.14% (110/186), 84.78% (156/186) and 94.62% (176/186) respectively. It is concluded that the incidence of ABO-HDN is high. The main models of ABO-HDN were O-A and O-B. There was no significant difference in the incidence between O-A and O-B incompatible pregnancies. Three hemolysis tests are high sensitivity and are helpful in early diagnosis and early treatment of HDN.

  11. Association between the ABO locus and hematological traits in Korean

    Directory of Open Access Journals (Sweden)

    Hong Kyung-Won

    2012-09-01

    Full Text Available Abstract Background Recently, genome-wide association studies identified a pleiotropic gene locus, ABO, as being significantly associated with hematological traits. To confirm the effects of ABO on hematological traits, we examined the link between the ABO locus and hematological traits in Korean population-based cohorts. Results Six tagging SNPs for ABO were analyzed with regard to their effects on hematological traits [white blood cell count (WBC, red blood cell count (RBC, platelet (Plat, mean corpuscular volume (MCV, and mean corpuscular haemoglobin concentration (MCHC]. Linear regression analyses were performed, controlling for recruitment center, sex, and age as covariates. Of the 6 tagging SNPs, 3 (rs2073823, rs8176720, and rs495828 and 3 (rs2073823, rs8176717, and rs687289 were significantly associated with RBC and MCV, respectively (Bonferroni correction p-value criteria r2s = 0.99. Of the remaining 3 SNPs (rs8176720, rs8176717 and rs687289, rs8176717 generated an independent signal with moderate p-value (= 0.045 when it was adjusted for by rs2073823 (the most significant SNP. We also identified a copy number variation (CNV that was tagged by the SNP rs8176717, the minor allele of which correlated with the deletion allele of CNV. Our haplotype analysis indicated that the haplotype that contained the CNV deletion was significantly associated with MCV (β ± se = 0.363 ± 0.118, p =2.09 × 10-3. Conclusions Our findings confirm that ABO is one of the genetic factors that are associated with hematological traits in the Korean population. This result is notable, because GWASs fail to evaluate the link between a CNV and phenotype traits.

  12. Fe-doping induced Griffiths-like phase in La0.7Ba0.3CoO3

    International Nuclear Information System (INIS)

    Wan-Guo, Huang; Xiang-Qun, Zhang; Guo-Ke, Li; Young, Sun; Qing-An, Li; Zhao-Hua, Cheng

    2009-01-01

    The effect of Fe-doping on the magnetic properties of the ABO 3 -type perovskite cobaltites La 0.7 Ba 0.3 Co 1–y Fe y O 3 (0 ≤ y ≤ 0.80) is reported. With no apparent structural change in any doped sample, the Curie temperature (T C ) and the magnetization (M) are greatly suppressed for y ≤ 0.30 samples, while a distinct increase in T C for the y = 0.40 sample is observed. With the further increase of Fe concentration, T C increases monotonically. Griffiths-like phases in 0.40 ≤ y ≤ 0.60 samples are confirmed. The formation of the Griffiths-like phase is ascribed to B-site disordering induced isolation of ferromagnetic (FM) clusters above T C . (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  13. The role of ABO blood groups in Crohn's disease and in monitoring response to infliximab treatment.

    Science.gov (United States)

    Yu, Qiao; Wang, Lingyun; Zhang, Shenghong; Feng, Ting; Li, Li; Chen, Baili; Chen, Minhu

    2016-09-01

    The variation in ABO blood groups is reported to be associated with multiple diseases. Infliximab (IFX) has been widely used in the treatment of Crohn's disease (CD). We aim to investigate the distribution of ABO blood groups in Chinese patients with CD and to explore its impact on response to IFX. Patients with CD were consecutively recruited to the study between 2007 and 2014. CD patients receiving IFX therapy were followed for at least two years. In 293 patients with CD, most patients (40.6%) had blood type O (119/293). The odds ratio (OR) of CD in blood type O patients was 1.06 (95%CI: 0.6-1.86; p=0.84) compared to all other blood types. Among those CD patients, 107 patients received IFX treatment. One year after the first course of IFX, a significant association was found between the overall ABO system and outcomes of IFX treatment (pblood type AB (OR=4.42, 95% CI: 1.04-18.76; p=0.044) were more likely to achieve mucosal healing, while CD patients with blood type A had a high risk of losing response (OR=0.38, 95% CI: 0.15-0.96; p=0.040). ABO blood groups are not associated with prevalence of CD. Patients with blood type AB had a better response to IFX while those with blood type A appeared to have a risk of losing response to IFX.

  14. The nature of dynamic disorder in lead halide perovskite crystals (Conference Presentation)

    Science.gov (United States)

    Yaffe, Omer; Guo, Yinsheng; Hull, Trevor; Stoumpos, Costas; Tan, Liang Z.; Egger, David A.; Zheng, Fan; Szpak, Guilherme; Semonin, Octavi E.; Beecher, Alexander N.; Heinz, Tony F.; Kronik, Leeor; Rappe, Andrew M.; Kanatzidis, Mercouri G.; Owen, Jonathan S.; Pimenta, Marcos A.; Brus, Louis E.

    2016-09-01

    We combine low frequency Raman scattering measurements with first-principles molecular dynamics (MD) to study the nature of dynamic disorder in hybrid lead-halide perovskite crystals. We conduct a comparative study between a hybrid (CH3NH3PbBr3) and an all-inorganic lead-halide perovskite (CsPbBr3). Both are of the general ABX3 perovskite formula, and have a similar band gap and structural phase sequence, orthorhombic at low temperature, changing first to tetragonal and then to cubic symmetry as temperature increases. In the high temperature phases, we find that both compounds show a pronounced Raman quasi-elastic central peak, indicating that both are dynamically disordered.

  15. Perovskite phase thin films and method of making

    Science.gov (United States)

    Boyle, Timothy J.; Rodriguez, Mark A.

    2000-01-01

    The present invention comprises perovskite-phase thin films, of the general formula A.sub.x B.sub.y O.sub.3 on a substrate, wherein A is selected from beryllium, magnesium, calcium, strontium, and barium or a combination thereof; B is selected from niobium and tantalum or a combination thereof; and x and y are mole fractions between approximately 0.8 and 1.2. More particularly, A is strontium or barium or a combination thereof and B is niobium or tantalum or a combination thereof. Also provided is a method of making a perovskite-phase thin film, comprising combining at least one element-A-containing compound, wherein A is selected from beryllium, magnesium, calcium, strontium or barium, with at least one element-B-containing compound, wherein B niobium or tantalum, to form a solution; adding a solvent to said solution to form another solution; spin-coating the solution onto a substrate to form a thin film; and heating the film to form the perovskite-phase thin film.

  16. SINGLE-CENTER EXPERIENCE OF ABO-INCOMPATIBLE LIVER TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    S. V. Gautier

    2011-01-01

    Full Text Available Since 2008 up to 2010 eight ABO-incompatible liver transplantations have been performed in our center: one of them was urgent liver transplantation to adult patient from deceased donor, other seven were transplantations of left lateral segment to children from living relative donors. Own experience, as well as world one, proves, that barrier of ABO-incompatibility can be overcome more successfully in liver transplantation, particularly in pediatric population, that in other solid organs transplantation. Good results can be achieved even with less ag- gressive immunosuppressive therapy. Recipient conditioning before operation can significantly improve results of ABO-incompatible liver transplantation, but as own experience has shown, often there’s no need to hold some special preparation of children, because their anti-ABO antibodies are very low or absent before transplantation and do not increase after it. Thereby ABO-incompatible liver transplantation is reasonable in urgent cases and in pediatric population because of the limited pull of living relative donors for children. 

  17. An electron diffraction and bond valence sum study of the space group symmetries and structures of the photocatalytic 1:1 ordered A2InNbO6 double perovskites (A=Ca2+, Sr2+, Ba2+)

    International Nuclear Information System (INIS)

    Ting, V.; Liu, Y.; Withers, R.L.; Krausz, E.

    2004-01-01

    A careful investigation has been carried out into the space group symmetries, structures and crystal chemistries of the 1:1 B-site ordered double perovskites A 2 InNbO 6 (A=Ca 2+ , Sr 2+ , Ba 2+ ) using a combination of bond valence sum calculations, powder XRD and electron diffraction. A recent investigation of these compounds by Yin et al. reported a random distribution of In 3+ and Nb 5+ ions onto the perovskite B-site positions of these compounds and hence Pm3-barm (a=a p , subscript p for parent perovskite sub-structure) space group symmetry for the A=Ba and Sr compounds and Pnma (a=a p +b p , b=-a p +b p , c=2c p ) space group symmetry for the A=Ca compound. A careful electron diffraction study, however, shows that both the A=Ca and Sr compounds occur at room temperature in P12 1 /n1 (a=a p +b p , b=-a p +b p , c=2c p ) perovskite-related superstructure phases while the A=Ba compound occurs in the Fm3-barm, a=2a p , elpasolite structure type. Bond valence sum calculations are used to explain why this should be so as well as to provide a useful first-order approximation to the structures of each of the compounds

  18. Analysis of cathode materials of perovskite structure for solid oxide fuel cells, sofc s; Analisis de materiales catodicos de estructura perovskita para celdas de combustible de oxido solido, sofcs

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado F, J.; Espino V, J.; Avalos R, L. [Universidad Michoacana de San Nicolas de Hidalgo, Facultad de Ingenieria Quimica, Santiago Tapia 403, Morelia, Michoacan (Mexico)

    2015-07-01

    Fuel cells directly and efficiently convert the chemical energy of a fuel into electrical energy. Of the various types of fuel cells, the solid oxide (Sofc), combine the advantages in environmentally benign energy generation with fuel flexibility. However, the need for high operating temperatures (800 - 1000 grades C) has resulted in high costs and major challenges in relation to the compatibility the cathode materials. As a result, there have been significant efforts in the development of intermediate temperature Sofc (500 - 700 grades C). A key obstacle for operation in this temperature range is the limited activity of traditional cathode materials for electrochemical reduction oxygen. In this article, the progress of recent years is discussed in cathodes for Sofc perovskite structure (ABO{sub 3}), more efficient than the traditionally used La{sub 1-x}Sr{sub x}MnO{sub 3-δ} (LSM) or (La, Sr) CoO{sub 3}. Such is the case of mixed conductors (MIEC) double perovskite structure (A A B{sub 2}O{sub 5+δ}) using different doping elements as La, Sr, Fe, Ti, Cr, Sm, Co, Cu, Pr, Nd, Gd, dy, Mn, among others, which could improve the operational performance of existing cathode materials, promoting the development of optimized intermediate temperature Sofc designs. (Author)

  19. Carrier injection and recombination processes in perovskite CH3NH3PbI3 solar cells studied by electroluminescence spectroscopy

    Science.gov (United States)

    Handa, Taketo; Okano, Makoto; Tex, David M.; Shimazaki, Ai; Aharen, Tomoko; Wakamiya, Atsushi; Kanemitsu, Yoshihiko

    2016-02-01

    Organic-inorganic hybrid perovskite materials, CH3NH3PbX3 (X = I and Br), are considered as promising candidates for emerging thin-film photovoltaics. For practical implementation, the degradation mechanism and the carrier dynamics during operation have to be clarified. We investigated the degradation mechanism and the carrier injection and recombination processes in perovskite CH3NH3PbI3 solar cells using photoluminescence (PL) and electroluminescence (EL) imaging spectroscopies. By applying forward bias-voltage, an inhomogeneous distribution of the EL intensity was clearly observed from the CH3NH3PbI3 solar cells. By comparing the PL- and EL-images, we revealed that the spatial inhomogeneity of the EL intensity is a result of the inhomogeneous luminescence efficiency in the perovskite layer. An application of bias-voltage for several tens of minutes in air caused a decrease in the EL intensity and the conversion efficiency of the perovskite solar cells. The degradation mechanism of perovskite solar cells under bias-voltage in air is discussed.

  20. Heterovalent Dopant Incorporation for Bandgap and Type Engineering of Perovskite Crystals

    KAUST Repository

    Abdelhady, Ahmed L.

    2016-01-02

    Controllable doping of semiconductors is a fundamental technological requirement for electronic and optoelectronic devices. As intrinsic semiconductors, hybrid perovskites have so far been a phenomenal success in photovoltaics. The inability to dope these materials heterovalently (or aliovalently) has greatly limited their wider utilizations in electronics. Here we show an efficient in situ chemical route that achieves the controlled incorporation of trivalent cations (Bi3+, Au3+, or In3+) by exploiting the retrograde solubility behavior of perovskites. We term the new method dopant incorporation in the retrograde regime. We achieve Bi3+ incorporation that leads to bandgap tuning (∼300 meV), 104 fold enhancement in electrical conductivity, and a change in the sign of majority charge carriers from positive to negative. This work demonstrates the successful incorporation of dopants into perovskite crystals while preserving the host lattice structure, opening new avenues to tailor the electronic and optoelectronic properties of this rapidly emerging class of solution-processed semiconductors. © 2016 American Chemical Society.

  1. Heterovalent Dopant Incorporation for Bandgap and Type Engineering of Perovskite Crystals

    KAUST Repository

    Abdelhady, Ahmed L.; Saidaminov, Makhsud I.; Banavoth, Murali; Adinolfi, Valerio; Voznyy, Oleksandr; Katsiev, Khabiboulakh; Alarousu, Erkki; Comin, Riccardo; Dursun, Ibrahim; Sinatra, Lutfan; Sargent, Edward H.; Mohammed, Omar F.; Bakr, Osman

    2016-01-01

    Controllable doping of semiconductors is a fundamental technological requirement for electronic and optoelectronic devices. As intrinsic semiconductors, hybrid perovskites have so far been a phenomenal success in photovoltaics. The inability to dope these materials heterovalently (or aliovalently) has greatly limited their wider utilizations in electronics. Here we show an efficient in situ chemical route that achieves the controlled incorporation of trivalent cations (Bi3+, Au3+, or In3+) by exploiting the retrograde solubility behavior of perovskites. We term the new method dopant incorporation in the retrograde regime. We achieve Bi3+ incorporation that leads to bandgap tuning (∼300 meV), 104 fold enhancement in electrical conductivity, and a change in the sign of majority charge carriers from positive to negative. This work demonstrates the successful incorporation of dopants into perovskite crystals while preserving the host lattice structure, opening new avenues to tailor the electronic and optoelectronic properties of this rapidly emerging class of solution-processed semiconductors. © 2016 American Chemical Society.

  2. Association of ABO and Rh blood groups with breast cancer.

    Science.gov (United States)

    Meo, Sultan Ayoub; Suraya, Faryal; Jamil, Badar; Rouq, Fwziah Al; Meo, Anusha Sultan; Sattar, Kamran; Ansari, Mohammad Javed; Alasiri, Saleh A

    2017-11-01

    The aim of this study was to determine the association of "ABO" and "Rhesus" blood groups with incidence of breast cancer. In this study, we identified 70 research documents from data based search engines including "PubMed", "ISI-Web of Knowledge", "Embase" and "Google Scholar". The research papers were selected by using the primary key-terms including "ABO blood type", "Rhesus" blood type and "breast cancer". The research documents in which "ABO" and "Rhesus" blood types and breast cancer was debated were included. After screening, we reviewed 32 papers and finally we selected 25 research papers which met the inclusion criteria and remaining documents were excluded. Blood group "A" has high incidence of breast cancer (45.88%), blood group "O" has (31.69%); "B" (16.16%) and blood group "AB" has (6.27%) incidence of breast cancer. Blood group "A" has highest and blood group "AB" has least association with breast cancer. Furthermore, "Rhesus +ve" blood group has high incidence of breast cancer (88.31%) and "Rhesus -ve" blood group has least association with breast cancer (11.68%). Blood group "A" and "Rhesus +ve" have high risk of breast cancer, while blood type "AB" and "Rhesus -ve" are at low peril of breast cancer. Physicians should carefully monitor the females with blood group "A" and "Rh +ve" as these females are more prone to develop breast cancer. To reduce breast cancer incidence and its burden, preventive and screening programs for breast cancer especially in young women are highly recommended.

  3. Role of grain size on magnetic properties of La0.7Sr0.3MnO3

    International Nuclear Information System (INIS)

    Yadav, Priyanka A.; Adhi, K.P.; Patil, S.I.; Deshmukh, Alka V.

    2012-01-01

    The perovskite compound has the form ABO 3 , where A site is rare earth element and B site is occupied by Mn ions. Undoped perovskite Manganites like LaMnO 3 is antiferromagnetic insulator. While divalent doped Manganites of the form R (1-x) A x MnO 3 (where R: Trivalent rare earth ion, A: divalent alkali ion) exhibit properties like insulator to metal and paramagnetic to ferromagnetic transitions, colossal magnetoresistance, charge ordered behaviour, phase separation etc. Divalent doping (e.g. Ca, Sr, Ba) causes Mn 3+ to change in Mn 4+ state far charge compensation, depending on the doping concentration. During last decade, lot of work has been carried out on single crystal and polycrystalline perovskite Manganites. But very few reports have been found on nanoparticles of hole doped Manganites. Hence to study the effect of particle size on the properties of perovskite Manganites, we have synthesized the nanosized powder of La 0.7 Sr 0.3 MnO 3 (LSMO) by using citrate-gel method. The samples are sintered from 600-1200 ° C by the step of 50° C for four hours. The size of particles was determined using X-ray diffraction and Field Emission Scanning Electron Microscopy technique. The average particle size is in the range 17-20 nm for sample prepared at 600° C. It was found that size of nanoparticles increased with increasing sintering temperature. Magnetization measurements of the sample were carried out with the help of Vibrating Sample Magnetometer (VSM) at room temperature. Saturation magnetization was found to be increased with increasing particle size giving evidence of formation of dead magnetic layer on the surface. The coercivity of nanoparticles follows the same trend as explained by Cullity. A.C. susceptibility measurements for these samples show systematic increase in magnetic transition temperature and approach the bulk value with increase in the particle size. (author)

  4. Perovskites as electrodes of solid cells in sensitive elements of oxygen ion

    International Nuclear Information System (INIS)

    Gandurska, J.; Sniezynska, I.; Marek, A.; Szwagierczak, D.; Kulawik, J.

    1997-01-01

    The perovskite family comprises many compounds used in electronic applications. In this work perovskite materials based on LaCrO 3 were investigated, destined for electrodes of solid electrolyte oxygen sensors. lanthanum chromite powders modified by calcium, strontium and aluminium were prepared by the coprecipitation-calcination technique. The powders were examined using thermal analysis, x-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. Introductory studies of electromotive force of oxygen cells with yttria stabilized zirconia as solid electrolyte and perovskite-based electrodes proved that it is possible to replace expensive Pt electrodes by much cheaper perovskite ones. (author)

  5. Dendrimer ligands-capped CH3NH3PbBr3 perovskite nanocrystals with delayed halide exchange and record stability against both moisture and water

    Science.gov (United States)

    Xu, Yiren; Xu, Shuhong; Shao, Haibao; Jiang, Han; Cui, Yiping; Wang, Chunlei

    2018-06-01

    CH3NH3PbBr3 perovskite nanocrystals (NCs) suffer from poor stability because of their high sensitivity to environmental moisture and water. To solve this problem, previous works mainly focus on embedding perovskite NCs into water-resistant matrix to form large composites (size of microns or larger). As an alternative solution without serious changing of NC size, enhancing the stability of perovskite NCs themselves by ligand engineering is rarely reported. In this work, we used hyperbranched polyamidoamine (PAMAM) dendrimers with two different generations (G0 and G4) to synthesize CH3NH3PbBr3 perovskite NCs with high photoluminescence (PL) quantum yields (QY) above 70% and a new record stability. A novel dendrimers generation-dependent stability of perovskite NCs was observed. The water-resistance time is 18 h (27 h) for perovskite NCs capped by G0 (G4) generation of PAMAM, which is 7 times (11 times) longer than that of traditional oleic acid-capped NCs. Similar PAMAM generation-related stability is also observed in moisture-resistance tests. The stability time against moisture is 500 h (800 h) for G0 (G4) generation of PAMAM-capped perovskite NCs, which is a new record stability time against moisture for CH3NH3PbBr3 perovskite NCs. In addition, our results also indicate that PAMAM ligands outside perovskite NCs can dramatically slow down the speed of halide exchange. Even for the mixture of perovskite NCs with two different halide composition, the original luminescence properties of PAMAM-capped perovskite NCs can retain after mixing. In view of slow halide exchange speed, excellent water and moisture stability, PAMAM dendrimers-capped perovskite NCs and their mixture are available as color conversion single layer in fabrication of light-emitting diodes (LED).

  6. Dendrimer ligands-capped CH3NH3PbBr3 perovskite nanocrystals with delayed halide exchange and record stability against both moisture and water.

    Science.gov (United States)

    Xu, Yiren; Xu, Shuhong; Shao, Haibao; Jiang, Han; Cui, Yiping; Wang, Chunlei

    2018-06-08

    CH 3 NH 3 PbBr 3 perovskite nanocrystals (NCs) suffer from poor stability because of their high sensitivity to environmental moisture and water. To solve this problem, previous works mainly focus on embedding perovskite NCs into water-resistant matrix to form large composites (size of microns or larger). As an alternative solution without serious changing of NC size, enhancing the stability of perovskite NCs themselves by ligand engineering is rarely reported. In this work, we used hyperbranched polyamidoamine (PAMAM) dendrimers with two different generations (G0 and G4) to synthesize CH 3 NH 3 PbBr 3 perovskite NCs with high photoluminescence (PL) quantum yields (QY) above 70% and a new record stability. A novel dendrimers generation-dependent stability of perovskite NCs was observed. The water-resistance time is 18 h (27 h) for perovskite NCs capped by G0 (G4) generation of PAMAM, which is 7 times (11 times) longer than that of traditional oleic acid-capped NCs. Similar PAMAM generation-related stability is also observed in moisture-resistance tests. The stability time against moisture is 500 h (800 h) for G0 (G4) generation of PAMAM-capped perovskite NCs, which is a new record stability time against moisture for CH 3 NH 3 PbBr 3 perovskite NCs. In addition, our results also indicate that PAMAM ligands outside perovskite NCs can dramatically slow down the speed of halide exchange. Even for the mixture of perovskite NCs with two different halide composition, the original luminescence properties of PAMAM-capped perovskite NCs can retain after mixing. In view of slow halide exchange speed, excellent water and moisture stability, PAMAM dendrimers-capped perovskite NCs and their mixture are available as color conversion single layer in fabrication of light-emitting diodes (LED).

  7. Electrochemical hydrogen property improved in nano-structured perovskite oxide LaFeO3 for Ni/MH battery

    Science.gov (United States)

    Wang, Qiang; Deng, Gang; Chen, Zhiqian; Chen, Yungui; Cheng, Nanpu

    2013-02-01

    Perovskite oxide LaFeO3, as a novel candidate for the electrode of Ni/MH battery, holds high specific capacity and good cyclical durability at elevated temperatures. However, the poor electrochemical kinetics is a bottleneck for the application of this type of material. By use of nano-structured materials, there are greatly enhanced values of exchange current density I0 and hydrogen diffusion coefficient D, which resulted in an improvement of electrochemical kinetics, a much higher specific capacity and excellent stability during cycling for nano-structured LaFeO3. In theory, there is a significant possibility of further advancing the hydrogen reaction kinetics of perovskite type oxides for Ni/MH battery.

  8. 7 PREVALENCE OF Rh AND ABO BLOOD GROUPS IN HIV ...

    African Journals Online (AJOL)

    Bioline

    Summary: HIV status and blood groups determination (Rhesus and ABO groups) in 3691 pregnant ... quick test kits and tested for blood group types with anti-sera A,B,AB, and D. Overall, the prevalence of blood group .... Theory,Techniques,.

  9. Organic-Inorganic Perovskites: Structural Versatility for Functional Materials Design.

    Science.gov (United States)

    Saparov, Bayrammurad; Mitzi, David B

    2016-04-13

    Although known since the late 19th century, organic-inorganic perovskites have recently received extraordinary research community attention because of their unique physical properties, which make them promising candidates for application in photovoltaic (PV) and related optoelectronic devices. This review will explore beyond the current focus on three-dimensional (3-D) lead(II) halide perovskites, to highlight the great chemical flexibility and outstanding potential of the broader class of 3-D and lower dimensional organic-based perovskite family for electronic, optical, and energy-based applications as well as fundamental research. The concept of a multifunctional organic-inorganic hybrid, in which the organic and inorganic structural components provide intentional, unique, and hopefully synergistic features to the compound, represents an important contemporary target.

  10. rights reserved Relationship between ABO Blood Groups and Lipid

    African Journals Online (AJOL)

    ADOWIE PERE

    Key Words: Lipoproteins, Blood groups, cardiovascular diseases, triglycerides. After the discovery of ABO blood groups. (Lansteiner, 1900), several studies have reported that the occurence of some diseases can be correlated with blood group types e.g. carcinoma of stomach (Aird et al., 1953), cardiometabolic diseases ...

  11. MicroRNA-29b-1 impairs in vitro cell proliferation, self‑renewal and chemoresistance of human osteosarcoma 3AB-OS cancer stem cells.

    Science.gov (United States)

    Di Fiore, Riccardo; Drago-Ferrante, Rosa; Pentimalli, Francesca; Di Marzo, Domenico; Forte, Iris Maria; D'Anneo, Antonella; Carlisi, Daniela; De Blasio, Anna; Giuliano, Michela; Tesoriere, Giovanni; Giordano, Antonio; Vento, Renza

    2014-11-01

    Osteosarcoma (OS) is the most common type of bone cancer, with a peak incidence in the early childhood. Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. MicroRNAs (miRNAs) have been implicated in the maintenance of the CSC phenotype, thus, identification of CSC-related miRNAs would provide information for a better understanding of CSCs. Downregulation of miRNA-29 family members (miR-29a/b/c; miR‑29s) was observed in human OS, however, little is known about the functions of miR-29s in human OS CSCs. Previously, during the characterization of 3AB-OS cells, a CSC line selected from human OS MG63 cells, we showed a potent downregulation of miR-29b. In this study, after stable transfection of 3AB-OS cells with miR-29b-1, we investigated the role of miR-29b-1 in regulating cell proliferation, sarcosphere-forming ability, clonogenic growth, chemosensitivity, migration and invasive ability of 3AB-OS cells, in vitro. We found that, miR-29b-1 overexpression consistently reduced both, 3AB-OS CSCs growth in two- and three-dimensional culture systems and their sarcosphere- and colony-forming ability. In addition, while miR-29b-1 overexpression sensitized 3AB-OS cells to chemotherapeutic drug-induced apoptosis, it did not influence their migratory and invasive capacities, thus suggesting a context-depending role of miR-29b-1. Using publicly available databases, we proceeded to identify potential miR-29b target genes, known to play a role in the above reported functions. Among these targets we analyzed CD133, N-Myc, CCND2, E2F1 and E2F2, Bcl-2 and IAP-2. We also analyzed the most important stemness markers as Oct3/4, Sox2 and Nanog. Real-time RT-PCR and western-blot analyses showed that miR-29b-1 negatively regulated the expression of these markers. Overall, the results show that miR-29b-1 suppresses stemness properties of 3AB-OS CSCs and suggest that developing miR-29b-1 as a novel

  12. Room temperature oxidative intercalation with chalcogen hydrides: Two-step method for the formation of alkali-metal chalcogenide arrays within layered perovskites

    International Nuclear Information System (INIS)

    Ranmohotti, K.G. Sanjaya; Montasserasadi, M. Dariush; Choi, Jonglak; Yao, Yuan; Mohanty, Debasish; Josepha, Elisha A.; Adireddy, Shiva; Caruntu, Gabriel; Wiley, John B.

    2012-01-01

    Highlights: ► Topochemical reactions involving intercalation allow construction of metal chalcogenide arrays within perovskite hosts. ► Gaseous chalcogen hydrides serve as effect reactants for intercalation of sulfur and selenium. ► New compounds prepared by a two-step intercalation strategy are presented. -- Abstract: A two-step topochemical reaction strategy utilizing oxidative intercalation with gaseous chalcogen hydrides is presented. Initially, the Dion-Jacobson-type layered perovskite, RbLaNb 2 O 7 , is intercalated reductively with rubidium metal to make the Ruddlesden-Popper-type layered perovskite, Rb 2 LaNb 2 O 7 . This compound is then reacted at room-temperature with in situ generated H 2 S gas to create Rb-S layers within the perovskite host. Rietveld refinement of X-ray powder diffraction data (tetragonal, a = 3.8998(2) Å, c = 15.256(1) Å; space group P4/mmm) shows the compound to be isostructural with (Rb 2 Cl)LaNb 2 O 7 where the sulfide resides on a cubic interlayer site surrounded by rubidium ions. The mass increase seen on sulfur intercalation and the refined S site occupation factor (∼0.8) of the product indicate a higher sulfur content than expected for S 2− alone. This combined with the Raman studies, which show evidence for an H-S stretch, indicate that a significant fraction of the intercalated sulfide exists as hydrogen sulfide ion. Intercalation reactions with H 2 Se (g) were also carried out and appear to produce an isostructural selenide compound. The utilization of such gaseous hydride reagents could significantly expand multistep topochemistry to a larger number of intercalants.

  13. Perovskites A/sub 2/sup(II)Bsub(0. 5)sup(I)Bsub(0. 5)sup(III)Wsup(VI)O/sub 6/

    Energy Technology Data Exchange (ETDEWEB)

    Roller, H; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

    1978-05-01

    Compounds of type A/sub 2/sup(II)Bsub(0.5)sup(I)Bsub(0.5)sup(III)Wsup(VI)O/sub 6/ can be obtained with Asup(II) = Ba; Bsup(I) = Li, Na and Bsup(III) = La, Nd, Sm, Gd, Y, In, Sc just as with Asup(II) = Sr; Bsup(I) = Li and Bsup(III) = La, Nd, Sm, Gd, Y, In (all cubic ordered perovskites). For the cubic perovskites Sr/sub 2/Nasub(0.5)Lasub(0.5)WO/sub 6/ and Sr/sub 2/Nasub(0.5)Ndsub(0.5)WO/sub 6/ additional superlattice reflections are observed (a approximately equal to 16.4 A). The compounds Sr/sub 2/Nasub(0.5)Bsub(0.5)sup(III)WO/sub 6/ crystallize with Bsup(III) = Sm, Gd in a monoclinic and with Bsup(III) = Y, In in a rhombic distorted perovskite lattice. For the perovskites with A = Sr - dependent on ionic radii of the B ions - two different lattice types are present.

  14. The effect of ABO blood incompatibility on corneal transplant failure in conditions with low-risk of graft rejection.

    Science.gov (United States)

    Dunn, Steven P; Stark, Walter J; Stulting, R Doyle; Lass, Jonathan H; Sugar, Alan; Pavilack, Mark A; Smith, Patricia W; Tanner, Jean Paul; Dontchev, Mariya; Gal, Robin L; Beck, Roy W; Kollman, Craig; Mannis, Mark J; Holland, Edward J

    2009-03-01

    To determine whether corneal graft survival over a 5-year follow-up period was affected by ABO blood type compatibility in participants in the Cornea Donor Study undergoing corneal transplantation principally for Fuchs dystrophy or pseudophakic corneal edema, conditions at low-risk for graft rejection. Multi-center prospective, double-masked, clinical trial. ABO blood group compatibility was determined for 1,002 donors and recipients. During a 5-year follow-up period, episodes of graft rejection were documented, and graft failures were classified as to whether or not they were attributable to immunologic rejection. Endothelial cell density was determined by a central reading center for a subset of subjects. ABO donor-recipient incompatibility was not associated with graft failure attributable to any cause including graft failure because of rejection, or with the occurrence of a rejection episode. The 5-year cumulative incidence of graft failure attributable to rejection was 32 (6%) for recipients with ABO recipient-donor compatibility and 12 (4%) for those with ABO incompatibility (hazard ratio, 0.65; 95% confidence interval, 0.33 to 1.25; P = .20). The 5-year incidence for a definite rejection episode, irrespective of whether graft failure ultimately occurred, was 64 (12%) for ABO compatible compared with 25 (8%) for ABO incompatible cases (P = .09). Among clear grafts at 5 years, percent loss of endothelial cells was similar in ABO compatible and incompatible cases. In patients undergoing penetrating keratoplasty for Fuchs dystrophy or pseudophakic corneal edema, ABO matching is not indicated since ABO incompatibility does not increase the risk of transplant failure attributable to graft rejection.

  15. Nickel oxide electrode interlayer in CH3 NH3 PbI3 perovskite/PCBM planar-heterojunction hybrid solar cells.

    Science.gov (United States)

    Jeng, Jun-Yuan; Chen, Kuo-Cheng; Chiang, Tsung-Yu; Lin, Pei-Ying; Tsai, Tzung-Da; Chang, Yun-Chorng; Guo, Tzung-Fang; Chen, Peter; Wen, Ten-Chin; Hsu, Yao-Jane

    2014-06-25

    This study successfully demonstrates the application of inorganic p-type nickel oxide (NiOx ) as electrode interlayer for the fabrication of NiOx /CH3 NH3 PbI3 perovskite/PCBM PHJ hybrid solar cells with a respectable solar-to-electrical PCE of 7.8%. The better energy level alignment and improved wetting of the NiOx electrode interlayer significantly enhance the overall photovoltaic performance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Discrepancy in abo blood grouping

    International Nuclear Information System (INIS)

    Khan, M.N.; Ahmed, Z.; Khan, T.A.

    2013-01-01

    Discrepancies in blood typing is one of the major reasons in eliciting a transfusion reaction. These discrepancies can be avoided through detailed analysis for the blood typing. Here, we report a subgroup of blood group type-B in the ABO system. Donor's blood was analyzed by employing commercial antisera for blood grouping. The results of forward (known antisera) and reverse (known antigen) reaction were not complimentary. A detailed analysis using the standard protocols by American Association of Blood Banking revealed the blood type as a variant of blood group-B instead of blood group-O. This is suggestive of the fact that blood group typing should be performed with extreme care and any divergence, if identified, should be properly resolved to avoid transfusion reactions. Moreover, a major study to determine the blood group variants in Pakistani population is needed. (author)

  17. Blood Mixing Upregulates Platelet Membrane-Bound CD40 Ligand Expression in vitro Independent of Abo Compatibility.

    Science.gov (United States)

    Huang, Go-Shine; Hu, Mei-Hua; Lin, Tso-Chou; Lin, Yi-Chang; Tsai, Yi-Ting; Lin, Chih-Yuan; Ke, Hung-Yen; Zheng, Xu-Zhi; Tsai, Chien-Sung

    2017-11-30

    Platelets play a central role in the inflammation response via CD40 ligand (CD40L) expression, which may lead to transfusion reactions. The precise role of platelet CD40L-mediated inflammation in transfusion reactions is unclear. Therefore, we assessed the effects of in vitro blood mixing on platelet CD40L expression. In addition, we examined the effect of ABO compatibility on CD40L expression. Donor packed red blood cells were acquired from a blood bank, and recipient blood was obtained from patients undergoing cardiac surgery and prepared as washed platelets. Donor blood was mixed with suspended, washed recipient platelets to obtain a final mixing ratio of 1%, 5%, or 10% (vol/vol). The blood mixtures were divided into three groups: Group M, cross-matched blood-type mixing (n = 20); Group S, ABO type-specific uncross-matched blood (n = 20); and Group I, ABO incompatibility (not ABO type-specific blood and not process cross-matched) mixing (n = 20). The blood mixtures were used to detect platelet membrane-bound CD40L expression by flow cytometry. Blood mixing resulted in an increase in CD40L expression in Group M (P role in the induction of CD40L expression.

  18. The electronic and optical properties of CH3NH3MoI3 perovskite

    Science.gov (United States)

    Kansara, Shivam; Sonvane, Yogesh; Gupta, Sanjeev K.

    2018-05-01

    In this work, a first-principles theoretical study of hybrid perovskite CH3NH3MoI3 is performed using PBE exchange-correlation approximations in density functional theory. The results of electronic band structure are 0.90 eV (M-point: Direct) and 0.60 eV (R-X point: Indirect), respectively. We have also calculated the dielectric properties such as real, imaginary, extension coefficient (K) and reflectivity (R) properties of hybrid perovskite CH3NH3MoI3. The low-bandgap molecules are used to absorb near-IR range and typically having a bandgap smaller than 1.6 eV. This is particularly attractive in organic photovoltaics (OPV), photodetectors (PDs), and ambipolar field-effect transistors (FETs).

  19. Effect of ABO blood type on the outcomes of patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors.

    Science.gov (United States)

    Omae, Kenji; Fukuma, Shingo; Ikenoue, Tatsuyoshi; Kondo, Tsunenori; Takagi, Toshio; Ishihara, Hiroki; Tanabe, Kazunari; Fukuhara, Shunichi

    2017-09-01

    To assess the effect of blood type on survival outcomes and adverse events (AEs) in patients treated with tyrosine kinase inhibitors (TKIs) for metastatic renal cell carcinoma (mRCC). Patients who received TKIs as first-line therapy for mRCC between 2008 and 2015 at our hospital were included in the study (n = 136). Patients were divided into 2 groups based on their blood type as O and non-O. Survival outcomes and AEs were compared according to blood type. Cox regression models were used for univariate and multivariate survival analyses. Of the 136 patients, 34 (25%) and 102 (75%) had O and non-O blood types, respectively. Blood type O was associated with an increased number of disease sites. There were no differences between the 2 groups with respect to other baseline characteristics. The progression-free survival in patients with O and non-O blood types was 12.1 and 11.6 months, respectively; the overall survival was 34.4 and 24.8 months, respectively. On univariate and multivariate analyses, the ABO blood type was not a significant prognostic factor for progression-free survival or overall survival. Furthermore, the incidences of serious AEs were similar in the 2 blood groups. ABO blood type was not associated with survival outcomes or incidences of serious AEs in mRCC patients treated with TKIs. However, blood type O may be associated with an increased number of disease sites. Copyright © 2017. Published by Elsevier Inc.

  20. Study of total oxidation of ethanol using the perovskite-type oxides LaBO{sub 3} (B= Mn, Ni, Fe); Estudo da oxidacao total do etanol usando oxidos tipo perovskita LaBO{sub 3} (B= Mn, Ni, Fe)

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Ana Brigida [Centro Federal de Educacao Tecnologica do Espirito Santo, Vitoria, ES (Brazil). Centro de Ciencias e Tecnologias Quimicas]. E-mail: brigida@cefetes.br; Silva, Paulo Roberto Nagipe da [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil). Centro de Ciencias e Tecnologia; Freitas, Jair C.C. [Universidade Federal do Espirito Santo, Vitoria, ES (Brazil). Centro de Ciencias Exatas. Dept. de Fisica; Almeida, Clara Muniz de [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Fisica

    2007-09-15

    The present work investigated the effect of coprecipitation-oxidant synthesis on the specific surface area of perovskite-type oxides LaBO{sub 3} (BMn, Ni, Fe) for total oxidation of ethanol. The perovskite-type oxides were characterized by X-ray diffraction, nitrogen adsorption (BET method), thermogravimetric analysis (TGA-DTA), TPR and X-ray photoelectron spectroscopy (XPS). Through method involving the coprecipitation-oxidant was possible to obtain catalysts with different BET specific surface areas, of 33-51 m{sup 2}/g. The results of the catalytic test confirmed that all oxides investigated in this work have specific catalytic activity for total oxidation of ethanol, though the temperatures for total conversion change for each transition metal. (author)

  1. What makes the difference in perovskite titanates?

    Science.gov (United States)

    Bussmann-Holder, Annette; Roleder, Krystian; Ko, Jae-Hyeon

    2018-06-01

    We have investigated in detail the lattice dynamics of five different perovskite titanates ATiO3 (A = Ca, Sr, Ba, Pb, Eu) where the A sites are occupied by +2 ions. In spite of the largely ionic character of these ions, the properties of these compounds differ substantially. They range from order/disorder like, to displacive ferroelectric, quantum paraelectric, and antiferromagnetic. All compounds crystallize in the cubic structure at high temperature and undergo structural phase transitions to tetragonal symmetry, partly followed by further transitions to lower symmetries. Since the TiO6 moiety is the essential electronic and structural unit, the question arises, what makes the significant difference between them. It is shown that the lattice dynamics of these compounds are very different, and that mode-mode coupling effects give rise to many distinct properties. In addition, the oxygen ion nonlinear polarizability plays a key role since it dominates the anharmonicity of these perovskites and determines the structural instability.

  2. Thermally induced A'-A site exchange in novel layered perovskites Ag2[Ca1.5M3O10] (M = Nb, Ta).

    Science.gov (United States)

    Bhuvanesh, Nattamai S P; Woodward, Patrick M

    2002-12-04

    We have synthesized and characterized new layered perovskites Ag2[A1.5M3O10] (A = Ca, M = Nb, Ta), from their lithium analogues, by soft-chemical ion exchange. These oxides show topotactic irreversible thermally induced A'-A site exchange, resulting in Ag1.1Ca0.9[Ca0.6Ag0.9M3O10], conferred from our high-temperature X-ray and ionic conductivity studies. The latter phases are the first compounds where Ag+ ions reside in both A' and A sites in layered perovskites. The absence of similar phase transition for A = Sr suggests that these transitions strongly depend on the size, charge, and the coordination preference of A' and A cations. This result provides a new synthetic tool for modifying the occupation of the 12-coordinate A site of layered perovskites using soft chemical routes.

  3. Enhancement of photoresponse property of perovskite solar cell by aluminium chloride (AlCl3)

    Science.gov (United States)

    Ghosh, S. S.; Sil, A.

    2018-05-01

    The fabrication of a three layer solar cell device is a new area of research. The formation of perovskite phase is evident from x-ray diffraction and its particle size is observed by microstructural analysis. A thin layer of gold coating over the device increases the surface conductivity. Direct contact between a SnCl2 or AlCl3 based perovskite with the gold coating increases the durability of the film but decreases the hole transport properties due to absence of an organic hole transport material. The absorbance spectroscopy analysis gives characteristic peaks showing the evidence of ITO, TiO2 (rutile) and Sn2+ complexes present in the Sn-perovskite film or Al3+ complexes present within the Al-perovskite cell. The desired absorbance near 550 nm due to Al3+ complexes causes a much higher flow of current on illumination and thus is also evidenced by the presence of comparatively high intensity PL spectra in the Al-perovskite system which occurred due to free exciton formation near band edge excitation. The fill factor of the devices is estimated as ∼0.83 and ∼0.65 for Sn-perovskite and Al-perovskite devices respectively. The PCE values of Sn-perovskite and Al-perovskite devices are calculated 0.39% and 0.96% respectively, which establish Al-perovskite film as a useful component for future solar cell device manufacturing.

  4. Synthesis and characterization of a-site doped LaTiO3 nano perovskites

    International Nuclear Information System (INIS)

    Bradha, M.; Ashok, Anuradha

    2013-01-01

    Nano-sized lanthanum titanate perovskites (La (1-x) A x TiO 3 ) (A= Ba, Sr, Ca) were prepared by sol-gel method and calcined at 800℃. The synthesised perovskites were characterized by Thermogravimetry/ Differential thermal analysis (TGA/DTA), X-ray diffraction (XRD) and High Resolution Transmission Electron Microscopy (HRTEM) etc. LaTiO 3 is a perovskite having prominent interest for a variety of applications such as dielectric, insulators, charge-transport properties etc. It is a defect perovskite, with transport properties varying from insulating to metallic based on oxygen stoichiometry. In a quest to observe the effect of the nano size on its properties, lanthanum titanate (LaTiO 3 ) nano perovskites with different dopants on the A-site were prepared by using sol-gel method. In the present work we discuss the synthesis and structural analysis of (La 0.8 A 0.2 TiO 3 ). Phase purity and structural analysis of the calcined samples were performed by powder X-ray diffraction (XRD, with CuKα radiation). In addition to this, morphology and crystal structure was examined by Transmission Electron Microscopy (TEM) using a JEOL JEM 2100 HRTEM. HRTEM studies indicate that the nano perovskites are of size around 20 nm. Ring pattern in SAED also confirms that the perovskite is polycrystalline/nanocrystalline. More detailed study on high resolution images and crystal structure shed light on the reason for the properties exhibited by this perovskites

  5. Pressure-Induced Metallization of the Halide Perovskite (CH 3 NH 3 )PbI 3

    Energy Technology Data Exchange (ETDEWEB)

    Jaffe, Adam; Lin, Yu [Photon; Mao, Wendy L. [Photon; Karunadasa, Hemamala I.

    2017-03-10

    We report the metallization of the hybrid perovskite semiconductor (MA)PbI3 (MA = CH3NH3+) with no apparent structural transition. We tracked its bandgap evolution during compression in diamond-anvil cells using absorption spectroscopy and observed strong absorption over both visible and IR wavelengths at pressures above ca. 56 GPa, suggesting the imminent closure of its optical bandgap. The metallic character of (MA)PbI3 above 60 GPa was confirmed using both IR reflectivity and variable-temperature dc conductivity measurements. The impressive semiconductor properties of halide perovskites have recently been exploited in a multitude of optoelectronic applications. Meanwhile, the study of metallic properties in oxide perovskites has revealed diverse electronic phenomena. Importantly, the mild synthetic routes to halide perovskites and the templating effects of the organic cations allow for fine structural control of the inorganic lattice. Pressure-induced closure of the 1.6 eV bandgap in (MA)PbI3 demonstrates the promise of the continued study of halide perovskites under a range of thermodynamic conditions, toward realizing wholly new electronic properties.

  6. Polymorphism of tungsten perovskite compounds Ba/sub 2/SEsub(0. 67)WO/sub 6/

    Energy Technology Data Exchange (ETDEWEB)

    Schittenhelm, H J; Kemmler-Sack, S [Tuebingen Univ. (F.R. Germany). Inst. fuer Anorganische Chemie

    1976-09-01

    The compounds Ba/sub 2/SEsub(0.67)WO/sub 6/ with SE = Gd-Lu are polymorphic. Above 1200/sup 0/C the instable cubic modification (ordered perovskite with 4 formula units Ba/sub 2/SEsub(0.67)vacantsub(0.33)WO/sub 6/ per cell) transforms irreversibly into a hexagonal modification with completely filled cationic lattice. For Ba/sub 2/Eusub(0.67)WO/sub 6/ the transformation is incomplete. With SE = Nd and Sm only the cubic modification is formed.

  7. ABO blood groups and oral premalignancies: A clinical study in selected Indian population.

    Science.gov (United States)

    Bhateja, S; Arora, G

    2014-01-01

    Background: The ABO blood group antigens are present on the surface of red blood cells and various epithelial cells. As the majority of human cancers are derived from epithelial cells, changes in blood group antigens constitute an important aspect of human cancers. The aim of the study was to establish clinical usefulness of ABO blood group as a predisposing factor in early diagnosis and management of patients with oral precancerous lesions/conditions. Materials and Methods: The study sample consisted of 50 control and 50 oral precancer (25 leukoplakia and 25 Oral Submucous Fibrosis) confirmed by histopathologic examination. All samples were subjected to blood group testing and their prevalence was compared by Z-test using STATA version 8. Results: The "A" blood group was prevalent among the precancerous group. Significant differences on prevalences of blood groups were found (P blood group. Conclusion: Blood group type should be considered along with other risk factors to understand the individual patient's risk and further studies in larger samples with inclusion of Rh factor is needed to elucidate the relationship with ABO blood group types.

  8. [Genotyping of ABO Blood Group in Partial Population of Yunnan Province by SNaPshot Technology].

    Science.gov (United States)

    Yu, S X; Zeng, F M; Jin, Y Z; Wan, H J; Zhai, D; Xing, Y M; Cheng, B W

    2017-06-01

    To detect the genotype of ABO blood group by SNaPshot technology. DNA were extracted from the peripheral blood samples with known blood groups (obtained by serology) of 107 unrelated individuals in Yunnan. Six SNP loci of the 261th, 297th, 681th, 703th, 802th, and 803th nucleotide positions were detected by SNaPshot Multiplex kit, and relevant genetics parameters were calculated. In 107 blood samples, the allele frequencies of types A, B, O A , and O G were 0.355 1, 0.168 2, 0.230 0 and 0.247 6, respectively, while that of types A G and cis AB were not detected. The genotyping results of ABO blood group were consistent with that of serologic testing. SNaPshot technology can be adapted for genotyping of ABO blood group. Copyright© by the Editorial Department of Journal of Forensic Medicine

  9. Interfacial B-site atomic configuration in polar (111) and non-polar (001) SrIrO3/SrTiO3 heterostructures

    Science.gov (United States)

    Anderson, T. J.; Zhou, H.; Xie, L.; Podkaminer, J. P.; Patzner, J. J.; Ryu, S.; Pan, X. Q.; Eom, C. B.

    2017-09-01

    The precise control of interfacial atomic arrangement in ABO3 perovskite heterostructures is paramount, particularly in cases where the subsequent electronic properties of the material exhibit geometrical preferences along polar crystallographic directions that feature inevitably complex surface reconstructions. Here, we present the B-site interfacial structure in polar (111) and non-polar (001) SrIrO3/SrTiO3 interfaces. The heterostructures were examined using scanning transmission electron microscopy and synchrotron-based coherent Bragg rod analysis. Our results reveal the preference of B-site intermixing across the (111) interface due to the polarity-compensated SrTiO3 substrate surface prior to growth. By comparison, the intermixing at the non-polar (001) interface is negligible. This finding suggests that the intermixing may be necessary to mitigate epitaxy along heavily reconstructed and non-stoichiometric (111) perovskite surfaces. Furthermore, this preferential B-site configuration could allow the geometric design of the interfacial perovskite structure and chemistry to selectively engineer the correlated electronic states of the B-site d-orbital.

  10. Interfacial B-site atomic configuration in polar (111 and non-polar (001 SrIrO3/SrTiO3 heterostructures

    Directory of Open Access Journals (Sweden)

    T. J. Anderson

    2017-09-01

    Full Text Available The precise control of interfacial atomic arrangement in ABO3 perovskite heterostructures is paramount, particularly in cases where the subsequent electronic properties of the material exhibit geometrical preferences along polar crystallographic directions that feature inevitably complex surface reconstructions. Here, we present the B-site interfacial structure in polar (111 and non-polar (001 SrIrO3/SrTiO3 interfaces. The heterostructures were examined using scanning transmission electron microscopy and synchrotron-based coherent Bragg rod analysis. Our results reveal the preference of B-site intermixing across the (111 interface due to the polarity-compensated SrTiO3 substrate surface prior to growth. By comparison, the intermixing at the non-polar (001 interface is negligible. This finding suggests that the intermixing may be necessary to mitigate epitaxy along heavily reconstructed and non-stoichiometric (111 perovskite surfaces. Furthermore, this preferential B-site configuration could allow the geometric design of the interfacial perovskite structure and chemistry to selectively engineer the correlated electronic states of the B-site d-orbital.

  11. CH3 NH3 PbBr3 Perovskite Nanocrystals as Efficient Light-Harvesting Antenna for Fluorescence Resonance Energy Transfer.

    Science.gov (United States)

    Muthu, Chinnadurai; Vijayan, Anuja; Nair, Vijayakumar C

    2017-05-04

    Hybrid perovskites have created enormous research interest as a low-cost material for high-performance photovoltaic devices, light-emitting diodes, photodetectors, memory devices and sensors. Perovskite materials in nanocrystal form that display intense luminescence due to the quantum confinement effect were found to be particularly suitable for most of these applications. However, the potential use of perovskite nanocrystals as a light-harvesting antenna for possible applications in artificial photosynthesis systems is not yet explored. In the present work, we study the light-harvesting antenna properties of luminescent methylammonium lead bromide (CH 3 NH 3 PbBr 3 )-based perovskite nanocrystals using fluorescent dyes (rhodamine B, rhodamine 101, and nile red) as energy acceptors. Our studies revealed that CH 3 NH 3 PbBr 3 nanocrystals are an excellent light-harvesting antenna, and efficient fluorescence resonance energy transfer occurs from the nanocrystals to fluorescent dyes. Further, the energy transfer efficiency is found to be highly dependent on the number of anchoring groups and binding ability of the dyes to the surface of the nanocrystals. These observations may have significant implications for perovskite-based light-harvesting devices and their possible use in artificial photosynthesis systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Effects of GeI2 or ZnI2 addition to perovskite CH3NH3PbI3 photovoltaic devices

    Science.gov (United States)

    Tanaka, Hiroki; Ohishi, Yuya; Oku, Takeo

    2018-01-01

    CH3NH3PbI3 added with GeI2 or ZnI2 perovskite photovoltaic devices were fabricated characterized. The surface coverages of the perovskite layers were improved by the addition of GeI2 or ZnI2. Formation of PbI2 observed for the pristine CH3NH3PbI3 was suppressed by the GeI2 or ZnI2 addition, which resulted in the improvement of the conversion efficiencies of the perovskite photovoltaic devices.

  13. Crystalline behaviour and electrical properties of manganese perovskites substituted on A or B sites: ErMnO3 modified by Ca and EuMnO3 modified by Co

    Directory of Open Access Journals (Sweden)

    Tartaj, J.

    2010-06-01

    Full Text Available The structural and electrical features of the manganites solid solutions (Er,CaMnO3 and Eu(Co,MnO3, have been studied by X-ray diffraction and conductivity measurements. Powders were prepared by solid-state reaction between the component oxides and Calcium carbonate. Incorporation of Co2+ on the lattice in the B sites or the Ca2+ on the A sites leads to changes in the parameters and symmetry of the perovskite compound EuMnO3 and hexagonal ErMnO3 respectively. The phase transition depends on the amount of substituted Jahn-Teller Mn3+ cations. Solid solutions based on Eu(Mn,CoO3 perovskite compound change from O’-type to O-type orthorhombic perovskite symmetry when the Mn3+ cation amount decreases, because of the progressive substitution by Co. This transition occurs for an amount of Co2+ as low as ~10 at% Co2+ cation. The (Er,CaMnO3 based solid solutions showed a different behaviour. From x=0.25 there is a change in the symmetry of the solid solution from hexagonal to orthorhombic, O’-type perovskite. Steric influence seems to play a secondary role on the lattice distortion of manganites. Sintered samples of the perovskite solid solutions were measured for establishing their electrical properties. All the samples showed semiconducting behaviour.

    Las características estructurales y eléctricas de las soluciones sólidas de manganitas (Er,CaMnO3 y Eu(Co,MnO3, han sido estudiadas por difracción de rayos X y medidas de la conductividad en continua. Los polvos fueron preparados por reacción en estado sólido entre los óxidos componentes y carbonato de calcio. La incorporación de Co2+ en la red en los sitios B o de Ca2+ en los sitios A conduce a cambios en los parámetros y la simetría de EuMnO3 perovskita y ErMnO3 hexagonal, respectivamente

  14. ABO Blood Type and Stroke Risk: The REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

    Science.gov (United States)

    Zakai, Neil A.; Judd, Suzanne E.; Alexander, Kristine; McClure, Leslie A.; Kissela, Brett M.; Howard, George; Cushman, Mary

    2016-01-01

    Background ABO blood type is an inherited trait associated with coagulation factor levels and vascular outcomes. Objectives To assess the association of blood type with stroke and whether blood type contributes to racial disparities in stroke in the United States. Patients and Methods The REasons for Geographic and Racial Differences in Stroke (REGARDS) Study recruited 30,239 participants between 2003-07. Using a case-cohort design, blood type was genotyped in 646 participants with stroke and a 1,104 participant cohort random sample. Cox models adjusting for Framingham stroke risk factors assessed the association of blood type with stroke. Results Over 5.8 years of follow-up, blood types A or B versus type O were not associated with stroke. Blood type AB versus O was associated with an increased risk of stroke (adjusted HR 1.83; 95% CI 1.01, 3.30). The association of blood type AB versus O was greater in those without diabetes (adjusted HR 3.33; 95% CI 1.61, 6.88) than those with diabetes (adjusted HR 0.49; 95% CI 0.17, 1.44) (p-interaction = 0.02). Factor VIII levels accounted for 60% (95% CI 11%, 98%) of the association of AB blood type and stroke risk. Conclusion Blood type AB is associated with an increased risk of stroke that is not attenuated by conventional stroke risk factors and factor VIII levels were associated with 60% of the association. While blood type AB is rare in the U.S. population, it is a significant stroke risk factor and may play an important role in stroke risk in these individuals. PMID:24444093

  15. Strain effects on the spin polarized electron gas in ABO3/SrTiO3 (A = Pr, Nd and B = Al, Ga) heterostructures

    KAUST Repository

    Nazir, Safdar

    2013-04-11

    The spin polarized two dimensional electron gas in the correlated ABO3/SrTiO3 (A = Pr, Nd and B = Al, Ga) heterostructures is investigated by ab-initio calculations using density functional theory. Structural relaxation shows a strong buckling at and near the TiO2 terminated n-type interface (IFs) due to significant TiO6 octahedral distortions. We find in all cases, metallic states in a very narrow region of the SrTiO3, in agreement with experimental results. We demonstrate that the interface magnetism strongly reacts to the magnitude of the lattice strain. The orbital occupations and, hence, the charge carrier density change systematically as a function of the lattice mismatch between the component materials.

  16. Strain effects on the spin polarized electron gas in ABO3/SrTiO3 (A = Pr, Nd and B = Al, Ga) heterostructures

    KAUST Repository

    Nazir, Safdar; Schwingenschlö gl, Udo

    2013-01-01

    The spin polarized two dimensional electron gas in the correlated ABO3/SrTiO3 (A = Pr, Nd and B = Al, Ga) heterostructures is investigated by ab-initio calculations using density functional theory. Structural relaxation shows a strong buckling at and near the TiO2 terminated n-type interface (IFs) due to significant TiO6 octahedral distortions. We find in all cases, metallic states in a very narrow region of the SrTiO3, in agreement with experimental results. We demonstrate that the interface magnetism strongly reacts to the magnitude of the lattice strain. The orbital occupations and, hence, the charge carrier density change systematically as a function of the lattice mismatch between the component materials.

  17. Evaluation of an automated microplate technique in the Galileo system for ABO and Rh(D) blood grouping.

    Science.gov (United States)

    Xu, Weiyi; Wan, Feng; Lou, Yufeng; Jin, Jiali; Mao, Weilin

    2014-01-01

    A number of automated devices for pretransfusion testing have recently become available. This study evaluated the Immucor Galileo System, a fully automated device based on the microplate hemagglutination technique for ABO/Rh (D) determinations. Routine ABO/Rh typing tests were performed on 13,045 samples using the Immucor automated instruments. Manual tube method was used to resolve ABO forward and reverse grouping discrepancies. D-negative test results were investigated and confirmed manually by the indirect antiglobulin test (IAT). The system rejected 70 tests for sample inadequacy. 87 samples were read as "No-type-determined" due to forward and reverse grouping discrepancies. 25 tests gave these results because of sample hemolysis. After further tests, we found 34 tests were caused by weakened RBC antibodies, 5 tests were attributable to weak A and/or B antigens, 4 tests were due to mixed-field reactions, and 8 tests had high titer cold agglutinin with blood qualifications which react only at temperatures below 34 degrees C. In the remaining 11 cases, irregular RBC antibodies were identified in 9 samples (seven anti-M and two anti-P) and two subgroups were identified in 2 samples (one A1 and one A2) by a reference laboratory. As for D typing, 2 weak D+ samples missed by automated systems gave negative results, but weak-positive reactions were observed in the IAT. The Immucor Galileo System is reliable and suited for ABO and D blood groups, some reasons may cause a discrepancy in ABO/D typing using a fully automated system. It is suggested that standardization of sample collection may improve the performance of the fully automated system.

  18. Structural and thermal studies of H2La2/3Ta2O7, a protonated layered perovskite

    International Nuclear Information System (INIS)

    Le Berre, F.; Crosnier-Lopez, M.P.; Fourquet, J.L.

    2006-01-01

    We have synthesised the new protonated layered perovskite H 2 La 2/3 Ta 2 O 7 which is related to the Ruddlesden-Popper family. This compound is obtained by ionic exchange starting from Li 2 La 2/3 Ta 2 O 7 maintained in dilute HNO 3 at 60 deg. C. Thermal X-ray diffraction and DTA/TGA revealed interesting dehydration properties with formation of a layered anhydrous phase leading at higher temperature (1550 deg. C) to La 1/3 TaO 3 . This latter compound exhibits the original lanthanum ordering expected similarly to that of the Li form, while at 900 deg. C a metastable form, presenting a disordered La distribution, is observed

  19. Crystallographic Investigations into Properties of Acentric Hybrid Perovskite Single Crystals NH(CH3)3SnX3(X = Cl, Br)

    KAUST Repository

    Dang, Yangyang; Zhong, Cheng; Zhang, Guodong; Ju, Dianxing; Wang, Lei; Xia, Shengqing; Xia, Haibing; Tao, Xutang

    2016-01-01

    substitute for the lead in the halides perovskites and solving the ambiguous crystal structures and phase transition of NH(CH3)3SnX3 (X = Cl, Br). Here, we report the bulk crystal growths and different crystal morphologies of orthorhombic hybrid perovskites

  20. Single-crystal perovskite CH3NH3PbBr3 prepared by cast capping method for light-emitting diodes

    Science.gov (United States)

    Nguyen, Van-Cao; Katsuki, Hiroyuki; Sasaki, Fumio; Yanagi, Hisao

    2018-04-01

    In this study, electroluminescence from single crystals of CH3NH3PbBr3 perovskite is explored. The cast capping method was applied to fabricate simple devices with an ITO/CH3NH3PbBr3/ITO structure. The devices showed a low operation voltage of 2 V and a pure green luminescence with full width at half maximum of ∼20 nm. However, the emission occurring at the crystal edges demonstrated blinking with a subsecond time interval, which is similar to the previously reported photoluminescence behavior of nanocrystal perovskites. This electroluminescence blinking may provide new insight into the recombination processes depending on the carrier traps and defects of emission layers in perovskite light-emitting devices.

  1. Modulation of electronic and optical properties in mixed halide perovskites CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x)

    Science.gov (United States)

    Zhou, Ziqi; Cui, Yu; Deng, Hui-Xiong; Huang, Le; Wei, Zhongming; Li, Jingbo

    2017-03-01

    The recent discovery of lead halide perovskites with band gaps in the visible presents important potential in the design of high efficient solar cells. CsPbCl3, CsPbBr3 and CsPbI3 are stable compounds within this new family of semiconductors. By performing the first-principles calculation, we explore the structural, electronic and optical properties of CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) with various compositions of halide atoms. Structural stability is demonstrated with halide atoms distributing randomly at the halide atomic sites. CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) exhibit the modulation of their band gaps by varying the halide composition. Our results also indicate that CsPbCl3xBr3(1-x) and CsPbBr3xI3(1-x) with different halide compositions are suitable to application to solar cells for the general features are well preserved. Good absorption to lights of different wavelengths has been obtained in these mixed halide perovskites.

  2. Ruddlesden-Popper compounds (SrO)(LaFeO3)n (n = 1 and 2) as p-type semiconductors for photocatalytic hydrogen production

    International Nuclear Information System (INIS)

    Chen, Hongmei; Sun, Xiaoqin; Xu, Xiaoxiang

    2017-01-01

    Graphical abstract: Two layered ferrites LaSrFeO 4 and La 2 SrFe 2 O 7 have been investigated which demonstrate interesting p-type semconductivity and efficient hydrogen production from water. Display Omitted -- Abstract: Here we report two Ruddlesden-Popper type ferrite perovskites (SrO)(LaFeO 3 ) n (n = 1 and 2) which demonstrate p-type semiconductivity. Their crystal structure, optical absorption and other physicochemical properties have been systematically explored. Our results show that both ferrites crystallize in tetragonal symmetry with structural lamination along c axis. Efficient photocatalytic hydrogen production has been achieved for both samples under full range and visible light illumination. Better performance is noticed for LaSrFeO 4 with apparent quantum efficiency approaches 0.31% and 0.19% under full range and visible light illumination, respectively. The p-type semiconductivity is verified by their cathodic photocurrent as well as negative Mott-Schottky slop during Photoelectrochemical measurement. The relative lower activity for La 2 SrFe 2 O 7 compared to LaSrFeO 4 is likely due to its higher defect concentration which facilitates charge recombination. Both compounds exhibit anisotropic phenomenon for charge migrations according to theoretical calculations. Their p-type semiconductivity, strong visible light absorption, chemical inertness and high abundance of constituent elements signify promising applications in the field of solar energy conversion and optoelectronics.

  3. Raman scattering in La1-xSrxFeO3-δ thin films: annealing-induced reduction and phase transformation

    Science.gov (United States)

    Islam, Mohammad A.; Xie, Yujun; Scafetta, Mark D.; May, Steven J.; Spanier, Jonathan E.

    2015-04-01

    Raman scattering in thin film La0.2Sr0.8FeO3-δ on MgO(0 0 1) collected at 300 K after different stages of annealing at selected temperatures T (300 K topotactic transformation of the crystal structure from that of the rhombohedral ABO3 perovskites to that of Brownmillerite-like structure consisting of octahedrally and tetrahedrally coordinated Fe atoms.

  4. Room-temperature polar order in [NH4][Cd(HCOO)3]--a hybrid inorganic-organic compound with a unique perovskite architecture.

    Science.gov (United States)

    Gómez-Aguirre, L C; Pato-Doldán, B; Stroppa, A; Yáñez-Vilar, S; Bayarjargal, L; Winkler, B; Castro-García, S; Mira, J; Sánchez-Andújar, M; Señarís-Rodríguez, M A

    2015-03-02

    We report on the hybrid inorganic-organic ammonium compound [NH4][Cd(HCOO)3], which displays a most unusual framework structure: instead of the expected 4(9)·6(6) topology, it shows an ABX3 perovskite architecture with the peculiarity and uniqueness (among all the up-to-date reported hybrid metal formates) that the Cd ions are connected only by syn-anti formate bridges, instead of anti-anti ones. This change of the coordination mode of the formate ligand is thus another variable that can provide new possibilities for tuning the properties of these versatile functional metal-organic framework materials. The room-temperature crystal structure of [NH4][Cd(HCOO)3] is noncentrosymmetric (S.G.: Pna21) and displays a polar axis. DFT calculations and symmetry mode analysis show that the rather large polarization arising from the off-center shift of the ammonium cations in the cavities (4.33 μC/cm(2)) is partially canceled by the antiparallel polarization coming from the [Cd(HCOO)3](-) framework, thus resulting in a net polarization of 1.35 μC/cm(2). As shown by second harmonic generation studies, this net polarization can be greatly increased by applying pressure (Pmax = 14 GPa), an external stimulus that, in turn, induces the appearance of new structural phases, as confirmed by Raman spectroscopy.

  5. Gene frequencies of ABO and rhesus blood groups and ...

    African Journals Online (AJOL)

    The distribution and gene frequencies of ABO and rhesus (Rh) blood groups and haemoglobin variants for samples of the Nigerian population at Ogbomoso was determined. Data consisting of records of blood groups and haemoglobin types of different ages ranging from infants to adults for a period of 4 to 6 years (1995 ...

  6. ABO-Incompatible Adult Living Donor Liver Transplantation Under the Desensitization Protocol With Rituximab.

    Science.gov (United States)

    Song, G-W; Lee, S-G; Hwang, S; Kim, K-H; Ahn, C-S; Moon, D-B; Ha, T-Y; Jung, D-H; Park, G-C; Kim, W-J; Sin, M-H; Yoon, Y-I; Kang, W-H; Kim, S-H; Tak, E-Y

    2016-01-01

    ABO incompatibility is no longer considered a contraindication for adult living donor liver transplantation (ALDLT) due to various strategies to overcome the ABO blood group barrier. We report the largest single-center experience of ABO-incompatible (ABOi) ALDLT in 235 adult patients. The desensitization protocol included a single dose of rituximab and total plasma exchange. In addition, local graft infusion therapy, cyclophosphamide, or splenectomy was used for a certain time period, but these treatments were eventually discontinued due to adverse events. There were three cases (1.3%) of in-hospital mortality. The cumulative 3-year graft and patient survival rates were 89.2% and 92.3%, respectively, and were comparable to those of the ABO-compatible group (n = 1301). Despite promising survival outcomes, 17 patients (7.2%) experienced antibody-mediated rejection that manifested as diffuse intrahepatic biliary stricture; six cases required retransplantation, and three patients died. ABOi ALDLT is a feasible method for expanding a living liver donor pool, but the efficacy of the desensitization protocol in targeting B cell immunity should be optimized. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  7. ABO Blood Group and Dementia Risk--A Scandinavian Record-Linkage Study.

    Directory of Open Access Journals (Sweden)

    Senthil K Vasan

    Full Text Available Dementia includes a group of neuro-degenerative disorders characterized by varying degrees of cognitive impairment. Recent data indicates that blood group AB is associated with impaired cognition in elderly patients. To date there are no large-scale studies that have examined the relationship between ABO blood group and dementia-related disorders in detail.We used data from the SCANDAT2 database that contains information on over 1.6 million blood donors from 1968 in Sweden and 1981 from Denmark. The database was linked with health outcomes data from nationwide patient and cause of death registers to investigate the relationship between blood groups and risk of different types of dementia. The incident rate ratios were estimated using log-linear Poisson regression models.Among 1,598,294 donors followed over 24 million person-years of observation we ascertained 3,615 cases of Alzheimer's disease, 1,842 cases of vascular dementia, and 9,091 cases of unspecified dementia. Overall, our study showed no association between ABO blood group and risk of Alzheimer's disease, vascular dementia or unspecified dementia. This was also true when analyses were restricted to donors aged 70 years or older except for a slight, but significantly decreased risk of all dementia combined in subjects with blood group A (IRR, 0.93; 95% confidence interval [CI], 0.88-0.98, compared to those with blood group O.Our results provide no evidence that ABO blood group influences the risk of dementia.

  8. Lanthanide gallate perovskite-type substrates for epitaxial, high-Tc superconducting Ba2YCu3O7-δ films

    International Nuclear Information System (INIS)

    Giess, E.A.; Sandstrom, R.L.; Gallagher, W.J.; Gupta, A.; Shinde, S.L.; Cook, R.F.; Cooper, E.L.; O'Sullivan, E.M.J.; Roldan, J.M.; Segmuller, A.D.; Angilello, J.

    1990-01-01

    This paper reports on the use of lanthanide gallate perovskite-type substrates for the deposition of epitaxial, high-T c superconducting Ba 2 YCu 3 O 7-δ (BYCO) films. They were also found to have moderate dielectric constants (∼25 compared to ∼ 277 for SrTiO 3 ). This study was undertaken to further explore the use of LaGaO 3 , NdGaO 3 , SrTiO 3 , MgO, and Y-stabilized ZrO 2 substrates, prepared from single-crystal joules grown by several suppliers using the Czochralski method. Films were prepared by cylindrical magnetron sputtering and laser ablation. Substrate evaluations included measurement of dielectric constant and loss, thermal expansion, and mechanical hardness and toughness. In addition to their moderate dielectric constants, they were found to have satisfactory mechanical properties, except for the twinning tendency of LaGaO 3 . Lattice mismatch strains were calculated for orthorhombic BYCO films on a number of substrates. NdGaO 3 was found to have the best lattice match with BYCO, and is now available twin-free

  9. Non-hydrolytic metal oxide films for perovskite halide overcoating and stabilization

    Science.gov (United States)

    Martinson, Alex B.; Kim, In Soo

    2017-09-26

    A method of protecting a perovskite halide film from moisture and temperature includes positioning the perovskite halide film in a chamber. The chamber is maintained at a temperature of less than 200 degrees Celsius. An organo-metal compound is inserted into the chamber. A non-hydrolytic oxygen source is subsequently inserted into the chamber. The inserting of the organo-metal compound and subsequent inserting of the non-hydrolytic oxygen source into the chamber is repeated for a predetermined number of cycles. The non-hydrolytic oxygen source and the organo-metal compound interact in the chamber to deposit a non-hydrolytic metal oxide film on perovskite halide film. The non-hydrolytic metal oxide film protects the perovskite halide film from relative humidity of greater than 35% and a temperature of greater than 150 degrees Celsius, respectively.

  10. Room temperature oxidative intercalation with chalcogen hydrides: Two-step method for the formation of alkali-metal chalcogenide arrays within layered perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Ranmohotti, K.G. Sanjaya; Montasserasadi, M. Dariush; Choi, Jonglak; Yao, Yuan; Mohanty, Debasish; Josepha, Elisha A.; Adireddy, Shiva; Caruntu, Gabriel [Department of Chemistry and the Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148-2820 (United States); Wiley, John B., E-mail: jwiley@uno.edu [Department of Chemistry and the Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148-2820 (United States)

    2012-06-15

    Highlights: ► Topochemical reactions involving intercalation allow construction of metal chalcogenide arrays within perovskite hosts. ► Gaseous chalcogen hydrides serve as effect reactants for intercalation of sulfur and selenium. ► New compounds prepared by a two-step intercalation strategy are presented. -- Abstract: A two-step topochemical reaction strategy utilizing oxidative intercalation with gaseous chalcogen hydrides is presented. Initially, the Dion-Jacobson-type layered perovskite, RbLaNb{sub 2}O{sub 7}, is intercalated reductively with rubidium metal to make the Ruddlesden-Popper-type layered perovskite, Rb{sub 2}LaNb{sub 2}O{sub 7}. This compound is then reacted at room-temperature with in situ generated H{sub 2}S gas to create Rb-S layers within the perovskite host. Rietveld refinement of X-ray powder diffraction data (tetragonal, a = 3.8998(2) Å, c = 15.256(1) Å; space group P4/mmm) shows the compound to be isostructural with (Rb{sub 2}Cl)LaNb{sub 2}O{sub 7} where the sulfide resides on a cubic interlayer site surrounded by rubidium ions. The mass increase seen on sulfur intercalation and the refined S site occupation factor (∼0.8) of the product indicate a higher sulfur content than expected for S{sup 2−} alone. This combined with the Raman studies, which show evidence for an H-S stretch, indicate that a significant fraction of the intercalated sulfide exists as hydrogen sulfide ion. Intercalation reactions with H{sub 2}Se{sub (g)} were also carried out and appear to produce an isostructural selenide compound. The utilization of such gaseous hydride reagents could significantly expand multistep topochemistry to a larger number of intercalants.

  11. Oxygen storage capacity and structural properties of Ni-doped LaMnO3 perovskites

    International Nuclear Information System (INIS)

    Ran, Rui; Wu, Xiaodong; Weng, Duan; Fan, Jun

    2013-01-01

    Graphical abstract: Dynamic OSC of (a) fresh and (b) aged LaMn 1−x Ni x O 3 perovskites (0.1 Hz). Aged condition: 1050 °C, 5 h, 7% steam in air. The LaMn 1−x Ni x O 3 perovskites exhibit considerable dynamic OSC in comparison to CeO 2 –ZrO 2 (CZ), even after 1050 °C hydrothermal ageing for 5 h. Highlights: •Ni-doped LaMnO 3 perovskites exhibit very large dynamic OSC and high oxygen storage rate. •Mn 4+ is favourable to the releasable oxygen. •Doping of Ni ions increase the Mn 4+ content and the oxygen vacancies. •Doping of Ni ions reduce the BO 6 distortion in the LaMnO 3 perovskites. -- Abstract: A series of Ni doped LaMnO 3 perovskites were prepared by a sol–gel method as oxygen storage materials. Powder X-ray diffraction (XRD), X-ray adsorption fine structure (XAFS), oxygen storage capacity (OSC) and H 2 -temperature program reduction (TPR) measurements were performed to investigate the OSC of the perovskites as well as the effects of Ni on the structural properties. The results showed that the Ni-doped LaMnO 3 perovskite exhibited very large dynamic OSC and high oxygen release rate, which provided a possibility to serve as an oxygen storage material candidate in three-way catalysts. The available oxygen species below 500 °C primarily originated from the redox reaction between Mn 4+ and Mn 3+ , and the more Mn 4+ were favourable to the releasable oxygen. The doping of appropriate Ni ions promoted the OSC of the LaMnO 3 perovskites by increasing the Mn 4+ content and adjusting the structural defects. On the other hand, the doped Ni ions could make the BO 6 distortion disappearing in the LaMnO 3 perovskites to reduce the lattice oxygen activity

  12. Using Low Temperature Photoluminescence Spectroscopy to Investigate CH3NH3PbI3 Hybrid Perovskite Degradation

    Directory of Open Access Journals (Sweden)

    Khaoula Jemli

    2016-07-01

    Full Text Available Investigating the stability and evaluating the quality of the CH3NH3PbI3 perovskite structures is quite critical both to the design and fabrication of high-performance perovskite devices and to fundamental studies of the photophysics of the excitons. In particular, it is known that, under ambient conditions, CH3NH3PbI3 degrades producing some PbI2. We show here that low temperature Photoluminescence (PL spectroscopy is a powerful tool to detect PbI2 traces in hybrid perovskite layers and single crystals. Because PL spectroscopy is a signal detection method on a black background, small PbI2 traces can be detected, when other methods currently used at room temperature fail. Our study highlights the extremely high stability of the single crystals compared to the thin layers and defects and grain boundaries are thought to play an important role in the degradation mechanism.

  13. Association of ABO blood groups with diabetes mellitus | Kamil ...

    African Journals Online (AJOL)

    Objective: So far no studies have been performed in Malaysia to look at association of diabetes mellitus (DM) with blood groups. We studied the association of ABO blood groups with DM type 2. Patients and methodology: It was a case control study conducted at Kepala Batas Hospital Batas, Penang, Malaysia in the year ...

  14. Comparative study of phase structure and dielectric properties for K0.5Bi0.5TiO3-BiAlO3 and LaAlO3-BiAlO3

    International Nuclear Information System (INIS)

    Hou, Yudong; Zheng, Mupeng; Si, Meiju; Cui, Lei; Zhu, Mankang; Yan, Hui

    2013-01-01

    In this work, two perovskite-type compounds, K 0.5 Bi 0.5 TiO 3 and LaAlO 3 , have been selected as host material to incorporate with BiAlO 3 using a solid-state reaction route. The phase evolution and dielectric properties for both systems have been investigated in detail. For the K 0.5 Bi 0.5 TiO 3 -BiAlO 3 system, it is interesting to find that when using Bi 2 O 3 , Al 2 O 3 , K 2 CO 3 , and TiO 2 as starting materials, the formed compounds are K 0.5 Bi 0.5 TiO 3 -K 0.5 Bi 4.5 Ti 4 O 15 and Al 2 O 3 only plays a dopant role. There are two distinct dielectric peaks appearing in the patterns of temperature dependence of dielectric constant, corresponding to the phase-transition points of perovskite-type K 0.5 Bi 0.5 TiO 3 and Aurivillius-type K 0.5 Bi 4.5 Ti 4 O 15 , independently. In comparison, using Bi 2 O 3 , Al 2 O 3 , and La 2 O 3 as starting materials, the pure perovskite phase LaAlO 3 -BiAlO 3 can be obtained. Compared to the inherent paraelectric behavior in LaAlO 3 , the diffuse phase-transition phenomena can be observed in the LaAlO 3 -BiAlO 3 binary system, which corresponds well to the Vogel-Fulcher (VF) relationship. Moreover, compared to pure LaAlO 3 , the synthesized LaAlO 3 -BiAlO 3 compound shows enhanced dielectric properties, which are promising in application as gate dielectric materials. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Cation-Dependent Light-Induced Halide Demixing in Hybrid Organic-Inorganic Perovskites.

    Science.gov (United States)

    Sutter-Fella, Carolin M; Ngo, Quynh P; Cefarin, Nicola; Gardner, Kira L; Tamura, Nobumichi; Stan, Camelia V; Drisdell, Walter S; Javey, Ali; Toma, Francesca M; Sharp, Ian D

    2018-06-13

    Mixed cation metal halide perovskites with increased power conversion efficiency, negligible hysteresis, and improved long-term stability under illumination, moisture, and thermal stressing have emerged as promising compounds for photovoltaic and optoelectronic applications. Here, we shed light on photoinduced halide demixing using in situ photoluminescence spectroscopy and in situ synchrotron X-ray diffraction (XRD) to directly compare the evolution of composition and phase changes in CH(NH 2 ) 2 CsPb-halide (FACsPb-) and CH 3 NH 3 Pb-halide (MAPb-) perovskites upon illumination, thereby providing insights into why FACs-perovskites are less prone to halide demixing than MA-perovskites. We find that halide demixing occurs in both materials. However, the I-rich domains formed during demixing accumulate strain in FACsPb-perovskites but readily relax in MA-perovskites. The accumulated strain energy is expected to act as a stabilizing force against halide demixing and may explain the higher Br composition threshold for demixing to occur in FACsPb-halides. In addition, we find that while halide demixing leads to a quenching of the high-energy photoluminescence emission from MA-perovskites, the emission is enhanced from FACs-perovskites. This behavior points to a reduction of nonradiative recombination centers in FACs-perovskites arising from the demixing process and buildup of strain. FACsPb-halide perovskites exhibit excellent intrinsic material properties with photoluminescence quantum yields that are comparable to MA-perovskites. Because improved stability is achieved without sacrificing electronic properties, these compositions are better candidates for photovoltaic applications, especially as wide bandgap absorbers in tandem cells.

  16. Efficiency enhancement of perovskite solar cells using structural and morphological improvement of CH3NH3PbI3 absorber layers

    Science.gov (United States)

    Alidaei, Maryam; Izadifard, Morteza; Ghazi, Mohammad E.; Ahmadi, Vahid

    2018-01-01

    Perovskite solar cells have been heavily investigated due to their unique properties such as high power conversion efficiency (PCE), low-cost fabrication by solution processes, high diffusion length, large absorption coefficient, and direct and tunable band gap. PCE of perovskite devices is strongly dependent on the absorber layer properties such as morphology, crystallinity, and compactness, which are required to be optimized. In this work, the CH3NH3PbI3 (170-480 nm) absorber layers with various methylammonium iodine (MAI) concentrations (7, 10, 20 and 40 mg ml-1) and perovskite solar cells with the fluorine-doped tin oxide (400 nm)/C-TiO2 (30 nm)/Meso-TiO2 (400 nm)/CH3NH3PbI3 (170-480 nm)/P3HT (30 nm)/Au (100 nm) structure were fabricated. A two-step solution process was used for deposition of the CH3NH3PbI3 absorber layers. The morphology, crystal structure, and optical properties of the perovskite layer grown on glass and also the photovoltaic properties of the fabricated solar cells were studied. The results obtained showed that by controlling the deposition conditions, due to the reduction in charge recombination, PCE enhancement of the perovskite solar cell (up to 11.6%) was accessible.

  17. Synthesis and Characterization of Perovskite Type La1-xSrxAlO3-sigma(0<=X<=0.3) by Co-Precipitation Method

    International Nuclear Information System (INIS)

    Mahmoud, O.; Abderezak, G.

    2015-01-01

    This work shows the electrochemical activity of O/sub 2/ evolution reaction in KOH of perovskite type- aluminate oxide (La/sub 1-x/Sr/sub x/AlO/sub 3-sigma/ with x = 0, 0.1, 0.2, 0.3). La/sub 1-x/Sr/sub x/AlO/sub 3-sigma/ (03) was prepared by co-precipitation method. The white precipitates were then washed in distilled water by centrifugation, and calcined at 1000/degree C/ for 6h, the pure phase was characterized by X-ray diffraction (XRD), thermal gravimetric analysis and differential thermal (TG/DSC), Fourier transform infrared spectroscopy (FTIR), specific surface area (BET). The MEB micrographs are shown of the spherical grains and uniform agglomeration of the grains. The oxide powders were used as the films to form a support on Ni/oxides. Oxygen evolution on each oxide catalyst was signed in the cyclic voltammetry with +- 15 V range and the electrochemical impedance in the equivalent of 100 kHz. The results point out the electrode activity and stability of the x = 0.3 composition. (author)

  18. Perovskite Oxide Thin Film Growth, Characterization, and Stability

    Science.gov (United States)

    Izumi, Andrew

    Studies into a class of materials known as complex oxides have evoked a great deal of interest due to their unique magnetic, ferroelectric, and superconducting properties. In particular, materials with the ABO3 perovskite structure have highly tunable properties because of the high stability of the structure, which allows for large scale doping and strain. This also allows for a large selection of A and B cations and valences, which can further modify the material's electronic structure. Additionally, deposition of these materials as thin films and superlattices through techniques such as pulsed laser deposition (PLD) results in novel properties due to the reduced dimensionality of the material. The novel properties of perovskite oxide heterostructures can be traced to a several sources, including chemical intermixing, strain and defect formation, and electronic reconstruction. The correlations between microstructure and physical properties must be investigated by examining the physical and electronic structure of perovskites in order to understand this class of materials. Some perovskites can undergo phase changes due to temperature, electrical fields, and magnetic fields. In this work we investigated Nd0.5Sr 0.5MnO3 (NSMO), which undergoes a first order magnetic and electronic transition at T=158K in bulk form. Above this temperature NSMO is a ferromagnetic metal, but transitions into an antiferromagnetic insulator as the temperature is decreased. This rapid transition has interesting potential in memory devices. However, when NSMO is deposited on (001)-oriented SrTiO 3 (STO) or (001)-oriented (LaAlO3)0.3-(Sr 2AlTaO6)0.7 (LSAT) substrates, this transition is lost. It has been reported in the literature that depositing NSMO on (110)-oriented STO allows for the transition to reemerge due to the partial epitaxial growth, where the NSMO film is strained along the [001] surface axis and partially relaxed along the [11¯0] surface axis. This allows the NSMO film enough

  19. Monte Carlo simulation study of magnetocaloric effect in NdMnO{sub 3} perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, PB 63 46000 Safi (Morocco); Laboratoire de Magnétisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Université Mohammed V, Faculté des Sciences, B.P. 1014, Rabat (Morocco); Jabar, A. [Laboratoire de Magnétisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Université Mohammed V, Faculté des Sciences, B.P. 1014, Rabat (Morocco); Benyoussef, A. [Laboratoire de Magnétisme et Physique des Hautes Energies L.M.P.H.E.URAC 12, Université Mohammed V, Faculté des Sciences, B.P. 1014, Rabat (Morocco); Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); Hamedoun, M. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hlil, E.K. [Institut Curie, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France)

    2016-03-01

    The magnetocaloric effect in NdMnO{sub 3} perovskite is investigated by using the Monte Carlo simulations. The Curie temperature T{sub C} of NdMnO{sub 3} compound is deduced from the variation of the magnetization vs. the temperature with different values of external magnetic field. The variation of magnetization with the external magnetic field H is given. The specific heat with the temperature is established for different external magnetic field. The thermal magnetic entropy for different external magnetic field and different exchange interactions in NdMnO{sub 3} compound is obtained. The adiabatic temperature change is obtained. The relative cooling power with different external magnetic field is established. The magnetocaloric effect has been investigated from magnetization. - Highlights: • Results obtained show that the PM–FM transition is of second order in NdMnO{sub 3}. • Critical properties of NdSi at the FM–PM transition have been analyzed. • The Curie temperature and magnetic entropy have been obtained.

  20. Intravenous immunoglobulin in ABO and Rh hemolytic diseases of newborn.

    Science.gov (United States)

    Nasseri, Fatemeh; Mamouri, Gholam A; Babaei, Homa

    2006-12-01

    To evaluate whether the use of intravenous immunoglobulin in newborn infants with isoimmune hemolytic jaundice due to Rh and ABO incompatibility is an effective treatment in reducing the need for exchange transfusion. This study included all direct Coombs' test positive Rh and ABO isoimmunized babies, who admitted in the Neonatal Intensive Care Unit of Ghaem Hospital of Mashhad University of Medical Sciences, Iran, from October 2003 to October 2004. Significant hyperbilirubinemia was defined as rising by >or=0.5 mg/dl per hour. Babies were randomly assigned to received phototherapy with intravenous immunoglobulin (IVIg) 0.5 g/kg over 4 hours, every 12 hours for 3 doses (study group) or phototherapy alone (control group). Exchange transfusion was performed in any group if serum bilirubin exceeded >or=20mg/dl or rose by >or=1mg/dl/h. A total of 34 babies were eligible for this study (17 babies in each group). The number of exchange transfusion, duration of phototherapy and hospitalization days, were significant shorter in the study group versus control group. When we analyzed the outcome results in ABO and Rh hemolytic disease separately, the efficacy of IVIg was significantly better in Rh versus ABO isoimmunization. Late anemia was more common in the IVIg group 11.8% versus 0%, p=0.48. Adverse effects were not observed during IVIg administration. Administration of IVIg to newborns with significant hyperbilirubinemia due to Rh hemolytic disease reduced the need for exchange transfusion but in ABO hemolytic disease there was no significant difference between IVIg and double surface blue light phototherapy.

  1. HNbO3 and HTaO3: new cubic perovskites prepared from LiNbO3 and LiTaO3 via ion exchange

    International Nuclear Information System (INIS)

    Rice, C.E.; Jackel, J.L.

    1982-01-01

    The synthesis of HNbO 3 and HTaO 3 from LiNbO 3 via ion exchange in hot aqueous acid solutions is reported. This reaction is accompanied by a topotactic structural transformation from the rhombohedral LiNbO 3 structure to the cubic perovskite structure; cell constants are a = 3.822(1) angstrom for HNbO 3 and 3.810(2) angstrom for HTaO 3 . These new compounds have been characterized by powder X-ray diffraction, thermogravimetric analysis, and solid-state NMR. They are electronic insulators and have low ionic conductivity. Evidence of partially proton-exchange phases Li/sub 1-x/H/sub x/MO 3 was also seen. The possible significance of this ion exchange reaction for devices using LiNbO 3 or LiTaO 3 is discussed

  2. Electrochemical reduction of nitrous oxide on La1-xSrxFeO3 perovskites

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent

    2010-01-01

    The electrochemical reduction of nitrous oxide and oxygen has been studied on cone-shaped electrodes of La1-xSrxFeO3-delta perovskites in an all solid state cell, using cyclic voltammetry. It was shown that the activity of the La1-xSrxFeO3-delta perovskites for the electrochemical reduction...... of nitrous oxide mainly depends on the amount of Fe(III) and oxide ion vacancies. The activity of the La1-xSrxFeO3-delta perovskites towards the electrochemical reduction of nitrous oxide is much lower than the activity of the La1-xSrxFeO3-delta perovskites towards the electrochemical reduction of oxygen...

  3. Energetics and crystal chemistry of Ruddlesden-Popper type structures in high T(sub c) ceramic superconductors

    Science.gov (United States)

    Dwivedi, Anurag; Cormack, A. N.

    1990-01-01

    The formation of Ruddlesden-Popper type layers (alternating slabs of rocksalt and perovskite structures) is seen in these oxides which is similar in many respects to what is seen in the system Sr-Ti-O. However, it was observed that there are some significant differences, for example the rocksalt and perovskite blocks in new superconducting compounds are not necessarily electrically, unlike in Sr-Ti-O systems. This will certainly render an additional coulombic bonding energy between two different types of blocks and may well lead to significant differences in their structural chemistry. In the higher order members of the various homologous series, additional Cu-O planes are inserted in the perovskite blocks. In order for the unit cell to electrically neutral the net positive charge on rocksalt block (which remains constant throughout the homologous series) should be balanced by an equal negative charge on perovskite block. It, thus becomes necessary to create oxygen vacancies in the basic perovskite structure, when width of the perovskite slab changes on addition of extra Cu-O planes. Results of atomistic simulations suggest that these missing oxygen ions allow the Cu-O planes to buckle in these compounds. This is also supported by the absence of buckling in the first member of Bi-containing compounds in which there are no missing oxygen ions and the Sr-Ti-O series of compounds. Additional results are presented on the phase stability of polytypoid structures in these crystal chemically complex systems. The studies will focus on the determination of the location of Cu(3+) in the structures of higher order members of the La-Cu-O system and whether Cu(3+) ions or oxygen vacancies are energetically more favorable charge compensating mechanism.

  4. A novel paper-based assay for the simultaneous determination of Rh typing and forward and reverse ABO blood groups.

    Science.gov (United States)

    Noiphung, Julaluk; Talalak, Kwanrutai; Hongwarittorrn, Irin; Pupinyo, Naricha; Thirabowonkitphithan, Pannawich; Laiwattanapaisal, Wanida

    2015-05-15

    We propose a new, paper-based analytical device (PAD) for blood typing that allows for the simultaneous determination of ABO and Rh blood groups on the same device. The device was successfully fabricated by using a combination of wax printing and wax dipping methods. A 1:2 blood dilution was used for forward grouping, whereas whole blood could be used for reverse grouping. A 30% cell suspension of A-cells or B-cells was used for haemagglutination on the reverse grouping side. The total assay time was 10 min. The ratio between the distance of red blood cell movement and plasma separation is the criterion for agglutination and indicates the presence of the corresponding antigen or antibody. The proposed PAD has excellent reproducibility in that the same blood groups, namely A, AB, and O, were reported by using different PADs that were fabricated on the same day (n=10). The accuracy for detecting blood group A (n=12), B (n=13), AB (n=9), O (n=14), and Rh (n=48) typing were 92%, 85%, 89%, 93%, and 96%, respectively, in comparison with the conventional slide test method. The haematocrit of the sample affects the accuracy of the results, and appropriate dilution is suggested before typing. In conclusion, this study proposes a novel method that is straightforward, time-saving, and inexpensive for the simultaneous determination of ABO and Rh blood groups, which is promising for use in developing countries. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Thermally induced structural evolution and performance of mesoporous block copolymer-directed alumina perovskite solar cells.

    KAUST Repository

    Tan, Kwan Wee

    2014-04-11

    Structure control in solution-processed hybrid perovskites is crucial to design and fabricate highly efficient solar cells. Here, we utilize in situ grazing incidence wide-angle X-ray scattering and scanning electron microscopy to investigate the structural evolution and film morphologies of methylammonium lead tri-iodide/chloride (CH3NH3PbI(3-x)Cl(x)) in mesoporous block copolymer derived alumina superstructures during thermal annealing. We show the CH3NH3PbI(3-x)Cl(x) material evolution to be characterized by three distinct structures: a crystalline precursor structure not described previously, a 3D perovskite structure, and a mixture of compounds resulting from degradation. Finally, we demonstrate how understanding the processing parameters provides the foundation needed for optimal perovskite film morphology and coverage, leading to enhanced block copolymer-directed perovskite solar cell performance.

  6. Thermally induced structural evolution and performance of mesoporous block copolymer-directed alumina perovskite solar cells.

    KAUST Repository

    Tan, Kwan Wee; Moore, David T; Saliba, Michael; Sai, Hiroaki; Estroff, Lara A; Hanrath, Tobias; Snaith, Henry J; Wiesner, Ulrich

    2014-01-01

    Structure control in solution-processed hybrid perovskites is crucial to design and fabricate highly efficient solar cells. Here, we utilize in situ grazing incidence wide-angle X-ray scattering and scanning electron microscopy to investigate the structural evolution and film morphologies of methylammonium lead tri-iodide/chloride (CH3NH3PbI(3-x)Cl(x)) in mesoporous block copolymer derived alumina superstructures during thermal annealing. We show the CH3NH3PbI(3-x)Cl(x) material evolution to be characterized by three distinct structures: a crystalline precursor structure not described previously, a 3D perovskite structure, and a mixture of compounds resulting from degradation. Finally, we demonstrate how understanding the processing parameters provides the foundation needed for optimal perovskite film morphology and coverage, leading to enhanced block copolymer-directed perovskite solar cell performance.

  7. Thermally Induced Structural Evolution and Performance of Mesoporous Block Copolymer-Directed Alumina Perovskite Solar Cells

    Science.gov (United States)

    2015-01-01

    Structure control in solution-processed hybrid perovskites is crucial to design and fabricate highly efficient solar cells. Here, we utilize in situ grazing incidence wide-angle X-ray scattering and scanning electron microscopy to investigate the structural evolution and film morphologies of methylammonium lead tri-iodide/chloride (CH3NH3PbI3–xClx) in mesoporous block copolymer derived alumina superstructures during thermal annealing. We show the CH3NH3PbI3–xClx material evolution to be characterized by three distinct structures: a crystalline precursor structure not described previously, a 3D perovskite structure, and a mixture of compounds resulting from degradation. Finally, we demonstrate how understanding the processing parameters provides the foundation needed for optimal perovskite film morphology and coverage, leading to enhanced block copolymer-directed perovskite solar cell performance. PMID:24684494

  8. Evolution of Photoluminescence, Raman, and Structure of CH3NH3PbI3 Perovskite Microwires Under Humidity Exposure

    Science.gov (United States)

    Segovia, Rubén; Qu, Geyang; Peng, Miao; Sun, Xiudong; Shi, Hongyan; Gao, Bo

    2018-03-01

    Self-assembled organic-inorganic CH3NH3PbI3 perovskite microwires (MWs) upon humidity exposure along several weeks were investigated by photoluminescence (PL) spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD). We show that, in addition to the common perovskite decomposition into PbI2 and the formation of a hydrated phase, humidity induced a gradual PL redshift at the initial weeks that is stabilized for longer exposure ( 21 nm over the degradation process) and an intensity enhancement. Original perovskite Raman band and XRD reflections slightly shifted upon humidity, indicating defects formation and structure distortion of the MWs crystal lattice. By correlating the PL, Raman, and XRD results, it is believed that the redshift of the MWs PL emission was originated from the structural disorder caused by the incorporation of H2O molecules in the crystal lattice and radiative recombination through moisture-induced subgap trap states. Our study provides insights into the optical and structural response of organic-inorganic perovskite materials upon humidity exposure.

  9. Composition-dependent emission linewidth broadening in lead bromide perovskite (APbBr3, A = Cs and CH3NH3) nanoparticles.

    Science.gov (United States)

    Ham, Sujin; Chung, Heejae; Kim, Tae-Woo; Kim, Jiwon; Kim, Dongho

    2018-02-01

    Lead halide perovskite nanoparticles (NPs) are attractive as they exhibit excellent color purity and have a tunable band gap, and can thus be applied in highly efficient photovoltaic and light-emitting diodes. Fundamental studies of emission linewidth broadening due to spectral shifts in perovskite NPs may suggest a way to improve their color purity. However, the carrier-induced Stark shift that causes spectral diffusion still requires investigation. In this study, we explore composition-related emission linewidth broadening by comparing CsPbBr3 and CH 3 NH 3 PbBr 3 (MAPbBr3) perovskite NPs. We find that the MAPbBr3 NPs are more sensitive to fluctuations in the local electric fields than the CsPbBr3 NPs due to an intrinsic difference in the dipole moment between the two A cations (Cs and MA), which shows a carrier-induced Stark shift. The results indicate that the compositions of perovskite NPs are closely associated with emission linewidth broadening and they also provide insights into the development of NP-based devices with high color purity.

  10. ABO blood group distribution and ischaemic heart disease

    International Nuclear Information System (INIS)

    Lutfullah, A.; Bhatti, T.A.; Hanif, A.; Shaikh, S.H.

    2011-01-01

    To study the association of ABO blood groups with ischaemic heart disease (IHD) in our setting. Analytic comparative study. Department of Cardiology, Mayo hospital, Lahore over a period of two years from January 2008 to December 2009. The study group included 907 patients of IHD. The distribution of ABO blood groups in IHD patients was compared with the control group of 907 non-IHD individuals. Data was analyzed using SPSS 16. Chi-square test for significance was used. P-value less than 0.05 was taken as significant. In this study, the following pattern of ABO blood groups was observed in IHD patients and non-IHD patients respectively : Blood group A 251 (27.67%) and 248 (27.34%); Blood group B 329 (36.27%) and 358 (39.47%); Blood group O 235 (25.90%) and 240 (24.46%); Blood group AB 92 (10.14%) and 61 (6.72%), P-value = 0.06. There is no association of ABO blood groups and ischaemic heart disease. (author)

  11. Molecular genotyping of ABO blood groups in some population groups from India.

    Science.gov (United States)

    Ray, Sabita; Gorakshakar, Ajit C; Vasantha, K; Nadkarni, Anita; Italia, Yazdi; Ghosh, Kanjaksha

    2014-01-01

    Indian population is characterized by the presence of various castes and tribal groups. Various genetic polymorphisms have been used to differentiate among these groups. Amongst these, the ABO blood group system has been extensively studied. There is no information on molecular genotyping of ABO blood groups from India. Therefore, the main objective of this study was to characterize the common A, B and O alleles by molecular analysis in some Indian population groups. One hundred samples from the mixed population from Mumbai, 101 samples from the Dhodia tribe and 100 samples from the Parsi community were included in this study. Initially, the samples were phenotyped by standard serologic techniques. PCR followed by single strand conformational polymorphsim (SSCP) was used for molecular ABO genotyping. Samples showing atypical SSCP patterns were further analysed by DNA sequencing to characterize rare alleles. Seven common ABO alleles with 19 different genotypes were found in the mixed population. The Dhodias showed 12 different ABO genotypes and the Parsis revealed 15 different ABO genotypes with six common ABO alleles identified in each of them. Two rare alleles were also identified. This study reports the distribution of molecular genotypes of ABO alleles among some population groups from India. Considering the extremely heterogeneous nature of the Indian population, in terms of various genotype markers like blood groups, red cell enzymes, etc., many more ABO alleles are likely to be encountered.

  12. Resonant halide perovskite nanoparticles

    Science.gov (United States)

    Tiguntseva, Ekaterina Y.; Ishteev, Arthur R.; Komissarenko, Filipp E.; Zuev, Dmitry A.; Ushakova, Elena V.; Milichko, Valentin A.; Nesterov-Mueller, Alexander; Makarov, Sergey V.; Zakhidov, Anvar A.

    2017-09-01

    The hybrid halide perovskites is a prospective material for fabrication of cost-effective optical devices. Unique perovskites properties are used for solar cells and different photonic applications. Recently, perovskite-based nanophotonics has emerged. Here, we consider perovskite like a high-refractive index dielectric material, which can be considered to be a basis for nanoparticles fabrication with Mie resonances. As a result, we fabricate and study resonant perovskite nanoparticles with different sizes. We reveal, that spherical nanoparticles show enhanced photoluminescence signal. The achieved results lay a cornerstone in the field of novel types of organic-inorganic nanophotonics devices with optical properties improved by Mie resonances.

  13. Perovskite structures in the formation of nano-rods in REBa2Cu3O7-δ films self-organization to perovskite structures

    International Nuclear Information System (INIS)

    Mukaida, Masashi; Kai, Hideki; Shingai, Yuki

    2009-01-01

    Cubic perovskite structure has been found to play an important role for the nano-rod formation in REBa 2 Cu 3 O 7-δ films. BaWO 4 , with a sheelite structure, and BaNb 2 O 6 , with a tungsten bronze structure, were doped into REBa 2 Cu 3 O 7-δ targets. Laser-deposited, these materials form nano-rods in REBa 2 Cu 3 O 7-δ films accompanied by Ln elements, resulting in the composition of a pseudo-cubic perovskite structure. This was confirmed by selected area electron diffraction patterns (SADP) and composition mapping using energy-dispersive X-ray spectroscopy scanning transmission electron microscope (EDS-STEM) analysis. BaWO 4 with a sheelite structure, and BaNb 2 O 6 with a tungsten bronze structure, doped into targets no longer retain their structures, but can form pseudo-cubic perovskite structures in laser-deposited REBa 2 Cu 3 O 7-δ films. The perovskite crystal structure is thought to be important for nano-rod formation in the laser deposited REBa 2 Cu 3 O 7-δ film. (author)

  14. Effects of Different Solvents on the Planar Hetero-junction Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Lin Shunquan

    2015-01-01

    Full Text Available The perovskite (CH3NH3PbI3 films on the planar hetero-junction perovskite solar cells (PHJ-PSCs are fabricated by “two-steps” process with the wet spin-coating method. The precursor (PbI2 solutions are compounded with 4 types of solvents: N-Methyl Pyrrolidone (NMP, γ-butyrolactone (GBL, Dimethyl Sulfoxide (DMSO and N, N-dimethylformamide (DMF. All the solutions have the same concentration. The influences of different precursor solvents to the micro-structures of CH3NH3PbI3 films and device performance are studied. Atomic force microscopy (AFM and scanning electron microscope (SEM are used to characterize the CH3NH3PbI3 films. The results indicate that the CH3NH3PbI3 film using DMF solvent possesses more rough morphology and thickest thickness. The monolithic PHJ-PSCs devices based on DMF solvent are tested under a standard one sun of simulated solar irradiation (AM1.5. The results show that the open-circuit voltage (Voc reaches 872mV, the short-circuit current (Jsc reaches 9.35mA/cm2, the filling factor(FF is 0.62 and the photo-current conversion efficiency (PCE is 5.05%. DMF is the best one among these 4 types of solvents for PHJ-PSCs.

  15. Efficient CH3NH3PbI3 perovskite/fullerene planar heterojunction hybrid solar cells with oxidized Ni/Au/Cu transparent electrode

    Science.gov (United States)

    Lai, Wei-Chih; Lin, Kun-Wei; Guo, Tzung-Fang; Chen, Peter; Liao, Yuan-Yu

    2018-02-01

    We demonstrated the performance of inverted CH3NH3PbI3 perovskite-based solar cells (SCs) with a thermally oxidized nickel/gold/copper (Ni/Au/Cu) trilayer transparent electrode. Oxidized Ni/Au/Cu is a high transparent layer and has less resistance than the oxidized Ni/Au layer. Like the oxidized Ni/Au layer, oxidized Ni and Cu in oxidized Ni/Au/Cu could perform as a hole transport layer of the perovskite-based SCs. It leads to improved perovskite SC performance on an open circuit voltage of 1.01 V, a short circuit current density of 14.36 mA/cm2, a fill factor of 76.7%, and a power conversion efficiency (η%) of 11.1%. The η% of perovskite SCs with oxidized Ni (10 nm)/Au (6 nm)/Cu (1 nm) improved by approximately 10% compared with that of perovskite SCs with oxidized Ni/Au.

  16. Reversible modulation of CsPbBr3 perovskite nanocrystal/gold nanoparticle heterostructures.

    Science.gov (United States)

    Chen, Shanshan; Lyu, Danya; Ling, Tao; Guo, Weiwei

    2018-04-19

    A facile strategy is illustrated to reversibly modulate CsPbBr3 perovskite nanocrystal/Au nanoparticle heterostructures with the reversible formation and fragmentation of gold nanoparticles anchored to the corners and surface of CsPbBr3 perovskite nanocrystals. The modulation process was performed under ambient conditions and could be conducted for cycles.

  17. Clinical use of the ABO-Scoring Index: reliability and subtraction frequency.

    Science.gov (United States)

    Lieber, William S; Carlson, Sean K; Baumrind, Sheldon; Poulton, Donald R

    2003-10-01

    This study tested the reliability and subtraction frequency of the study model-scoring system of the American Board of Orthodontists (ABO). We used a sample of 36 posttreatment study models that were selected randomly from six different orthodontic offices. Intrajudge and interjudge reliability was calculated using nonparametric statistics (Spearman rank coefficient, Wilcoxon, Kruskal-Wallis, and Mann-Whitney tests). We found differences ranging from 3 to 6 subtraction points (total score) for intrajudge scoring between two sessions. For overall total ABO score, the average correlation was .77. Intrajudge correlation was greatest for occlusal relationships and least for interproximal contacts. Interjudge correlation for ABO score averaged r = .85. Correlation was greatest for buccolingual inclination and least for overjet. The data show that some judges, on average, were much more lenient than others and that this resulted in a range of total scores between 19.7 and 27.5. Most of the deductions were found in the buccal segments and most were related to the second molars. We present these findings in the context of clinicians preparing for the ABO phase III examination and for orthodontists in their ongoing evaluation of clinical results.

  18. Layered Halide Double Perovskites Cs3+nM(II)nSb2X9+3n (M = Sn, Ge) for Photovoltaic Applications.

    Science.gov (United States)

    Tang, Gang; Xiao, Zewen; Hosono, Hideo; Kamiya, Toshio; Fang, Daining; Hong, Jiawang

    2018-01-04

    Over the past few years, the development of lead-free and stable perovskite absorbers with excellent performance has attracted extensive attention. Much effort has been devoted to screening and synthesizing this type of solar cell absorbers. Here, we present a general design strategy for designing the layered halide double perovskites Cs 3+n M(II) n Sb 2 X 9+3n (M = Sn, Ge) with desired photovoltaic-relevant properties by inserting [MX 6 ] octahedral layers, based on the principles of increased electronic dimensionality. Compared to Cs 3 Sb 2 I 9 , more suitable band gaps, smaller carrier effective masses, larger dielectric constants, lower exciton binding energies, and higher optical absorption can be achieved by inserting variable [SnI 6 ] or [GeI 6 ] octahedral layers into the [Sb 2 I 9 ] bilayers. Moreover, our results show that adjusting the thickness of inserted octahedral layers is an effective approach to tune the band gaps and carrier effective masses in a large range. Our work provides useful guidance for designing the promising layered antimony halide double perovskite absorbers for photovoltaic applications.

  19. BaZrO3 perovskite nanoparticles as emissive material for organic/inorganic hybrid light-emitting diodes

    DEFF Research Database (Denmark)

    Tamulevičius, S.; Ivaniuk, K.; Cherpak, V.

    2017-01-01

    In the present work we have demonstrated double-channel emission from organic exciplexes coupled to inorganic nanoparticles. The process is demonstrated by yellow-green emission in light-emitting diodes based on organic exciplexes hybridized with perovskite-type dispersed BaZrO3 nanoparticles...

  20. Reversal of the sign of giant magnetoresistance upon boron filling in RPd{sub 3} compounds (R=Tb,Er)

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Abhishek [S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata-700098 (India); Mazumdar, Chandan; Ranganathan, R, E-mail: abhishek.phy@gmail.co, E-mail: chandan.mazumar@saha.ac.i, E-mail: r.ranganathan@saha.ac.i [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata-700064 (India)

    2010-01-01

    We report the study of magnetic and transport properties of binary intermetallic compounds RPd{sub 3} (R: Tb and Er) and boron-filled perovskite compounds RPd{sub 3}B. Our results suggest that the magnetic and transport behavior of boron-filled compositions is substantially different compared to that of undoped compounds. For example, TbPd{sub 3} and ErPd{sub 3} exhibit negative magnetoresistance, while boron-filled TbPd{sub 3}B and ErPd{sub 3}B shows positive magnetoresistance. In addition, our results also suggest that there exists a strong correlation between magnetic and electrical-transport behavior of these systems.

  1. The oxidation of carbon monoxide over transition metal doped lanthanum manganates nanoparticles

    International Nuclear Information System (INIS)

    Fal Desai, M.S.; Salker, A.V.

    2012-01-01

    Lanthanum manganates perovskites (ABO 3 ) has been widely studied and applied. Many perovskites with A and B sites doped with different metals show good catalytic activity in many oxidation reactions than the individual perovskite. In present study, an attempt has been made to show comparative account of CO oxidation by doping the B site with different cations using sol-gel method

  2. High-Performance CH3NH3PbI3-Inverted Planar Perovskite Solar Cells with Fill Factor Over 83% via Excess Organic/Inorganic Halide.

    Science.gov (United States)

    Jahandar, Muhammad; Khan, Nasir; Lee, Hang Ken; Lee, Sang Kyu; Shin, Won Suk; Lee, Jong-Cheol; Song, Chang Eun; Moon, Sang-Jin

    2017-10-18

    The reduction of charge carrier recombination and intrinsic defect density in organic-inorganic halide perovskite absorber materials is a prerequisite to achieving high-performance perovskite solar cells with good efficiency and stability. Here, we fabricated inverted planar perovskite solar cells by incorporation of a small amount of excess organic/inorganic halide (methylammonium iodide (CH 3 NH 3 I; MAI), formamidinium iodide (CH(NH 2 ) 2 I; FAI), and cesium iodide (CsI)) in CH 3 NH 3 PbI 3 perovskite film. Larger crystalline grains and enhanced crystallinity in CH 3 NH 3 PbI 3 perovskite films with excess organic/inorganic halide reduce the charge carrier recombination and defect density, leading to enhanced device efficiency (MAI+: 14.49 ± 0.30%, FAI+: 16.22 ± 0.38% and CsI+: 17.52 ± 0.56%) compared to the efficiency of a control MAPbI 3 device (MAI: 12.63 ± 0.64%) and device stability. Especially, the incorporation of a small amount of excess CsI in MAPbI 3 perovskite film leads to a highly reproducible fill factor of over 83%, increased open-circuit voltage (from 0.946 to 1.042 V), and short-circuit current density (from 18.43 to 20.89 mA/cm 2 ).

  3. ABO, rhesus blood groups and transfusion-transmitted infections ...

    African Journals Online (AJOL)

    Background: Few studies focused on the study of blood groups in Gabon. This study aimed to determine the phenotypic frequency of ABO and Rhesus antigens in blood donors of Libreville and to assess the association between ABO blood groups and transfusion-transmitted infections. Materials and Methods: The study of ...

  4. Perovskite Catalysts—A Special Issue on Versatile Oxide Catalysts

    Directory of Open Access Journals (Sweden)

    Yu-Chuan Lin

    2014-08-01

    Full Text Available Perovskite-type catalysts have been prominent oxide catalysts for many years due to attributes such as flexibility in choosing cations, significant thermal stability, and the unique nature of lattice oxygen. Nearly 90% metallic elements of the Periodic Table can be stabilized in perovskite’s crystalline framework [1]. Moreover, by following the Goldschmidt rule [2], the A- and/or B-site elements can be partially substituted, making perovskites extremely flexible in catalyst design. One successful example is the commercialization of noble metal-incorporated perovskites (e.g., LaFe0.57Co0.38Pd0.05O3 for automotive emission control used by Daihatsu Motor Co. Ltd. [3]. Thus, growing interest in, and application of perovskites in the fields of material sciences, heterogeneous catalysis, and energy storage have prompted this Special Issue on perovskite catalysts. [...

  5. Properties and applications of perovskite proton conductors

    Directory of Open Access Journals (Sweden)

    Eduardo Caetano Camilo de Souza

    2010-09-01

    Full Text Available A brief overview is given of the main types and principles of solid-state proton conductors with perovskite structure. Their properties are summarized in terms of the defect chemistry, proton transport and chemical stability. A good understanding of these subjects allows the manufacturing of compounds with the desired electrical properties, for application in renewable and sustainable energy devices. A few trends and highlights of the scientific advances are given for some classes of protonic conductors. Recent results and future prospect about these compounds are also evaluated. The high proton conductivity of barium cerate and zirconate based electrolytes lately reported in the literature has taken these compounds to a highlight position among the most studied conductor ceramic materials.

  6. Structural, optical and morphological studies of Cd2+ doping in CH3NH3PbI3 perovskite semiconductor at Pb2+ site for photovoltaic applications

    Science.gov (United States)

    Parrey, Khursheed; Warish, Mohd.; Devi, Nisha; Niazi, A.; Aziz, A.; Ansari, S. G.

    2018-05-01

    Doping of semiconductors in a controlled mannner have paramount technological importance as far as the optical and electronic properties of the devices are concerned. Hybrid organic-inorganic perovskites (HOPs) as intrinsic semiconductors have sensational properties required for both the solar photovoltaics and perovskite light emitting diodes. However, undoped and complexity in the dpoing process of HOPs have limited their exploitation in the field of elcronics. In this papper we present the synthesis of HOP semiconductor (CH3NH3PbI3) doped in Pb2+ position by Cd2+. We studied the effect of the incorporation of Cd2+ into the crystalline structure and analysed the changes in the properties like crystal structure, optical absorption and the surface morphology. The structure of HOPs confirmed by X-ray diffraction analysis is tetragonal perovskite type. It can be found that the crystallinity of the samples was enhanced with the doping concentration as the intensity of diffraction peaks were observed to increase with doping. The absorption spectra as obtained from UV-Visible spectrophotometry and Tauc plot analysis indicated that the band gap observed (1.73 eV) is direct type and gets reduced to 1.67 eV with the doping concentration. The red shift may be due to the increase in the size of nanocrystalline material with doping.

  7. Effect of La doping on the ferroic order in Pb-based perovskite-type relaxor ferroelectrics

    Science.gov (United States)

    Maier, B. J.; Welsch, A.-M.; Mihailova, B.; Angel, R. J.; Zhao, J.; Paulmann, C.; Engel, J. M.; Marshall, W. G.; Gospodinov, M.; Petrova, D.; Bismayer, U.

    2011-04-01

    The structural alteration induced by the substitution of three-valent cations with an isotropic electronic outermost shell for Pb2+ in perovskite-type relaxors was investigated in the solid solutions Pb1-xLaxSc(1+x)/2Ta(1-x)/2O3, x =0.08 (PST-La) and Pb1-xLaxSc(1+x)/2Nb(1-x)/2O3, x =0.23 (PSN-La). In order to distinguish the “charge” effects from “strain” effects associated with the incorporation of La3+ in the structure, Sr-containing PbSc0.5Nb0.5O3 was characterized as well. The structure of the compounds was analyzed by in situ Raman spectroscopy, single-crystal x-ray diffraction, and powder neutron diffraction at different temperatures or pressures. It is shown that the embedding of La3+ strongly affects the ferroic structural species due to strain effects through a disturbance of the system of lone-pair electrons associated with Pb2+ and a decrease in the tolerance factor. La doping suppresses the dynamical coupling between off-centered Pb and B-site cations and enhances antiphase BO6 octahedral tilting which, depending on the level of doping, may lead to long-range order of antiphase BO6 tilts at ambient conditions and frustrated antiferroelectric order of Pb ions at low temperatures.

  8. Interplay between organic cations and inorganic framework and incommensurability in hybrid lead-halide perovskite CH3NH3PbBr3

    Science.gov (United States)

    Guo, Yinsheng; Yaffe, Omer; Paley, Daniel W.; Beecher, Alexander N.; Hull, Trevor D.; Szpak, Guilherme; Owen, Jonathan S.; Brus, Louis E.; Pimenta, Marcos A.

    2017-09-01

    Organic-inorganic coupling in the hybrid lead-halide perovskite is a central issue in rationalizing the outstanding photovoltaic performance of these emerging materials. Here, we compare and contrast the evolution of the structure and dynamics of hybrid CH3NH3PbBr3 and inorganic CsPbBr3 lead-halide perovskites with temperature, using Raman spectroscopy and single-crystal x-ray diffraction. Results reveal a stark contrast between their order-disorder transitions, which are abrupt for the hybrid whereas smooth for the inorganic perovskite. X-ray diffraction observes an intermediate incommensurate phase between the ordered and the disordered phases in CH3NH3PbBr3 . Low-frequency Raman scattering captures the appearance of a sharp soft mode in the incommensurate phase, ascribed to the theoretically predicted amplitudon mode. Our work highlights the interaction between the structural dynamics of organic cation CH3NH3+ and the lead-halide framework, and unravels the competition between tendencies for the organic and inorganic moieties to minimize energy in the incommensurate phase of the hybrid perovskite structure.

  9. Conductivity of CH{sub 3}NH{sub 3}PbI{sub 3} thin film perovskite stored in ambient atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Gebremichael, Bizuneh, E-mail: bizunehme@gmail.com [Physics Department, Addis Ababa University, Addis Ababa, P.O. Box 1176 (Ethiopia); Alemu, Getachew [Physics Department, Addis Ababa University, Addis Ababa, P.O. Box 1176 (Ethiopia); Tessema Mola, Genene [School of Chemistry & Physics, University of KwaZulu-Nat al, Pietermaritzburg Campus, Private Bag X01, Scottsville 3209 (South Africa)

    2017-06-01

    Time dependent conductivity loss in CH{sub 3}NH{sub 3}PbI{sub 3} thin film perovskite stored in ambient atmosphere were studied based on electrical and optical measurements. Recent investigations on thin film perovskite solar cell suggest that in the steady state operation of the device, the V{sub oc} is unchanged by continuous illumination of light. Rather the reduction in the power conversion efficiency is caused by significant reduction of the short circuit current (J{sub sc}). In this paper, the effect of light on the optical absorption and electrical conductivity of the CH{sub 3}NH{sub 3}PbI{sub 3} thin film which is deposited on a glass substrate is investigated. The temperature dependent conductivity measurements indicated that the dominant conduction mechanism in the film perovskite is electronic rather than ionic.

  10. Engineering of CH 3 NH 3 PbI 3 Perovskite Crystals by Alloying Large Organic Cations for Enhanced Thermal Stability and Transport Properties

    KAUST Repository

    Peng, Wei

    2016-07-28

    The number of studies on organic–inorganic hybrid perovskites has soared in recent years. However, the majority of hybrid perovskites under investigation are based on a limited number of organic cations of suitable sizes, such as methylammonium and formamidinium. These small cations easily fit into the perovskite\\'s three-dimensional (3D) lead halide framework to produce semiconductors with excellent charge transport properties. Until now, larger cations, such as ethylammonium, have been found to form 2D crystals with lead halide. Here we show for the first time that ethylammonium can in fact be incorporated coordinately with methylammonium in the lattice of a 3D perovskite thanks to a balance of opposite lattice distortion strains. This inclusion results in higher crystal symmetry, improved material stability, and markedly enhanced charge carrier lifetime. This crystal engineering strategy of balancing opposite lattice distortion effects vastly increases the number of potential choices of organic cations for 3D perovskites, opening up new degrees of freedom to tailor their optoelectronic and environmental properties.

  11. Elastic softness of hybrid lead halide perovskites

    KAUST Repository

    Ferreira, A. C.

    2018-01-26

    Much recent attention has been devoted towards unravelling the microscopic optoelectronic properties of hybrid organic-inorganic perovskites (HOP). Here we investigate by coherent inelastic neutron scattering spectroscopy and Brillouin light scattering, low frequency acoustic phonons in four different hybrid perovskite single crystals: MAPbBr3, FAPbBr3, MAPbI3 and α-FAPbI3 (MA: methylammonium, FA: formamidinium). We report a complete set of elastic constants caracterized by a very soft shear modulus C44. Further, a tendency towards an incipient ferroelastic transition is observed in FAPbBr3. We observe a systematic lower sound group velocity in the technologically important iodide-based compounds compared to the bromide-based ones. The findings suggest that low thermal conductivity and hot phonon bottleneck phenomena are expected to be enhanced by low elastic stiffness, particularly in the case of the ultrasoft α-FAPbI3.

  12. Ba2+ Doped CH3NH3PbI3 to Tune the Energy State and Improve the Performance of Perovskite Solar Cells

    International Nuclear Information System (INIS)

    Zhang, Hanbing; Shang, Ming-hui; Zheng, Xiaoying; Zeng, Zhaobing; Chen, Renjie; Zhang, Ying; Zhang, Jing; Zhu, Yuejin

    2017-01-01

    Highlights: •Ba doping enlarges the energy band gap of MAPb 1-x Ba x I 3 . •Voc and Jsc are enhanced in perovskite solar cells. •DFT calculation proves the experiment results. -- Abstract: Elements substitution and doping in perovskite CH 3 NH 3 PbI 3 exhibit versatile tunability of energy band structure and opto-electric properties. Ba 2+ is chosen to substitute Pb 2+ for its similar valence state and ionic radius with Pb 2+ . Ba 2+ doping in perovskite (mol% <5) slightly enlarges the optic energy gap by conduction band minimum(CBM) upshifting to vacuum energy level, which is due to the smaller electronegativity of Ba than Pb. The enlarged band gap is also verified by density function theory calculations. In n-i-p structure perovskite solar cells (PSCs), because of the higher CBM of doped perovskite, the Fermi energy difference between n and p side is enlarged and the electron injection from the perovskite to TiO 2 is improved. Thus, both the photovoltage and photocurrent are improved by small amount Ba 2+ doping, resulting optimized 17.4% efficiency under AM1.5. This work reveals the relationship between the doping element property and the energy band structure of the perovskite, and highlights the doping method to improve the performance of PSCs.

  13. High temperature-induced phase transitions in Sr{sub 2}GdRuO{sub 6} complex perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Triana, C.A.; Corredor, L.T.; Landinez Tellez, D.A. [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, Bogota D.C. A.A. 14490 (Colombia); Roa-Rojas, J., E-mail: jroar@unal.edu.co [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, Bogota D.C. A.A. 14490 (Colombia)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Crystal structure, thermal expansion and phase transitions at high-temperature of Sr{sub 2}GdRuO{sub 6} perovskite has been investigated. Black-Right-Pointing-Pointer X-ray diffraction pattern at 298 K of Sr{sub 2}GdRuO{sub 6} corresponds to monoclinic perovskite-type structure with P2{sub 1}/n space group. Black-Right-Pointing-Pointer Evolution of X-ray diffraction patterns at high-temperature shows that the Sr{sub 2}GdRuO{sub 6} perovskite suffers two-phase transitions. Black-Right-Pointing-Pointer At 573 K the X-ray diffraction pattern of Sr{sub 2}GdRuO{sub 6} corresponds to monoclinic perovskite-type structure with I2/m space group. Black-Right-Pointing-Pointer At 1273 K the Sr{sub 2}GdRuO{sub 6} perovskite suffers a complete phase-transition from monoclinic I2/m (no. 12) to tetragonal I4/m (no. 87). -- Abstract: The crystal structure behavior of the Sr{sub 2}GdRuO{sub 6} complex perovskite at high-temperature has been investigated over a wide temperature range between 298 K {<=} T {<=} 1273 K. Measurements of X-ray diffraction at room-temperature and Rietveld analysis of the experimental patterns show that this compound crystallizes in a monoclinic perovskite-like structure, which belongs to the P2{sub 1}/n (no. 14) space group and 1:1 ordered arrangement of Ru{sup 5+} and Gd{sup 3+} cations over the six-coordinate M sites. Experimental lattice parameters were obtained to be a =5.8103(5) Angstrom-Sign , b =5.8234(1) Angstrom-Sign , c =8.2193(9) Angstrom-Sign , V = 278.11(2) Angstrom-Sign {sup 3} and angle {beta} = 90.310(5) Degree-Sign . The high-temperature analysis shows the occurrence of two-phase transitions on this material. First, at 573 K it adopts a monoclinic perovskite-type structure with I2/m (no. 12) space group with lattice parameters a = 5.8275(6) Angstrom-Sign , b = 5.8326(3) Angstrom-Sign , c = 8.2449(2) Angstrom-Sign , V = 280.31(3) Angstrom-Sign {sup 3} and angle {beta} = 90.251(3) Degree-Sign . Close

  14. Light-Responsive Ion-Redistribution-Induced Resistive Switching in Hybrid Perovskite Schottky Junctions

    KAUST Repository

    Guan, Xinwei

    2017-11-23

    Hybrid Perovskites have emerged as a class of highly versatile functional materials with applications in solar cells, photodetectors, transistors, and lasers. Recently, there have also been reports on perovskite-based resistive switching (RS) memories, but there remain open questions regarding device stability and switching mechanism. Here, an RS memory based on a high-quality capacitor structure made of an MAPbBr3 (CH3NH3PbBr3) perovskite layer sandwiched between Au and indium tin oxide (ITO) electrodes is reported. Such perovskite devices exhibit reliable RS with an ON/OFF ratio greater than 103, endurance over 103 cycles, and a retention time of 104 s. The analysis suggests that the RS operation hinges on the migration of charged ions, most likely MA vacancies, which reversibly modifies the perovskite bulk transport and the Schottky barrier at the MAPbBr3/ITO interface. Such perovskite memory devices can also be fabricated on flexible polyethylene terephthalate substrates with high bendability and reliability. Furthermore, it is found that reference devices made of another hybrid perovskite MAPbI3 consistently exhibit filament-type switching behavior. This work elucidates the important role of processing-dependent defects in the charge transport of hybrid perovskites and provides insights on the ion-redistribution-based RS in perovskite memory devices.

  15. Correlation of Lip Prints with Gender, ABO Blood Groups and Intercommissural Distance.

    Science.gov (United States)

    Verma, Pradhuman; Sachdeva, Suresh K; Verma, Kanika Gupta; Saharan, Swati; Sachdeva, Kompal

    2013-07-01

    In forensics, the mouth allows for a myriad of possibilities. Lip print on glass or cigarette butt found at crime scenes may link to a suspect. Hence, a dentist has to actively play his role in personal identification and criminal investigation. To investigate the uniqueness of the lip print patterns in relation to gender, ABO blood groups and intercommissural distance (ICD). The study was conducted on 208 randomly selected students. The lip print of each subject was obtained and pattern was analyzed according to Tsuchihashi classification. The blood group and ICD at rest position was recorded for each. The study showed that Type II (branched) lip pattern to be most prominent. The B+ blood group was the most common in both genders and the ICD is higher in males. The lip print pattern does not show any correlation between ABO blood groups, gender, and ICD. The lip print pattern shows no correlation with gender, ABO blood groups, or ICD. Further studies with larger samples are required to obtain statistical significance of this correlation.

  16. Self-assembled single-phase perovskite nanocomposite thin films.

    Science.gov (United States)

    Kim, Hyun-Suk; Bi, Lei; Paik, Hanjong; Yang, Dae-Jin; Park, Yun Chang; Dionne, Gerald F; Ross, Caroline A

    2010-02-10

    Thin films of perovskite-structured oxides with general formula ABO(3) have great potential in electronic devices because of their unique properties, which include the high dielectric constant of titanates, (1) high-T(C) superconductivity in cuprates, (2) and colossal magnetoresistance in manganites. (3) These properties are intimately dependent on, and can therefore be tailored by, the microstructure, orientation, and strain state of the film. Here, we demonstrate the growth of cubic Sr(Ti,Fe)O(3) (STF) films with an unusual self-assembled nanocomposite microstructure consisting of (100) and (110)-oriented crystals, both of which grow epitaxially with respect to the Si substrate and which are therefore homoepitaxial with each other. These structures differ from previously reported self-assembled oxide nanocomposites, which consist either of two different materials (4-7) or of single-phase distorted-cubic materials that exhibit two or more variants. (8-12) Moreover, an epitaxial nanocomposite SrTiO(3) overlayer can be grown on the STF, extending the range of compositions over which this microstructure can be formed. This offers the potential for the implementation of self-organized optical/ferromagnetic or ferromagnetic/ferroelectric hybrid nanostructures integrated on technologically important Si substrates with applications in magnetooptical or spintronic devices.

  17. Gene distribution of ABO blood type system on the Dengue Hemorrhagic Fever (DHF) patients in the working area of Puskesmas Bonto Bangun, District of Rilau Ale, Bulukumba

    Science.gov (United States)

    Sjafaraenan; Alvionita, D. N.; Agus, R.; Sabran, A.

    2018-03-01

    This research is about gene distribution of ABO blood type system on the Dengue Hemorrhagic Fever (DHF) patients in the working area of Puskesmas Bonto Bangun, District of Rilau Ale, Bulukumba. This research aimed to determine the blood type which is most affected by DHF using ABO blood type system. In this research, there are 104 samples, 8 of them were attacked by DF and 96 were attacked by DHF. From the 96 patients of DHF, there were 38 patients with A-blood type, 17 patients with B-blood type, 36 patients with O-blood type and 5 patients of AB-blood type. The data were tested using genotype frequency test and the results showed that the percentage of A-homozygous blood type (IAIA) is 0:09%; A heterozygous blood type (IAIo) is 0:36%; B-homozygous blood type (IBIB) is 0.01%; B heterozygous blood type (IB Io) is 0.12%; AB blood type (IAIB) is 0.06% and O blood type (IoIo) is 12:36%. So the biggest frequency of genotype are IAIo (0.36%) and IoIo (0.36%). The results showed that O blood type gene is the most affected by DHF. Then continued by the regression test between blood type and DHF, it is obtained that the correlation value is 1 which indicated that there is a strong relationship.

  18. Improving the Morphology of the Perovskite Absorber Layer in Hybrid Organic/Inorganic Halide Perovskite MAPbI3 Solar Cells

    Directory of Open Access Journals (Sweden)

    I. J. Ogundana

    2017-01-01

    Full Text Available Recently, perovskite solar cells have attracted tremendous attention due to their excellent power conversion efficiency, low cost, simple fabrications, and high photovoltaic performance. Furthermore, the perovskite solar cells are lightweight and possess thin film and semitransparency. However, the nonuniformity in perovskite layer constitutes a major setback to the operation mechanism, performance, reproducibility, and degradation of perovskite solar cells. Therefore, one of the main challenges in planar perovskite devices is the fabrication of high quality films with controlled morphology and least amount of pin-holes for high performance thin film perovskite devices. The poor reproducibility in perovskite solar cells hinders the accurate fabrication of practical devices for use in real world applications, and this is primarily as a result of the inability to control the morphology of perovskites, leading to large variability in the characteristics of perovskite solar cells. Hence, the focus of research in perovskites has been mostly geared towards improving the morphology and crystallization of perovskite absorber by selecting the optimal annealing condition considering the effect of humidity. Here we report a controlled ambient condition that is necessary to grow uniform perovskite crystals. A best PCE of 7.5% was achieved along with a short-circuit current density of 15.2 mA/cm2, an open-circuit voltage of 0.81 V, and a fill factor of 0.612 from the perovskite solar cell prepared under 60% relative humidity.

  19. Mixed valent perovskites Ba/sub 3/B/sup 3 +/Ru/sub 2/sup(4. 5+)O/sub 9/. Catalytic activity of perovskite oxides with noble metals

    Energy Technology Data Exchange (ETDEWEB)

    Treiber, U; Kemmler-Sack, S; Ehmann, A; Schaller, H U; Duerrschmidt, E; Thumm, I; Bader, H [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1981-10-01

    The black compounds Ba/sub 3/B/sup 3 +/Ru/sub 2/O/sub 9/ crystallize with B/sup 3 +/ = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Y in a hexagonal BaTiO/sub 3/ structure (6L, sequence (hcc)/sub 2/) with an ordered distribution (1:2 order) of B/sup 3 +/ and ruthenium (BO/sub 6/ single octahedra; Ru/sub 2/O/sub 9/ double groups). The mean oxidation state of ruthenium is about +4.5. The properties are compared with those of other isotypic stacking polytypes Ba/sub 3/B/sup 3 +/M/sub 2/sup(4.5)O/sub 9/ (M/sub 2/ = IrRu, Ir/sub 2/, PtRu) and Ba/sub 3/B/sup 2 +/M/sub 2//sup 5 +/O/sub 9/ (M = Ru, Ir). The results of activity tests concerning the efficiency of perovskite oxides with noble metals in respect of the oxidation of CO or CHsub(x) and the reduction of NOsub(x) are reported.

  20. Intravenous Immunoglobulin G Treatment in ABO Hemolytic Disease of the Newborn, is it Myth or Real?

    Science.gov (United States)

    Beken, Serdar; Hirfanoglu, Ibrahim; Turkyilmaz, Canan; Altuntas, Nilgun; Unal, Sezin; Turan, Ozden; Onal, Esra; Ergenekon, Ebru; Koc, Esin; Atalay, Yildiz

    2014-03-01

    Intravenous Immunoglobulin G (IVIG) therapy has been used as a component of the treatment of hemolytic disease of the newborn. There is still no consensus on its use in ABO hemolytic disease of the newborn routinely. The aim of this study is to determine whether administration of IVIG to newborns with ABO incompatibility is necessary. One hundred and seventeen patients with ABO hemolytic disease and positive Coombs test were enrolled into the study. The subjects were healthy except jaundice. Infants were divided into two groups: Group I (n = 71) received one dose of IVIG (1 g/kg) and LED phototherapy whereas Group II (n = 46) received only LED phototherapy. One patient received erythrocyte transfusion in Group I, no exchange transfusion was performed in both groups. Mean duration of phototherapy was 3.1 ± 1.3 days in Group I and 2.27 ± 0.7 days in Group II (p hemolytic disease. Meticulus follow-up of infants with ABO hemolytic disease and LED phototherapy decreases morbidity. IVIG failed to show preventing hemolysis in ABO hemolytic disease.

  1. Solid state synthesis and structural refinement of polycrystalline La ...

    Indian Academy of Sciences (India)

    Perovskite structure based ceramic precursors have a characteristic property of substitution in the ``A" site of the ABO3 structure. This makes them a potential material for nuclear waste management in synthetic rock (SYNROC) technology. In order to simulate the mechanism of rare earth fixation in perovskite, La ...

  2. Enhancement of magnetoresistance and ferromagnetic coupling in the complex perovskites CaCu{sub 3}(Mn{sub 4−x}Al{sub x})O{sub 12} (x = 0, 0.2, 0.4, and 0.6): A neutron diffraction study

    Energy Technology Data Exchange (ETDEWEB)

    Ben Hassine, R.; Cherif, W. [Faculty of Sciences, Sfax University, Sfax, B.P. 1171-3000 (Tunisia); Sánchez-Benítez, J. [Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Mompean, F. J.; Alonso, J. A., E-mail: ja.alonso@icmm.csic.es [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, Cantoblanco, E-28049 Madrid (Spain); Fernández-Díaz, M. T. [Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9 (France); Elhalouani, F. [National School of Engineers, Sfax University, Sfax, B.P. W 3038 (Tunisia)

    2015-09-14

    New compounds of the series CaCu{sub 3}(Mn{sub 4−x}Al{sub x})O{sub 12} have been prepared under high pressure conditions (2 GPa), in the presence of KClO{sub 4} as oxidizing agent to stabilize Mn{sup 3+,4+} mixed valence. The polycrystalline samples have been characterized by x-ray diffraction, neutron powder diffraction (NPD), magnetic, and magnetotransport measurements. All the samples are cubic, space group Im-3. These oxides adopt a superstructure of ABO{sub 3} perovskite given by the long-range 1:3 ordering of Ca{sup 2+} and Cu{sup 2+} ions at the A sublattice. The NPD study for x = 0.4 shows that Al{sup 3+} ions are statistically distributed at the octahedral positions, being the (Mn,Al)O{sub 6} octahedra strongly tilted, with superexchange (Mn,Al)-O-(Mn,Al) angles of 142.1°. Also, neutron data clearly show that some Mn{sup 3+} ions (0.65(2) per formula) are located together with Cu{sup 2+} at the square-planar 6b positions. Regarding the magnetic properties, all the compounds present a spontaneous increase of the magnetization below T{sub C}, typical of ferro-or ferrimagnetic materials, with T{sub C} decreasing upon Al introduction. The magnetic structure determined from low-temperature NPD data unveils a ferromagnetic coupling between (Cu{sup 2+}, Mn{sup 3+}){sub 6b} spins and Mn{sub 8c} spins at octahedral positions; this is in contrast with the ferrimagnetic structure observed for RCu{sub 3}Mn{sub 4}O{sub 12} and CaCu{sub 3}Mn{sub 4}O{sub 12}, where an AFM coupling is observed between both magnetic sublattices. Interestingly, an enhancement of the magnetoresistance effect is observed for x = 0.2, well beyond that found for the parent compound. This effect, in materials subtly doped with non-magnetic elements at the Mn positions, may be of interest for applications.

  3. Fabrication and characterization of perovskite-based CH{sub 3}NH{sub 3}Pb{sub 1-x}Ge{sub x}I{sub 3}, CH{sub 3}NH{sub 3}Pb{sub 1-x}Tl{sub x}I{sub 3} and CH{sub 3}NH{sub 3}Pb{sub 1-x}In{sub x}I{sub 3} photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Ohishi, Yuya; Oku, Takeo, E-mail: oku@mat.usp.ac.jp; Suzuki, Atsushi [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

    2016-02-01

    Perovskite-type CH{sub 3}NH{sub 3}PbI{sub 3}-based photovoltaic devices were fabricated and characterized. Doping effects of thallium (Tl), indium (In), or germanium (Ge) element on the photovoltaic properties and surface structures of the perovskite phase were investigated. The open circuit voltage increased by Ge addition, and fill factors were improved by adding a small amount of Ge, Tl or In. In addition, the wavelength range of incident photon conversion efficiencies was expanded by the Tl addition.

  4. Magnetic characterization of Nd0.8Sr0.2(Mn1-x Co x )O3 perovskites

    International Nuclear Information System (INIS)

    Vidal, Karmele; Lezama, Luis; Arriortua, Maria I.; Rojo, Teofilo; Gutierrez, Jon; Barandiaran, Jose M.

    2005-01-01

    We present a magnetic study of the family of perovskites Nd 0.8 Sr 0.2 (Mn 1- x Co x )O 3 (x=0.1, 0.2 and 0.3). These compositions have been prepared by using both the sol-gel method and the freeze-drying technique. As a result, we have obtained polycrystalline powder-like samples. We have obtained pure compounds that have been indexed in the Pnma space group. The study of their magnetic properties shows a decrease of the measured low-temperature magnetic moment as the content of Co increases in the composition. However, a similar magnetic ordering temperature of about 130 K has been determined for all samples. All the studied compounds show insulating behaviour of the electrical resistivity

  5. One-Year stable perovskite solar cells by 2D/3D interface engineering

    Science.gov (United States)

    Grancini, G.; Roldán-Carmona, C.; Zimmermann, I.; Mosconi, E.; Lee, X.; Martineau, D.; Narbey, S.; Oswald, F.; de Angelis, F.; Graetzel, M.; Nazeeruddin, Mohammad Khaja

    2017-06-01

    Despite the impressive photovoltaic performances with power conversion efficiency beyond 22%, perovskite solar cells are poorly stable under operation, failing by far the market requirements. Various technological approaches have been proposed to overcome the instability problem, which, while delivering appreciable incremental improvements, are still far from a market-proof solution. Here we show one-year stable perovskite devices by engineering an ultra-stable 2D/3D (HOOC(CH2)4NH3)2PbI4/CH3NH3PbI3 perovskite junction. The 2D/3D forms an exceptional gradually-organized multi-dimensional interface that yields up to 12.9% efficiency in a carbon-based architecture, and 14.6% in standard mesoporous solar cells. To demonstrate the up-scale potential of our technology, we fabricate 10 × 10 cm2 solar modules by a fully printable industrial-scale process, delivering 11.2% efficiency stable for >10,000 h with zero loss in performances measured under controlled standard conditions. This innovative stable and low-cost architecture will enable the timely commercialization of perovskite solar cells.

  6. ABO blood group and risk of cancer

    DEFF Research Database (Denmark)

    Vasan, Senthil K; Hwang, Jinseub; Rostgaard, Klaus

    2016-01-01

    groups and site-specific cancer risk in a large cohort of healthy blood donors from Sweden and Denmark. RESULTS: A total of 1.6 million donors were followed over 27 million person-years (20 million in Sweden and 7 million in Denmark). We observed 119,584 cancer cases. Blood groups A, AB and B were......INTRODUCTION: The associations between ABO blood group and cancer risk have been studied repeatedly, but results have been variable. Consistent associations have only been reported for pancreatic and gastric cancers. MATERIALS AND METHODS: We estimated associations between different ABO blood...... associated either with increased or decreased risk of cancer at 13 anatomical sites (p≤0.05), compared to blood group O. Consistent with assessment using a false discovery rate approach, significant associations with ABO blood group were observed for cancer of the pancreas, breast, and upper gastrointestinal...

  7. Strong excitonic interactions in the oxygen K-edge of perovskite oxides

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Kota; Miyata, Tomohiro [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan); Olovsson, Weine [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Mizoguchi, Teruyasu, E-mail: teru@iis.u-tokyo.ac.jp [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan)

    2017-07-15

    Excitonic interactions of the oxygen K-edge electron energy-loss near-edge structure (ELNES) of perovskite oxides, CaTiO{sub 3}, SrTiO{sub 3}, and BaTiO{sub 3}, together with reference oxides, MgO, CaO, SrO, BaO, and TiO{sub 2}, were investigated using a first-principles Bethe–Salpeter equation calculation. Although the transition energy of oxygen K-edge is high, strong excitonic interactions were present in the oxygen K-edge ELNES of the perovskite oxides, whereas the excitonic interactions were negligible in the oxygen K-edge ELNES of the reference compounds. Detailed investigation of the electronic structure suggests that the strong excitonic interaction in the oxygen K-edge ELNES of the perovskite oxides is caused by the directionally confined, low-dimensional electronic structure at the Ti–O–Ti bonds. - Highlights: • Excitonic interaction in oxygen-K edge is investigated. • Strong excitonic interaction is found in the oxygen-K edge of perovskite oxides. • The strong excitonic interaction is ascribed to the low-dimensional and confined electronic structure.

  8. Interacciones hiperfinas en BaxSr1-xHfO3

    Directory of Open Access Journals (Sweden)

    López García, A.

    1999-10-01

    Full Text Available In order to determine the microscopic role of cation A in ABO3 perovskites the hyperfine interaction in the Sr1-xBaxHfO3 system using Perturbed Angular Correlation spectroscopy (PAC is studied. As a previous result the compositions x = 0.50 and 0.25 are shown. The PAC spectra were obtained in the temperature range from 20 to 1000ºC. In both compounds a phase transition to higher symmetry structure was observed at T≈400 and 200ºC, respectively. This structure is proposed to be cubic in both compositions. The results are compared with those obtained in SrHfO3 and BaHfO3.Con el fin de determinar el papel microscópico que juega el catión A en las perovskitas ABO3 se estudia la interacción hiperfina el sistema Sr1-xBaxHfO3 usando la espectroscopia Correlaciones Angulares Perturbadas (PAC en función de la temperatura y la composición. Como resultado previo se muestra en este trabajo, el estudio de las composiciones x = 0.5 y 0.75. Las medidas PAC se realizaron en el intervalo de temperaturas que va desde 20 a 1000ºC. Para x=0.50 y 0.75 se determinó una transición a una fase de mayor simetría a T≈400 y 200ºC, respectivamente. Se propone que esta fase de mayor simetría es cúbica en ambas composiciones. Los resultados obtenidos son comparados con los compuestos puros SrHfO3 y BaHfO3.

  9. Trapping charges at grain boundaries and degradation of CH3NH3Pb(I1-x Br x )3 perovskite solar cells

    Science.gov (United States)

    Phuong Nguyen, Bich; Kim, Gee Yeong; Jo, William; Kim, Byeong Jo; Jung, Hyun Suk

    2017-08-01

    The electrical properties of CH3NH3Pb(I1-x Br x )3 (x = 0.13) perovskite materials were investigated under ambient conditions. The local work function and the local current were measured using Kelvin probe force microscopy and conductive atomic force microscopy, respectively. The degradation of the perovskite layers depends on their grain size. As the material degrades, an additional peak in the surface potential appears simultaneously with a sudden increase and subsequent relaxation of the local current. The potential bending at the grain boundaries and the intragrains is the most likely reason for the change of the local current surface of the perovskite layers. The improved understanding of the degradation mechanism garnered from this study helps pave the way toward an improved photo-conversion efficiency in perovskite solar cells.

  10. Design of Perovskite Oxides as Anion-Intercalation-Type Electrodes for Supercapacitors: Cation Leaching Effect.

    Science.gov (United States)

    Liu, Yu; Dinh, Jim; Tade, Moses O; Shao, Zongping

    2016-09-14

    Oxygen ions can be exploited as a charge carrier to effectively realize a new type of anion-intercalation supercapacitor. In this study, to get some useful guidelines for future materials development, we comparatively studied SrCoO3-δ (SC), Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF), and Co3O4 as electrodes in supercapacitors with aqueous alkaline electrolyte. The effect of interaction between the electrode materials with the alkaline solution was focused on the structure and specific surface area of the electrode material, and ultimately the electrochemical performance was emphasized. Both BSCF and SC were found to experience cation leaching in alkaline solution, resulting in an increase in the specific surface area of the material, but overleaching caused the damage of perovskite structure of BSCF. Barium leaching was more serious than strontium, and the cation leaching was component dependent. Although high initial capacitance was achieved for BSCF, it was not a good candidate as intercalation-type electrode for supercapacitor because of poor cycling stability from serious Ba(2+) and Sr(2+) leaching. Instead, SC was a favorable electrode candidate for practical use in supercapacitors due to its high capacity and proper cation leaching capacity, which brought beneficial effect on cycling stability. It is suggested that cation leaching effect should be seriously considered in the development of new perovskite materials as electrodes for supercapacitors.

  11. Association between Cheiloscopic Patterns and ABO Blood Groups among South Indian Population.

    Science.gov (United States)

    Khanapure, Sneha; Suhas, H G; Potdar, Shrudha; Sam, George; Sudeep, C B; Arjun, M R

    2017-07-01

    Human beings have few characteristics that are unique from others. Lip prints are one of such feature. They are not changed throughout the life and are not influenced by injuries, diseases, or environmental changes. According to the various antigen-antibody reactions in the bloodstream, different individuals have specific blood groups. To study the distribution of lip print patterns among individuals with different ABO and Rh blood groups and also to know the relation between their characters and blood groups. In the present study, lip prints were collected randomly from 85 individuals, and their blood group matching was performed. This is to identify the most common lip print type and to know any association between lip print types and blood groups. Tsuchihashi's classification of lip prints was used to compare with the ABO and Rh blood grouping systems. It was observed that in individuals with B+, A+, and O- blood groups, predominant pattern was Type IV and individuals having blood group O+ and AB+ common lip print pattern was Type II. This study showed strong association between lip print patterns and ABO blood groups as some blood groups were not included in statistical analysis; further studies including larger sample are essential to substantiate the results. Correlating lip print with blood group helps in identification of the suspects. Along with lip prints, another biological record that remains unchanged throughout the lifetime of a person is the blood group. Determining the blood group of a person from the samples obtained at the site of crime and also recovering lip prints from site can help identify a person.

  12. Morphology-photovoltaic property correlation in perovskite solar cells: One-step versus two-step deposition of CH3NH3PbI3

    Directory of Open Access Journals (Sweden)

    Jeong-Hyeok Im

    2014-08-01

    Full Text Available Perovskite CH3NH3PbI3 light absorber is deposited on the mesoporous TiO2 layer via one-step and two-step coating methods and their photovoltaic performances are compared. One-step coating using a solution containing CH3NH3I and PbI2 shows average power conversion efficiency (PCE of 7.5%, while higher average PCE of 13.9% is obtained from two-step coating method, mainly due to higher voltage and fill factor. The coverage, pore-filling, and morphology of the deposited perovskite are found to be critical in photovoltaic performance of the mesoporous TiO2 based perovskite solar cells.

  13. Chlorine Incorporation in the CH3NH3PbI3 Perovskite: Small Concentration, Big Effect.

    Science.gov (United States)

    Quarti, Claudio; Mosconi, Edoardo; Umari, Paolo; De Angelis, Filippo

    2017-01-03

    The role of chlorine doping in CH 3 NH 3 PbI 3 represents an important open issue in the use of hybrid perovskites for photovoltaic applications. In particular, even if a positive role of chlorine doping on perovskite film formation and on material morphology has been demonstrated, an inherent positive effect on the electronic and photovoltaic properties cannot be excluded. Here we carried out periodic density functional theory and Car-Parrinello molecular dynamics simulations, going down to ∼1% doping, to investigate the effect of chlorine on CH 3 NH 3 PbI 3 . We found that such a small doping has important effects on the dynamics of the crystalline structure, both with respect to the inorganic framework and with respect to the cation libration motion. Together, we observe a dynamic spatial localization of the valence and conduction states in separated spatial material regions, which takes place in the 10 -1 ps time scale and which could be the key to ease of exciton dissociation and, likely, to small charge recombination in hybrid perovskites. Moreover, such localization is enhanced by chlorine doping, demonstrating an inherent positive role of chlorine doping on the electronic properties of this class of materials.

  14. Engineering of CH 3 NH 3 PbI 3 Perovskite Crystals by Alloying Large Organic Cations for Enhanced Thermal Stability and Transport Properties

    KAUST Repository

    Peng, Wei; Miao, Xiaohe; Adinolfi, Valerio; Alarousu, Erkki; El Tall, Omar; Emwas, Abdul-Hamid M.; Zhao, Chao; Walters, Grant; Liu, Jiakai; Ouellette, Olivier; Pan, Jun; Banavoth, Murali; Sargent, Edward H.; Mohammed, Omar F.; Bakr, Osman

    2016-01-01

    The number of studies on organic–inorganic hybrid perovskites has soared in recent years. However, the majority of hybrid perovskites under investigation are based on a limited number of organic cations of suitable sizes, such as methylammonium and formamidinium. These small cations easily fit into the perovskite's three-dimensional (3D) lead halide framework to produce semiconductors with excellent charge transport properties. Until now, larger cations, such as ethylammonium, have been found to form 2D crystals with lead halide. Here we show for the first time that ethylammonium can in fact be incorporated coordinately with methylammonium in the lattice of a 3D perovskite thanks to a balance of opposite lattice distortion strains. This inclusion results in higher crystal symmetry, improved material stability, and markedly enhanced charge carrier lifetime. This crystal engineering strategy of balancing opposite lattice distortion effects vastly increases the number of potential choices of organic cations for 3D perovskites, opening up new degrees of freedom to tailor their optoelectronic and environmental properties.

  15. Enhanced photovoltaic performance of CH3NH3PbBrXI3-X-based perovskite solar cells via anti-solvent extraction

    Science.gov (United States)

    Jiang, Zhaoyi; Zhang, Weijia; Lu, Chaoqun; Ma, Denghao; Liu, Haixu; Yu, Wei; Zhang, Yu; Ma, Qiang; Zhang, Yulong

    2018-06-01

    In this paper, the two-step sequential deposition method was used to prepare the CH3NH3PbBrXI3-X films by introducing CH3NH3Br in the precursors. The surface morphology of the PbI2 films was controlled by anti-solvent extraction (ASE) to improve the microstructure and photo-physical properties of the perovskite films. It was noteworthy that, compared to the compact PbI2 films, the porous PbI2 films facilitated the growth of crystals and bromine incorporation in films, and the prepared perovskite films exhibited enlarged grain size, increased light absorption, enhanced Br incorporation and prolonged carrier lifetime, which resulted in excellent photo-electrical properties of the CH3NH3PbBrXI3-X films. With porous PbI2 templates, the inverted planar perovskite solar cells based on films with appropriate Br incorporation (CH3NH3Br/CH3NH3I mole ratio = 3/7) showed a photovoltaic conversion efficiency (PCE) of 14.9%, and the stability of the devices in air was elevated. Consequently, the high-quality CH3NH3PbBrXI3-X films can be obtained with porous PbI2 templates for improving the performance of the perovskite solar cells.

  16. Multiferroic behavior associated with an order-disorder hydrogen bonding transition in metal-organic frameworks (MOFs) with the perovskite ABX3 architecture.

    Science.gov (United States)

    Jain, Prashant; Ramachandran, Vasanth; Clark, Ronald J; Zhou, Hai Dong; Toby, Brian H; Dalal, Naresh S; Kroto, Harold W; Cheetham, Anthony K

    2009-09-30

    Multiferroic behavior in perovskite-related metal-organic frameworks of general formula [(CH(3))(2)NH(2)]M(HCOO)(3), where M = Mn, Fe, Co, and Ni, is reported. All four compounds exhibit paraelectric-antiferroelectric phase transition behavior in the temperature range 160-185 K (Mn: 185 K, Fe: 160 K; Co: 165 K; Ni: 180 K); this is associated with an order-disorder transition involving the hydrogen bonded dimethylammonium cations. On further cooling, the compounds become canted weak ferromagnets below 40 K. This research opens up a new class of multiferroics in which the electrical ordering is achieved by means of hydrogen bonding.

  17. Relativistic GW calculations on CH3NH3PbI3 and CH3NH3SnI3 perovskites for solar cell applications.

    Science.gov (United States)

    Umari, Paolo; Mosconi, Edoardo; De Angelis, Filippo

    2014-03-26

    Hybrid AMX3 perovskites (A = Cs, CH3NH3; M = Sn, Pb; X = halide) have revolutionized the scenario of emerging photovoltaic technologies, with very recent results demonstrating 15% efficient solar cells. The CH3NH3PbI3/MAPb(I(1-x)Cl(x))3 perovskites have dominated the field, while the similar CH3NH3SnI3 has not been exploited for photovoltaic applications. Replacement of Pb by Sn would facilitate the large uptake of perovskite-based photovoltaics. Despite the extremely fast progress, the materials electronic properties which are key to the photovoltaic performance are relatively little understood. Density Functional Theory electronic structure methods have so far delivered an unbalanced description of Pb- and Sn-based perovskites. Here we develop an effective GW method incorporating spin-orbit coupling which allows us to accurately model the electronic, optical and transport properties of CH3NH3SnI3 and CH3NH3PbI3, opening the way to new materials design. The different CH3NH3SnI3 and CH3NH3PbI3 electronic properties are discussed in light of their exploitation for solar cells, and found to be dominantly due to relativistic effects. These effects stabilize the CH3NH3PbI3 material towards oxidation, by inducing a deeper valence band edge. Relativistic effects, however, also increase the material band-gap compared to CH3NH3SnI3, due to the valence band energy downshift (~0.7 eV) being only partly compensated by the conduction band downshift (~0.2 eV).

  18. Shell model for BaTiO3-Bi(Zn1/2Ti1/2)O3 perovskite solid solutions

    Science.gov (United States)

    Vielma, J.; Jackson, D.; Roundy, D.; Schneider, G.

    2010-03-01

    Even though the composition of BaTiO3-Bi(Zn1/2Ti1/2)O3 perovskite solid solutions is similar to other ferroelectric compounds, the dielectric response is unusual. Results of permittivity measurements as a function of temperature show a diffuse phase transition indicative of a weakly coupled relaxor behavior.footnotetextC. C. Huang and D. P. Cann, J. Appl. Phys. 104, 024117 (2008) To investigate the weakly coupled relaxor behavior in these materials at intermediate length scales we are developing a newly calibrated shell model based on first-principles supercell calculations of both the solid solution and its compositional endpoints. Initial results for its phase diagram will presented.

  19. Outcomes Following ABO-Incompatible Kidney Transplantation Performed After Desensitization by Nonantigen-Specific Immunoadsorption.

    Science.gov (United States)

    Becker, Luis E; Siebert, Daniela; Süsal, Caner; Opelz, Gerhard; Leo, Albrecht; Waldherr, Rüdiger; Macher-Goeppinger, Stephan; Schemmer, Peter; Schaefer, Sebastian Markus; Klein, Katrin; Beimler, Jörg; Zeier, Martin; Schwenger, Vedat; Morath, Christian

    2015-11-01

    For desensitization of ABO-incompatible kidney transplant recipients we recently proposed nonantigen-specific immunoadsorption (IA) and rituximab. We now compared clinical outcomes of 34 ABO-incompatible living-donor kidney recipients who were transplanted using this protocol with that of 68 matched ABO-compatible patients. In addition, we analyzed efficacy and cost of nonantigen-specific as compared to blood group antigen-specific IA. Before desensitization, the median isoagglutinin titer of 34 ABO-incompatible patients was 1:64 (Coombs technique). Patients received a median of 7 preoperative IA treatments. Twenty-four patients had a median of 2 additional plasmapheresis treatments to reach the preoperative target isoagglutinin titer of 1:8 or less. After a median postoperative follow-up of 22 months, overall graft survival in the ABO-incompatible group was not significantly different from that in ABO-compatible patients (log-rank P = 0.20), whereas patient survival tended to be lower (log-rank P = 0.05). The incidence of rejection episodes was 15% in both groups. The ABO-incompatible kidney recipients had a higher incidence of BK virus replication (P = 0.04) and nephropathy (P = 0.01) and showed more often colonization with multidrug resistant bacteria (P = 0.02). In comparison to blood group antigen-specific IA, nonantigen-specific IA showed equal efficacy but was associated with reduction in cost. Clinical outcomes of ABO-incompatible patients desensitized with a nonantigen-specific IA device and rituximab do not differ from that of matched ABO-compatible patients although a trend toward reduced patient survival was noted. Special attention must be paid to the higher incidence of BK virus infection in recipients of ABO-incompatible grafts.

  20. Optical constants of CH3NH3PbBr3 perovskite thin films measured by spectroscopic ellipsometry

    KAUST Repository

    Alias, Mohd Sharizal

    2016-07-14

    The lack of optical constants information for hybrid perovskite of CH3NH3PbBr3 in thin films form can delay the progress of efficient LED or laser demonstration. Here, we report on the optical constants (complex refractive index and dielectric function) of CH3NH3PbBr3 perovskite thin films using spectroscopic ellipsometry. Due to the existence of voids, the refractive index of the thin films is around 8% less than the single crystals counterpart. The energy bandgap is around 2.309 eV as obtained from photoluminescence and spectrophotometry spectra, and calculated from the SE analysis. The precise measurement of optical constants will be useful in designing optical devices using CH3NH3PbBr3 thin films.

  1. Relationship between ABO blood groups and head and neck cancer among Greek patients.

    Science.gov (United States)

    Kakava, Kassiani; Karelas, Ioannis; Koutrafouris, Ioannis; Damianidis, Savvas; Stampouloglou, Paulos; Papadakis, Georgios; Xenos, Antonios; Krania, Foteini; Sarof, Paulos; Tasopoulos, Georgios; Petridis, Nikolaos

    2016-01-01

    We examined the association of ABO blood groups with the different types of head and neck cancers. 195 diagnosed cases and 801 controls were selected from a Greek tertiary cancer center. Information regarding type of head and neck cancer and ABO blood group was collected and registered. The O blood group was found to be most prevalent followed by A, B and AB among the controls, whereas blood group A followed by O, B and AB was most prevalent among cancer patients. The difference among the distribution between the cases and controls was statistically significant in blood group A (pblood group A had 1.52-fold higher risk of developing head and neck cancer compared to people of other blood groups. Blood group A was found to be a potential risk factor for the development of head and neck cancers.

  2. Preparation and characterization of La1-xCexCoO3 perovskite oxides for energy materials

    International Nuclear Information System (INIS)

    Nyamdavaa, E.; Sevjidsuren, G.; Altantsog, P.; Yuanga, E.

    2016-01-01

    Cerium-doped lanthanum cobaltite perovskites (La 1-x Ce x CoO 3 with x = 0,0.2, 0.4) were prepared by the sol-gel method (calcined for 5 h at 750°C) and characterized by X-ray diffraction (XRD), X-ray absorption (XAS), energy-dispersive X-ray spectroscopy (EDS), and BET surface area analysis. The results showed that the cerium doping promoted the structural transformation of LaCoO 3 from rhombohedral into the cubic structure. High specific surface area and small crystallite size are achieved at x = 0.2. The XAS results confirmed the formation of compound La 1-x Ce x CoO 3 . [ru

  3. The association of ABO blood type with disease recurrence and mortality among patients with urothelial carcinoma of the bladder undergoing radical cystectomy.

    Science.gov (United States)

    Gershman, Boris; Moreira, Daniel M; Tollefson, Matthew K; Frank, Igor; Cheville, John C; Thapa, Prabin; Tarrell, Robert F; Thompson, Robert Houston; Boorjian, Stephen A

    2016-01-01

    To evaluate the association of ABO blood type with clinicopathologic outcomes and mortality among patients with urothelial carcinoma of the bladder treated with radical cystectomy (RC). We identified 2,086 consecutive patients who underwent RC between 1980 and 2008. Postoperative recurrence-free survival (RFS) and cancer-specific survival (CSS) were estimated using the Kaplan Meier method and compared with the log-rank test. Cox proportional hazards regression models were used to evaluate the association of ABO blood type with outcomes. A total of 913 (44%), 881 (42%), 216 (10%), and 76 (4%) patients had blood type O, A, B, and AB, respectively. Median postoperative follow-up among survivors was 11.0 years (interquartile range: 7.7-15.9y). Overall, 1,561 patients died, with 770 deaths attributable to bladder cancer. Non-O blood type was associated with significantly worse 5-year RFS (65% vs. 69%; P = 0.04) and/or CSS (64% vs. 70%; P = 0.02). In particular, among patients with≤pT2N0 disease, the 5-year RFS for those with non-O vs. O blood type was 75% vs. 82%, respectively (P = 0.002), whereas the 5-year CSS was 77% vs. 85%, respectively (P = 0.001). Moreover, on multivariable analysis, blood type A remained independently associated with an increased risk of cancer-specific mortality (hazard ratio = 1.22; P = 0.01). Non-O blood type, particularly blood type A, is associated with a significantly increased risk of death from bladder cancer among patients undergoing RC. If validated, the utility of a multimodal therapy approach, including perioperative chemotherapy, or more frequent postoperative surveillance in this cohort warrants further study. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Strong excitonic interactions in the oxygen K-edge of perovskite oxides.

    Science.gov (United States)

    Tomita, Kota; Miyata, Tomohiro; Olovsson, Weine; Mizoguchi, Teruyasu

    2017-07-01

    Excitonic interactions of the oxygen K-edge electron energy-loss near-edge structure (ELNES) of perovskite oxides, CaTiO 3 , SrTiO 3 , and BaTiO 3 , together with reference oxides, MgO, CaO, SrO, BaO, and TiO 2 , were investigated using a first-principles Bethe-Salpeter equation calculation. Although the transition energy of oxygen K-edge is high, strong excitonic interactions were present in the oxygen K-edge ELNES of the perovskite oxides, whereas the excitonic interactions were negligible in the oxygen K-edge ELNES of the reference compounds. Detailed investigation of the electronic structure suggests that the strong excitonic interaction in the oxygen K-edge ELNES of the perovskite oxides is caused by the directionally confined, low-dimensional electronic structure at the Ti-O-Ti bonds. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. ABO-Rh blood groups distribution in cardiac syndrome X patients

    OpenAIRE

    Kheradmand, Fatemeh; Rasmi, Yousef; Nemati, Mohaddeseh; Mohammadzad, Mir Hossein Seyed

    2012-01-01

    Background: Data on frequency distribution of ABO-Rh blood groups in cardiac syndrome X (CSX) patients are not available. We aimed to investigate the distribution of ABO-Rh blood groups in these patients. Materials and Methods: A total of 247 CSX patients’ records were reviewed in a cross-sectional study from 2006 to 2010. One hundred forty six patients (59.1%) were female, and the mean patient age was 52 ± 11 years. The frequency of ABO-Rh blood groups was compared to the frequency of these ...

  6. CH3NH3PbI3 grain growth and interfacial properties in meso-structured perovskite solar cells fabricated by two-step deposition

    Science.gov (United States)

    Yao, Zhibo; Wang, Wenli; Shen, Heping; Zhang, Ye; Luo, Qiang; Yin, Xuewen; Dai, Xuezeng; Li, Jianbao; Lin, Hong

    2017-12-01

    Although the two-step deposition (TSD) method is widely adopted for the high performance perovskite solar cells (PSCs), the CH3NH3PbI3 perovskite crystal growth mechanism during the TSD process and the photo-generated charge recombination dynamics in the mesoporous-TiO2 (mp-TiO2)/CH3NH3PbI3/hole transporting material (HTM) system remains unexploited. Herein, we modified the concentration of PbI2 (C(PbI2)) solution to control the perovskite crystal properties, and observed an abnormal CH3NH3PbI3 grain growth phenomenon atop mesoporous TiO2 film. To illustrate this abnormal grain growth mechanism, we propose that a grain ripening process is taking place during the transformation from PbI2 to CH3NH3PbI3, and discuss the PbI2 nuclei morphology, perovskite grain growing stage, as well as Pb:I atomic ratio difference among CH3NH3PbI3 grains with different morphology. These C(PbI2)-dependent perovskite morphologies resulted in varied charge carrier transfer properties throughout the mp-TiO2/CH3NH3PbI3/HTM hybrid, as illustrated by photoluminescence measurement. Furthermore, the effect of CH3NH3PbI3 morphology on light absorption and interfacial properties is investigated and correlated with the photovoltaic performance of PSCs.

  7. Naphthalene Diimide Based n-Type Conjugated Polymers as Efficient Cathode Interfacial Materials for Polymer and Perovskite Solar Cells.

    Science.gov (United States)

    Jia, Tao; Sun, Chen; Xu, Rongguo; Chen, Zhiming; Yin, Qingwu; Jin, Yaocheng; Yip, Hin-Lap; Huang, Fei; Cao, Yong

    2017-10-18

    A series of naphthalene diimide (NDI) based n-type conjugated polymers with amino-functionalized side groups and backbones were synthesized and used as cathode interlayers (CILs) in polymer and perovskite solar cells. Because of controllable amine side groups, all the resulting polymers exhibited distinct electronic properties such as oxidation potential of side chains, charge carrier mobilities, self-doping behaviors, and interfacial dipoles. The influences of the chemical variation of amine groups on the cathode interfacial effects were further investigated in both polymer and perovskite solar cells. We found that the decreased electron-donating property and enhanced steric hindrance of amine side groups substantially weaken the capacities of altering the work function of the cathode and trap passivation of the perovskite film, which induced ineffective interfacial modifications and declining device performance. Moreover, with further improvement of the backbone design through the incorporation of a rigid acetylene spacer, the resulting polymers substantially exhibited an enhanced electron-transporting property. Upon use as CILs, high power conversion efficiencies (PCEs) of 10.1% and 15.2% were, respectively, achieved in polymer and perovskite solar cells. Importantly, these newly developed n-type polymers were allowed to be processed over a broad thickness range of CILs in photovoltaic devices, and a prominent PCE of over 8% for polymer solar cells and 13.5% for perovskite solar cells can be achieved with the thick interlayers over 100 nm, which is beneficial for roll-to-roll coating processes. Our findings contribute toward a better understanding of the structure-performance relationship between CIL material design and solar cell performance, and provide important insights and guidelines for the design of high-performance n-type CIL materials for organic and perovskite optoelectronic devices.

  8. Histopathological Study of Central Nervous System Lesions: Emphasizing Association of Neoplasms with ABO Blood Groups.

    Science.gov (United States)

    Kumarguru, B N; Pallavi, P; Sunila; Manjunath, G V; Vasan, T S; Rajalakshmi, B R

    2017-04-01

    The Central Nervous System (CNS) lesions show considerable geographic and racial variations with respect to the incidence and the pattern of distribution of lesions. The ABO blood status is a readily accessible factor in genetic constitution of the patients. It has been shown to be associated with many diseases. But the influence of blood group status on the pathogenesis of brain tumours is still unclear. To study various histopathological patterns of CNS lesions and to evaluate the association of CNS tumours with the distribution of ABO blood groups in documented cases. In the present study, 147 cases were analyzed. It was an analytical type of study, done at JSS Medical College, Mysore, over a period of 2 years and 8 months from January 2009 to August 2011. Histopathology slides were routinely stained by Haematoxylin and Eosin (H&E) stain. Special stains were performed in selected cases. Blood group of the patients and the control group were documented. Blood group distribution pattern was assessed in relation to histopathological diagnosis of various CNS tumours. Histopathological diagnosis of 147 cases included neoplastic lesions (84.35%) and non-neoplastic lesions (15.64%). Neoplastic lesions (84.35%) constituted the majority, which included neuroepithelial tumours (29.25%) as predominant pattern. Non-neoplastic lesions constituted only 15.64%, which included inflammatory lesion (8.16%) as the predominant pattern. ABO blood group data was available in 92 cases (84.4%) of neoplastic lesions, which included 71 cases (48.29%) of primary CNS neoplasms categorized according to WHO grades. The control group constituted 21,067 healthy voluntary donors. Blood group O was the most frequent blood group in neoplastic lesions (40.21%) and primary CNS neoplasms categorized according to WHO grades (45.07%). The association between the CNS neoplasms and ABO blood groups was not statistically significant (p = 0.055). But a definite change in the pattern of distribution of ABO

  9. Late antibody-mediated rejection after ABO-incompatible kidney transplantation during Gram-negative sepsis

    NARCIS (Netherlands)

    A. de Weerd (Annelies); A.G. Vonk (Alieke); H. van der Hoek (Hans); M. van Groningen (Marian); W. Weimar (Willem); M.G.H. Betjes (Michiel); M. Agteren (Madelon)

    2014-01-01

    textabstractBackground: The major challenge in ABO-incompatible transplantation is to minimize antibody-mediated rejection. Effective reduction of the anti-ABO blood group antibodies at the time of transplantation has made ABO-incompatible kidney transplantation a growing practice in our hospital

  10. Two-Dimensional Halide Perovskites for Emerging New- Generation Photodetectors

    DEFF Research Database (Denmark)

    Tang, Yingying; Cao, Xianyi; Chi, Qijin

    2018-01-01

    Compared to their conventional three-dimensional (3D) counterparts, two-dimensional (2D) halide perovskites have attracted more interests recently in a variety of areas related to optoelectronics because of their unique structural characteristics and enhanced performances. In general, there are two...... distinct types of 2D halide perovskites. One represents those perovskites with an intrinsic layered crystal structure (i.e. MX6 layers, M = metal and X = Cl, Br, I), the other defines the perovskites with a 2D nanostructured morphology such as nanoplatelets and nanosheets. Recent studies have shown that 2D...... halide perovskites hold promising potential for the development of new-generation photodetectors, mainly arising from their highly efficient photoluminescence and absorbance, color tunability in the visible-light range and relatively high stability. In this chapter, we present the summary and highlights...

  11. A New Generation of Luminescent Materials Based on Low-Dimensional Perovskites

    KAUST Repository

    Pan, Jun

    2017-06-02

    Low-dimensional perovskites with high luminescence properties are promising materials for optoelectronic applications. In this article, properties of two emerging types of low-dimensional perovskites are discussed, including perovskite quantum dots CsPbX3 (X = Cl, Br or I) and zero-dimensional perovskite Cs4PbBr6. Moreover, their application for light down conversion in LCD backlighting systems and in visible light communication are also presented. With their superior optical properties, we believe that further development of these materials will potentially open more prospective applications, especially for optoelectronics devices.

  12. CsPbBr3:xEu3+ perovskite QD borosilicate glass: a new member of the luminescent material family.

    Science.gov (United States)

    Yuan, Rongrong; Shen, Lingli; Shen, Chenyang; Liu, Jianming; Zhou, Lei; Xiang, Weidong; Liang, Xiaojuan

    2018-03-29

    Eu3+ ions were introduced into the lattices of CsPbBr3 perovskite QDs and a tunable multicolour emission from CsPbBr3:xEu3+ perovskite QD glass was successfully obtained. Multicolour LEDs that were fabricated by combining the as-prepared CsPbBr3:xEu3+ QD glasses with a UV chip were also researched in this study.

  13. Speculations on the existence of hydride ions in proton conducting oxides

    DEFF Research Database (Denmark)

    Poulsen, F.W.

    2001-01-01

    The chemical and physical nature of the hydride ion is briefly treated. Several reactions of the hydride ion in oxides or oxygen atmosphere are given, A number of perovskites and inverse perovskites are listed. which contain the H- ion on the oxygen or B-anion sites in the archetype ABO(3) System...

  14. The role of nonmagnetic d{sup 0} vs. d{sup 10}B-type cations on the magnetic exchange interactions in osmium double perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Hai L., E-mail: Hai.Feng@cpfs.mpg.de [Max Planck Institute for Chemical Physics of Solids, Dresden 01187 (Germany); Yamaura, Kazunari [Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Tjeng, Liu Hao [Max Planck Institute for Chemical Physics of Solids, Dresden 01187 (Germany); Jansen, Martin, E-mail: M.Jansen@fkf.mpg.de [Max Planck Institute for Chemical Physics of Solids, Dresden 01187 (Germany); Max Planck Institute for Solid State Research, Stuttgart 70569 (Germany)

    2016-11-15

    Polycrystalline samples of double perovskites Ba{sub 2}BOsO{sub 6} (B=Sc, Y, In) were synthesized by solid state reactions. They adopt the cubic double perovskite structures (space group, Fm-3m) with ordered B and Os arrangements. Ba{sub 2}BOsO{sub 6} (B=Sc, Y, In) show antiferromagnetic transitions at 93 K, 69 K, and 28 K, respectively. The Weiss-temperatures are −590 K for Ba{sub 2}ScOsO{sub 6}, −571 K for Ba{sub 2}YOsO{sub 6}, and −155 K for Ba{sub 2}InOsO{sub 6}. Sc{sup 3+} and Y{sup 3+} have the open-shell d{sup 0} electronic configuration, while In{sup 3+} has the closed-shell d{sup 10}. This indicates that a d{sup 0} B-type cation induces stronger overall magnetic exchange interactions in comparison to a d{sup 10}. Comparison of Ba{sub 2}BOsO{sub 6} (B=Sc, Y, In) to their Sr and Ca analogues shows that the structural distortions weaken the overall magnetic exchange interactions. - Graphical abstract: Magnetic properties of osmium double perovskites Ba{sub 2}BOsO{sub 6} (B=Sc, Y, In) were studied. Comparison of Ba{sub 2}BOsO{sub 6}indicates that a d{sup 0} B-type cation induces stronger overall magnetic exchange interactions in comparison to a d{sup 10}. - Highlights: • Magnetic properties of double perovskites Ba{sub 2}BOsO{sub 6} (B=Sc, Y, In) were studied. • A d{sup 0}B-type cation induces stronger magnetic interactions than a d{sup 10}. • Structural distortions weaken the overall Os{sup 5+}-Os{sup 5+} magnetic interactions.

  15. Luminescence behaviour of room temperature chemical processed all-inorganic CsPbCl3 perovskite cubes

    Science.gov (United States)

    Paul, T.; Chatterjee, B. K.; Maiti, S.; Besra, N.; Thakur, S.; Sarkar, S.; Chanda, K.; Das, A.; Sarkar, P. K.; Sardar, K.; Chattopadhyay, K. K.

    2018-05-01

    All inorganic perovskites with different halide constituent have recently truncated the eyes of researchers owing to their intriguing optoelectronic features and thereby their usage perspective in photovoltaic applications, light emitting didoes and lasing devices. Here, adopting a simple, environment benign ambient conditioned chemical synthesis approach we have realized high quality cesium lead halide perovskite (CsPbCl3) cube. The crystallinity and morphological characterizations were performed by X-ray diffraction and field emission scanning electron microscope measurements respectively while the chemical composition were examined via energy-dispersive X-ray spectroscopic measurement. The as synthesized cubes crystallized in cubic phase and exhibited intense photoluminescence emission at ˜418 nm with a small FWHM value and prolonged photoluminescence decay time˜41 ns. Besides photoluminescence, these cubes displayed strong cathodoluminescence also. Accelerating voltage dependent cathodoluminescence study showed discernable differences in luminescence behaviour. We expect this synthetic strategy to be promising as it can be easily scaled up to produce bulk quantity nanoforms of different inorganic perovskites in subtle manner for the realization of several types of nanoscale devices.

  16. Creep behavior of perovskite-type oxides Ba0.5Sr0.5(Co0.8Fe0.2)1−xZrxO3−δ

    NARCIS (Netherlands)

    Stournari, V.; ten Donkelaar, S.F.P.; Malzbender, J.; Beck, T.; Singheiser, L.; Bouwmeester, Henricus J.M.

    2015-01-01

    Compressive creep tests have been performed on perovskite-type oxides Ba0.5Sr0.5(Co0.8Fe0.2)1–xZrxO3−δ (BSCF-Z100·x), where x = 0.01, 0.03, 0.05 and 0.1, for the use as oxygen transport membrane, in air at 800–950 °C and at nominal stresses of 30 MPa and 63 MPa. X-ray diffraction and microstructural

  17. Double functions of porous TiO2 electrodes on CH3NH3PbI3 perovskite solar cells: Enhancement of perovskite crystal transformation and prohibition of short circuiting

    Directory of Open Access Journals (Sweden)

    Govindhasamy Murugadoss

    2014-08-01

    Full Text Available In order to analyze the crystal transformation from hexagonal PbI2 to CH3NH3PbI3 by the sequential (two-step deposition process, perovskite CH3NH3PbI3 layers were deposited on flat and/or porous TiO2 layers. Although the narrower pores using small nanoparticles prohibited the effective transformation, the porous-TiO2 matrix was able to help the crystal transformation of PbI2 to CH3NH3PbI3 by sequential two-step deposition. The resulting PbI2 crystals in porous TiO2 electrodes did not deteriorate the photovoltaic effects. Moreover, it is confirmed that the porous TiO2 electrode had served the function of prohibiting short circuits between working and counter electrodes in perovskite solar cells.

  18. Ab initio study of perovskite type oxide materials for solid oxide fuel cells

    Science.gov (United States)

    Lee, Yueh-Lin

    2011-12-01

    Perovskite type oxides form a family of materials of significant interest for cathodes and electrolytes of solid oxide fuel cells (SOFCs). These perovskites not only are active catalysts for surface oxygen reduction (OR) reactions but also allow incorporating the spilt oxygen monomers into their bulk, an unusual and poorly understood catalytic mechanism that couples surface and bulk properties. The OR mechanisms can be influenced strongly by defects in perovskite oxides, composition, and surface defect structures. This thesis work initiates a first step in developing a general strategy based on first-principles calculations for detailed control of oxygen vacancy content, transport rates of surface and bulk oxygen species, and surface/interfacial reaction kinetics. Ab initio density functional theory methods are used to model properties relevant for the OR reactions on SOFC cathodes. Three main research thrusts, which focus on bulk defect chemistry, surface defect structures and surface energetics, and surface catalytic properties, are carried to investigate different level of material chemistry for improved understanding of key physics/factors that govern SOFC cathode OR activity. In the study of bulk defect chemistry, an ab initio based defect model is developed for modeling defect chemistry of LaMnO 3 under SOFC conditions. The model suggests an important role for defect interactions, which are typically excluded in previous defect models. In the study of surface defect structures and surface energetics, it is shown that defect energies change dramatically (1˜2 eV lower) from bulk values near surfaces. Based on the existing bulk defect model with the calculated ab initio surface defect energetics, we predict the (001) MnO 2 surface oxygen vacancy concentration of (La0.9Sr0.1 )MnO3 is about 5˜6 order magnitude higher than that of the bulk under typical SOFC conditions. Finally, for surface catalytic properties, we show that area specific resistance, oxygen

  19. Effects of CuBr addition to CH3NH3PbI3(Cl) perovskite photovoltaic devices

    Science.gov (United States)

    Oku, Takeo; Ohishi, Yuya; Tanaka, Hiroki

    2018-01-01

    Effects of CuBr addition to perovskite CH3NH3PbI3(Cl) precursor solutions on photovoltaic properties were investigated. The CH3NH3Pb(Cu)I3(Cl,Br)-based photovoltaic devices were fabricated by a spin-coating technique, and the microstructures of the devices were investigated by X-ray diffraction, optical microscopy and scanning electron microscopy. Current density-voltage characteristics were improved by a small amount of CuBr addition, which resulted in improvement of the conversion efficiencies of the devices. The structure analysis showed decrease of unit cell volume and increase of Cu/Br composition by the CuBr addition, which would indicate the Cu/Br substitution at the Pb/I sites in the perovskite crystal, respectively.

  20. Dependence of Acetate-Based Antisolvents for High Humidity Fabrication of CH3NH3PbI3 Perovskite Devices in Ambient Atmosphere.

    Science.gov (United States)

    Yang, Fu; Kapil, Gaurav; Zhang, Putao; Hu, Zhaosheng; Kamarudin, Muhammad Akmal; Ma, Tingli; Hayase, Shuzi

    2018-05-16

    High-efficiency perovskite solar cells (PSCs) need to be fabricated in the nitrogen-filled glovebox by the atmosphere-controlled crystallization process. However, the use of the glovebox process is of great concern for mass level production of PSCs. In this work, notable efficient CH 3 NH 3 PbI 3 solar cells can be obtained in high humidity ambient atmosphere (60-70% relative humidity) by using acetate as the antisolvent, in which dependence of methyl, ethyl, propyl, and butyl acetate on the crystal growth mechanism is discussed. It is explored that acetate screens the sensitive perovskite intermediate phases from water molecules during perovskite film formation and annealing. It is revealed that relatively high vapor pressure and high water solubility of methyl acetate (MA) leads to the formation of highly dense and pinhole free perovskite films guiding to the best power conversion efficiency (PCE) of 16.3% with a reduced hysteresis. The devices prepared using MA showed remarkable shelf life stability of more than 80% for 360 h in ambient air condition, when compared to the devices fabricated using other antisolvents with low vapor pressure and low water solubility. Moreover, the PCE was still kept at 15.6% even though 2 vol % deionized water was added in the MA for preparing the perovskite layer.

  1. Formation Dynamics of CH3NH3PbI3 Perovskite Following Two-Step Layer Deposition.

    Science.gov (United States)

    Patel, Jay B; Milot, Rebecca L; Wright, Adam D; Herz, Laura M; Johnston, Michael B

    2016-01-07

    Hybrid metal-halide perovskites have emerged as a leading class of semiconductors for optoelectronic devices because of their desirable material properties and versatile fabrication methods. However, little is known about the chemical transformations that occur in the initial stages of perovskite crystal formation. Here we follow the real-time formation dynamics of MAPbI3 from a bilayer of lead iodide (PbI2) and methylammonium iodide (MAI) deposited through a two-step thermal evaporation process. By lowering the substrate temperature during deposition, we are able to initially inhibit intermixing of the two layers. We subsequently use infrared and visible light transmission, X-ray diffraction, and photoluminescence lifetime measurements to reveal the room-temperature transformations that occur in vacuum and ambient air, as MAI diffuses into the PbI2 lattice to form MAPbI3. In vacuum, the transformation to MAPbI3 is incomplete as unreacted MAI is retained in the film. However, exposure to moist air allows for conversion of the unreacted MAI to MAPbI3, demonstrating that moisture is essential in making MAI more mobile and thus aiding perovskite crystallization. These dynamic processes are reflected in the observed charge-carrier lifetimes, which strongly fluctuate during periods of large ion migration but steadily increase with improving crystallinity.

  2. First principal studya of structural, electronic and thermodynamic properties of KTaO3-perovskite.

    Directory of Open Access Journals (Sweden)

    Hiadsi S.

    2013-03-01

    Full Text Available The results of first-principles theoretical study of structural, elastic, electronic and thermodynamic properties of KTaO3 compound, have been performed using the full-potential linear augmented plane-wave method plus local orbitals (FP-APW+lo as implemented in the Wien2k code. The exchange-correlation energy, is treated in generalized gradient approximation (GGA using the Perdew–Burke–Ernzerhof (PBE96 and PBEsol, Perdew 2008 parameterization. Also we have used the Engel-Vosko GGA optimizes the corresponding potential for band structure calculations. The calculated equilibrium parameter is in good agreement with other works. The elastic constants were calculated by using the Mehl method. The electronic band structure of this compound has been calculated using the Angel-Vosko (EV generalized gradient approximation (GGA for the exchange correlation potential. We deduced that KTaO3-perovskite exhibit an indirect from R to Γ point. To complete the fundamental characterization of KTaO3 material we have analyzed the thermodynamic properties using the quasi-harmonic Debye model.

  3. Antisolvent-assisted powder engineering for controlled growth of hybrid CH3NH3PbI3 perovskite thin films

    Directory of Open Access Journals (Sweden)

    Yong Chan Choi

    2017-02-01

    Full Text Available We develop antisolvent-assisted powder engineering for the controlled growth of hybrid inorganic-organic CH3NH3PbI3 (MAPbI3 perovskite thin films. The powders, which are used as the precursors for solution processing, are synthesized by pouring a MAPbI3 precursor solution into various antisolvents, such as dichloromethane, chloroform, diethyl ether, and toluene. Two types of powders having different colors are obtained, depending on the antisolvent used. The choice of the antisolvent used for synthesizing the powders strongly influences not only the phases of the powders but also the morphology and structure of the thin films subsequently fabricated by solution processing. This, in turn, affects the photovoltaic performance.

  4. Light-Independent Ionic Transport in Inorganic Perovskite and Ultrastable Cs-Based Perovskite Solar Cells.

    Science.gov (United States)

    Zhou, Wenke; Zhao, Yicheng; Zhou, Xu; Fu, Rui; Li, Qi; Zhao, Yao; Liu, Kaihui; Yu, Dapeng; Zhao, Qing

    2017-09-07

    Due to light-induced effects in CH 3 NH 3 -based perovskites, such as ion migration, defects formation, and halide segregation, the degradation of CH 3 NH 3 -based perovskite solar cells under maximum power point is generally implicated. Here we demonstrated that the effect of light-enhanced ion migration in CH 3 NH 3 PbI 3 can be eliminated by inorganic Cs substitution, leading to an ultrastable perovskite solar cell. Quantitatively, the ion migration barrier for CH 3 NH 3 PbI 3 is 0.62 eV under dark conditions, larger than that of CsPbI 2 Br (0.45 eV); however, it reduces to 0.07 eV for CH 3 NH 3 PbI 3 under illumination, smaller than that for CsPbI 2 Br (0.43 eV). Meanwhile, photoinduced halide segregation is also suppressed in Cs-based perovskites. Cs-based perovskite solar cells retained >99% of the initial efficiency (10.3%) after 1500 h of maximum power point tracking under AM1.5G illumination, while CH 3 NH 3 PbI 3 solar cells degraded severely after 50 h of operation. Our work reveals an uncovered mechanism for stability improvement by inorganic cation substitution in perovskite-based optoelectronic devices.

  5. Evolution of loss tangent with structural ordering of the perovskite-type Ba_3CaNb_2O_9 ceramics

    International Nuclear Information System (INIS)

    Rodrigues, J.E.F.S.; Correr, W.R.; Hernandes, A.C.; Castro, P.J.; Pizani, P.S.

    2016-01-01

    In this paper, we investigate the microwave dielectric properties considering the de-gree of disorder, which plays a fundamental role in the values of dielectric loss, for the perovskite-type Ba_3CaNb_2O_9 ceramics. Dense ceramics were prepared by con-ventional method in solid state reactions and their dielectric properties were then ob-tained as a function of sintering time. The coexistence of domains in the 1:1 (cubic) and the 1:2 (trigonal) ordering types in all samples was realized. Specifically, the in-crease of sintering time tends to reduce the domains 1:1, raising the unloaded quality factor (Q_u). The domain (1:1) acts as a lattice vibration damping, thus increasing the dielectric loss at resonance. The best performance was recorded in sintered ceramic at 1500° C for 32 h: ε_r = 43 (relative permittivity), Q_u × f_R = 15,752 GHz (resonant frequency f_R = 7.76 GHz) and τ_f = 278 ppm/deg C (coefficient of resonant frequency variation with temperature). (author)

  6. Genetic characterization of the ABO blood group in Neandertals

    Directory of Open Access Journals (Sweden)

    Bertranpetit Jaume

    2008-12-01

    Full Text Available Abstract Background The high polymorphism rate in the human ABO blood group gene seems to be related to susceptibility to different pathogens. It has been estimated that all genetic variation underlying the human ABO alleles appeared along the human lineage, after the divergence from the chimpanzee lineage. A paleogenetic analysis of the ABO blood group gene in Neandertals allows us to directly test for the presence of the ABO alleles in these extinct humans. Results We have analysed two male Neandertals that were retrieved under controlled conditions at the El Sidron site in Asturias (Spain and that appeared to be almost free of modern human DNA contamination. We find a human specific diagnostic deletion for blood group O (O01 haplotype in both Neandertal individuals. Conclusion These results suggest that the genetic change responsible for the O blood group in humans predates the human and Neandertal divergence. A potential selective event associated with the emergence of the O allele may have therefore occurred after humans separated from their common ancestor with chimpanzees and before the human-Neandertal population divergence.

  7. ABO Blood Groups Influence Macrophage-mediated Phagocytosis of Plasmodium falciparum-infected Erythrocytes

    Science.gov (United States)

    Branch, Donald R.; Hult, Annika K.; Olsson, Martin L.; Liles, W. Conrad; Cserti-Gazdewich, Christine M.; Kain, Kevin C.

    2012-01-01

    Erythrocyte polymorphisms associated with a survival advantage to Plasmodium falciparum infection have undergone positive selection. There is a predominance of blood group O in malaria-endemic regions, and several lines of evidence suggest that ABO blood groups may influence the outcome of P. falciparum infection. Based on the hypothesis that enhanced innate clearance of infected polymorphic erythrocytes is associated with protection from severe malaria, we investigated whether P. falciparum-infected O erythrocytes are more efficiently cleared by macrophages than infected A and B erythrocytes. We show that human macrophages in vitro and mouse monocytes in vivo phagocytose P. falciparum-infected O erythrocytes more avidly than infected A and B erythrocytes and that uptake is associated with increased hemichrome deposition and high molecular weight band 3 aggregates in infected O erythrocytes. Using infected A1, A2, and O erythrocytes, we demonstrate an inverse association of phagocytic capacity with the amount of A antigen on the surface of infected erythrocytes. Finally, we report that enzymatic conversion of B erythrocytes to type as O before infection significantly enhances their uptake by macrophages to observed level comparable to that with infected O wild-type erythrocytes. These data provide the first evidence that ABO blood group antigens influence macrophage clearance of P. falciparum-infected erythrocytes and suggest an additional mechanism by which blood group O may confer resistance to severe malaria. PMID:23071435

  8. Mixed-valent perovskites of the type Ba/sub 3/Bsup(III)PtRuO/sub 9/

    Energy Technology Data Exchange (ETDEWEB)

    Kemmler-Sack, S; Ehmann, A; Herrmann, M [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1981-08-01

    Compounds of type Ba/sub 3/Bsup(III)PtRuO/sub 9/ - with a mean oxydation state of the noble metals of +4.5 - crystallize with Bsup(III) = Gd-Lu, Y in a variant of hexagonal BaTiO/sub 3/ type with ordered cationic distribution. Intensity calculations on powder data of Ba/sub 3/YPtRuO/sub 9/ (a = 5.88/sub 8/; c = 14.7/sub 0/ A) gave in the space group P6/sub 3//mmc (sequence (hcc)/sub 2/) a refined, intensity related R' value of 5.9%. With Bsup(III) = Eu the lattice is monoclinic and for Bsup(III) = Sm, Nd, La triclinic distorted.

  9. Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals.

    Science.gov (United States)

    Cha, Ji-Hyun; Han, Jae Hoon; Yin, Wenping; Park, Cheolwoo; Park, Yongmin; Ahn, Tae Kyu; Cho, Jeong Ho; Jung, Duk-Young

    2017-02-02

    High-quality and millimeter-sized perovskite single crystals of CsPbBr 3 and Cs 4 PbBr 6 were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr 3 crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs 4 PbBr 6 crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr 3 , which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr 6 ] 4- octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.

  10. Symmetry breaking and electrical conductivity of La0.7Sr0.3Cr0.4Mn0.6O3perovskite as SOFC anode material

    International Nuclear Information System (INIS)

    Reyes-Rojas, A.; Alvarado-Flores, J.; Esparza-Ponce, H.; Esneider-Alcala, M.; Espitia-Cabrera, I.; Torres-Moye, E.

    2011-01-01

    Research highlights: → Perovskite-type La 0.7 Sr 0.3 Cr 0.4 Mn 0.6 O 3-δ -NiO nucleation kinetics. Symmetry-breaking by introducing Ni 2+ cations at 1050 deg. C. Phase transition from high temperature aristotype R3-bar c to hettotype I4/mmm. At low Ni concentration ρ resistivity decreases when increasing the temperature. For Ni concentration higher than 25% ρ resistivity increases. - Abstract: This work is focused on nanocrystalline solid oxide fuel cell synthesis and characterization (SOFC) anodes of La 0.7 Sr 0.3 Cr 0.4 Mn 0.6 O 3-δ (perovskite-type) with Nickel. Perovskite-type oxide chemical reactivity, nucleation kinetics and phase composition related with La 0.7 Sr 0.3 Cr 0.4 Mn 0.6 O 3-δ -NiO to La 0.7 Sr 0.3 Cr 0.4 Mn 0.6 O 3-δ -Ni transformation have been analyzed. SOFC anode powders were obtained by sol-gel synthesis, using polyvinyl alcohol as an organic precursor to get a porous cermet electrode after sintering at 1365 deg. C and oxide reduction by hydrogen at 800 deg. C/1050 deg. C for 8 h in a horizontal tubular reactor furnace under 10% H 2 /N 2 atmosphere. Composite powders were compressed into 10-mm diameter discs with 25-75 wt% Ni. Electrical and structural characterization by four-point probe method for conductivity, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Rietveld method were carried out. Symmetry-breaking by phase transition from high temperature aristotype R3-bar c to hettotype I4/mmm has been identified and confirmed by XRD and Rietveld method which can be produced by introducing Ni 2+ cations in the perovskite solid solution. Rietveld analysis suggests that Ni contents are directly proportional to La 0.7 Sr 0.3 Cr 0.4 Mn 0.6 NiO 3.95 tetragonal structure cell volume and inversely proportional to Ni cubic structure cell volume after reduction at 1050 deg. C. Kinetic analysis indicated that the Johnson-Mehl-Avrami equation is able to provide a good fit to phase

  11. Synthesis process and structural characterization of the Sr{sub 2}EuRuO{sub 6} complex perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Triana, C.A.; Landinez Tellez, D.A. [Grupo de Fisica de Nuevos Materiales (GFNM), Departamento de Fisica, Universidad Nacional de Colombia, Bogota D.C. A.A. 5997 (Colombia); Roa-Rojas, J., E-mail: jroar@unal.edu.co [Grupo de Fisica de Nuevos Materiales (GFNM), Departamento de Fisica, Universidad Nacional de Colombia, Bogota D.C. A.A. 5997 (Colombia)

    2012-03-05

    Highlights: Black-Right-Pointing-Pointer Crystal structure, surface morphology and composition of Sr{sub 2}EuRuO{sub 6} have been studied. Black-Right-Pointing-Pointer Sr{sub 2}EuRuO{sub 6} crystallize in a monoclinic perovskite-type structure in P2{sub 1}/n space group. Black-Right-Pointing-Pointer Ru{sup 5+} and Eu{sup 3+} ions are on the six coordinate M sites, Sr{sup 2+} is located in the A-site. Black-Right-Pointing-Pointer Scanning electron microscopy and Scherrer formula shows a particle size of D = 34.2 nm. Black-Right-Pointing-Pointer Activation energy Q through the Arrhenius plot for Sr{sub 2}EuRuO{sub 6} is close to 39.6 kJ/mol. - Abstract: The Sr{sub 2}EuRuO{sub 6} complex perovskite has been synthesized by the solid-state reaction method and the crystal structure, surface morphology and composition have been investigated. Results of powder X-ray diffraction measurements and Rietveld analysis show that this compound crystallizes in a monoclinic distorted perovskite-type structure, which belongs to the monoclinic P2{sub 1}/n (no. 14) space group, that corresponds to the (a{sup +}b{sup -}b{sup -}) tilt system on the Glazer notation. The structure presents an alternating distribution of the Ru{sup 5+} and Eu{sup 3+} ions on the six coordinate M sites, while the Sr{sup 2+} is located in the A-site of the Sr{sub 2}EuRuO{sub 6} complex perovskite, with lattice parameters a = 5.7996(5) Angstrom-Sign , b = 5.8960(7) Angstrom-Sign , c = 8.3234(6) Angstrom-Sign , angle {beta} = 90.234(7) Degree-Sign and V = 284.61(4) Angstrom-Sign {sup 3}. Morphological analysis of this material, performed by scanning electron microscopy (SEM), allows to establish the granular feature of compound with agglomerates from amongst Almost-Equal-To 1 to 3 {mu}m size, and by means of the Scherrer formula was calculated a particle size of D = 34.2 nm. Result suggests that crystal structure of the Sr{sub 2}EuRuO{sub 6} suffers grain size-induced polarization rotation, which produces a

  12. ABO and Rh blood groups frequency in women with HER2 positive breast cancer.

    Science.gov (United States)

    Urun, Y; Utkan, G; Altundag, K; Arslan, O; Onur, H; Arslan, U Y; Kocer, M; Dogan, I; Senler, F C; Yalcin, B; Demirkazik, A; Akbulut, H; Icli, F

    2012-01-01

    The role of genetic factors in the development of cancer is widely accepted. Data on the role of ABO blood group and Rh factor in breast cancer is inconclusive. The aim of this study was to investigate the presence of a possible association between HER2 (+) breast cancer in Turkish women and ABO blood groups and Rh factor. In 294 female patients with HER2 (+) breast cancer, ABO blood groups and Rh factor were examined. The relationship of blood groups with age, menopausal status, and family history of cancer, estrogen receptor (ER), progesterone receptor (PR) and HER2 status of these patients was evaluated. Blood groups distribution of 22,821 healthy blood donors was also assessed and compared with the patients' blood groups distribution. The median patient age was 47 years (range 20-80) and 56% of the patients were premenopausal. ER and PR were positive in 50 and 60% of the patients, respectively. Overall, the ABO blood group distribution of the 294 HER2 (+) breast cancer patients was similar to that of the healthy blood donors (p=0.36). Likewise there was no correlation between blood type and ER, PR and menopausal status. Rh (-) patients had more frequent family cancer history and this difference was significant for patients with blood group B Rh (-) and O Rh (-) (p = 0.04). In the present study we didn't find any relationship between HER2 status and ABO blood group and Rh factor. However, further studies with larger number of patients are needed to establish the role (if any) of blood groups in patients with breast cancer.

  13. Electron-Rotor Interaction in Organic-Inorganic Lead Iodide Perovskites Discovered by Isotope Effects.

    Science.gov (United States)

    Gong, Jue; Yang, Mengjin; Ma, Xiangchao; Schaller, Richard D; Liu, Gang; Kong, Lingping; Yang, Ye; Beard, Matthew C; Lesslie, Michael; Dai, Ying; Huang, Baibiao; Zhu, Kai; Xu, Tao

    2016-08-04

    We report on the carrier-rotor coupling effect in perovskite organic-inorganic hybrid lead iodide (CH3NH3PbI3) compounds discovered by isotope effects. Deuterated organic-inorganic perovskite compounds including CH3ND3PbI3, CD3NH3PbI3, and CD3ND3PbI3 were synthesized. Devices made from regular CH3NH3PbI3 and deuterated CH3ND3PbI3 exhibit comparable performance in band gap, current-voltage, carrier mobility, and power conversion efficiency. However, a time-resolved photoluminescence (TRPL) study reveals that CH3NH3PbI3 exhibits notably longer carrier lifetime than that of CH3ND3PbI3, in both thin-film and single-crystal formats. Furthermore, the comparison in carrier lifetime between CD3NH3PbI3 and CH3ND3PbI3 single crystals suggests that vibrational modes in methylammonium (MA(+)) have little impact on carrier lifetime. In contrast, the fully deuterated compound CD3ND3PbI3 reconfirmed the trend of decreasing carrier lifetime upon the increasing moment of inertia of cationic MA(+). Polaron model elucidates the electron-rotor interaction.

  14. Constructing Efficient and Stable Perovskite Solar Cells via Interconnecting Perovskite Grains.

    Science.gov (United States)

    Hou, Xian; Huang, Sumei; Ou-Yang, Wei; Pan, Likun; Sun, Zhuo; Chen, Xiaohong

    2017-10-11

    A high-quality perovskite film with interconnected perovskite grains was obtained by incorporating terephthalic acid (TPA) additive into the perovskite precursor solution. The presence of TPA changed the crystallization kinetics of the perovskite film and promoted lateral growth of grains in the vicinity of crystal boundaries. As a result, sheet-shaped perovskite was formed and covered onto the bottom grains, which made some adjacent grains partly merge together to form grains-interconnected perovskite film. Perovskite solar cells (PSCs) with TPA additive exhibited a power conversion efficiency (PCE) of 18.51% with less hysteresis, which is obviously higher than that of pristine cells (15.53%). PSCs without and with TPA additive retain 18 and 51% of the initial PCE value, respectively, aging for 35 days exposed to relative humidity 30% in air without encapsulation. Furthermore, MAPbI 3 film with TPA additive shows superior thermal stability to the pristine one under 100 °C baking. The results indicate that the presence of TPA in perovskite film can greatly improve the performance of PSCs as well as their moisture resistance and thermal stability.

  15. Jahn-Teller distortions, cation ordering and octahedral tilting in perovskites

    International Nuclear Information System (INIS)

    Lufaso, M.W.; Woodward, P.M.

    2004-01-01

    In transition metal oxides, preferential occupation of specific d orbitals on the transition metal ion can lead to the development of a long-range ordered pattern of occupied orbitals. This phenomenon, referred to as orbital ordering, is usually observed indirectly from the cooperative Jahn-Teller distortions (CJTDs) that result as a consequence of the orbital ordering. This paper examines the interplay between orbital ordering, octahedral tilting and cation ordering in perovskites. Both ternary AMX 3 perovskites containing an active Jahn-Teller (J-T) ion on the octahedral site and quaternary A 2 MM'X 6 perovskites containing a J-T ion on one-half of the octahedral sites have been examined. In AMX 3 perovskites, the tendency is for the occupied 3d 3x 2 -r 2 and 3d 3z 2 -r 2 orbitals to order in the ac plane, as exemplified by the crystal structures of LaMnO 3 and KCuF 3 . This arrangement maintains a favorable coordination environment for the anion sites. In AMX 3 perovskites, octahedral tilting tends to enhance the magnitude of the J-T distortions. In A 2 MM'X 6 perovskites, the tendency is for the occupied 3d 3z 2 -r 2 orbitals to align parallel to the c axis. This pattern maintains a favorable coordination environment about the symmetric M'-cation site. The orbital ordering found in rock-salt ordered A 2 MM'X 6 perovskites is compatible with octahedral rotations about the c axis (Glazer tilt system a 0 a 0 c - ) but appears to be incompatible with GdFeO 3 -type octahedral tilting (tilt system - b + a - ). (orig.)

  16. Fullerene-Based Electron Transport Layers for Semi-Transparent MAPbBr3 Perovskite Films in Planar Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Lung-Chien Chen

    2016-10-01

    Full Text Available In this study, four kinds of structures—[6,6]-phenyl-C61-butyric acid methyl ester (PCBM, PCBM/fullerene (C60, C60/bathocuproine (BCP, and PCBM/C60/BCP—were used as electron transport layers, and the structure, and optical and electronic behaviors of MAPbBr3 perovskite layers after annealing treatments were observed. The experimental results indicate that PCBM/C60 bi-layer structure is acceptable for MAPbBr3 planar perovskite solar cells due to electron step transporting. Low-temperature annealing is suitable for smooth and large grain MAPbBr3 films. The semi-transparent yellow C60/PCBM/MAPbBr3/PEDOT:PSS/ITO glass-structure solar cells exhibit the best performance with a power conversion efficiency of 4.19%. The solar cells are revealed to be suitable for application in building integrated photovoltaic (BIPV systems.

  17. Stability Issues on Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Xing Zhao

    2015-11-01

    Full Text Available Organo lead halide perovskite materials like methylammonium lead iodide (CH3NH3PbI3 and formamidinium lead iodide (HC(NH22PbI3 show superb opto-electronic properties. Based on these perovskite light absorbers, power conversion efficiencies of the perovskite solar cells employing hole transporting layers have increased from 9.7% to 20.1% within just three years. Thus, it is apparent that perovskite solar cell is a promising next generation photovoltaic technology. However, the unstable nature of perovskite was observed when exposing it to continuous illumination, moisture and high temperature, impeding the commercial development in the long run and thus becoming the main issue that needs to be solved urgently. Here, we discuss the factors affecting instability of perovskite and give some perspectives about further enhancement of stability of perovskite solar cell.

  18. Qualitative analysis fingertip patterns in ABO blood group

    OpenAIRE

    S. V. KShirsagar

    2013-01-01

    The inheritance of the dermatoglyphic patterns is polygenic. The genetic basis of the blood group is well established. The correlation between the dermatoglyphic patterns and the ABO blood group is studied by some workers in different populations. In the present study, the correlation between dermatoglyphics and ABO blood group is studied in the Marathwada Region of Maharashtra. The qualitative data included fingertip patterns and three indices. It was observed that, the Arch pattern is more ...

  19. Al2 O3 Underlayer Prepared by Atomic Layer Deposition for Efficient Perovskite Solar Cells.

    Science.gov (United States)

    Zhang, Jinbao; Hultqvist, Adam; Zhang, Tian; Jiang, Liangcong; Ruan, Changqing; Yang, Li; Cheng, Yibing; Edoff, Marika; Johansson, Erik M J

    2017-10-09

    Perovskite solar cells, as an emergent technology for solar energy conversion, have attracted much attention in the solar cell community by demonstrating impressive enhancement in power conversion efficiencies. However, the high temperature and manually processed TiO 2 underlayer prepared by spray pyrolysis significantly limit the large-scale application and device reproducibility of perovskite solar cells. In this study, lowtemperature atomic layer deposition (ALD) is used to prepare a compact Al 2 O 3 underlayer for perovskite solar cells. The thickness of the Al 2 O 3 layer can be controlled well by adjusting the deposition cycles during the ALD process. An optimal Al 2 O 3 layer effectively blocks electron recombination at the perovskite/fluorine-doped tin oxide interface and sufficiently transports electrons through tunneling. Perovskite solar cells fabricated with an Al 2 O 3 layer demonstrated a highest efficiency of 16.2 % for the sample with 50 ALD cycles (ca. 5 nm), which is a significant improvement over underlayer-free PSCs, which have a maximum efficiency of 11.0 %. Detailed characterization confirms that the thickness of the Al 2 O 3 underlayer significantly influences the charge transfer resistance and electron recombination processes in the devices. Furthermore, this work shows the feasibility of using a high band-gap semiconductor such as Al 2 O 3 as the underlayer in perovskite solar cells and opens up pathways to use ALD Al 2 O 3 underlayers for flexible solar cells. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Catalytic properties of perovskite-type mixed oxides, La/sub 1-x/Sr/sub x/CoO/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, T; Misono, M; Yoneda, Y

    1982-02-01

    The reactivity and related properties of oxygen both in the bulk and on the surface has been investigated for perovskite-type mixed oxides (La/sub 1-x/Sr,sub x/CoO/sub 3/), in regard to the effects of Sr/sup 2 +/-substitution and calcination temperature. The reducibility and the readiness of oxygen desorption increased with the Sr/sup 2 +/- content, x, but the reoxidation became slower with x. These results have been explained on the basis of the change in the chemical potential of lattice oxygen. The diffusivity of oxygen in the bulk and the ability to activate the oxygen molecule also increased with x. Oxygen vacancies in the bulk and on the surface, which tended to increase with x, are likely responsible for these reactions. The release of oxygen from the bulk became more difficult as the calcination temperature increased, in conformity with the trend of the catalytic activity.

  1. Influence of iridium on the reactivity of LaFeO3 base perovskites

    DEFF Research Database (Denmark)

    Kindermann, L.; Das, D.; Bahadur, D.

    1998-01-01

    The influence of iridium on the reactivity of powder mixtures made of perovskites and 8 mol% yttria stabilized zirconia (8 YSZ) is reported. Iridium is added to the perovskites of the composition (La0.6M0.4)(z)Fe0.8TM0.2O3-delta (M = Sr, Ca; TM = Mn, Co; z = 0.90, 1.00) via the gaseous phase....... Iridium is present in the perovskite lattice as Ir4+ replacing iron as is evident from XRD and TEM/EDX results. Compatibility studies carried out at 1000 degrees C demonstrate that iridium has considerable influence on the reactivity. The results are discussed with respect to the stability...... of the perovskites, thermodynamic activities, Ir(IV)-O bonding, tolerance factor and oxygen migration....

  2. Large polarons in lead halide perovskites

    Science.gov (United States)

    Miyata, Kiyoshi; Meggiolaro, Daniele; Trinh, M. Tuan; Joshi, Prakriti P.; Mosconi, Edoardo; Jones, Skyler C.; De Angelis, Filippo; Zhu, X.-Y.

    2017-01-01

    Lead halide perovskites show marked defect tolerance responsible for their excellent optoelectronic properties. These properties might be explained by the formation of large polarons, but how they are formed and whether organic cations are essential remain open questions. We provide a direct time domain view of large polaron formation in single-crystal lead bromide perovskites CH3NH3PbBr3 and CsPbBr3. We found that large polaron forms predominantly from the deformation of the PbBr3− frameworks, irrespective of the cation type. The difference lies in the polaron formation time, which, in CH3NH3PbBr3 (0.3 ps), is less than half of that in CsPbBr3 (0.7 ps). First-principles calculations confirm large polaron formation, identify the Pb-Br-Pb deformation modes as responsible, and explain quantitatively the rate difference between CH3NH3PbBr3 and CsPbBr3. The findings reveal the general advantage of the soft [PbX3]− sublattice in charge carrier protection and suggest that there is likely no mechanistic limitations in using all-inorganic or mixed-cation lead halide perovskites to overcome instability problems and to tune the balance between charge carrier protection and mobility. PMID:28819647

  3. Hybrid perovskite resulting from the solid-state reaction between the organic cations and perovskite layers of alpha1-(Br-(CH(2))(2)-NH(3))(2)PbI(4).

    Science.gov (United States)

    Sourisseau, Sebastien; Louvain, Nicolas; Bi, Wenhua; Mercier, Nicolas; Rondeau, David; Buzaré, Jean-Yves; Legein, Christophe

    2007-07-23

    The alpha1-(Br-(CH(2))(2)-NH(3))(2)PbI(4) hybrid perovskite undergoes a solid-state transformation, that is, the reaction between the organic cations and the perovskite layers to give the new hybrid perovskite (Br-(CH(2))(2)-NH(3))(2-x)(I-(CH(2))(2)-NH(3))(x)PbBr(x)I(4-x), based on mixed halide inorganic layers. This transformation has been followed by a conventional powder X-ray diffraction system equipped with a super speed detector, and both solid-state (13)C NMR and ESI/MS measurements have been adopted in the estimation of the rate of halide substitution. The first reaction step leads to the special composition of x approximately 1 (A phase), while the complete substitution is not achieved even at elevated temperature (x(max) approximately 1.85 (B phase)). This unprecedented solid-state reaction between organic and inorganic components of a hybrid perovskite can be considered as a completely new strategy to achieve interesting hybrid perovskites.

  4. Homogeneous Synthesis and Electroluminescence Device of Highly Luminescent CsPbBr3 Perovskite Nanocrystals.

    Science.gov (United States)

    Wei, Song; Yang, Yanchun; Kang, Xiaojiao; Wang, Lan; Huang, Lijian; Pan, Daocheng

    2017-03-06

    Highly luminescent CsPbBr 3 perovskite nanocrystals (PNCs) are homogeneously synthesized by mixing toluene solutions of PbBr 2 and cesium oleate at room temperature in open air. We found that PbBr 2 can be easily dissolved in nonpolar toluene in the presence of tetraoctylammonium bromide, which allows us to homogeneously prepare CsPbBr 3 perovskite quantum dots and prevents the use of harmful polar organic solvents, such as N,N-dimethylformamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. Additionally, this method can be extended to synthesize highly luminescent CH 3 NH 3 PbBr 3 perovskite quantum dots. An electroluminescence device with a maximal luminance of 110 cd/m 2 has been fabricated by using high-quality CsPbBr 3 PNCs as the emitting layer.

  5. Semiconducting tin and lead iodide perovskites with organic cations: phase transitions, high mobilities, and near-infrared photoluminescent properties.

    Science.gov (United States)

    Stoumpos, Constantinos C; Malliakas, Christos D; Kanatzidis, Mercouri G

    2013-08-05

    A broad organic-inorganic series of hybrid metal iodide perovskites with the general formulation AMI3, where A is the methylammonium (CH3NH3(+)) or formamidinium (HC(NH2)2(+)) cation and M is Sn (1 and 2) or Pb (3 and 4) are reported. The compounds have been prepared through a variety of synthetic approaches, and the nature of the resulting materials is discussed in terms of their thermal stability and optical and electronic properties. We find that the chemical and physical properties of these materials strongly depend on the preparation method. Single crystal X-ray diffraction analysis of 1-4 classifies the compounds in the perovskite structural family. Structural phase transitions were observed and investigated by temperature-dependent single crystal X-ray diffraction in the 100-400 K range. The charge transport properties of the materials are discussed in conjunction with diffuse reflectance studies in the mid-IR region that display characteristic absorption features. Temperature-dependent studies show a strong dependence of the resistivity as a function of the crystal structure. Optical absorption measurements indicate that 1-4 behave as direct-gap semiconductors with energy band gaps distributed in the range of 1.25-1.75 eV. The compounds exhibit an intense near-IR photoluminescence (PL) emission in the 700-1000 nm range (1.1-1.7 eV) at room temperature. We show that solid solutions between the Sn and Pb compounds are readily accessible throughout the composition range. The optical properties such as energy band gap, emission intensity, and wavelength can be readily controlled as we show for the isostructural series of solid solutions CH3NH3Sn(1-x)Pb(x)I3 (5). The charge transport type in these materials was characterized by Seebeck coefficient and Hall-effect measurements. The compounds behave as p- or n-type semiconductors depending on the preparation method. The samples with the lowest carrier concentration are prepared from solution and are n-type; p-type

  6. Patterning of Perovskite Single Crystals

    KAUST Repository

    Corzo, Daniel

    2017-06-12

    As the internet-of-things hardware integration continues to develop and the requirements for electronics keep diversifying and expanding, the necessity for specialized properties other than the classical semiconductor performance becomes apparent. The success of emerging semiconductor materials depends on the manufacturability and cost as much as on the properties and performance they offer. Solution-based semiconductors are an emerging concept that offers the advantage of being compatible with large-scale manufacturing techniques and have the potential to yield high-quality electronic devices at a lower cost than currently available solutions. In this work, patterns of high-quality MAPbBr3 perovskite single crystals in specific locations are achieved through the modification of the substrate properties and solvent engineering. The fabrication of the substrates involved modifying the surface adhesion forces through functionalization with self-assembled monolayers and patterning them by photolithography processes. Spin coating and blade coating were used to deposit the perovskite solution on the modified silicon substrates. While single crystal perovskites were obtained with the modification of substrates alone, solvent engineering helped with improving the Marangoni flows in the deposited droplets by increasing the contact angle and lowering the evaporation rate, therefore controlling and improving the shape of the grown perovskite crystals. The methodology is extended to other types of perovskites such as the transparent MAPbCl3 and the lead-free MABi2I9, demonstrating the adaptability of the process. Adapting the process to electrode arrays opened up the path towards the fabrication of optoelectronic devices including photodetectors and field-effect transistors, for which the first iterations are demonstrated. Overall, manufacturing and integration techniques permitting the fabrication of single crystalline devices, such as the method in this thesis work, are

  7. Magnetic interactions in rhenium-containing rare earth double perovskites Sr{sub 2}LnReO{sub 6} (Ln=rare earths)

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, Atsuhide; Doi, Yoshihiro; Hinatsu, Yukio, E-mail: hinatsu@sci.hokudai.ac.jp

    2017-04-15

    The perovskite-type compounds containing both rare earth and rhenium Sr{sub 2}LnReO{sub 6} (Ln=Y, Tb-Lu) have been prepared. Powder X-ray diffraction measurements and Rietveld analysis show that Ln{sup 3+} and Re{sup 5+} ions are structurally ordered at the B site of the perovskite SrBO{sub 3}. Magnetic anomalies are found in their magnetic susceptibility and specific heat measurements at 2.6–20 K for Ln=Y, Tb, Dy, Yb, Lu compounds. They are due to magnetic interactions between Re{sup 5+} ions. The results of the magnetic hysteresis and remnant magnetization measurements for Sr{sub 2}YReO{sub 6} and Sr{sub 2}LuReO{sub 6} indicate that the antiferromagnetic interactions between Re{sup 5+} ions below transition temperatures have a weak ferromagnetic component. The analysis of the magnetic specific heat data for Sr{sub 2}YbReO{sub 6} shows that both the Yb{sup 3+} and Re{sup 5+} ions magnetically order at 20 K. For the case of Sr{sub 2}DyReO{sub 6}, magnetic ordering of the Re{sup 5+} moments occurs at 93 K, and with decreasing temperature, the moments of Dy{sup 3+} ferromagnetically order at 5 K from the measurements of magnetic susceptibility and specific heat. - Graphical abstract: Crystal structure of double perovskite Sr{sub 2}LnReO{sub 6}. Red and black lines show cubic and monoclinic unit cells, respectively. - Highlights: • Double perovskites Sr{sub 2}LnReO{sub 6} (Ln=rare earths) were prepared. • They show an antiferromagnetic transition at 2.6–20 K. • In Sr{sub 2}DyReO{sub 6}, Dy and Re moments magnetically order at 5 and 93 K, respectively.

  8. Fabrication of single phase 2D homologous perovskite microplates by mechanical exfoliation

    Science.gov (United States)

    Li, Junze; Wang, Jun; Zhang, Yingjun; Wang, Haizhen; Lin, Gaoming; Xiong, Xuan; Zhou, Weihang; Luo, Hongmei; Li, Dehui

    2018-04-01

    The two-dimensional (2D) Ruddlesden-Popper type perovskites have attracted intensive interest for their great environmental stability and various potential optoelectronic applications. Fundamental understanding of the photophysical and electronic properties of the 2D perovskites with pure single phase is essential for improving the performance of the optoelectronic devices and designing devices with new architectures. Investigating the optical and electronic properties of these materials with pure single phase is required to obtain pure single phase 2D perovskites. Here, we report on an alternative approach to fabricate (C4H9NH3)2(CH3NH3) n-1Pb n I3n+1 microplates with pure single n-number perovskite phase for n  >  2 by mechanical exfoliation. Micro-photoluminescence and absorption spectroscopy studies reveal that the as-synthesized 2D perovskite plates for n  >  2 are comprised by dominant n-number phase and small inclusions of hybrid perovskite phases with different n values, which is supported by excitation power dependent photoluminescence. By mechanical exfoliation method, 2D perovskite microplates with the thickness of around 20 nm are obtained, which surprisingly have single n-number perovskite phase for n  =  2-5. In addition, we have demonstrated that the exfoliated 2D perovskite microplates can be integrated with other 2D layered materials such as boron nitride, and are able to be transferred to prefabricated electrodes for photodetections. Our studies not only provide a strategy to prepare 2D perovskites with a single n-number perovskite phase allowing us to extract the basic optical and electronic parameters of pure phase perovskites, but also demonstrate the possibility to integrate the 2D perovskites with other 2D layered materials to extend the device’s functionalities.

  9. Curtailing Perovskite Processing Limitations via Lamination at the Perovskite/Perovskite Interface

    Energy Technology Data Exchange (ETDEWEB)

    Van Hest, Marinus F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Moore, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Klein, Talysa [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Christians, Jeffrey A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Beard, Matthew C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Berry, Joseph J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dunfield, Sean P. [University of Colorado; Fabian, David M. [University of California Irvine; Dixon, Alex G. [University of Colorado; Dou, Benjia [University of Colorado; Ardo, Shane [University of California Irvine; Shaheen, Sean E. [University of Colorado

    2018-04-24

    Standard layer-by-layer solution processing methods constrain lead-halide perovskite device architectures. The layer below the perovskite must be robust to the strong organic solvents used to form the perovskite while the layer above has a limited thermal budget and must be processed in nonpolar solvents to prevent perovskite degradation. To circumvent these limitations, we developed a procedure where two transparent conductive oxide/transport material/perovskite half stacks are independently fabricated and then laminated together at the perovskite/perovskite interface. Using ultraviolet-visible absorption spectroscopy, external quantum efficiency, X-ray diffraction, and time-resolved photoluminesence spectroscopy, we show that this procedure improves photovoltaic properties of the perovskite layer. Applying this procedure, semitransparent devices employing two high-temperature oxide transport layers were fabricated, which realized an average efficiency of 9.6% (maximum: 10.6%) despite series resistance limitations from the substrate design. Overall, the developed lamination procedure curtails processing constraints, enables new device designs, and affords new opportunities for optimization.

  10. Shelf life stability comparison in air for solution processed pristine PDPP3T polymer and doped spiro-OMeTAD as hole transport layer for perovskite solar cell

    Directory of Open Access Journals (Sweden)

    Ashish Dubey

    2016-06-01

    Full Text Available This data in brief includes forward and reverse scanned current density–voltage (J–V characteristics of perovskite solar cells with PDPP3T and spiro-OMeTAD as HTL, stability testing conditions of perovskite solar cell shelf life in air for both PDPP3T and spiro-OMeTAD as HTL as per the description in Ref. [1], and individual J–V performance parameters acquired with increasing time exposed in ambient air are shown for both type of devices using PDPP3T and spiro-OMeTAD as HTL. The data collected in this study compares the device stability with time for both PDPP3T and spiro-OMeTAD based perovskite solar cells and is directly related to our research article “solution processed pristine PDPP3T polymer as hole transport layer for efficient perovskite solar cells with slower degradation” [2].

  11. Frequencies and ethnic distribution of ABO and RhD blood groups in China: a population-based cross-sectional study.

    Science.gov (United States)

    Liu, Jue; Zhang, Shikun; Wang, Qiaomei; Shen, Haiping; Zhang, Yiping; Liu, Min

    2017-12-03

    ABO and RhD blood groups are key factors affecting blood transfusion safety. The distribution of ABO and RhD blood groups varies globally, but limited data exist for ethnic distributions of these blood groups in Asian populations. We aimed to evaluate the distribution of ABO and RhD blood groups among Chinese ethnic groups. A population-based cross-sectional study. Data on ABO groups and ethnicities were obtained from the National Free Preconception Health Examination Project (NFPHEP) with participants from 220 counties of 31 provinces in China PARTICIPANTS: There were 3 832 034 participants aged 21-49 years who took part in the NFPHEP from January 2010 to December 2012 and were included in this study. The proportion of ABO and RhD blood groups among different ethnic groups was calculated. ABO and RhD blood distribution was significantly different among nine ethnic groups (Pgroups, the Yi group had more A phenotypes (34.0%), and the Manchu (33.7%) and Mongolian (33.3%) ethnic groups had more B phenotypes. The Zhuang group had the greatest proportion of O phenotypes (41.8%), followed by the Miao group (37.7%). AB phenotypes were more frequent in the Uygur ethnic group (10.6%) but lower in the Zhuang group (5.5%). Meanwhile, RhD negativity (RhD-) was greater in the Uygur group (3.3%) than in the Mongolian (0.3%) and Manchu ethnic groups (0.4%). O RhD- blood groups were more frequent in the Uygur group (0.8%) than in the other ethnic groups (0.1%-0.4%, Pblood phenotypes vary across different ethnic groups in China. The diversity in the distribution of the ABO and RhD blood groups in different ethnic groups should be considered when developing rational and evidence-based strategies for blood collection and management. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Potassium doped methylammonium lead iodide (MAPbI3) thin films as a potential absorber for perovskite solar cells; structural, morphological, electronic and optoelectric properties

    Science.gov (United States)

    Muzammal uz Zaman, Muhammad; Imran, Muhammad; Saleem, Abida; Kamboh, Afzal Hussain; Arshad, Muhammad; Khan, Nawazish Ali; Akhter, Parvez

    2017-10-01

    In this article, we have demonstrated the doping of K in the light absorbing CH3NH3PbI3 perovskite i.e. (M = CH3, A = NH3; x = 0-1). One of the major merits of methylammonium lead iodide (CH3NH3PbI3) perovskites is that they act as efficient absorbing material of light in photovoltaic cell imparting long carrier lifetime and optimum band gap. The structural, morphological, electronic and optoelectric properties of potassium (K) doped light absorber methylammonium lead iodide (CH3NH3PbI3) perovskites are reported here i.e. Kx(MA)1-xPbI3 (M = CH3, A =NH3; x = 0-1). The thin films of perovskites (x = 0-1) were deposited by spin coating on cleaned FTO substrates and characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), current-voltage (IV), X-ray photoelectron spectroscopy (XPS) and Diffused reflectance spectroscopy (DRS) analysis. The organic constituents i.e. MA = CH3NH3, in perovskites solar cells induce instability even at the room temperature. To overcome such instabilities we have replaced the organic constituents by K because both of them have electropositive nature. Potassium successfully replaces the CH3NH3. Initially, this compound grows in a tetragonal crystal structure, however, beyond 30% doping of potassium orthorhombic distortions are induced in the parent tetragonal unit cell. Such phase transformation is microscopically visible in the electron micrographs of doped samples; cubic grains for MAPbI3 begin to transform into strip like structures in K-doped samples. The resistance of the samples is decreased for partial K-doping, which we suggested to be arising due to the electropositive nature of K. It is observed that the binding energy difference between Pb4f and I3d core levels are very similar in all the investigated systems and show formal oxidation states. Also, the partially doped samples showed increased absorption and bandgaps around 1.5 eV which is an optimum value for solar absorption.

  13. Calcium doped MAPbI3 with better energy state alignment in perovskite solar cells

    Science.gov (United States)

    Lu, Chaojie; Zhang, Jing; Hou, Dagang; Gan, Xinlei; Sun, Hongrui; Zeng, Zhaobing; Chen, Renjie; Tian, Hui; Xiong, Qi; Zhang, Ying; Li, Yuanyuan; Zhu, Yuejin

    2018-05-01

    The organic-inorganic perovskite material with better energy alignment in the solar cell device will have a profound impact on the solar cell performance. It is valuable to tune the energy states by element substitution and doping in perovskites. Here, we present that Ca2+ is incorporated into CH3NH3PbI3, which up-shifts the valence band maximum and the conduction band minimum, leading to a difference between the bandgap and the Fermi level in the device. Consequently, Ca2+ incorporation results in an enhancement of the photovoltage and photocurrent, achieving a summit efficiency of 18.3% under standard 1 sun (AM 1.5). This work reveals the doped perovskite to improve the solar cell performance by tuning the energy state.

  14. Crystal structure and magnetoresistance of La0.7Ca0.3MnO3 perovskite at room temperature

    International Nuclear Information System (INIS)

    Engkir Sukirman; Wisnu Ari Adi; Yustinus Purwamargapratala

    2012-01-01

    A comparative study on crystal structure and magnetoresistance (MR) of La 0.7 Ca 0.3 MnO 3 (LCMO) perovskite toward LaMnO 3 (LMO) and CaMnO 3 (CMO) parent compounds have been carried out to study the change of LCMO due to magnetic fields variations at room temperature. The LCMO, LMO and CMO were synthesized using high energy milling (HEM) method. The precursors obtained were pressed into pellet and sintered at T s = 1350°C for 6 hours. The qualitative analysis were conducted by x-rays diffraction technique using Rietveld method. The MR effect on the samples were measured using four point probe (FPP) method and the surface structure of pellets were observed by scanning electron microscope (SEM). The samples have the same crystal structure, namely orthorhombic, space group: Pnma, No. 62. The lattice parameters of LCMO were successfully confirmed until four decimal precision, namely a = 5.4851(3) Å, b = 7.7601(4) Å, c = 5.5185(2) Å. The lattice parameters for LMO and CMO successively are a = 5.4405(9) Å, b = 7.717(1) Å, c = 5.537(1) Å and a = 5.2973(6) Å, b = 7.477(1) Å, c = 5.281 (1) Å. All samples have grain diameter of around 1,000 nm with a globule like form and every grain consists of 27 crystallites. The MR for LCMO, LMO and CMO samples at room temperature are -10.1; -7.3 dan -12.3%, respectively, and comparable with the one of multilayers based GMR [Cu/NiFeCo] x10 /Ta. The LCMO perovskite bulk can be used to detect the magnetic microbeads and ferrofluid. (author)

  15. Comparative frequency and allelic distribution of ABO and Rh (D ...

    African Journals Online (AJOL)

    Background: Allelic distribution of major blood groups (ABO and rhesus) has not been defined in Bangladeshi population. Determinants of blood group frequency in this region have not been studied properly. Aim: To determine ABO and rhesus blood group frequency and allelic distribution in a multiethnic area of ...

  16. Thorough analysis of unorthodox ABO deletions called by the 1000 Genomes project.

    Science.gov (United States)

    Möller, M; Hellberg, Å; Olsson, M L

    2018-02-01

    ABO remains the clinically most important blood group system, but despite earlier extensive research, significant findings are still being made. The vast majority of catalogued ABO null alleles are based on the c.261delG polymorphism. Apart from c.802G>A, other mechanisms for O alleles are rare. While analysing the data set from the 1000 Genomes (1000G) project, we encountered two previously uncharacterized deletions, which needed further exploration. The Erythrogene database, complemented with bioinformatics software, was used to analyse ABO in 2504 individuals from 1000G. DNA samples from selected 1000G donors and African blood donors were examined by allele-specific PCR and Sanger sequencing to characterize predicted deletions. A 5821-bp deletion encompassing exons 5-7 was called in twenty 1000G individuals, predominantly Africans. This allele was confirmed and its exact deletion point defined by bioinformatic analyses and in vitro experiments. A PCR assay was developed, and screening of African samples revealed three donors heterozygous for this deletion, which was thereby phenotypically established as an O allele. Analysis of upstream genetic markers indicated an ancestral origin from ABO*O.01.02. We estimate this deletion as the 3rd most common mechanism behind O alleles. A 24-bp deletion was called in nine individuals and showed greater diversity regarding ethnic distribution and allelic background. It could neither be confirmed by in silico nor in vitro experiments. A previously uncharacterized ABO deletion among Africans was comprehensively mapped and a genotyping strategy devised. The false prediction of another deletion emphasizes the need for cautious interpretation of NGS data and calls for strict validation routines. © 2017 International Society of Blood Transfusion.

  17. ABO blood groups, Rhesus factor, and anaphylactic reactions due to Hymenoptera stings.

    Science.gov (United States)

    Pałgan, Krzysztof; Bartuzi, Zbigniew; Chrzaniecka, Elżbieta

    2017-09-21

    Numerous publications indicate that the prevalence of some infectious, neoplastic and immunological diseases are associated with ABO blood groups. The aim of this study was to verify whether ABO and Rh blood groups are associated with severe anaphylactic reactions after Hymenoptera stings. A study was undertaken of 71,441 Caucasian subjects living in the same geographic area. The study group included 353 patients with diagnosed systemic anaphylaxis to Hymenoptera venom. Control group included 71,088 healthy blood donors. Frequencies of ABO and Rhesus groups in the study and control groups were compared using univariate and multivariate analyses. No statistically significant interactions were observed between the ABO blood group and anaphylactic reactions to Hymenoptera.

  18. Highly Efficient 2D/3D Hybrid Perovskite Solar Cells via Low-Pressure Vapor-Assisted Solution Process.

    Science.gov (United States)

    Li, Ming-Hsien; Yeh, Hung-Hsiang; Chiang, Yu-Hsien; Jeng, U-Ser; Su, Chun-Jen; Shiu, Hung-Wei; Hsu, Yao-Jane; Kosugi, Nobuhiro; Ohigashi, Takuji; Chen, Yu-An; Shen, Po-Shen; Chen, Peter; Guo, Tzung-Fang

    2018-06-08

    The fabrication of multidimensional organometallic halide perovskite via a low-pressure vapor-assisted solution process is demonstrated for the first time. Phenyl ethyl-ammonium iodide (PEAI)-doped lead iodide (PbI 2 ) is first spin-coated onto the substrate and subsequently reacts with methyl-ammonium iodide (MAI) vapor in a low-pressure heating oven. The doping ratio of PEAI in MAI-vapor-treated perovskite has significant impact on the crystalline structure, surface morphology, grain size, UV-vis absorption and photoluminescence spectra, and the resultant device performance. Multiple photoluminescence spectra are observed in the perovskite film starting with high PEAI/PbI 2 ratio, which suggests the coexistence of low-dimensional perovskite (PEA 2 MA n -1 Pb n I 3 n +1 ) with various values of n after vapor reaction. The dimensionality of the as-fabricated perovskite film reveals an evolution from 2D, hybrid 2D/3D to 3D structure when the doping level of PEAI/PbI 2 ratio varies from 2 to 0. Scanning electron microscopy images and Kelvin probe force microscopy mapping show that the PEAI-containing perovskite grain is presumably formed around the MAPbI 3 perovskite grain to benefit MAPbI 3 grain growth. The device employing perovskite with PEAI/PbI 2 = 0.05 achieves a champion power conversion efficiency of 19.10% with an open-circuit voltage of 1.08 V, a current density of 21.91 mA cm -2 , and a remarkable fill factor of 80.36%. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Improvement of CH3NH3PbI3 thin film using the additive 1,8-diiodooctane for planar heterojunction perovskite cells

    Science.gov (United States)

    Abdulrahman, Solh; Wang, Chunhua; Cao, Chenghao; Zhang, Chujun; Yang, Junliang; Jiang, Li

    2017-10-01

    The thin-film quality is critical for obtaining high-performance perovskite solar cells (PSCs). The additive 1,8-diiodooctane (DIO) was used to control the morphology and structure of CH3NH3PbI3 perovskite thin films, and planar heterojunction (PHJ) PSCs with an architecture of ITO/PEDOT: PSS/CH3NH3PbI3/PCBM/Al was fabricated. It was found that the DIO played an important role on CH3NH3PbI3 thin-film quality and the performance of PHJ-PSCs. With the optimal volume ratio of 2%, the compact and uniform high-quality CH3NH3PbI3 thin films with enhanced crystallinity and less roughness were achieved, resulting in the great improvement of power conversion efficiency (PCE) from about 4.5% to over 9.0%. The research results indicate that the additive DIO is a simple and effective method to produce high-quality perovskite thin film and accordingly develop high-performance PHJ-PSCs.

  20. Magnetic and electrical transport properties of perovskite manganites Pr0.6Sr0.4MxMn1-xO3 (M = Fe, Co, Ni

    Directory of Open Access Journals (Sweden)

    X. S. Ge

    2017-12-01

    Full Text Available Powder samples of ABO3 perovskite manganites with the composition Pr0.6Sr0.4MxMn1-xO3 (M=Fe, Co, or Ni, 0.00≤x≤0.25 were synthesized using the sol-gel method. X-ray diffraction analyses showed that all three sets of samples had a single phase with an orthorhombic structure. The magnetic moment, μobs, of the samples at 10 K, decreased slowly for x≤0.10, whereas μobs decreased rapidly for x≥0.10. The dependences of μobs on the doping level x for the three series of samples were fitted successfully. In the fitting process, Mn, Fe, Co, and Ni cations were assumed to be trivalent, and the magnetic moment directions of Fe3+, Co3+, and Ni3+ cations were assumed to be canted antiferromagnetically coupled with Mn3+ cations. The cant angle ϕ decreased with the increase in x for x≤0.10 for Fe- and Ni-doped (x≤0.15 for Co-doped samples and increased rapidly when x≥0.10 (x≥0.15 for Co-doped samples. These properties are discussed using an oxygen 2p itinerant electron model, which is very similar to the oxygen 2p hole model proposed by Alexandrov et al. [Phys. Rev. Lett. 96, 117003 (2006].

  1. Rietveld refinement of the crystal structure of perovskite solar cells using CH3NH3PbI3 and other compounds

    Science.gov (United States)

    Ando, Yuji; Ohishi, Yuya; Suzuki, Kohei; Suzuki, Atsushi; Oku, Takeo

    2018-01-01

    The crystal structures of perovskite thin films including CH3NH3PbI3, CH3NH3Pb1-xSbxI3, and CH3NH3PbI3-yCly in the solar cell configuration were studied by using Rietveld refinement. For the CH3NH3PbI3 and CH3NH3Pb1-xSbxI3 samples, satisfactory agreement with the measured profiles was obtained with a weighted profile R-factor (Rwp) of as low as 3%. It was shown that the site occupancy of methylammonium (MA) was decreased in the antimonized cell due to the compensation effect of an increased positive charge brought about by replacing Pb2+ with Sb3+. Photovoltaic measurements showed that the power conversion efficiency was enhanced by adding a small amount of Sb to the CH3NH3PbI3 cell, but it was monotonically decreased as the mole fraction of Sb exceeded 0.03. This variation of the conversion efficiency was considered as a result of suppressed crystallization of PbI2 and carrier recombination via MA vacancies in the antimonized cells. In the case of CH3NH3PbI2.88Cl0.12 sample, the agreement with the measured profile with an Rwp of as high as 7% suggested the co-existence of cubic and tetragonal phases in the chlorinated cell.

  2. Relation between ABO blood groups and Helicobacter pylori infection in symptomatic patients

    Directory of Open Access Journals (Sweden)

    Jaff MS

    2011-09-01

    Full Text Available Mohamad Salih Jaff Pathology Department, College of Medicine, Hawler Medical University (formerly Salahuddin University, Erbil, Kurdistan Region, Iraq Abstract: Epidemiological studies have demonstrated higher frequencies of the O blood group and the nonsecretor phenotype of ABH antigens among patients suffering from peptic ulcers. Since Helicobacter pylori has been established as the main etiological factor in this disease, controversies about the associations of the ABO and Lewis blood group phenotypes and secretor and nonsecretor phenotypes in relation to susceptibility towards infection by this bacillus have been presented. The aim of this study was to verify the frequencies of ABO and Rhesus (Rh blood groups in H. pylori seropositive symptomatic patients. The study included (n = 1108 patients with dyspepsia symptoms referred from an outpatient clinic in Erbil city for investigation. Age, sex, and residency were recorded as a routine laboratory framework. Patients underwent SD Bioline (Standard Diagnostics Inc, Kyonggi-do, South Korea and enzyme-linked immunosorbent assay serologic tests for H. pylori. ABO blood group phenotypes were determined by a standard hemagglutination test. Results showed that 64.8% of patients (n = 718/1108 were seropositive for H. pylori infection, and (35.2% (n = 390/1108 were seronegative. Of the seropositive patients, 40.8% (n = 293/718 were male and 59.2% (n = 425/718 were female; while of the seronegative patients, 46.7% (n = 182/390 were male and 53.3% (n = 208/390 were female. The mean age for seropositives and seronegatives was (38.0 ± 14.6 years and (37.6 ± 15.7 years respectively. The frequency of the ABO and Rh-positive (Rh+ blood groups among seropositive patients was (A = 32.0%, B = 19.5%, AB = 6.7%, O = 41.8%, and Rh+ = 92.5% and was (A = 32.3%, B = 28.2%, AB = 8.0%, O = 31.5%, and Rh+ = 92.5% in seronegatives. The results of this study suggest that ABO blood groups, age, and gender influence

  3. Relative Risks of Thrombosis and Bleeding in Different ABO Blood Groups.

    Science.gov (United States)

    Franchini, Massimo; Lippi, Giuseppe

    2016-03-01

    The ABO blood group system is composed of complex carbohydrate molecules (i.e., the A, B, and H determinants) that are widely expressed on the surface of red blood cells and in a variety of other cell and tissues. Along with their pivotal role in transfusion and transplantation medicine, the ABO antigens participate in many other physiological processes and, in particular, are important determinants of von Willebrand factor and factor VIII circulating plasma levels. The precise influence of the ABO system on hemostasis has led the way to the investigation of a putative implication in the risk of developing cardiovascular disorders. Along with the underlying molecular mechanisms, the current knowledge on the role of ABO blood group antigens in both the thrombotic and hemorrhagic risk will be summarized in this narrative review. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. Relation of ABO blood groups to the severity of coronary atherosclerosis: an Gensini score assessment.

    Science.gov (United States)

    Gong, Ping; Luo, Song-Hui; Li, Xiao-Lin; Guo, Yuan-Lin; Zhu, Cheng-Gang; Xu, Rui-Xia; Li, Sha; Dong, Qian; Liu, Geng; Chen, Juan; Zeng, Rui-Xiang; Li, Jian-Jun

    2014-12-01

    Although the study on the relationship between ABO blood groups and coronary atherosclerosis has a long history, few data is available regarding ABO to severity of coronary atherosclerosis in a large cohort study. Therefore, the present study aimed to investigate the relation of the ABO blood groups to the severity of coronary atherosclerosis assessed by Gensini score (GS) in a large Chinese cohort undergoing coronary angiography. A total of 2919 consecutive patients undergoing coronary angiography were enrolled, and their baseline characteristics and ABO blood groups were collected. The GS was calculated as 1st tertile (0-10), 2nd tertile (11-36), 3rd tertile (>36) according to angiographic results. The relation of the ABO blood groups to GS was investigated. The frequency of blood group A was significantly higher in the upper GS tertiles (24.4% vs. 28.2% vs. 29.5%, p = 0.032). Multivariable linear regression analysis revealed that blood group A was independently associated with GS (β = 0.043, p = 0.017). Likewise, multivariable logistic regression analysis showed that group A remained significantly associated with mid-high GS (OR = 1.44, 95% CI 1.16-1.80, p = 0.001), and the group O was showed as a protective factor (OR = 0.77, 95% CI = 0.65-0.92, p = 0.004). In this large Chinese cohort study, the data indicated that there was an association between ABO blood groups and the severity of coronary atherosclerosis. Moreover, the blood group A was an independent risk factor for serious coronary atherosclerosis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Fabrication and Characterization of a Perovskite-Type Solar Cell with a Substrate Size of 70 mm

    Directory of Open Access Journals (Sweden)

    Takeo Oku

    2015-10-01

    Full Text Available A perovskite-type solar cell with a substrate size of 70 mm × 70 mm was fabricated by a simple spin-coating method using a mixed solution. The photovoltaic properties of the TiO2/CH3NH3PbI3-based photovoltaic devices were investigated by current density-voltage characteristic and incident photon to current conversion efficiency measurements. Their short-circuit current densities were almost constant over a large area. The photoconversion efficiency was influenced by the open-circuit voltage, which depended on the distance from the center of the cell.

  6. Dense ceramic membranes: A review of the state of the art

    Directory of Open Access Journals (Sweden)

    Kozhukharov, V.

    1999-02-01

    Full Text Available During the past several years the concepts of oxygen permeation through mixed valency ceramic membranes possess special interest. In this context, a classification and brief review of the major membrane ceramic materials will be presented. The focus will be on dense ceramic membranes as elements for advanced application. A discussion will be proposed for mixed conductor ceramics as perovskite ABO3 compounds. Dense membranes on perovskite base are the object of the present review and some details about processing and characterization of double (A- and B-site substituted La1-x Sr(BaxCo0.8Fe0.2O3-d perovskites will be presented.

    El concepto de permeación de oxígeno a través de membranas cerámicas de valencia mixta, ha venido adquiriendo especial relevancia a lo largo de los últimos años. En este contexto se hace se efectúa una clasificación y breve revisión de los materiales cerámicos más relevantes utilizados como membranas. En particular se orienta la descripción hacia las membranas cerámicas densas para aplicaciones avanzadas. Se propone un análisis de los conductores cerámicos mixtos, como los compuestos de tipo perovskita ABO3. Se realiza una revisión de los materiales de este tipo existentes, así como se describen algunos aspectos sobre el procesamiento y caracterización de las perovskitas tipo La1-x Sr(BaxCo0.8Fe0.2O3-d doblemente sustituidas (lugares A- y B-.

  7. First-principles analysis of ferroelectric transition in MnSnO3 and MnTiO3 perovskites

    Science.gov (United States)

    Kang, Sung Gu

    2018-06-01

    The ferroelectric instabilities of an artificially adopted Pnma structure in low tolerance perovskites have been explored (Kang et al., 2017) [4], where an unstable A-site environment was reported to be the major driving source for the low tolerance perovskites to exhibit ferroelectric instability. This study examined the ferroelectric transition of two magnetic perovskite materials, MnSnO3 and MnTiO3, in Pnma phase. Phase transitions to the Pnma phase at elevated pressures were observed. MnSnO3, which has a lower (larger) tolerance factor (B-site cation radius), showed a higher ferroelectric mode amplitude than MnTiO3. The distribution of the bond length of Mn-O and the mean quadratic elongation (QE) of octahedra (SnO6 or TiO6) were investigated for structural analysis. However, MnTiO3 showed a larger spontaneous polarization than MnSnO3 due to high Born effective charges of titanium. This study is useful because it provides a valuable pathway to the design of promising multiferroic materials.

  8. Prediction of possible CaMnO3 modifications using an ab initio minimization data-mining approach.

    Science.gov (United States)

    Zagorac, Jelena; Zagorac, Dejan; Zarubica, Aleksandra; Schön, J Christian; Djuris, Katarina; Matovic, Branko

    2014-10-01

    We have performed a crystal structure prediction study of CaMnO3 focusing on structures generated by octahedral tilting according to group-subgroup relations from the ideal perovskite type (Pm\\overline 3 m), which is the aristotype of the experimentally known CaMnO3 compound in the Pnma space group. Furthermore, additional structure candidates have been obtained using data mining. For each of the structure candidates, a local optimization on the ab initio level using density-functional theory (LDA, hybrid B3LYP) and the Hartree--Fock (HF) method was performed, and we find that several of the modifications may be experimentally accessible. In the high-pressure regime, we identify a post-perovskite phase in the CaIrO3 type, not previously observed in CaMnO3. Similarly, calculations at effective negative pressure predict a phase transition from the orthorhombic perovskite to an ilmenite-type (FeTiO3) modification of CaMnO3.

  9. Flexible All-Inorganic Perovskite CsPbBr3 Nonvolatile Memory Device.

    Science.gov (United States)

    Liu, Dongjue; Lin, Qiqi; Zang, Zhigang; Wang, Ming; Wangyang, Peihua; Tang, Xiaosheng; Zhou, Miao; Hu, Wei

    2017-02-22

    All-inorganic perovskite CsPbX 3 (X = Cl, Br, or I) is widely used in a variety of photoelectric devices such as solar cells, light-emitting diodes, lasers, and photodetectors. However, studies to understand the flexible CsPbX 3 electrical application are relatively scarce, mainly due to the limitations of the low-temperature fabricating process. In this study, all-inorganic perovskite CsPbBr 3 films were successfully fabricated at 75 °C through a two-step method. The highly crystallized films were first employed as a resistive switching layer in the Al/CsPbBr 3 /PEDOT:PSS/ITO/PET structure for flexible nonvolatile memory application. The resistive switching operations and endurance performance demonstrated the as-prepared flexible resistive random access memory devices possess reproducible and reliable memory characteristics. Electrical reliability and mechanical stability of the nonvolatile device were further tested by the robust current-voltage curves under different bending angles and consecutive flexing cycles. Moreover, a model of the formation and rupture of filaments through the CsPbBr 3 layer was proposed to explain the resistive switching effect. It is believed that this study will offer a new setting to understand and design all-inorganic perovskite materials for future stable flexible electronic devices.

  10. The role of deep acceptor centers in the oxidation of acceptor-doped wide-band-gap perovskites ABO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Putilov, L.P., E-mail: lev.putilov@gmail.com; Tsidilkovski, V.I.

    2017-03-15

    The impact of deep acceptor centers on defect thermodynamics and oxidation of wide-band-gap acceptor-doped perovskites without mixed-valence cations is studied. These deep centers are formed by the acceptor-bound small hole polarons whose stabilization energy can be high enough (significantly higher than the hole-acceptor Coulomb interaction energy). It is shown that the oxidation enthalpy ΔH{sub ox} of oxide is determined by the energy ε{sub A} of acceptor-bound states along with the formation energy E{sub V} of oxygen vacancies. The oxidation reaction is demonstrated to be either endothermic or exothermic, and the regions of ε{sub A} and E{sub V} values corresponding to the positive or negative ΔH{sub ox} are determined. The contribution of acceptor-bound holes to the defect thermodynamics strongly depends on the acceptor states depth ε{sub A}: it becomes negligible at ε{sub A} less than a certain value (at which the acceptor levels are still deep). With increasing ε{sub A}, the concentration of acceptor-bound small hole polarons can reach the values comparable to the dopant content. The results are illustrated with the acceptor-doped BaZrO{sub 3} as an example. It is shown that the experimental data on the bulk hole conductivity of barium zirconate can be described both in the band transport model and in the model of hopping small polarons localized on oxygen ions away from the acceptor centers. Depending on the ε{sub A} magnitude, the oxidation reaction can be either endothermic or exothermic for both mobility mechanisms.

  11. A-site ordered perovskite CaCu3Cu2Ir2O12−δ with square-planar and octahedral coordinated Cu ions

    International Nuclear Information System (INIS)

    Zhao Qing; Wang Qing-Tao; Yin Yun-Yu; Dai Jian-Hong; Shen Xi; Yang Jun-Ye; Yu Ri-Cheng; Long You-Wen; Hu Zhi-Wei; Li Xiao-Dong

    2016-01-01

    A novel CaCu 3 Cu 2 Ir 2 O 12−δ polycrystalline sample was synthesized at 8 GPa and 1373 K. Rietveld structural analysis shows that this compound crystallizes in an -type A-site ordered perovskite structure with space group Im-3. X-ray absorption spectra reveal a +2-charge state for both the square-planar and octahedral coordinated Cu ions, and the valence state of Ir is found to be about +5. Although the A-site Ca and the A′-site Cu 2+ are 1:3 ordered at fixed atomic positions, the distribution of B-site Cu 2+ and Ir 5+ is disorderly. As a result, no long-range magnetic ordering is observed at temperatures down to 2 K. Electrical transport and heat capacity measurements demonstrate itinerant electronic behavior. The crystal structure is stable with pressure up to 35.7 GPa at room temperature. (paper)

  12. Efficient Lead-Free Solar Cells Based on Hollow {en}MASnI3 Perovskites.

    Science.gov (United States)

    Ke, Weijun; Stoumpos, Constantinos C; Spanopoulos, Ioannis; Mao, Lingling; Chen, Michelle; Wasielewski, Michael R; Kanatzidis, Mercouri G

    2017-10-18

    Tin-based perovskites have very comparable electronic properties to lead-based perovskites and are regarded as possible lower toxicity alternates for solar cell applications. However, the efficiency of tin-based perovskite solar cells is still low and they exhibit poor air stability. Here, we report lead-free tin-based solar cells with greatly enhanced performance and stability using so-called "hollow" ethylenediammonium and methylammonium tin iodide ({en}MASnI 3 ) perovskite as absorbers. Our results show that en can improve the film morphology and most importantly can serve as a new cation to be incorporated into the 3D MASnI 3 lattice. When the cation of en becomes part of the 3D structure, a high density of SnI 2 vacancies is created resulting in larger band gap, larger unit cell volume, lower trap-state density, and much longer carrier lifetime compared to classical MASnI 3 . The best-performing {en}MASnI 3 solar cell has achieved a high efficiency of 6.63% with an open circuit voltage of 428.67 mV, a short-circuit current density of 24.28 mA cm -2 , and a fill factor of 63.72%. Moreover, the {en}MASnI 3 device shows much better air stability than the neat MASnI 3 device. Comparable performance is also achieved for cesium tin iodide solar cells with en loading, demonstrating the broad scope of this approach.

  13. Perovskite semiconductor La(Ni{sub 0.75}W{sub 0.25})O{sub 3} nanoparticles for visible-light-absorbing photocatalytic material

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Lei; Xie, Hongde, E-mail: xiehongde@suda.edu.cn; Pu, Yinfu; Huang, Yanlin [Soochow University, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science (China); Qin, Lin; Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Pukyong National University, Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering (Korea, Republic of)

    2017-01-15

    La(Ni{sub 0.75}W{sub 0.25})O{sub 3} perovskite oxide was prepared via the sol–gel Pechini route. The pure crystalline phase was verified via X-ray diffraction measurements and Rietveld structure refinements. Some measurements were applied to characterize the surface of the nanoparticles such as transmission electron microscopy, scanning electron microscope, energy-dispersive X-ray spectroscopy, specific surface area, and X-ray photo-electron spectroscopy measurements. The optical measurement confirmed that this perovskite oxide can absorb the visible light presenting low band energy of 2.41 eV. The d–d allowed transitions in Ni{sup 2+}-O octahedral have great contributions to the narrow band-gap. The Ni{sup 2+}-containing perovskite was applied as a photocatalyst showing the desirable photodegradation ability for methylene blue solutions under the excitation of visible-light. The photocatalysis activities were discussed in the relationship with its special perovskite-type structure such as the NiO{sub 6} color centers and multivalent cation ions etc.

  14. Low-Dimensional-Networked Metal Halide Perovskites: The Next Big Thing

    KAUST Repository

    Saidaminov, Makhsud I.

    2017-03-03

    Low-dimensional-networked (low-DN) perovskite derivatives are bulk quantum materials in which charge carriers are localized within ordered metal halide sheets, rods, or clusters that are separated by cationic lattices. After two decades of hibernation, this class of semiconductors reemerged in the past two years, largely catalyzed by the interest in alternative, more stable absorbers to CH3NH3PbI3-type perovskites in photovoltaics. Whether low-DN perovskites will surpass other photovoltaic technologies remains to be seen, but their impressively high photo- and electroluminescence yields have already set new benchmarks in light emission applications. Here we offer our perspective on the most exciting advances in materials design of low-DN perovskites for energy- and optoelectronic-related applications. The next few years will usher in an explosive growth in this tribe of quantum materials, as only a few members have been synthesized, while the potential library of compositions and structures is believed to be much larger and is yet to be discovered.

  15. Impact of Ultrathin C60 on Perovskite Photovoltaic Devices.

    Science.gov (United States)

    Liu, Dianyi; Wang, Qiong; Traverse, Christopher J; Yang, Chenchen; Young, Margaret; Kuttipillai, Padmanaban S; Lunt, Sophia Y; Hamann, Thomas W; Lunt, Richard R

    2018-01-23

    Halide perovskite solar cells have seen dramatic progress in performance over the past several years. Certified efficiencies of inverted structure (p-i-n) devices have now exceeded 20%. In these p-i-n devices, fullerene compounds are the most popular electron-transfer materials. However, the full function of fullerenes in perovskite solar cells is still under investigation, and the mechanism of photocurrent hysteresis suppression by fullerene remains unclear. In previous reports, thick fullerene layers (>20 nm) were necessary to fully cover the perovskite film surface to make good contact with perovskite film and avoid large leakage currents. In addition, the solution-processed fullerene layer has been broadly thought to infiltrate into the perovskite film to passivate traps on grain boundary surfaces, causing suppressed photocurrent hysteresis. In this work, we demonstrate an efficient perovskite photovoltaic device with only 1 nm C 60 deposited by vapor deposition as the electron-selective material. Utilizing a combination of fluorescence microscopy and impedance spectroscopy, we show that the ultrathin C 60 predominately acts to extract electrons from the perovskite film while concomitantly suppressing the photocurrent hysteresis by reducing space charge accumulation at the interface. This work ultimately helps to clarify the dominant role of fullerenes in perovskite solar cells while simplifying perovskite solar cell design to reduce manufacturing costs.

  16. Hexagonal perovskites with cationic vacancies. 33. Compounds of type Ba/sub 6-x/Sr/sub x/B/sub 2-y//sup 3 +/SE/sub y//sup 3 +/W/sub 3/vacantO/sub 18/

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, I; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

    1982-12-01

    In the series Ba/sub 6-x/Sr/sub x/Lu/sub 2-y/SE/sub y//sup 3 +/W/sub 3/vacantO/sub 18/ a substitution of Sr/sup 2 +/ for Ba/sup 2 +/ is possible. According to intensity calculations on powder data of BaSr/sub 5/Lu/sub 1.6/Ho/sub 0.4/W/sub 3/vacantO/sub 18/ the compounds crystallize in a rhombohedral 18 L type with the sequence (hhccc)/sub 3/; space group R-3m. The refined, intensity related R' value is 11.5%. The differences in properties (diffuse reflectance spectra, photoluminescence) between the hexagonal modifications Ba/sub 6/B/sub 2-y//sup 3 +/SE/sub y//sup 3 +/W/sub 3/vacantO/sub 18/ (B/sup 3 +/ = Gd, Y, Lu; SE/sup 3 +/ = Sm, Eu, Tb, Dy, Ho, Er, Tm) and the corresponding cubic HT modifications are discussed.

  17. Structures of ordered tungsten- or molybdenum-containing quaternary perovskite oxides

    International Nuclear Information System (INIS)

    Day, Bradley E.; Bley, Nicholas D.; Jones, Heather R.; McCullough, Ryan M.; Eng, Hank W.; Porter, Spencer H.; Woodward, Patrick M.; Barnes, Paris W.

    2012-01-01

    The room temperature crystal structures of six A 2 MMoO 6 and A 2 MWO 6 ordered double perovskites were determined from X-ray and neutron powder diffraction data. Ba 2 MgWO 6 and Ba 2 CaMoO 6 both adopt cubic symmetry (space group Fm3-bar m, tilt system a 0 a 0 a 0 ). Ba 2 CaWO 6 has nearly the same tolerance factor (t=0.972) as Ba 2 CaMoO 6 (t=0.974), yet it surprisingly crystallizes with I4/m symmetry indicative of out-of-phase rotations of the MO 6 octahedra about the c-axis (a 0 a 0 c − ). Sr 2 ZnMoO 6 (t=0.979) also adopts I4/m symmetry; whereas, Sr 2 ZnWO 6 (t=0.976) crystallizes with monoclinic symmetry (P2 1 /n) with out-of-phase octahedral tilting distortions about the a- and b-axes, and in-phase tilting about the c-axis (a − a − c + ). Ca 2 CaWO 6 (t=0.867) also has P2 1 /n symmetry with large tilting distortions about all three crystallographic axes and distorted CaO 6 octahedra. Analysis of 93 double perovskites and their crystal structures showed that while the type and magnitude of the octahedral tilting distortions are controlled primarily by the tolerance factor, the identity of the A-cation acts as the secondary structure directing factor. When A=Ba 2+ the boundary between cubic and tetragonal symmetries falls near t=0.97, whereas when A=Sr 2+ this boundary falls somewhere between t=1.018 and t=0.992. - Graphical abstract: A survey of the tolerance factor of 41 Mo/W- and 52 Nb/Ta-containing quaternary perovskites plotted as a function of the difference between the two six-coordinate M-cation ionic radii. Compounds with cubic symmetry are represented by diamonds, those with tetragonal symmetry are represented by squares, those with I2/m monoclinic symmetry are represented by ×, and those with P2 1 /n monoclinic symmetry are represented by triangles. White symbols represent compositions where A=Ba 2+ , gray symbols represent compositions where A=Sr 2+ , and black symbols represent where A=Ca 2+ . The filled circle represents rhombohedral Ba 2

  18. Lead Acetate Based Hybrid Perovskite Through Hot Casting for Planar Heterojunction Solar Cells

    Science.gov (United States)

    Shin, Gwang Su; Choi, Won-Gyu; Na, Sungjae; Gökdemir, Fatma Pinar; Moon, Taeho

    2018-03-01

    Flawless coverage of a perovskite layer is essential in order to achieve realistic high-performance planar heterojunction solar cells. We present that high-quality perovskite layers can be efficiently formed by a novel hot casting route combined with MAI (CH3NH3I) and non-halide lead acetate (PbAc2) precursors under ambient atmosphere. Casting temperature is controlled to produce various perovskite microstructures and the resulted crystalline layers are found to be comprised of closely packed islands with a smooth surface structure. Lead acetate employed perovskite solar cells are fabricated using PEDOT:PSS and PCBM charge transporting layers, in p- i- n type planar architecture. Especially, the outstanding open-circuit voltage demonstrates the high crystallinity and dense coverage of the produced perovskite layers by this facile route.

  19. Novel Solvent-free Perovskite Deposition in Fabrication of Normal and Inverted Architectures of Perovskite Solar Cells

    Science.gov (United States)

    Nejand, Bahram Abdollahi; Gharibzadeh, Saba; Ahmadi, Vahid; Shahverdi, H. Reza

    2016-01-01

    We introduced a new approach to deposit perovskite layer with no need for dissolving perovskite precursors. Deposition of Solution-free perovskite (SFP) layer is a key method for deposition of perovskite layer on the hole or electron transport layers that are strongly sensitive to perovskite precursors. Using deposition of SFP layer in the perovskite solar cells would extend possibility of using many electron and hole transport materials in both normal and invert architectures of perovskite solar cells. In the present work, we synthesized crystalline perovskite powder followed by successful deposition on TiO2 and cuprous iodide as the non-sensitve and sensitive charge transport layers to PbI2 and CH3NH3I solution in DMF. The post compressing step enhanced the efficiency of the devices by increasing the interface area between perovskite and charge transport layers. The 9.07% and 7.71% cell efficiencies of the device prepared by SFP layer was achieved in respective normal (using TiO2 as a deposition substrate) and inverted structure (using CuI as deposition substrate) of perovskite solar cell. This method can be efficient in large-scale and low cost fabrication of new generation perovskite solar cells. PMID:27640991

  20. Photoexcitation dynamics in solution-processed formamidinium lead iodide perovskite thin films for solar cell applications

    NARCIS (Netherlands)

    Fang, Hong-Hua; Wang, Feng; Adjokatse, Sampson; Zhao, Ni; Even, Jacky; Loi, Maria Antonietta

    Formamidinium lead iodide (FAPbI(3)) is a newly developed hybrid perovskite that potentially can be used in high-efficiency solution-processed solar cells. Here, the temperature-dependent dynamic optical properties of three types of FAPbI(3) perovskite films (fabricated using three different