WorldWideScience

Sample records for dysprosium phosphides

  1. Fatal aluminium phosphide poisoning

    Directory of Open Access Journals (Sweden)

    Meena Mahesh Chand

    2015-06-01

    Full Text Available Aluminium phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. AlP has currently aroused interest with a rising number of cases in the past four decades due to increased use for agricultural and non-agricultural purposes. Its easy availability in the markets has increased also its misuse for committing suicide. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. Poisoning with AlP has often occurred in attempts to commit suicide, and that more often in adults than in teenagers. This is a case of suicidal consumption of aluminium phosphide by a 32-year-old young medical anesthetist. Toxicological analyses detected aluminium phosphide. We believe that free access of celphos tablets in grain markets should be prohibited by law.

  2. Zinc Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Erdal Doğan

    2014-01-01

    Full Text Available Zinc phosphide has been used widely as a rodenticide. Upon ingestion, it gets converted to phosphine gas in the body, which is subsequently absorbed into the bloodstream through the stomach and the intestines and gets captured by the liver and the lungs. Phosphine gas produces various metabolic and nonmetabolic toxic effects. Clinical symptoms are circulatory collapse, hypotension, shock symptoms, myocarditis, pericarditis, acute pulmonary edema, and congestive heart failure. In this case presentation, we aim to present the intensive care process and treatment resistance of a patient who ingested zinc phosphide for suicide purposes.

  3. Dysprosium magneto-optical traps

    CERN Document Server

    Youn, Seo Ho; Ray, Ushnish; Lev, Benjamin L

    2010-01-01

    Magneto-optical traps (MOTs) of highly magnetic lanthanides open the door to explorations of novel phases of strongly correlated matter such as lattice supersolids and quantum liquid crystals. We recently reported the first MOTs of the five high abundance isotopes of the most magnetic atom, dysprosium. Described here are details of the experimental technique employed for repumper-free Dy MOTs containing up to half a billion atoms. Extensive characterization of the MOTs' properties---population, temperature, loading, metastable decay dynamics, trap dynamics---is provided.

  4. On polymorphism of dysprosium trichloride

    Energy Technology Data Exchange (ETDEWEB)

    Zakiryanova, Irina D.; Khokhlov, Vladimir A.; Salyulev, Alexander B.; Korzun, Iraida V. [RAS Ural Branch, Ekaterinburg (Russian Federation). Institute of High-Temperature Electrochemistry

    2015-07-01

    For the first time, the structure of crystalline DyCl{sub 3} over a wide temperature range from room temperature to melting point was studied by Raman spectroscopy. The phonon modes (cm{sup -1}) of dysprosium trichloride (monoclinic crystal lattice of AlCl{sub 3} type, Z = 4, CN = 6) at room temperature are 257 (A{sub 1g}), 201 (E{sub g}), 112 (E{sub g}), 88 (A{sub 1g}), and 63 (E{sub g}). The monoclinic structure of the crystalline DyCl{sub 3} C{sub 2h}{sup 3} symmetry was found to remain constant over the studied temperature range. No polymorphic transformation in the solid state was detected. Gravimetry, calorimetry, and mass spectrometry have been used in addition to support the conclusions made on the basis of Raman spectroscopic data.

  5. Gallium phosphide energy converters

    Energy Technology Data Exchange (ETDEWEB)

    Sims, P.E.; Dinetta, L.C.; Goetz, M.A.

    1995-10-01

    Gallium phosphide (GaP) energy converters may be successfully deployed to provide new mission capabilities for spacecraft. Betavoltaic power supplies based on the conversion of tritium beta decay to electricity using GaP energy converters can supply long term low-level power with high reliability. High temperature solar cells, also based on GaP, can be used in inward-bound missions greatly reducing the need for thermal dissipation. Results are presented for GaP direct conversion devices powered by Ni-63 and compared to the conversion of light emitted by tritiarated phosphors. Leakage currents as low as 1.2 x 10(exp {minus}17) A/sq cm have been measured and the temperature dependence of the reverse saturation current is found to have ideal behavior. Temperature dependent IV, QE, R(sub sh), and V(sub oc) results are also presented. These data are used to predict the high-temperature solar cell and betacell performance of GaP devices and suggest appropriate applications for the deployment of this technology.

  6. Resonance ionization spectroscopy in dysprosium

    Energy Technology Data Exchange (ETDEWEB)

    Studer, D., E-mail: dstuder@uni-mainz.de; Dyrauf, P.; Naubereit, P.; Heinke, R.; Wendt, K. [Johannes Gutenberg-Universität Mainz, Institut für Physik (Germany)

    2017-11-15

    We report on resonance ionization spectroscopy (RIS) of high-lying energy levels in dysprosium. We developed efficient excitation schemes and re-determined the first ionization potential (IP) via analysis of Rydberg convergences. For this purpose both two- and three-step excitation ladders were investigated. An overall ionization efficiency of 25(4) % could be demonstrated in the RISIKO mass separator of Mainz University, using a three-step resonance ionization scheme. Moreover, an extensive analysis of the even-parity 6sns- and 6snd-Rydberg-series convergences, measured via two-step excitation was performed. To account for strong perturbations in the observed s-series, the approach of multichannel quantum defect theory (MQDT) was applied. Considering all individual series limits we extracted an IP-value of 47901.76(5) cm{sup −1}, which agrees with the current literature value of 47901.7(6) cm{sup −1}, but is one order of magnitude more precise.

  7. The dysprosium-tin phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Eremenko, V.N.; Bulanova, M.V.; Martsenjuk, P.S. (I.N. Frantsevich Inst. for Problems of Materials Science, Kiev (Ukraine))

    1992-12-07

    The dysprosium-tin phase diagram was established by means of differential thermal, X-ray and microscopic analyses of 22 alloys. Seven intermetallic compounds were found to exist in the system. Dy[sub 5]Sn[sub 3] melts congruently at 1870 degC, and undergoes a polymorphous transformation at 1823 [+-] 6 degC. The intermetallics Dy[sub 5]Sn[sub 4], Dy[sub 11]Sn[sub 10], DySn, Dy[sub 4]Sn[sub 5], DySn[sub 2], DySn[sub 3] are formed peritectically at 1712 [+-]11, 1605 [+-]12, 1208 [+-]3, 1166 [+-]7, 1138 [+-]3 and 747 [+-]6 degC respectively. DySn[sub 3] exists in a narrow temperature range, in two polymorphous modifications. The transformation [beta]-DySn[sub 3] [yields] [alpha]-DySn[sub 3] occurs at 608 [+-] 12 degC, and at 499 [+-]2 degC [alpha]-DySn[sub 3] decomposes to DySn[sub 2] and the tin-rich melt. The dysprosium-rich eutectic crystallizes at 1204 [+-]10 degC and contains 13 at.% tin. The solid-state solubility of tin in dysprosium is about 3 at.%, and that of dysprosium in tin is negligible.

  8. Towards a new measurement of parity violation in dysprosium

    CERN Document Server

    Leefer, N; Antypas, D; Budker, D

    2014-01-01

    The dysprosium parity violation experiment concluded nearly 17 years ago with an upper limit on weak interaction induced mixing of nearly degenerate, opposite parity states in atomic dysprosium. While that experiment was limited in sensitivity by statistics, a new apparatus constructed in the interim for radio-frequency spectroscopy is expected to provide significant improvements to the statistical sensitivity. Preliminary work from the new PV experiment in dysprosium is presented with a discussion of the current statistical sensitivity and outlook.

  9. Dysprosium Modification of Cobalt Ferrite Ionic Magnetic Fluids

    Institute of Scientific and Technical Information of China (English)

    JIANG Rong-li; LIU Yong-chao; GENG Quan-rong; ZHAO Wen-tao

    2005-01-01

    Dysprosium composite cobalt ferrite ionic magnetic fluids were prepared by precipitation in the presence of Tri-sodium citrate. Influence of dysprosium modification on magnetic property is studied. The result shows that magnetic response toward exterior magnetic field can be improved by adding Dy3+. Studies also show that the increase of reaction temperature may improve the modification effect of dysprosium. By adding dysprosium ions, the average diameter of the magnetic nanoparticles will be decreased evidently. It is clear that the particles appear as balls, Cobalt ferrite with sizes of 12-15 nm, rare earth composite cobalt ferrite with sizes of 6-8 nm.

  10. Bismuth incorporation into gallium phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Jena, Puru [Virginia Commonwealth Univ. (United States); Kandalam, Anil K. [West Chester Univ. of Pennsylvania (United States); Christian, Theresa M. [National Renewable Energy Lab. (United States); Beaton, Daniel A. [National Renewable Energy Lab. (United States); Mascarenhas, Angelo [National Renewable Energy Lab. (United States); Alberi, Kirstin [National Renewable Energy Lab. (United States)

    2016-12-21

    Gallium phosphide bismide (GaP1-xBix) epilayers with bismuth fractions from 0.9% to 3.2%, as calculated from lattice parameter measurements, were studied with Rutherford backscattering spectrometry (RBS) to directly measure bismuth incorporation. The total bismuth fractions found by RBS were higher than expected from the lattice parameter calculations. Furthermore, in one analyzed sample grown by molecular beam epitaxy at 300 degrees C, 55% of incorporated bismuth was found to occupy interstitial sites. We discuss implications of this high interstitial incorporation fraction and its possible relationship to x-ray diffraction and photoluminescence measurements of GaP0.99Bi0.01.

  11. Can a dysprosium shortage threaten green energy technologies?

    NARCIS (Netherlands)

    Hoenderdaal, S.; Tercero Espinoza, L.; Marschneider-Weidemann, F.; Crijns - Graus, Wina

    2013-01-01

    Dysprosium, one of the various rare earth elements, is currently for more than 99% mined in China. As China is reducing its exports, new mining projects outside of China are needed to sustain supply and meet future demands. Dysprosium is mainly used in permanent magnets to retain the magnet's streng

  12. Can Ni phosphides become viable hydroprocessing catalysts?

    Energy Technology Data Exchange (ETDEWEB)

    Soled, S.; Miseo, S.; Baumgartner, J.; Guzman, J.; Bolin, T.; Meyer, R.

    2015-05-15

    We prepared higher surface area nickel phosphides than are normally found by reducing nickel phosphate. To do this, we hydrothermally synthesized Ni hydroxy phosphite precursors with low levels of molybdenum substitution. The molybdenum substitution increases the surface area of these precursors. During pretreatment in a sulfiding atmosphere (such as H2S/H2) dispersed islands of MoS2 segregate from the precursor and provide a pathway for H2 dissociation that allows reduction of the phosphite precursor to nickel phosphide at substantially lower temperatures than in the absence of MoS2. The results reported here show that to create nickel phosphides with comparable activity to conventional supported sulfide catalysts, one would have to synthesize the phosphide with surface areas exceeding 400 m2/g (i.e. with nanoparticles less than 30 Å in lateral dimension).

  13. Phenalenyl-based mononuclear dysprosium complexes

    Directory of Open Access Journals (Sweden)

    Yanhua Lan

    2016-07-01

    Full Text Available The phenalenyl-based dysprosium complexes [Dy(PLN2(HPLNCl(EtOH] (1, [Dy(PLN3(HPLN]·[Dy(PLN3(EtOH]·2EtOH (2 and [Dy(PLN3(H2O2]·H2O (3, HPLN being 9-hydroxy-1H-phenalen-1-one, have been synthesized. All compounds were fully characterized by means of single crystal X-ray analysis, paramagnetic 1H NMR, MALDI-TOF mass spectrometry, UV–vis spectrophotometry and magnetic measurements. Both static (dc and dynamic (ac magnetic properties of these complexes have been investigated, showing slow relaxation of magnetization, indicative of single molecule magnet (SMM behavior. Attempts to synthesize sublimable phenalenyl-based dysprosium complexes have been made by implementing a synthetic strategy under anhydrous conditions. The sublimed species were characterized and their thermal stability was confirmed. This opens up the possibility to deposit phenalenyl-based lanthanides complexes by sublimation onto surfaces, an important prerequisite for ongoing studies in molecular spintronics.

  14. Anisotropy in the Interaction of Ultracold Dysprosium

    CERN Document Server

    Kotochigova, Svetlana

    2011-01-01

    The nature of the interaction between ultracold atoms with a large orbital and spin angular momentum has attracted considerable attention. It was suggested that such interactions can lead to the realization of exotic states of highly correlated matter. Here, we report on a theoretical study of the competing anisotropic dispersion, magnetic dipole-dipole, and electric quadrupole-quadrupole forces between two dysprosium atoms. Each dysprosium atom has an orbital angular momentum L=6 and magnetic moment $\\mu=10\\mu_B$. We show that the dispersion coefficients of the ground state adiabatic potentials lie between 1865 a.u. and 1890 a.u., creating a non-negligible anisotropy with a spread of 25 a.u. and that the electric quadrupole-quadrupole interaction is weak compared to the other interactions. We also find that for interatomic separations $R< 50\\,a_0$ both the anisotropic dispersion and magnetic dipole-dipole potential are larger than the atomic Zeeman splittings for external magnetic fields of order 10 G to ...

  15. Sinterless Formation Of Contacts On Indium Phosphide

    Science.gov (United States)

    Weizer, Victor G.; Fatemi, Navid S.

    1995-01-01

    Improved technique makes it possible to form low-resistivity {nearly equal to 10(Sup-6) ohm cm(Sup2)} electrical contacts on indium phosphide semiconductor devices without damaging devices. Layer of AgP2 40 Angstrom thick deposited on InP before depositing metal contact. AgP2 interlayer sharply reduces contact resistance, without need for sintering.

  16. InP (Indium Phosphide): Into the future

    Science.gov (United States)

    Brandhorst, Henry W., Jr.

    1989-01-01

    Major industry is beginning to be devoted to indium phosphide and its potential applications. Key to these applications are high speed and radiation tolerance; however the high cost of indium phosphide may be an inhibitor to progress. The broad applicability of indium phosphide to many devices will be discussed with an emphasis on photovoltaics. Major attention is devoted to radiation tolerance and means of reducing cost of devices. Some of the approaches applicable to solar cells may also be relevant to other devices. The intent is to display the impact of visionary leadership in the field and enable the directions and broad applicability of indium phosphide.

  17. First search for double $\\beta$ decay of dysprosium

    CERN Document Server

    Belli, P; Cappella, F; Cerulli, R; Danevich, F A; d'Angelo, S; Di Vacri, M L; Incicchitti, A; Laubenstein, M; Nagorny, S S; Nisi, S; Tolmachev, A V; Tretyak, V I; Yavetskiy, R P

    2011-01-01

    A search for double $\\beta$ decay of dysprosium was realized for the first time with the help of an ultra low-background HP Ge $\\gamma$ detector. After 2512 h of data taking with a 322 g sample of dysprosium oxide limits on double beta processes in $^{156}$Dy and $^{158}$Dy have been established on the level of $T_{1/2}\\geq 10^{14}-10^{16}$ yr. Possible resonant double electron captures in $^{156}$Dy and $^{158}$Dy were restricted on a similar level. As a by-product of the experiment we have measured the radioactive contamination of the Dy$_2$O$_3$ sample and set limits on the $\\alpha$ decay of dysprosium isotopes to the excited levels of daughter nuclei as $T_{1/2}\\geq 10^{15} - 10^{17}$ yr.

  18. Aluminum phosphide poisoning: an unsolved riddle.

    Science.gov (United States)

    Anand, R; Binukumar, B K; Gill, Kiran Dip

    2011-08-01

    Aluminum phosphide (ALP), a widely used insecticide and rodenticide, is also infamous for the mortality and morbidity it causes in ALP-poisoned individuals. The toxicity of metal phosphides is due to phosphine liberated when ingested phosphides come into contact with gut fluids. ALP poisoning is lethal, having a mortality rate in excess of 70%. Circulatory failure and severe hypotension are common features of ALP poisoning and frequent cause of death. Severe poisoning also has the potential to induce multi-organ failure. The exact site or mechanism of its action has not been proved in humans. Rather than targeting a single organ to cause gross damage, ALP seems to work at the cellular level, resulting in widespread damage leading to multiorgan dysfunction (MOD) and death. There has been proof in vitro that phosphine inhibits cytochrome c oxidase. However, it is unlikely that this interaction is the primary cause of its toxicity. Mitochondria could be the possible site of maximum damage in ALP poisoning, resulting in low ATP production followed by metabolic shutdown and MOD; also, owing to impairment in electron flow, there could be free radical generation and damage, again producing MOD. Evidence of reactive oxygen species-induced toxicity owing to ALP has been observed in insects and rats. A similar mechanism could also play a role in humans and contribute to the missing link in the pathogenesis of ALP toxicity. There is no specific antidote for ALP poisoning and supportive measures are all that are currently available.

  19. Microwave-assisted synthesis of transition metal phosphide

    Science.gov (United States)

    Viswanathan, Tito

    2014-12-30

    A method of synthesizing transition metal phosphide. In one embodiment, the method has the steps of preparing a transition metal lignosulfonate, mixing the transition metal lignosulfonate with phosphoric acid to form a mixture, and subjecting the mixture to a microwave radiation for a duration of time effective to obtain a transition metal phosphide.

  20. Comment on " An update on toxicology of aluminum phosphide "

    Directory of Open Access Journals (Sweden)

    Omid Mehrpour

    2012-10-01

    Full Text Available I read with interest the recent published article by Dr Moghadamnia titled "An update on toxicology of aluminum phosphide". Since aluminum phosphide (AlP poisoning is an important medical concern in Iran, I have had the opportunities to work and publish many papers in this regard. I would like to comment on that paper.

  1. Synthesis, characterization and properties of hollow nickel phosphide nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Ni Yonghong; Tao Ali; Hu Guangzhi; Cao Xiaofeng; Wei Xianwen; Yang Zhousheng [College of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu 241000 (China)

    2006-10-14

    Nickel phosphide (Ni{sub 12}P{sub 5}) hollow nanospheres with a mean diameter of 100 nm and a shell thickness of 15-20 nm have been successfully prepared by a hydrothermal-microemulsion route, using NaH{sub 2}PO{sub 2} as a phosphorus source. XRD, EDS (HR)TEM, SEM and the SAED pattern were used to characterize the final product. Experiments showed that the as-prepared nickel phosphide hollow nanospheres could selectively catalytically degrade some organic dyes such as methyl red and Safranine T under 254 nm UV light irradiation. At the same time, the nickel phosphide hollow nanospheres showed a stronger ability to promote electron transfer between the glass-carbon electrode and adrenalin than nickel phosphide honeycomb-like particles prepared by a simple hydrothermal route. A possible formation process for nickel phosphide hollow nanospheres was suggested based on the experimental results.

  2. Neutron resonance parameters of dysprosium isotopes using neutron capture yields

    Energy Technology Data Exchange (ETDEWEB)

    Shin, S. G.; Kye, Y. U.; Cho, M. H. [POSTECH, Pohang (Korea, Republic of); Namkung, W. [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Kim, G. N. [Kyungpook National University, Daegu (Korea, Republic of); Lee, M. W.; Kang, Y. R. [Dongnam Inst. Of Radiological and Medical Science, Busan (Korea, Republic of)

    2015-10-15

    Dysprosium is used in the field of nuclear reactor system because it has a very large thermal neutron absorption cross-section. The dysprosium alloyed with special stainless steels is attractive for control in nuclear reactor because of the ability to absorb neutrons readily without swelling or contracting over time and its high melting point. Dysprosium is also one of fission products from the thermal fission of {sup 234}U, {sup 233}U, and {sup 239}Pu. The fission products are accumulated in the reactor core by the burn-up of the nuclear fuel and the poison effect is increased. Therefore, it is required to understand how Dysprosium as both a poison and an absorbing material in the control rod has an effect on the neutron population in a nuclear reactor system over all energy regions. Neutron Capture experiments on Dy isotopes were performed at the electron linear accelerator (LINAC) facility of the Rensselear Polytechnic Institute (RPI) in the neutron energy region from 10 eV to 1 keV. Resonance parameters were extracted by fitting the neutron capture data using the SAMMY multilevel R-matrix Bayesian code.

  3. Properties of Polydisperse Tin-doped Dysprosium and Indium Oxides

    Directory of Open Access Journals (Sweden)

    Malinovskaya Tatyana

    2017-01-01

    Full Text Available The results of investigations of the complex permittivity, diffuse-reflectance, and characteristics of crystal lattices of tin-doped indium and dysprosium oxides are presented. Using the methods of spectroscopy and X-ray diffraction analysis, it is shown that doping of indium oxide with tin results in a significant increase of the components of the indium oxide complex permittivity and an appearance of the plasma resonance in its diffuse-reflectance spectra. This indicates the appearance of charge carriers with the concentration of more than 1021 cm−3 in the materials. On the other hand, doping of the dysprosium oxide with the same amount of tin has no effect on its optical and electromagnetic properties.

  4. New synthesis method for nickel phosphide hydrotreating catalysts.

    Science.gov (United States)

    Yang, Shaofeng; Prins, Roel

    2005-09-07

    Nickel phosphide particles on silica and alumina support were prepared from metal or metal oxide particles by treatment with phosphine and hydrogen at moderate temperature, resulting in small particle sizes equivalent to that of the precursor particle size.

  5. Dysprosium titanate as an absorber material for control rods

    Science.gov (United States)

    Risovany, V. D.; Varlashova, E. E.; Suslov, D. N.

    2000-09-01

    Disprosium titanate is an attractive control rod material for the thermal neutron reactors. Its main advantages are: insignificant swelling, no out-gassing under neutron irradiation, rather high neutron efficiency, a high melting point (˜1870°C), non-interaction with the cladding at temperatures above 1000°C, simple fabrication and easily reprocessed non-radioactive waste. It can be used in control rods as pellets and powder. The disprosium titanate control rods have worked off in the MIR reactor for 17 years, in VVER-1000 - for 4 years without any operating problems. After post-irradiation examinations this type of control rod having high lifetime was recommended for the VVER and RBMK. The paper presents the examination results of absorber element dummies containing dysprosium titanate, irradiated in the SM reactor to the neutron fluence of 3.4×10 22 cm -2 ( E>0.1 MeV) and, also, the data on structure, thermal-physical properties of dysprosium titanate, efficiency of dysprosium titanate control rods.

  6. Indium phosphide nanowires and their applications in optoelectronic devices

    OpenAIRE

    2016-01-01

    Group IIIA phosphide nanocrystalline semiconductors are of great interest among the important inorganic materials because of their large direct band gaps and fundamental physical properties. Their physical properties are exploited for various potential applications in high-speed digital circuits, microwave and optoelectronic devices. Compared to II–VI and I–VII semiconductors, the IIIA phosphides have a high degree of covalent bonding, a less ionic character and larger exciton diameters. In t...

  7. Dysprosium electrodeposition from a hexaalkylguanidinium-based ionic liquid

    Science.gov (United States)

    Berger, Claudia A.; Arkhipova, Maria; Maas, Gerhard; Jacob, Timo

    2016-07-01

    The rare-earth element dysprosium (Dy) is an important additive that increases the magnetocrystalline anisotropy of neodymium magnets and additionally prevents from demagnetizing at high temperatures. Therefore, it is one of the most important elements for high-tech industries and is mainly used in permanent magnetic applications, for example in electric vehicles, industrial motors and direct-drive wind turbines. In an effort to develop a more efficient electrochemical technique for depositing Dy on Nd-magnets in contrast to commonly used costly physical vapor deposition, we investigated the electrochemical behavior of dysprosium(iii) trifluoromethanesulfonate in a custom-made guanidinium-based room-temperature ionic liquid (RTIL). We first examined the electrodeposition of Dy on an Au(111) model electrode. The investigation was carried out by means of cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS). The initial stages of metal deposition were followed by in situ scanning tunneling microscopy (STM). CV measurements revealed a large cathodic reduction peak, which corresponds to the growth of monoatomic high islands, based on STM images taken during the initial stages of deposition. XPS identified these deposited islands as dysprosium. A similar reduction peak was also observed on an Nd-Fe-B substrate, and positively identified as deposited Dy using XPS. Finally, we varied the concentration of the Dy precursor, electrolyte flow and temperature during Dy deposition and demonstrated that each of these parameters could be used to increase the thickness of the Dy deposit, suggesting that these parameters could be tuned simultaneously in a temperature-controlled flow cell to enhance the thickness of the Dy layer.The rare-earth element dysprosium (Dy) is an important additive that increases the magnetocrystalline anisotropy of neodymium magnets and additionally prevents from demagnetizing at high temperatures. Therefore, it is one of the most important

  8. Predictors of Poor Prognosis in Aluminum Phosphide Intoxication

    Directory of Open Access Journals (Sweden)

    Fakhredin Taghaddosi Nejad

    2012-05-01

    Full Text Available Background: Aluminum phosphide as a fumigant is extensively used for wheat preservation from rodents and bugs especially in silos worldwide. There is increasing number of acute intoxication with this potentially lethal compound because of its easy availability. We have tried to locate predictors of poor prognosis in patients with aluminum phosphide intoxication in order to find patients who need more strict medical cares. Methods: All cases of aluminum phosphide intoxication that had been referred to our hospital during April 2008 to March 2010 were studied by their medical dossiers. Pertinent data including vital signs, demographic features, clinical and lab findings, and incidence of any complication were collected and analyzed by the relevant statistical methods. Results: Sixty seven cases of aluminum phosphide intoxication were included in the study. 44.8% of them were male. 97% of cases were suicidal. Mean amount of ingestion was 1.23+/- 0.71 tablets. Mortality rate was 41.8%. ECG abnormality and need for mechanical ventilation had negative relation with outcome. Conclusion: Correlation between some findings and complications with outcome in aluminum phosphide intoxication can be used as guidance for risk assessment and treatment planning in the patients.

  9. Prognostic factors of acute aluminum phosphide poisoning

    Directory of Open Access Journals (Sweden)

    Louriz M

    2009-06-01

    Full Text Available Background : In Morocco, acute aluminum phosphide poisoning (AAlPP is a serious health care problem. It results in high mortality rate despite the progress of critical care. Aims : The present paper aims at determining the characteristics of AAlPP and evaluating its severity factors. Setting and design: We studied consecutive patients of AAlPP admitted to the medical intensive care unit (ICU (Ibn Sina Hospital, Rabat, Morocco between January 1992 and December 2007. Materials and Methods : Around 50 parameters were collected, and a comparison was made between survivor and nonsurvivor groups. Statistical Analysis : Data were analyzed using Fisher exact test, Mann-Whitney U test and Cox regression model. Results : Forty-nine patients were enrolled: 31 females and 18 males; their average age was 26± 11 years. The ingested dose of aluminum phosphide was 1.2± 0.7 g. Self-poisoning was observed in 47 cases, and the median of delay before admission to the hospital was 5.3 hours (range, 2.9-10 hours. Glasgow coma scale was 14± 2. Shock was reported in 42.6% of the patients. pH was 7.1± 0.4, and bicarbonate concentration was 16.3± 8.8 mmol/L. Electrocardiogram abnormalities were noted in 28 (57% cases. The mortality rate was 49% (24 cases. The prognostic factors were APACHE II (P= 0.01, low Glasgow coma scale (P= 0.022, shock (P= 0.0003, electrocardiogram abnormalities (P= 0.015, acute renal failure (P= 0.026, low prothrombin rate (P= 0.020, hyperleukocytosis (P= 0.004, use of vasoactive drugs (P< 0.001, use of mechanical ventilation (P= 0.003. Multivariate analysis by logistic regression revealed that mortality in AAlPP correlated with shock (RR = 3.82; 95% CI= 1.12-13.38; P= 0.036 and altered consciousness (RR= 3.26; 95% CI= 1.18-8.99; P= 0.022. Conclusion : AAlPP is responsible for a high mortality, which is primarily due to hemodynamic failure.

  10. Controlled synthesis and magnetic properties of nickel phosphide and bimetallic iron-nickel phosphide nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Bhupendra; Ho, Chia-Ling [National Cheng Kung University, Department of Chemical Engineering, Taiwan (China); Tseng, Yuan-Chieh [National Chiao Tung University, Department of Materials Science and Engineering, Taiwan (China); Lo, Chieh-Tsung, E-mail: tsunglo@mail.ncku.edu.tw [National Cheng Kung University, Department of Chemical Engineering, Taiwan (China)

    2012-02-15

    Nickel phosphide (Ni{sub 2}P) and bimetallic iron-nickel phosphides [(Fe{sub x}Ni{sub y}){sub 2}P] nanorods were fabricated by a seeded growth strategy. This strategy utilized pre-synthesized Fe{sub 3}O{sub 4} nanoparticles as seeds and the thermal decomposition of metal precursors by multiple injections in a solution containing trioctylphosphine and didodecyldimethylammonium bromide (DDAB). The nanorods were characterized by transmission electron microscopy, X-ray diffraction, and magnetic measurements were carried out using superconducting quantum interference device (SQUID). The rod length was tunable, ranging from 10 to 110 nm depending on the number of injections, whereas the diameter of the rods was nearly 6 nm. It was found that the rod size increased with the number of injections under the constant total injection concentration and reaction time. In addition, the effect of the DDAB quantity used as a co-surfactant was studied, which showed that an optimum quantity was required to achieve uniform nanorods. Magnetic characterizations were performed over the two kinds of nanorods to identify their respective magnetic phases. The results demonstrated that the Ni{sub 2}P nanorods were defined as a Curie-Weiss paramagnet, whereas the (Fe{sub x}Ni{sub y}){sub 2}P nanorods exhibited superparamagnetic characteristics.

  11. An update on toxicology of aluminum phosphide

    Science.gov (United States)

    2012-01-01

    Aluminum phosphide (AlP) is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. In Iran it is known as the “rice tablet”. AlP has currently aroused interest with increasing number of cases in the past four decades due to increased use in agricultural and non-agricultural purposesand also its easy availability in the markets has increased its misuse to commit suicide. Upon contact with moisture in the environment, AlP undergoes a chemical reaction yielding phosphine gas, which is the active pesticidal component. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. It was reported that AlP has a mortality rate more than 50% of intoxication cases. Poisoning with AlP has usually occurred in attempts to suicide. It is a more common case in adults rather than teen agers. In some eastern countries it is a very common agent with rapid action for suicide. Up to date, there is no effective antidote or treatment for its intoxication. Also, some experimental results suggest that magnesium sulfate, N-acetyl cysteine (NAC), glutathione, vitamin C and E, beta-carotenes, coconut oil and melatonin may play an important role in reducing the oxidative outcomes of phosphine. This article reviews the experimental and clinical features of AlP intoxication and tries to suggest a way to encounter its poisoning. PMID:23351193

  12. An Update on Toxicology of Aluminum Phosphide

    Directory of Open Access Journals (Sweden)

    Ali Akbar Moghhadamnia

    2012-09-01

    Full Text Available Aluminum phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. In Iran it is known as the "rice tablet". AlP has currently aroused interest with increasing number of cases in the past four decades due to increased use in agricultural and non-agricultural purposes and also its easy availability in the markets has increased its misuse to commit suicide. Upon contact with moisture in the environment, AlP undergoes a chemical reaction yielding phosphine gas, which is the active pesticidal component. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. It was reported that AlP has a mortality rate more than 50% of intoxication cases. Poisoning with AlP has usually occurred in attempts to suicide. It is a more common case in adults rather than teen agers. In some eastern countries it is a very common agent with rapid action for suicide. Up to date, there is no effective antidote or treatment for its intoxication. Also, some experimental results suggest that magnesium sulfate, N-acetyl cysteine (NAC, glutathione, vitamin C and E, beta-carotenes, coconut oil and melatonin may play an important role in reducing the oxidative outcomes of phosphine. This article reviews the experimental and clinical features of AlP intoxication and tries to suggest a way to encounter its poisoning.

  13. An update on toxicology of aluminum phosphide

    Directory of Open Access Journals (Sweden)

    Moghadamnia Ali

    2012-09-01

    Full Text Available Abstract Aluminum phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. In Iran it is known as the “rice tablet”. AlP has currently aroused interest with increasing number of cases in the past four decades due to increased use in agricultural and non-agricultural purposesand also its easy availability in the markets has increased its misuse to commit suicide. Upon contact with moisture in the environment, AlP undergoes a chemical reaction yielding phosphine gas, which is the active pesticidal component. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. It was reported that AlP has a mortality rate more than 50% of intoxication cases. Poisoning with AlP has usually occurred in attempts to suicide. It is a more common case in adults rather than teen agers. In some eastern countries it is a very common agent with rapid action for suicide. Up to date, there is no effective antidote or treatment for its intoxication. Also, some experimental results suggest that magnesium sulfate, N-acetyl cysteine (NAC, glutathione, vitamin C and E, beta-carotenes, coconut oil and melatonin may play an important role in reducing the oxidative outcomes of phosphine. This article reviews the experimental and clinical features of AlP intoxication and tries to suggest a way to encounter its poisoning.

  14. Acute aluminium phosphide poisoning, what is new?

    Directory of Open Access Journals (Sweden)

    Yatendra Singh

    2014-01-01

    Full Text Available Aluminium phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide that is commonly used for grain preservation. AlP has currently generated interest with increasing number of cases in the past four decades because of its increased use for agricultural and nonagricultural purposes, and also its easy availability in the markets has led to its increased misuse to commit suicide. Ingestion is usually suicidal in intent, uncommonly accidental and rarely homicidal. The poison affects all systems, shock, cardiac arrhythmias with varied ECG changes and gastrointestinal features being the most prominent. Diagnosis is made on the basis of clinical suspicion, a positive silver nitrate paper test to phosphine, and gastric aspirate and viscera biochemistry. Treatment includes early gastric lavage with potassium permanganate or a combination of coconut oil and sodium bicarbonate, administration of charcoal and palliative care. Specific therapy includes intravenous magnesium sulphate and oral coconut oil. Unfortunately, the lack of a specific antidote Results in very high mortality and the key to treatment lies in rapid decontamination and institution of resuscitative measures. This article aims to identify the salient features and mechanism of AlP poisoning along with its management strategies and prognostic variables.

  15. Carbon phosphide monolayers with superior carrier mobility

    Science.gov (United States)

    Wang, Gaoxue; Pandey, Ravindra; Karna, Shashi P.

    2016-04-01

    Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great promise for applications in high-performance electronics and optoelectronics.Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great

  16. Manganese phosphide thin films and nanorods grown on gallium phosphide and on glass substrates

    Science.gov (United States)

    Nateghi, N.; Lambert-Milot, S.; Ménard, D.; Masut, R. A.

    2016-05-01

    We report a simple and fast route to grow ferromagnetic manganese phosphide polycrystalline films and nanorods on GaP and on glass substrates using metalorganic vapor phase deposition. Increasing the growth temperature (≥600 °C) and growth time (≥30 min) results in nucleation of secondary MnP crystals on the primary grains. The secondary crystals grow faster along a specific direction of orthorhombic MnP (c-axis) and form long rods (up to 10 μm) whose diameters are in the nanoscale (20-100 nm). The nanorods can be easily detached from the glass substrate. The films exhibit ferromagnetic behavior with a range of transition temperatures, depending on the growth conditions.

  17. Evaluation of aluminum phosphide against wood-destroying insects.

    Science.gov (United States)

    Pant, Himani; Tripathi, Sadhna

    2012-02-01

    Aluminum phosphide, a well-known stored grain fumigant, available in solid formulation, has shown promise as wood fumigant. This chemical decomposes to phosphine when exposed to moisture. The feasibility of fumigant treatment to extend the service life of wood was evaluated in a small block test of two wood species. Hard wood (Mangifera indica L.) and conifer blocks (Pinus roxburghii Sargent) were fumigated with different concentrations (0.05, 0.1, 0.2, 0.4, 0.8, and 1.6%) of aluminum phosphide. Fumigated blocks were exposed to Lyctus africanus Lesne (Coleoptera; Lyctidae) larvae. Results revealed that aluminum phosphide showed complete mortality of Lyctus larvae at 0.2% concentration, that is, 0.93 g/m3 retention level. Mean mortality of 74% of Lyctus larvae was observed in soft wood blocks fumigated with lowest concentration, that is, 0.05% of aluminum phosphide, whereas in hard wood blocks > 85% mortality was observed at this concentration.

  18. Successful outcome in managing of aluminum phosphide poisoning

    Directory of Open Access Journals (Sweden)

    Samad Shams Vahdati

    2015-06-01

    Full Text Available Aluminum phosphide (ALP is a potent lethal substance, that use for agriculture purpose, as a pesticide. this substance may use for suicide, and it will kill the patient rapidly. we want to report a patient who use ALP for suicide purpose and was managed quickly in the emergency department and he became alive.

  19. A Nonaqueous Approach to the Preparation of Iron Phosphide Nanowires

    Directory of Open Access Journals (Sweden)

    She Houde

    2010-01-01

    Full Text Available Abstract Previous preparation of iron phosphide nanowires usually employed toxic and unstable iron carbonyl compounds as precursor. In this study, we demonstrate that iron phosphide nanowires can be synthesized via a facile nonaqueous chemical route that utilizes a commonly available iron precursor, iron (III acetylacetonate. In the synthesis, trioctylphosphine (TOP and trioctylphosphine oxide (TOPO have been used as surfactants, and oleylamine has been used as solvent. The crystalline structure and morphology of the as-synthesized products were characterized by powder X-ray diffraction (XRD and transmission electron microscopy (TEM. The obtained iron phosphide nanowires have a typical width of ~16 nm and a length of several hundred nanometers. Structural and compositional characterization reveals a hexagonal Fe2P crystalline phase. The morphology of as-synthesized products is greatly influenced by the ratio of TOP/TOPO. The presence of TOPO has been found to be essential for the growth of high-quality iron phosphide nanowires. Magnetic measurements reveal ferromagnetic characteristics, and hysteresis behaviors below the blocking temperature have been observed.

  20. Rational Design of Zinc Phosphide Heterojunction Photovoltaics

    Science.gov (United States)

    Bosco, Jeffrey Paul

    The prospect of terawatt-scale electricity generation using a photovoltaic (PV) device places strict requirements on the active semiconductor optoelectronic properties and elemental abundance. After reviewing the constraints placed on an ``earth-abundant'' solar absorber, we find zinc phosphide (α-Zn 3P2) to be an ideal candidate. In addition to its near-optimal direct band gap of 1.5 eV, high visible-light absorption coefficient (>10. 4cm-1), and long minority-carrier diffusion length (>5 μm), Zn3P 2 is composed of abundant Zn and P elements and has excellent physical properties for scalable thin-film deposition. However, to date, a Zn 3P2 device of sufficient efficiency for commercial applications has not been demonstrated. Record efficiencies of 6.0% for multicrystalline and 4.3% for thin-film cells have been reported, respectively. Performance has been limited by the intrinsic p-type conductivity of Zn3P 2 which restricts us to Schottky and heterojunction device designs. Due to our poor understanding of Zn3P2 interfaces, an ideal heterojunction partner has not yet been found. The goal of this thesis is to explore the upper limit of solar conversion efficiency achievable with a Zn3P2 absorber through the design of an optimal heterojunction PV device. To do so, we investigate three key aspects of material growth, interface energetics, and device design. First, the growth of Zn3P2 on GaAs(001) is studied using compound-source molecular-beam epitaxy (MBE). We successfully demonstrate the pseudomorphic growth of Zn3P2 epilayers of controlled orientation and optoelectronic properties. Next, the energy-band alignments of epitaxial Zn3P2 and II-VI and III-V semiconductor interfaces are measured via high-resolution x-ray photoelectron spectroscopy in order to determine the most appropriate heterojunction partner. From this work, we identify ZnSe as a nearly ideal n-type emitter for a Zn3P 2 PV device. Finally, various II-VI/Zn3P2 heterojunction solar cells designs are

  1. Acute Anterolateral Myocardial Infarction Due to Aluminum Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Bita Dadpour

    2013-08-01

    Full Text Available Aluminum phosphide (AlP is a highly effective rodenticide which is used as a suicide poison. Herein, a 24 year-old man who’d intentionally ingested about 1liter of alcohol and one tablet of AlP is reported. Acute myocardial infarction due to AlP poisoning has been occurred secondary to AIP poisoning. Cardiovascular complications are poor prognostic factors in AlP poisoning

  2. Dysprosium detector for neutron dosimetry in external beam radiotherapy

    Science.gov (United States)

    Ostinelli, A.; Berlusconi, C.; Conti, V.; Duchini, M.; Gelosa, S.; Guallini, F.; Vallazza, E.; Prest, M.

    2014-09-01

    Radiotherapy treatments with high-energy (>8 MeV) photon beams are a standard procedure in clinical practice, given the skin and near-target volumes sparing effect, the accurate penetration and the uniform spatial dose distribution. On the other hand, despite these advantages, neutrons may be produced via the photo-nuclear (γ,n) reactions of the high-energy photons with the high-Z materials in the accelerator head, in the treatment room and in the patient, resulting in an unwanted dose contribution which is of concern, given its potential to induce secondary cancers, and which has to be monitored. This work presents the design and the test of a portable Dysprosium dosimeter to be used during clinical treatments to estimate the "in vivo" dose to the patient. The dosimeter has been characterized and validated with tissue-equivalent phantom studies with a Varian Clinical iX 18 MV photon beam, before using it with a group of patients treated at the S. Anna Hospital in Como. The working principle of the dosimeter together with the readout chain and the results in terms of delivered dose are presented.

  3. Dysprosium detector for neutron dosimetry in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ostinelli, A.; Berlusconi, C.; Conti, V.; Duchini, M.; Gelosa, S. [Medical Physics - Sant' Anna Hospital, Como (Italy); Guallini, F. [EL.SE s.r.l. (Italy); Vallazza, E. [INFN, Trieste (Italy); Prest, M. [University of Insubria, Como (Italy)

    2014-09-21

    Radiotherapy treatments with high-energy (>8MeV) photon beams are a standard procedure in clinical practice, given the skin and near-target volumes sparing effect, the accurate penetration and the uniform spatial dose distribution. On the other hand, despite these advantages, neutrons may be produced via the photo-nuclear (γ,n) reactions of the high-energy photons with the high-Z materials in the accelerator head, in the treatment room and in the patient, resulting in an unwanted dose contribution which is of concern, given its potential to induce secondary cancers, and which has to be monitored. This work presents the design and the test of a portable Dysprosium dosimeter to be used during clinical treatments to estimate the “in vivo” dose to the patient. The dosimeter has been characterized and validated with tissue-equivalent phantom studies with a Varian Clinical iX 18 MV photon beam, before using it with a group of patients treated at the S. Anna Hospital in Como. The working principle of the dosimeter together with the readout chain and the results in terms of delivered dose are presented.

  4. Low Field Magnetic and Thermal Hysteresis in Antiferromagnetic Dysprosium

    Directory of Open Access Journals (Sweden)

    Iuliia Liubimova

    2017-06-01

    Full Text Available Magnetic and thermal hysteresis (difference in magnetic properties on cooling and heating have been studied in polycrystalline Dy (dysprosium between 80 and 250 K using measurements of the reversible Villari effect and alternating current (AC susceptibility. We argue that measurement of the reversible Villari effect in the antiferromagnetic phase is a more sensitive method to detect magnetic hysteresis than the registration of conventional B(H loops. We found that the Villari point, recently reported in the antiferromagnetic phase of Dy at 166 K, controls the essential features of magnetic hysteresis and AC susceptibility on heating from the ferromagnetic state: (i thermal hysteresis in AC susceptibility and in the reversible Villari effect disappears abruptly at the temperature of the Villari point; (ii the imaginary part of AC susceptibility is strongly frequency dependent, but only up to the temperature of the Villari point; (iii the imaginary part of the susceptibility drops sharply also at the Villari point. We attribute these effects observed at the Villari point to the disappearance of the residual ferromagnetic phase. The strong influence of the Villari point on several magnetic properties allows this temperature to be ranked almost as important as the Curie and Néel temperatures in Dy and likely also for other rare earth elements and their alloys.

  5. A Low-Symmetry Dysprosium Metallocene Single-Molecule Magnet with a High Anisotropy Barrier.

    Science.gov (United States)

    Pugh, Thomas; Chilton, Nicholas F; Layfield, Richard A

    2016-09-05

    The single-molecule magnet (SMM) properties of the isocarbonyl-ligated dysprosium metallocene [Cp*2 Dy{μ-(OC)2 FeCp}]2 (1Dy ), which contains a rhombus-shaped Dy2 Fe2 core, are described. Combining a strong axial [Cp*](-) ligand field with a weak equatorial field consisting of the isocarbonyl ligands leads to an anisotropy barrier of 662 cm(-1) in zero applied field. The dominant thermal relaxation pathways in 1Dy involves at least the fourth-excited Kramers doublet, thus demonstrating that prominent SMM behavior can be observed for dysprosium in low-symmetry environments.

  6. Surface reactions of molecular and atomic oxygen with carbon phosphide films.

    Science.gov (United States)

    Gorham, Justin; Torres, Jessica; Wolfe, Glenn; d'Agostino, Alfred; Fairbrother, D Howard

    2005-11-01

    The surface reactions of atomic and molecular oxygen with carbon phosphide films have been studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Carbon phosphide films were produced by ion implantation of trimethylphosphine into polyethylene. Atmospheric oxidation of carbon phosphide films was dominated by phosphorus oxidation and generated a carbon-containing phosphate surface film. This oxidized surface layer acted as an effective diffusion barrier, limiting the depth of phosphorus oxidation within the carbon phosphide film to phosphorus atoms as well as the degree of phosphorus oxidation. For more prolonged AO exposures, a highly oxidized phosphate surface layer formed that appeared to be inert toward further AO-mediated erosion. By utilizing phosphorus-containing hydrocarbon thin films, the phosphorus oxides produced during exposure to AO were found to desorb at temperatures >500 K under vacuum conditions. Results from this study suggest that carbon phosphide films can be used as AO-resistant surface coatings on polymers.

  7. Malonate complexes of dysprosium: synthesis, characterization and application for LI-MOCVD of dysprosium containing thin films.

    Science.gov (United States)

    Milanov, Andrian P; Seidel, Rüdiger W; Barreca, Davide; Gasparotto, Alberto; Winter, Manuela; Feydt, Jürgen; Irsen, Stephan; Becker, Hans-Werner; Devi, Anjana

    2011-01-07

    A series of malonate complexes of dysprosium were synthesized as potential metalorganic precursors for Dy containing oxide thin films using chemical vapor deposition (CVD) related techniques. The steric bulkiness of the dialkylmalonato ligand employed was systematically varied and its influence on the resulting structural and physico-chemical properties that is relevant for MOCVD was studied. Single crystal X-ray diffraction analysis revealed that the five homoleptic tris-malonato Dy complexes (1-5) are dimers with distorted square-face bicapped trigonal-prismatic geometry and a coordination number of eight. In an attempt to decrease the nuclearity and increase the solubility of the complexes in various solvents, the focus was to react these dimeric complexes with Lewis bases such as 2,2'-biypridyl and pyridine (6-9). This resulted in monomeric tris-malonato mono Lewis base adduct complexes with improved thermal properties. Finally considering the ease of synthesis, the monomeric nature and promising thermal characteristics, the silymalonate adduct complex [Dy(dsml)(3)bipy] (8) was selected as single source precursor for growing DySi(x)O(y) thin films by liquid injection metalorganic chemical vapor deposition (LI-MOCVD) process. The as-deposited films were analyzed for their morphology and composition by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, Rutherford backscattering (RBS) analysis and X-ray photoelectron spectroscopy.

  8. Exploration of dysprosium: the most critical element for Japan

    Science.gov (United States)

    Watanabe, Y.

    2012-04-01

    Dysprosium (Dy), one of the heavy rare earth elements, is used mainly as an additive for NdFeB permanent magnets which are installed in various modern industrial products such as voice coil motors in computers, factory automation machinery, hybrid and electric vehicles, home electronics, and wind turbine, to improve heat resistance of the magnets. Dy has been produced about 2,000t per year from the ores from ion adsorption type deposits in southern China. However, the produced amount of Dy was significantly reduced in 2011 in China due to reservation of heavy rare earth resources and protection of natural environment, resulting in soaring of Dy price in the world. In order to respond the increasing demand of Dy, unconventional supply sources are inevitably developed, in addition to heavy rare earth enriched ion adsorption type deposits outside China. Heavy rare earth elements including Dy are dominantly hosted in xenotime, fergusonite, zircon, eudialyte, keiviite, kainosite, iimoriite, etc. Concentration of xenotime is found in placer deposits in Malaysia and India, hydrothermal deposits associated with unconformity-type uranium mineralization (Athabasca basin in Canada, Western Australia), iron-oxide fluorite mineralization (South Africa) and Sn-bearing alkaline granite (Brazil). Zircon and fergusontie concentration is found as igneous and hydrothermal products in peralkaline syenite, alkaline granite and pegmatite (e.g., Nechalacho in Canada). Eudialyte concentration is found in some peralkaline syenite bodies in Greenland, Canada, Sweden and Russia. Among these sources, large Dy resources are estimated in the deposits hosted in peralkaline rocks (Nechalacho: 79,000t, Kvanefjeld: 49,000t, Norra Karr: 15,700t, etc.) compared to the present demand of Dy. Thus, Dy will be supplied from the deposits associated with peralkaline and alkaline deposits in future instead of ion adsorption type deposits in southern China.

  9. Long afterglow of trivalent dysprosium doped strontium aluminate

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuan Ming, E-mail: dongshanisland@126.com [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); Ma, Qing-lan [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); School of Electronics and Information, Nantong University, Jiangsu 226019 (China)

    2015-04-15

    Trivalent dysprosium doped strontium aluminate (SrA1{sub 2}O{sub 4}:Dy{sup 3+}) was synthesized via the sol–gel combustion method to realize green afterglow in the absence of Eu{sup 2+} luminescent centers. The morphology, crystal structure, photoluminescence and long afterglow of the SrAl{sub 2}O{sub 4}:Dy{sup 3+} were characterized with scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and photoluminescence spectroscopy, respectively. The bluish-green photoluminescence of SrAl{sub 2}O{sub 4}:Dy{sup 3+} consists of a broad emission band centered at about 520 nm and two characteristic emissions of Dy{sup 3+} ions centered at 480 and 575 nm, respectively. The green afterglow of SrAl{sub 2}O{sub 4}:Dy{sup 3+} is a broad emission band centered at around 520 nm, and the lifetime extracted from afterglow decay is found to be 53 s. The mechanism on the green afterglow from SrAl{sub 2}O{sub 4}:Dy{sup 3+} is discussed in terms of the possible defect levels in the host. - Highlights: • Broad band long-lasting afterglow is observed in SrAl{sub 2}O{sub 4}:Dy{sup 3+} phosphors. • Characteristic emissions of Dy{sup 3+} ions are superimposed on the broad PL of phosphors. • Dy{sup 3+} ions can also act as luminescent centers in addition to electron traps. • A mechanism on long afterglow of SrAl{sub 2}O{sub 4}:Dy{sup 3+} is proposed without Eu{sup 2+} activator.

  10. Low temperature spin reorientation in dysprosium iron garnet

    Energy Technology Data Exchange (ETDEWEB)

    Lahoubi, M; Younsi, W; Soltani, M L [Department of Physics, Badji-Mokhtar University, BP-12 Annaba, 23000 (Algeria); Voiron, J; Schmitt, D, E-mail: mlahoubi@gmail.co [Louis Neel Laboratory, CNRS-UJF, BP-166, 38042 Grenoble Cedex 9 (France)

    2009-03-01

    The spin reorientation (SR) phase transition in dysprosium iron garnet (Dy{sub 3}Fe{sub 5}O{sub 12} or DyIG) have been studied by specific heat C{sub p}(T) and high field magnetisation measurements M{sub T}(H) and M{sub H}(T) on single crystals at low temperature. A first order SR is observed with a sharp jump at T{sub SR} = 14.5+-0.5 K in the C{sub p}(T) curve which corresponds to a spontaneous change from the high temperature (HT) easy direction (111) to an (uuw) angular low temperature (LT) phases. Above T{sub SR}, the magnetic structure is described by the irreducible representation (IR) A{sub 2g} of the rhombohedral space group R 3 c. Below T{sub SR}, the magnetic structure changes in the monoclinic the space group C2/c with the IR A{sub g}. When the field H is kept aligned along the hard symmetry directions (100) and (110), we obtain respectively the variation of the angular positions theta(T) and theta'(T) from the total spontaneous magnetisation down to 1.5 K (theta = 39.23 deg. and theta' = 30.14 deg.) and the results are in good agreement with the previous observations in low fields. When the sample is allowed to rotate freely on itself, the critical field H{sub c}(T) between the HT(111) and the LT(uuw) angular phases permits us to precise the transition line up to 15 T and 40 K between the so called canted field induced (FI) and the associated collinear magnetic phases. The experimental magnetic phase diagram (MPD) is precisely determined in the (H{sub c}-T) plane and the domains of the existence and the stability of the two magnetic phases are specified.

  11. Anisotropic magnetic properties of dysprosium iron garnet (DyIG)

    Energy Technology Data Exchange (ETDEWEB)

    Lahoubi, M; Younsi, W; Soltani, M-L [Department of Physics, Badji-Mokhtar University, BP 12 - 23000 Annaba (Algeria); Ouladdiaf, B, E-mail: mlahoubi@gmail.co [Institut Laue Langevin, BP 156 - 38042 Grenoble Cedex 9 (France)

    2010-01-01

    The magnetic properties of dysprosium iron garnet (DyIG) have been studied by performing high resolution powder neutron diffraction experiments and high dc fields magnetizations on single crystals. Among all the reflections (hkl) indexed in the nuclear cubic space group (CSG) Ia 3-bar d with h+k+l=2n and k=[000], the superstructure lines (hkl)* forbidden by the symmetry (222)* and (622)* are not observed in the patterns at all temperatures. The pattern at 130 K is well interpreted within the magnetic modes F belonging to the irreducible representation (IR) T{sub 1g} of the CSG and identified to the room temperature ferrimagnetic Neel model. The high magnetic field behavior of the spontaneous collinear magnetic structure (MS) along the easy axis (EA) <111> is isotropic. Below 130 K, the patterns exhibit additional magnetic superstructure lines. They are associated to the appearance of the spontaneous non collinear MS which is described in the subgroup of the CSG, R 3-bar c within the IR A{sub 2g}. A strong magnetization anisotropy (MA) is observed at 1.5 K in the low symmetry phases were the spin reorientation transition (SR) occur at T{sub RS}=14.5 K. The onset of MA is detected below two characteristic temperatures, Ta{sub 1}=125 K and Ta{sub 2}=75 K respectively to the hard axis (HA) <100> and <110>. Symmetry arguments are used in the framework of the theory of representation analysis (RA) applied to the subgroup of R 3-bar c, C2/c within the IR A{sub g}. It seems that this MA results essentially from the difference between the spontaneous non collinear MS and the field induced (FI) configurations. All results are discussed with previous neutrons studies.

  12. Dysprosium-containing layered double hydroxides nanoparticles intercalated with biologically active species as an approach for theranostic systems

    KAUST Repository

    Arratia-Quijada, Jenny

    2015-10-23

    A layered double hydroxide structure including dysprosium cations was prepared by co-precipitation. The nanoparticles showed a linear relationship with the reciprocal relaxation spin-lattice (T1) time of water protons which is reflected as contrast in aqueous suspensions analyzed by magnetic resonance imaging. The interlayer space of dysprosium containing LDH was successfully intercalated with folate, ibuprofen and gallate ions, which are key molecules for recognition of some cancer cells and treatment of diseases. The paramagnetic property of the dysprosium-containing LDH detected in this work beside the ability to transport drugs open up the opportunity to design theranostic materials in a single crystal phase with nanometric dimensions.

  13. Synthesis, characterization and hydrotreating performance of supported tungsten phosphide catalysts

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Supported tungsten phosphide catalysts were prepared by temperature-programmed reduction of their precursors (supported phospho-tungstate catalysts) in H2 and characterized by X-ray diffraction (XRD),BET,temperature-programmed desorption of ammonia (NH3-TPD) and X-ray photoelectron spectroscopy (XPS).The reduction-phosphiding processes of the precursors were investigated by thermogravimetry and differential thermal analysis (TG-DTA) and the suitable phosphiding temperatures were defined.The hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities of the catalysts were tested by using thiophene,pyridine,dibenzothiophene,carbazole and diesel oil as the feed-stock.The TiO2,γ-Al2O3 supports and the Ni,Co promoters could remarkably increase and stabilize active W species on the catalyst surface.A suitable amount of Ni (3%-5%),Co (5%-7%) and V (1%-3%) could increase dispersivity of the W species and the BET surface area of the WP/γ-Al2O3 catalyst.The WP/γ-Al2O3 catalyst possesses much higher thiophene HDS and carbazole HDN activities and the WP/TiO2 catalyst has much higher dibenzothiophene (DBT) HDS and pyridine HDN activities.The Ni,Co and V can obviously promote the HDS activity and inhibit the HDN activity of the WP/γ-Al2O3 catalyst.The G-Ni5 catalyst possesses a much higher diesel oil HDS activity than the sulphided industrial NiW/γ-Al2O3 catalyst.In general,a support or promoter in the WP/γ-Al2O3 catalyst which can increase the amount and dispersivity of the active W species can promote its HDS and HDN activities.

  14. Effects of Dysprosium Oxide Doping on Microstructure and Properties of Barium Titanate Ceramic

    Institute of Scientific and Technical Information of China (English)

    Pu Yongping; Ren Huijun; Chen Wei; Chen Shoutian

    2005-01-01

    Different amounts of dysprosium oxide were incorporated into barium titanate powders synthesized by hydrothermal method. Relations of substitution behaviors and lattice parameters with solid-solubility were studied. Furthermore, the influences of dysprosium oxide doping fraction on grain size and dielectric properties of barium titanate ceramic, including dielectric constant and breakdown electric field strength, were investigated via scanning electron microscope, X-ray diffraction and electric property tester. The results show that dysprosium oxide can restrain abnormal grain growth during sintering and that fine-grained and high density of barium titanate ceramic can result in excellent dielectric properties. As mass fraction of dysprosium oxide is 0.6%, the lattice parameters of grain increase to the maximum because of the lowest vacancy concentration. The electric property parameters are cited as following: dielectric constant (25 ℃) reaches 4100, the change in relative dielectric constant with temperature is -10% to 10% within the range of -15~100 ℃, breakdown electric field strength (alternating current) achieves 3.2 kV·mm-1, which can be used in manufacturing high voltage ceramic capacitors.

  15. Sandwich-type tetrakis(phthalocyaninato) dysprosium-cadmium quadruple-decker SMM.

    Science.gov (United States)

    Wang, Hailong; Qian, Kang; Wang, Kang; Bian, Yongzhong; Jiang, Jianzhuang; Gao, Song

    2011-09-14

    Homoleptic tetrakis[2,3,9,10,16,17,23,24-octa(butyloxy)phthalocyaninato] dysprosium-cadmium quadruple-decker complex 1 was isolated in relatively good yield of 43% from a simple one-pot reaction. This compound represents the first sandwich-type tetrakis(phthalocyaninato) rare earth-cadmium quadruple-decker SMM that has been structurally characterized.

  16. In situ characterization of the nitridation of dysprosium during mechanochemical processing

    Energy Technology Data Exchange (ETDEWEB)

    Jaques, Brian J.; Osterberg, Daniel D.; Alanko, Gordon A.; Tamrakar, Sumit; Smith, Cole R.; Hurley, Michael F.; Butt, Darryl P., E-mail: DarrylButt@BoiseState.edu

    2015-01-15

    Highlights: • A nitridation reaction in a high energy planetary ball mill was monitored in situ. • Dysprosium mononitride was synthesized from Dy at low temperatures in short times. • Ideal gas law and in situ temperature and pressure used to assess reaction extent. • It is proposed that reaction rate is proportional to the creation of new surface. - Abstract: Processing of advanced nitride ceramics traditionally requires long durations at high temperatures and, in some cases, in hazardous atmospheres. In this study, dysprosium mononitride (DyN) was rapidly formed from elemental dysprosium in a closed system at ambient temperatures. An experimental procedure was developed to quantify the progress of the nitridation reaction during mechanochemical processing in a high energy planetary ball mill (HEBM) as a function of milling time and intensity using in situ temperature and pressure measurements, SEM, XRD, and particle size analysis. No intermediate phases were formed. It was found that the creation of fresh dysprosium surfaces dictates the rate of the nitridation reaction, which is a function of milling intensity and the number of milling media. These results show clearly that high purity nitrides can be synthesized with short processing times at low temperatures in a closed system requiring a relatively small processing footprint.

  17. Strategic Review of Arsenide, Phosphide and Nitride MOSFETs

    Directory of Open Access Journals (Sweden)

    Gourab Dutta

    2011-01-01

    Full Text Available Metal oxide semiconductor field effect transistor used as an amplifier and switch uses Si primarily as a channel material for its very stable oxide SiO2. In-spite of many advantages there are some restrictions for Si MOS, so the world is approaching towards compound semiconductor for higher frequency and current. The development of compound semiconductor metal oxide semiconductor is also facing critical problems due to the lack of availability of proper gate oxide material. Research is being conducted on arsenide and phosphide metal oxide semiconductor field effect transistor. Nitride channel MOS are in focus due to their high band gap, high current and high temperature uses.

  18. Novel synthetic routes to nanocomposites of transition metal phosphides

    Energy Technology Data Exchange (ETDEWEB)

    Milne, S.B.; Lukehart, C.M.; Wittig, J.E. [Vanderbilt Univ., Nashville, TN (United States)] [and others

    1996-10-01

    Novel routes to nanocomposites of transition metal phosphides will be presented. Silica xerogels containing covalently attached organometallic or other coordination compounds were prepared using standard sol-gel methods. The doped xerogels were thermally treated in a reducing atmosphere to yield the desired nanocomposite. Using these techniques, Fe{sub 2}P, RuP, Co{sub 2}P, Rh{sub 2}P, Ni{sub 2}P, Pd{sub 5}P{sub 2}, and PtP{sub 2} nanocomposites have been prepared and characterized.

  19. Optical and photocatalytic properties of indium phosphide nanoneedles and nanotubes

    DEFF Research Database (Denmark)

    Yu, Yanlong; Yu, Cuiyan; Xu, Tao

    2017-01-01

    , and Ultraviolet-visible (UV–vis) spectroscopy. The room temperature photoluminescence (PL) measurements showed that the InP nanoneedles and nanotubes possessed a pronounced blue shift in contrast to the bulk counterpart, which was ascribed to the crystalline defects effect. Moreover, the InP nanotubes exhibited......Large scale indium phosphide (InP) nanoneedles and nanotubes were synthesized through a facile solvothermal reaction. The morphology and microstructure of the samples were analyzed by employing scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy...

  20. Dysprosium complexes with the tetraphenylporphyrin macrocyclic ligand; Complejos de disprosio con el ligante macrociclico tetrafenilporfirina

    Energy Technology Data Exchange (ETDEWEB)

    Martinez M, V.; Padilla, J.; Ramirez, F.M

    1992-04-15

    In this report, the results obtained on the synthesis, characterization and study of the chemical behavior of dysprosium complex with the acetylacetone chelating agent (Hacac) and the tetraphenylporphyrin macrocyclic ligand (H{sub 2}TFP) are given. Based on the literature but according to our necessities and interest, the appropriate methodology settled down from the synthesis of prime matters until the obtaining and characterization of the products. The acetyl acetonate complex was obtained of mono hydrated dysprosium [Dy(acac){sub 3}. H{sub 2}0] and trihydrated [Dy(acac){sub 3} .3 H{sub 2}0], the mono tetra phenyl porphyrinate [Dy(TFP)(acac). 2 ac] the double sandwich of the dysprosium porphyrinate [Dy(TFP){sub 2}] and the triple sandwich of the dysprosium porphyrinate [Dy(TFP){sub 3}. 2 TCB] (TCB = trichlorobenzene). Its were characterized by their melting points, solubility, IR, UV, TGA and DTA both first and besides the techniques already mentioned for NMR'H, RPE and Magnetic susceptibility the three last complexes. From the spectroscopic point of view, IR and RPE its suggested the existence of a complex of inverse mixed valence [Dy(TFP){sup 2-} (TFP) {sup 1-}] for the Dy(TFP){sub 2} as a result of the existence of the free radical (TFP' {sup 1-} and that it was not in none of the other porphyrin compounds. In the NMR'H spectra of the compounds were not observed signals in the region from 0 to 10 ppm that which shows that the dysprosium complexes in special those of the porphyrin type are highly paramagnetic and its could be used as displacement reagents, creators of images and contrast agents of great utility in these days in studies of NMR, technique today by today used in medical diagnoses. (Author)

  1. Synthesis, structural characterization and in vitro testing of dysprosium containing silica particles as potential MRI contrast enhancing agents

    Science.gov (United States)

    Chiriac, L. B.; Trandafir, D. L.; Turcu, R. V. F.; Todea, M.; Simon, S.

    2016-11-01

    The work is focused on synthesis and structural characterization of novel dysprosium-doped silica particles which could be considered as MRI contrast agents. Sol-gel derived silica rich particles obtained via freeze-drying and spray-drying processing methods were structurally characterized by XRD, 29Si MAS-NMR and XPS methods. The occurrence of dysprosium on the outermost layer of dysprosium containing silica particles was investigated by XPS analysis. The MRI contrast agent characteristics have been tested using RARE-T1 and RARE-T2 protocols. The contrast of MRI images delivered by the investigated samples was correlated with their local structure. Dysprosium disposal on microparticles with surface structure characterised by decreased connectivity of the silicate network units favours dark T2-weighted MRI contrast properties.

  2. Dysprosium-containing layered double hydroxides nanoparticles intercalated with biologically active species as an approach for theranostic systems

    Energy Technology Data Exchange (ETDEWEB)

    Arratia-Quijada, Jenny [Departamento de Ciencias de la Salud, Centro Universitario Tonalá, Universidad de Guadalajara, Av. Nuevo Periférico No. 555, C.P. 48525, Tonalá, Jalisco (Mexico); Sánchez Jiménez, Cecilia [Departamento de Química, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Gurinov, Andrey [Research Resources Center for Magnetic Resonance, St. Petersburg State University, Universitetskiy pr. 26, 198504 St. Petersburg (Russian Federation); NMR Core Lab, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia); Pérez Centeno, Armando; Ceja Andrade, Israel [Departamento de Física, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Carbajal Arízaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.mx [Departamento de Química, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico)

    2016-01-15

    Graphical abstract: - Highlights: • LDH structure including dysprosium was prepared by co-precipitation. • LDH was capable to produce contrast in the T1 mode of MRI. • LDH were intercalated with folate, ibuprofen and gallate ions. - Abstract: A layered double hydroxide structure including dysprosium cations was prepared by co-precipitation. The nanoparticles showed a linear relationship with the reciprocal relaxation spin-lattice (T1) time of water protons which is reflected as contrast in aqueous suspensions analyzed by magnetic resonance imaging. The interlayer space of dysprosium containing LDH was successfully intercalated with folate, ibuprofen and gallate ions, which are key molecules for recognition of some cancer cells and treatment of diseases. The paramagnetic property of the dysprosium-containing LDH detected in this work beside the ability to transport drugs open up the opportunity to design theranostic materials in a single crystal phase with nanometric dimensions.

  3. Slow magnetic relaxation in a hydrogen-bonded 2D array of mononuclear dysprosium(III) oxamates.

    Science.gov (United States)

    Fortea-Pérez, Francisco R; Vallejo, Julia; Julve, Miguel; Lloret, Francesc; De Munno, Giovanni; Armentano, Donatella; Pardo, Emilio

    2013-05-01

    The reaction of N-(2,6-dimethylphenyl)oxamic acid with dysprosium(III) ions in a controlled basic media afforded the first example of a mononuclear lanthanide oxamate complex exhibiting a field-induced slow magnetic relaxation behavior typical of single-ion magnets (SIMs). The hydrogen-bond-mediated self-assembly of this new bifunctional dysprosium(III) SIM in the solid state provides a unique example of 2D hydrogen-bonded polymer with a herringbone net topology.

  4. [Case Report: Zinc phosphide poisoning after ingestion of a rodentizide in suicidal intention].

    Science.gov (United States)

    Simon, Christoph; Schneider, Ralf; Meininger, Dirk

    2016-01-01

    Zinc phosphide normally serves as a rodenticide but is occasionally ingested for suicide, potentially causing multiorgan failure. Phosphine gas is commonly in use for fumigation of grain silos and shipping containers.We describe a suicide attempt of a 54 year old female, the clinical symptoms, the treatment, the chemical and biochemical background and we give information on the potential occurrence of zinc phosphide and phosphine gas.

  5. Successful Treatment of Severe Metabolic Acidosis Due to Acute Aluminum Phosphide Poisoning With Peritoneal Dialysis: a Report of 2 Cases.

    Science.gov (United States)

    Bashardoust, Bahman; Farzaneh, Esmaeil; Habibzadeh, Afshin; Seyyed Sadeghi, Mir Salim

    2017-03-01

    Aluminum phosphide poisoning is common in our region. It can cause severe metabolic acidosis and persistent hypotension, which lead to cardiogenic shock and subsequently mortality. Oliguric or anuric acute kidney injury is seen in almost all patients with aluminum phosphide poisoning. Renal replacement therapies are recommended in these patients to improve metabolic acidosis and increase the rate of survival. We report 2 cases of severe acute aluminum phosphide poisoning treated successfully with peritoneal dialysis.

  6. Clinical characteristics of zinc phosphide poisoning in Thailand

    Science.gov (United States)

    Trakulsrichai, Satariya; Kosanyawat, Natcha; Atiksawedparit, Pongsakorn; Sriapha, Charuwan; Tongpoo, Achara; Udomsubpayakul, Umaporn; Rittilert, Panee; Wananukul, Winai

    2017-01-01

    Objective The objectives of this study were to describe the clinical characteristics and outcomes of poisoning by zinc phosphide, a common rodenticide in Thailand, and to evaluate whether these outcomes can be prognosticated by the clinical presentation. Materials and methods A 3-year retrospective cohort study was performed using data from the Ramathibodi Poison Center Toxic Exposure Surveillance System. Results In total, 455 poisonings were identified. Most were males (60.5%) and from the central region of Thailand (71.0%). The mean age was 39.91±19.15 years. The most common route of exposure was oral (99.3%). Most patients showed normal vital signs, oxygen saturation, and consciousness at the first presentation. The three most common clinical presentations were gastrointestinal (GI; 68.8%), cardiovascular (22.0%), and respiratory (13.8%) signs and symptoms. Most patients had normal blood chemistry laboratory results and chest X-ray findings at presentation. The median hospital stay was 2 days, and the mortality rate was 7%. Approximately 70% of patients underwent GI decontamination, including gastric lavage and a single dose of activated charcoal. In all, 31 patients were intubated and required ventilator support. Inotropic drugs were given to 4.2% of patients. Four moribund patients also received hyperinsulinemia–euglycemia therapy and intravenous hydrocortisone; however, all died. Patients who survived and died showed significant differences in age, duration from taking zinc phosphide to hospital presentation, abnormal vital signs at presentation (tachycardia, low blood pressure, and tachypnea), acidosis, hypernatremia, hyperkalemia, in-hospital acute kidney injury, in-hospital hypoglycemia, endotracheal tube intubation, and inotropic requirement during hospitalization (P<0.05). Conclusion Zinc phosphide poisoning causes fatalities. Most patients have mild symptoms, and GI symptoms are the most common. Patients who present with abnormal vital signs or

  7. Detection of Aluminium Phosphide and Zinc Phosphide by X-Ray Diffraction%X射线衍射法检测磷化铝磷化锌

    Institute of Scientific and Technical Information of China (English)

    马健; 王力春; 郭东东; 罗敬锋; 张忠

    2011-01-01

    Aluminium phosphide and zinc phosphide are detected by X-ray diffractometer and the powder of aluminium phoshphide and zinc phosphide is analyzed.Compared with traditional methods,the x-ray diffraction method has many advantages such as simplicity,high precision and reliability and is one of several nondestructive analysis techniques.%用X射线衍射仪检测磷化铝和磷化锌,并对磷化铝和磷化锌粉末进行分析,发现较之传统检测方法,其结果更可靠,操作更简便,且能得到样品的某些晶体参数,是仅有的几个无损分析技术之一。

  8. Dysprosium-Catalyzed Growth of Single-Walled Carbon Nanotube Arrays on Substrates

    Directory of Open Access Journals (Sweden)

    Qian Yong

    2009-01-01

    Full Text Available Abstract In this letter, we report that dysprosium is an effective catalyst for single-walled carbon nanotubes (SWNTs growth via a chemical vapor deposition (CVD process for the first time. Horizontally superlong well-oriented SWNT arrays on SiO2/Si wafer can be fabricated by EtOH-CVD under suitable conditions. The structure and properties are characterized by scanning electron microscopy, transition electron microscopy, Raman spectroscopy and atomic force microscopy. The results show that the SWNTs from dysprosium have better structural uniformity and better conductivity with fewer defects. This rare earth metal provides not only an alternative catalyst for SWNTs growth, but also a possible method to generate high percentage of superlong semiconducting SWNT arrays for various applications of nanoelectronic device.

  9. Direct Search for keV Sterile Neutrino Dark Matter with a Stable Dysprosium Target

    CERN Document Server

    Lasserre, T; Cribier, M; Merle, A; Mertens, S; Vivier, M

    2016-01-01

    We investigate a new method to search for keV-scale sterile neutrinos that could account for Dark Matter. Neutrinos trapped in our galaxy could be captured on stable $^{163}$Dy if their mass is greater than 2.83~keV. Two experimental realizations are studied, an integral counting of $^{163}$Ho atoms in dysprosium-rich ores and a real-time measurement of the emerging electron spectrum in a dysprosium-based detector. The capture rates are compared to the solar neutrino and radioactive backgrounds. An integral counting experiment using several kilograms of $^{163}$Dy could reach a sensitivity for the sterile-to-active mixing angle $\\sin^2\\theta_{e4}$ of $10^{-5}$ significantly exceeding current laboratory limits. Mixing angles as low as $\\sin^2\\theta_{e4} \\sim 10^{-7}$ / $\\rm m_{^{163}\\rm Dy}\\rm{(ton)}$ could possibly be explored with a real-time experiment.

  10. Fabrication and properties of gallium phosphide variable colour displays

    Science.gov (United States)

    Effer, D.; Macdonald, R. A.; Macgregor, G. M.; Webb, W. A.; Kennedy, D. I.

    1973-01-01

    The unique properties of single-junction gallium phosphide devices incorporating both red and green radiative recombination centers were investigated in application to the fabrication of monolithic 5 x 7 displays capable of displaying symbolic and alphanumeric information in a multicolor format. A number of potentially suitable material preparation techniques were evaluated in terms of both material properties and device performance. Optimum results were obtained for double liquid-phase-epitaxial process in which an open-tube dipping technique was used for n-layer growth and a sealed tipping procedure for subsequent p-layer growth. It was demonstrated that to prepare devices exhibiting a satisfactory range of dominant wavelengths which can be perceived as distinct emission colors extending from the red through green region of the visible spectrum involves a compromise between the material properties necessary for efficient red emission and those considered optimum for efficient green emission.

  11. Zinc phosphide intoxication of wild turkeys (Meleagris gallopavo).

    Science.gov (United States)

    Poppenga, Robert H; Ziegler, Andre F; Habecker, Perry L; Singletary, Don L; Walter, Mark K; Miller, Paul G

    2005-01-01

    Zinc phosphide (Zn3P2) is a rodenticide used to control a variety of small mammal species. It is available over-the-counter or as a restricted-use pesticide depending on how it is to be applied. The toxicity of Zn3P2 is dependent on the species exposed, whether the animal is able to vomit or not, and whether it is ingested on a full or empty stomach. Nontarget species can be exposed through inadvertent or intentional product misapplication. In this article we describe four mortality events in which wild turkeys (Meleagris gallopavo) were believed to have been intoxicated following the ingestion of baits containing Zn3P2.

  12. Computational prediction of the diversity of monolayer boron phosphide allotropes

    Science.gov (United States)

    Zhu, Zhili; Cai, Xiaolin; Niu, Chunyao; Wang, Chongze; Jia, Yu

    2016-10-01

    We propose previously unrecognized allotropes of monolayer boron phosphorus (BP) based on ab initio density functional calculations. In addition to the hexagonal structure of h-BP, four types of boron phosphide compounds were predicted to be stable as monolayers. They can form sp2 hybridized planar structures composed of 6-membered rings, and buckled geometries including 4-8 or 3-9 membered rings with sp3 like bonding for P atoms. The calculated Bader charges illustrate their ionic characters with the charge transfers from B to P atoms. The competing between the electrostatic energy and the bonding energy of sp2 and sp3 hybridizations reflected in P atoms results in multiple structures of BP. These 2D BP structures can be semiconducting or metallic depending on their geometric structures. Our findings significantly broaden the diversity of monolayer BP allotropes and provide valuable guidance to other 2D group-III-V allotropes.

  13. Band structures in silicene on monolayer gallium phosphide substrate

    Science.gov (United States)

    Ren, Miaojuan; Li, Mingming; Zhang, Changwen; Yuan, Min; Li, Ping; Li, Feng; Ji, Weixiao; Chen, Xinlian

    2016-07-01

    Opening a sizable band gap in the zero-gap silicene is a key issue for its application in nanoelectronics. We design new 2D silicene and GaP heterobilayer (Si/GaP HBL) composed of silicene and monolayer (ML) GaP. Based on first-principles calculations, we find that the interaction energies are in the range of -295.5 to -297.5 meV per unit cell, indicating a weak interaction between silicene and gallium phosphide (GaP) monolayer. The band gap changes ranging from 0.06 to 0.44 eV in hybrid HBLs. An unexpected indirect-direct band gap crossover is also observed in HBLs, dependent on the stacking pattern. These provide a possible way to design effective FETs out of silicene on GaP monolayer.

  14. AC surface photovoltage of indium phosphide nanowire networks

    Energy Technology Data Exchange (ETDEWEB)

    Lohn, Andrew J.; Kobayashi, Nobuhiko P. [California Univ., Santa Cruz, CA (United States). Baskin School of Engineering; California Univ., Santa Cruz, CA (US). Nanostructured Energy Conversion Technology and Research (NECTAR); NASA Ames Research Center, Moffett Field, CA (United States). Advanced Studies Laboratories

    2012-06-15

    Surface photovoltage is used to study the dynamics of photogenerated carriers which are transported through a highly interconnected three-dimensional network of indium phosphide nanowires. Through the nanowire network charge transport is possible over distances far in excess of the nanowire lengths. Surface photovoltage was measured within a region 10.5-14.5 mm from the focus of the illumination, which was chopped at a range of frequencies from 15 Hz to 30 kHz. Carrier dynamics were modeled by approximating the nanowire network as a thin film, then fitted to experiment suggesting diffusion of electrons and holes at approximately 75% of the bulk value in InP but with significantly reduced built-in fields, presumably due to screening by nanowire surfaces. (orig.)

  15. Optical properties of indium phosphide nanowire ensembles at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Lohn, Andrew J; Onishi, Takehiro; Kobayashi, Nobuhiko P [Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, University of California Santa Cruz-NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2010-09-03

    Ensembles that contain two types (zincblende and wurtzite) of indium phosphide nanowires grown on non-single crystalline surfaces were studied by micro-photoluminescence and micro-Raman spectroscopy at various low temperatures. The obtained spectra are discussed with the emphasis on the effects of differing lattice types, geometries, and crystallographic orientations present within an ensemble of nanowires grown on non-single crystalline surfaces. In the photoluminescence spectra, a typical Varshni dependence of band gap energy on temperature was observed for emissions from zincblende nanowires and in the high temperature regime energy transfer from excitonic transitions and band-edge transitions was identified. In contrast, the photoluminescence emissions associated with wurtzite nanowires were rather insensitive to temperature. Raman spectra were collected simultaneously from zincblende and wurtzite nanowires coexisting in an ensemble. Raman peaks of the wurtzite nanowires are interpreted as those related to the zincblende nanowires by a folding of the phonon dispersion.

  16. Preparation of Dysprosium Ferrite/Polyacrylamide Magnetic Composite Microsphere and Its Characterization

    Institute of Scientific and Technical Information of China (English)

    Hidehiro Kumazawa; Wang Zhifeng; Zhou Lanxiang; Zhang Hong; Li Yourong; Zhang Ming

    2005-01-01

    Using the technique of microemulsion polymerization with nano-reactor, dysprosium ferrite/polyacrylamide magnetic composite microsphere was prepared by one-step method in a single inverse microemulsion. The structure, average particle size, morphology of composite microsphere were characterized by FTIR, XRD, TEM and TGA. The magnetic responsibility of composite microsphere was also investigated. The results indicate that the magnetic composite microsphere possess high magnetic responsibility and suspension stability.

  17. {Delta}I = 2 energy staggering in normal deformed dysprosium nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M.A.; Brown, T.B.; Archer, D.E. [Florida State Univ., Tallahassee, FL (United States)] [and others

    1996-12-31

    Very high spin states (I{ge}50{Dirac_h}) have been observed in {sup 155,156,157}Dy. The long regular band sequences, free from sharp backbending effects, observed in these dysprosium nuclei offer the possibility of investigating the occurence of any {Delta}I = 2 staggering in normal deformed nuclei. Employing the same analysis techniques as used in superdeformed nuclei, certain bands do indeed demonstrate an apparent staggering and this is discussed.

  18. Poly[[[μ3-N′-(carboxymethylethylenediamine-N,N,N′-triacetato]dysprosium(III] trihydrate

    Directory of Open Access Journals (Sweden)

    Xiaomei Zhuang

    2010-11-01

    Full Text Available In the title coordination polymer, {[Dy(C10H13N2O8]·3H2O}n, the dysprosium(III ion is coordinated by two N atoms and six O atoms from three different (carboxymethylethylenediaminetriacetate ligands in a distorted square-antiprismatic geometry. The ligands connect the metal atoms, forming layers parallel to the ab plane. O—H...O hydrogen bonds further assemble adjacent layers into a three-dimensional supramolecular network.

  19. Making two dysprosium atoms rotate - Einstein-de Haas effect revisited

    OpenAIRE

    Górecki, Wojciech; Rzążewski, Kazimierz

    2016-01-01

    We present a numerical study of the behaviour of two magnetic dipolar atoms trapped in a harmonic potential and exhibiting the standard Einstein-de Haas effect while subject to a time dependent homogeneous magnetic field. Using a simplified description of the short range interaction and the full expression for the dipole-dipole forces we show, that under experimentally realisable conditions two dysprosium atoms may be pumped to a high ($l>20$) value of the relative orbital angular momentum.

  20. Deoxygenation of Palmitic Acid on Unsupported Transition-Metal Phosphides

    Energy Technology Data Exchange (ETDEWEB)

    Peroni, Marco [Technische Universität München, Department; Lee, Insu [Technische Universität München, Department; Huang, Xiaoyang [Technische Universität München, Department; Baráth, Eszter [Technische Universität München, Department; Gutiérrez, Oliver Y. [Technische Universität München, Department; Lercher, Johannes A. [Technische Universität München, Department; Institute

    2017-08-18

    Abstract Highly active bulk transition metal phosphides (WP, MoP, and Ni2P) were synthesized for the catalytic hydrodeoxygenation of palmitic acid, hexadecanol, hexadecanal, and microalgae oil. The specific activities positively correlated with the concentration of exposed metal sites, although the relative rates changed with temperature due to activation energies varying from 57 kJ·mol-1 for MoP to 142 kJ·mol-1 for WP. The reduction of the fatty acid to the aldehyde occurs through a Langmuir-Hinshelwood mechanism, where the rate-determining step is the addition of the second H to the hydrocarbon. On WP, the conversion of palmitic acid proceeds via R-CH2COOH R-CH2CHO R-CH2CH2OH R-CHCH2 R-CH2CH3 (hydrodeoxygenation). Decarbonylation of the intermittently formed aldehyde (R-CH2COOH R-CH2CHO R-CH3) was an important pathway on MoP and Ni2P. Conversion via dehydration to a ketene, followed by its decarbonylation occurred only on Ni2P. The rates of alcohol dehydration (R-CH2CH2OH R-CHCH2) correlate with the concentration of Lewis acid sites of the phosphides. Acknowledgements The authors would like to thank Roel Prins for the critical discussion of the results. We are also grateful to Xaver Hecht for technical support. Funding by the German Federal Ministry of Food and Agriculture in the framework of the Advanced Biomass Value project (03SF0446A) is gratefully acknowledged. J.A.L. acknowledges support for his contribution by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences for exploring non-oxidic supports for deoxygenation reactions.

  1. Phosphor Dysprosium-Doped Layered Double Hydroxides Exchanged with Different Organic Functional Groups

    Directory of Open Access Journals (Sweden)

    David Ricardo Martínez Vargas

    2013-01-01

    Full Text Available The layers of a Zn/Al layered double hydroxide (LDH were doped with Dy3+ cations. Among some compositions, the Zn2+ : Al3+ : Dy3+ molar ratio equal to 30 : 9 : 1 presented a single crystalline phase. Organic anions with carboxylic, amino, sulfate, or phosphate functional groups were intercalated as single layers between LDH layers as confirmed by X-ray diffraction and infrared spectroscopy. Photoluminescence spectra of the nitrate intercalated LDH showed a wide emission band with strong intensity in the yellow region (around 574 nm, originated due to symmetry distortion of the octahedral coordination in dysprosium centers. Moreover, a broad red band emission was also detected apparently due to the presence of zinc oxide. The distorted symmetry of the dysprosium coordination environment, also confirmed by X-ray photoelectron spectroscopy analysis, was modified after the intercalation with phenyl phosphonate (PP, aspartate (Asp, adipate (Adip, and serinate (Ser anions; the emission as measured from PL spectra of these LDH was more intense in the blue region (ca. 486 nm, thus indicating an increase in symmetry of dysprosium octahedrons. The red emission band from zinc oxide kept the same intensity after intercalation of dodecyl sulfate (DDS. An additional emission of unknown origin at λ = 767 nm was present in all LDHs.

  2. Systematic study on surface and magnetostructural changes in Mn-substituted dysprosium ferrite by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Rekha, G. [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Tholkappiyan, R. [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Department of Physics, College of Science, UAE University, Al-Ain 15551 (United Arab Emirates); Vishista, K., E-mail: raovishista@gmail.com [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Hamed, Fathalla [Department of Physics, College of Science, UAE University, Al-Ain 15551 (United Arab Emirates)

    2016-11-01

    Highlights: • Garnet type Dy{sub 3}Fe{sub 5-x}Mn{sub x}O{sub 12} (x = 0–0.06) nanoparticles of 88.4–86.8 nm were synthesized by hydrothermal method. • The Dy, Mn, Fe and O elements in the ferrites were confirmed from XPS. • The multiple oxidation states of Fe and Mn ions, bonding energy and cationic distributions of the samples were examined by XPS. • The magnetic property shows ferromagnetic behavior from VSM technique. • The results from these studies are correlated with respect to Mn dopant. - Abstract: Dysprosium iron garnets are of scientific importance because of the wide range of magnetic properties that can be obtained in substituting dysprosium by a rare earth metal. In the present work, the effect of Mn substitution on magnetostructural changes in dysprosium ferrite nanoparticles is studied. Highly crystalline pure and Mn doped dysprosium ferrite nanoparticles were synthesized by hydrothermal method. The samples were calcined at 1100 °C for 2 h in air atmosphere which is followed by characterization using XRD, FT-IR analysis, SEM, XPS and VSM. The average crystallite size of synthesized samples were calculated by X-ray diffraction falls in the range of 88.4–86.8 nm and was found to be in cubic garnet structure. For further investigation of the structure and corresponding changes in the tetrahedral and octahedral stretching vibrational bonds, FT-IR was used. The synthesized samples consist of multiple oxidation (Fe{sup 3+} and Fe{sup 2+}) states for Fe ions and (Mn{sup 3+} and Mn{sup 2+}) Mn ions analyzed in three ways of Fe 2p and Mn 2p spectra from the XPS analysis. With respect to Mn dopant in Dy{sub 3}Fe{sub 5}O{sub 12}, the cationic distributions of elements were discussed from high resolution XPS spectra by peak position and shift, area, width. To find out the porous/void surface morphology of the sample, scanning electron microscopy was used. From XPS analysis, the presence of elements (Dy, Mn, Fe and O) and their composition in the

  3. Synthesis, structural characterization and in vitro testing of dysprosium containing silica particles as potential MRI contrast enhancing agents

    Energy Technology Data Exchange (ETDEWEB)

    Chiriac, L.B.; Trandafir, D.L. [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Turcu, R.V.F. [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Todea, M. [Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Simon, S., E-mail: simons@phys.ubbcluj.ro [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania)

    2016-11-01

    Highlights: • Dysprosium containing silica microparticles obtained by freeze and spray drying. • Higher structural units interconnection achieved in freeze vs. spray dried samples. • Dy occurance on the outermost layer of the microparticles evidenced by XPS. • Enhanced MRI contrast observed for freeze dried samples with 5% mol Dy{sub 2}O{sub 3}. - Abstract: The work is focused on synthesis and structural characterization of novel dysprosium-doped silica particles which could be considered as MRI contrast agents. Sol-gel derived silica rich particles obtained via freeze-drying and spray-drying processing methods were structurally characterized by XRD, {sup 29}Si MAS-NMR and XPS methods. The occurrence of dysprosium on the outermost layer of dysprosium containing silica particles was investigated by XPS analysis. The MRI contrast agent characteristics have been tested using RARE-T{sub 1} and RARE-T{sub 2} protocols. The contrast of MRI images delivered by the investigated samples was correlated with their local structure. Dysprosium disposal on microparticles with surface structure characterised by decreased connectivity of the silicate network units favours dark T{sub 2}-weighted MRI contrast properties.

  4. Novel, high-activity hydroprocessing catalysts: Iron group phosphides

    Science.gov (United States)

    Wang, Xianqin

    A series of iron, cobalt and nickel transition metal phosphides was synthesized by means of temperature-programmed reduction (TPR) of the corresponding phosphates. The same materials, Fe2P, CoP and NO, were also prepared on a silica (SiO2) support. The phase purity of these catalysts was established by x-ray diffraction (XRD), and the surface properties were determined by N2 BET specific surface area (Sg) measurements and CO chemisorption. The activities of the silica-supported catalysts were tested in a three-phase trickle bed reactor for the simultaneous hydrodenitrogenation (HDN) of quinoline and hydrodesulfurization (HDS) of dibenzothiophene using a model liquid feed at realistic conditions (30 atm, 370°C). The reactivity studies showed that the nickel phosphide (Ni2P/SiO2) was the most active of the catalysts. Compared with a commercial Ni-Mo-S/gamma-Al 2O3 catalyst at the same conditions, Ni2P/silica had a substantially higher HDS activity (100% vs. 76%) and HDN activity (82% vs. 38%). Because of their good hydrotreating activity, an extensive study of the preparation of silica supported nickel phosphides, Ni2P/SiO 2, was carried out. The parameters investigated were the phosphorus content and the weight loading of the active phase. The most active composition was found to have a starting synthesis Ni/P ratio close to 1/2, and the best loading of this sample on silica was observed to be 18 wt.%. Extended x-ray absorption fine structure (EXAFS) and x-ray absorption near edge spectroscopy (XANES) measurements were employed to determine the structures of the supported samples. The main phase before and after reaction was found to be Ni2P, but some sulfur was found to be retained after reaction. A comprehensive scrutiny of the HDN reaction mechanism was also made over the Ni2P/SiO2 sample (Ni/P = 1/2) by comparing the HDN activity of a series of piperidine derivatives of different structure. It was found that piperidine adsorption involved an alpha-H activation

  5. Synthesis and catalytic activity of the metastable phase of gold phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, Deshani; Nigro, Toni A. E.; Dyer, I. D.; Alia, Shaun M.; Pivovar, Bryan S.; Vasquez, Yolanda

    2016-10-01

    Recently, transition metal phosphides have found new applications as catalysts for the hydrogen evolution reaction that has generated an impetus to synthesize these materials at the nanoscale. In this work, Au2P3 was synthesized utilizing the high temperature decomposition of tri-n-octylphosphine as a source of elemental phosphorous. Gold nanorods were used as morphological templates with the aim of controlling the shape and size of the resulting gold phosphide particles. We demonstrate that the surface capping ligand of the gold nanoparticle precursors can influence the purity and extent to which the gold phosphide phase will form. Gold nanorods functionalized with 1-dodecanethiol undergo digestive ripening to produce discrete spherical particles that exhibit reduced reactivity towards phosphorous, resulting in low yields of the gold phosphide. In contrast, gold phosphide was obtained as a phase pure product when cetyltrimethylammonium bromide functionalized gold nanorods are used instead. The Au2P3 nanoparticles exhibited higher activity than polycrystalline gold towards the hydrogen evolution reaction.

  6. Method of synthesizing bulk transition metal carbide, nitride and phosphide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Soon; Armstrong, Beth L; Schwartz, Viviane

    2015-04-21

    A method for synthesizing catalyst beads of bulk transmission metal carbides, nitrides and phosphides is provided. The method includes providing an aqueous suspension of transition metal oxide particles in a gel forming base, dropping the suspension into an aqueous solution to form a gel bead matrix, heating the bead to remove the binder, and carburizing, nitriding or phosphiding the bead to form a transition metal carbide, nitride, or phosphide catalyst bead. The method can be tuned for control of porosity, mechanical strength, and dopant content of the beads. The produced catalyst beads are catalytically active, mechanically robust, and suitable for packed-bed reactor applications. The produced catalyst beads are suitable for biomass conversion, petrochemistry, petroleum refining, electrocatalysis, and other applications.

  7. Optical Properties of Strained Wurtzite Gallium Phosphide Nanowires

    KAUST Repository

    Greil, J.

    2016-06-08

    Wurtzite gallium phosphide (WZ GaP) has been predicted to exhibit a direct bandgap in the green spectral range. Optical transitions, however, are only weakly allowed by the symmetry of the bands. While efficient luminescence has been experimentally shown, the nature of the transitions is not yet clear. Here we apply tensile strain up to 6% and investigate the evolution of the photoluminescence (PL) spectrum of WZ GaP nanowires (NWs). The pressure and polarization dependence of the emission together with a theoretical analysis of strain effects is employed to establish the nature and symmetry of the transitions. We identify the emission lines to be related to localized states with significant admixture of Γ7c symmetry and not exclusively related to the Γ8c conduction band minimum (CBM). The results emphasize the importance of strongly bound state-related emission in the pseudodirect semiconductor WZ GaP and contribute significantly to the understanding of the optoelectronic properties of this novel material.

  8. First-principles study of the structural and electronic properties of III-phosphides

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Rashid [Centre for High Energy Physics, University of the Punjab, Lahore 54590 (Pakistan)], E-mail: rasofi@hotmail.com; Fazal-e-Aleem [Centre for High Energy Physics, University of the Punjab, Lahore 54590 (Pakistan); Hashemifar, S. Javad; Akbarzadeh, Hadi [Department of Physics, Isfahan University of Technology, Isfahan 84156 (Iran, Islamic Republic of)

    2008-05-01

    We use density functional theory and different forms of the exchange-correlation approximation to calculate the structural and electronic properties of tetrahedrally coordinated III-phosphide semiconductors. The computed results for structural properties using generalized gradient approximation (GGA) agree well with the experimental data. For reliable description of energy band gap values, another form of GGA developed by Engel and Vosko has been applied. As anticipated, boron phosphide was found to be the hardest compound due to the strong B-P covalent bonding.

  9. Severe myocardial depression in a patient with aluminium phosphide poisoning: A clinical, electrocardiographical and histopathological correlation

    Directory of Open Access Journals (Sweden)

    Shah Viral

    2009-01-01

    Full Text Available Aluminium phosphide poisoning is very common in India. It is one of the most fatal poisons. The clinical spectrum of poisoning varies depending upon the dosage and duration of consumption. The main effect of the poison is due to the release of phosphine which inhibits cytochrome oxidase and thereby hampers cellular oxygen utilization. Almost any organ can be affected by aluminium phosphide poisoning. We report a case where the heart was the predominantly affected organ. We describe the clinical symptoms and signs and their correlation with electrocardiographic and histopathological examinations.

  10. Influence of exchange splitting on optical properties in gadolinium and dysprosium single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, Yu.V.; Bolotin, G.A. (AN SSSR, Sverdlovsk. Inst. Fiziki Metallov)

    1984-12-01

    The temperature dependences of optical conductivity in gadolinium and dysprosium single crystals at the light wave vector polarization along a hexagonal axis and in the basis plane are considered. A substantial anisotropy of interzonal absorption has been found. The sample transition into magnetically ordered state is shown to be accompanied by the emergence of resonance absorption peaks in the near infrared spectral region. The manifestation of these peculiarities is associated with quantum electron transitions between the s-, d-f- interaction-split energy bands near the Fermi level. Main peculiarities of the experimental spectrum of gadolinium optical conductivity found their reflection in theoretically calculated dispersion dependence.

  11. Therapeutic application of dysprosium-165-FHMA in the treatment of rheumatoid knee effusions

    Energy Technology Data Exchange (ETDEWEB)

    English, R.J.; Zalutsky, M.; Venkatesan, P.; Sledge, C.B.

    1986-03-01

    Radiation synovectomy utilizing a variety of radionuclides has proven to be an effective technique in the treatment of rheumatoid arthritis. The recent introduction of the short-lived radionuclide, Dysprosium-165 (/sup 165/Dy), as a replacement for the longer-lived radiocolloids has reduced nontarget dosimetry caused by leakage of the agent from the articular cavity. A review of the methods and status of radiation synovectomy, and the application of /sup 165/Dy-ferric hydroxide macroaggregates (FHMA) as an alternative therapeutic agent is described.

  12. Properties of dysprosium-doped gallium lanthanum sulfide fiber amplifiers operating at 1.3 microm.

    Science.gov (United States)

    Samson, B N; Schweizer, T; Hewak, D W; Laming, R I

    1997-05-15

    In light of recent progress in the fabrication of gallium lanthanum sulfide (GaLaS) fibers, we have modeled the performance of dysprosium-doped GaLaS fiber amplifiers operating at 1.3 microm . Based on experimental data, we find that the incorporation of a codopant (terbium) in the fiber core significantly shortens the optimum amplifier length from >30 m to approximately 3 m . Such a device may be practical, given the fiber losses currently achieved in GaLaS fibers.

  13. Boron Arsenide and Boron Phosphide for High Temperature and Luminescent Devices. [semiconductor devices - crystal growth/crystal structure

    Science.gov (United States)

    Chu, T. L.

    1975-01-01

    The crystal growth of boron arsenide and boron phosphide in the form of bulk crystals and epitaxial layers on suitable substrates is discussed. The physical, chemical, and electrical properties of the crystals and epitaxial layers are examined. Bulk crystals of boron arsenide were prepared by the chemical transport technique, and their carrier concentration and Hall mobility were measured. The growth of boron arsenide crystals from high temperature solutions was attempted without success. Bulk crystals of boron phosphide were also prepared by chemical transport and solution growth techniques. Techniques required for the fabrication of boron phosphide devices such as junction shaping, diffusion, and contact formation were investigated. Alloying techniques were developed for the formation of low-resistance ohmic contacts to boron phosphide. Four types of boron phosphide devices were fabricated: (1) metal-insulator-boron phosphide structures, (2) Schottky barriers; (3) boron phosphide-silicon carbide heterojunctions; and (4) p-n homojunctions. Easily visible red electroluminescence was observed from both epitaxial and solution grown p-n junctions.

  14. Effect of dysprosium on the kinetics and structural transformations during the decomposition of the supersaturated solid solution in magnesium-samarium alloys

    Science.gov (United States)

    Rokhlin, L. L.; Luk'yanova, E. A.; Tabachkova, N. Yu.; Dobatkina, T. V.; Tarytina, I. E.; Korol'kova, I. G.

    2017-03-01

    The effect of dysprosium added in the amounts such that it does not form an individual phase in equilibrium with solid magnesium on the decomposition of the supersaturated magnesium solid solution in Mg-Sm alloys is studied. The presence of dysprosium in Mg-Sm alloys is found to retard the decomposition of the supersaturated magnesium solid solution and to increase the hardening effect upon aging. When these alloys are aged, dysprosium is partly retained in the magnesium solid solution and partly enters into the compositions of the phases that form during the decomposition of the solid solution and are characteristic of Mg-Sm alloys.

  15. Cyclic single-molecule magnets: from the odd-numbered heptanuclear to a dimer of heptanuclear dysprosium clusters.

    Science.gov (United States)

    Tian, Haiquan; Bao, Song-Song; Zheng, Li-Min

    2016-02-01

    A heptanuclear and a dimer of heptanuclear dysprosium clusters (Dy7 and Dy14) have been successfully synthesized by ingenious coalescence of the single and double pyrazinyl hydrazone as well as phosphonate ligands. The complexes feature the largest odd-numbered cyclic lanthanide clusters reported thus far. Both exhibit single molecule magnet behaviors at low temperature.

  16. A comparison of the effects of symmetry and magnetoanisotropy on paramagnetic relaxation in related dysprosium single ion magnets.

    Science.gov (United States)

    Williams, Ursula J; Mahoney, Brian D; DeGregorio, Patrick T; Carroll, Patrick J; Nakamaru-Ogiso, Eiko; Kikkawa, James M; Schelter, Eric J

    2012-06-07

    Dysprosium complexes of the tmtaa(2-) ligand were synthesized and characterized by X-band EPR and magnetism studies. Both complexes demonstrate magnetoanisotropy and slow paramagnetic relaxation. Comparison of these compounds with the seminal phthalocyanine complex [Dy(Pc)(2)](-) shows the azaannulide complexes are more susceptible to relaxation through non-thermal pathways.

  17. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P. [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Gurinov, Andrey [Research Resources Center for Magnetic Resonance, Saint Petersburg State University, Universitetskij pr. 26, 198504 St. Petersburg (Russian Federation); Ortiz, Genaro Gabriel [Laboratorio Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano de Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Carbajal Arízaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.mx [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico)

    2015-03-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488 nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. - Highlights: • Hydroxyapatite functionalized with glucuronic acid reduced oxidative stress in rats. • Functionalization with folic acid reduced oxidative stress in rats. • Dysprosium doping does not affect the crystalline structure of hydroxyapatite. • Dysprosium doped particles are visible in fluorescent microscope. • Dysprosium doped particles act as MRI contrast agents.

  18. Tuning Slow Magnetic Relaxation in a Two-Dimensional Dysprosium Layer Compound through Guest Molecules.

    Science.gov (United States)

    Chen, Qi; Li, Jian; Meng, Yin-Shan; Sun, Hao-Ling; Zhang, Yi-Quan; Sun, Jun-Liang; Gao, Song

    2016-08-15

    A novel two-dimensional dysprosium(III) complex, [Dy(L)(CH3COO)]·0.5DMF·H2O·2CH3OH (1), has been successfully synthesized from a new pyridine-N-oxide (PNO)-containing ligand, namely, N'-(2-hydroxy-3-methoxybenzylidene)pyridine-N-oxidecarbohydrazide (H2L). Single-crystal X-ray diffraction studies reveal that complex 1 is composed of a dinuclear dysprosium subunit, which is further extended by the PNO part of the ligand to form a two-dimensional layer. Magnetic studies indicate that complex 1 shows well-defined temperature- and frequency-dependent signals under a zero direct-current (dc) field, typical of slow magnetic relaxation with an effective energy barrier Ueff of 33.6 K under a zero dc field. Interestingly, powder X-ray diffraction and thermogravimetric analysis reveal that compound 1 undergoes a reversible phase transition that is induced by the desorption and absorption of methanol and water molecules. Moreover, the desolvated sample [Dy(L)(CH3COO)]·0.5DMF (1a) also exhibits slow magnetic relaxation but with a higher anisotropic barrier of 42.0 K, indicating the tuning effect of solvent molecules on slow magnetic relaxation.

  19. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Omar, R. S., E-mail: ratnasuffhiyanni@gmail.com; Wagiran, H., E-mail: husin@utm.my; Saeed, M. A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru (Malaysia)

    2016-01-22

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B{sub 2}O{sub 3} − 20 CaO – 10 MgO-(y) Dy{sub 2}O{sub 3} with 0.05  mol % ≤ y ≤ 0.7  mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy{sub 2}O{sub 3} concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used.

  20. Low temperature synthesis of ternary metal phosphides using plasma for asymmetric supercapacitors

    KAUST Repository

    Liang, Hanfeng

    2017-04-06

    We report a versatile route for the preparation of metal phosphides using PH plasma for supercapacitor applications. The high reactivity of plasma allows rapid and low temperature conversion of hydroxides into monometallic, bimetallic, or even more complex nanostructured phosphides. These same phosphides are much more difficult to synthesize by conventional methods. Further, we present a general strategy for significantly enhancing the electrochemical performance of monometallic phosphides by substituting extrinsic metal atoms. Using NiCoP as a demonstration, we show that the Co substitution into NiP not only effectively alters the electronic structure and improves the intrinsic reactivity and electrical conductivity, but also stabilizes Ni species when used as supercapacitor electrode materials. As a result, the NiCoP nanosheet electrodes achieve high electrochemical activity and good stability in 1 M KOH electrolyte. More importantly, our assembled NiCoP nanoplates//graphene films asymmetric supercapacitor devices can deliver a high energy density of 32.9 Wh kg at a power density of 1301 W kg, along with outstanding cycling performance (83% capacity retention after 5000 cycles at 20 A g). This activity outperforms most of the NiCo-based materials and renders the NiCoP nanoplates a promising candidate for capacitive storage devices.

  1. Scaling Mesa Indium Phosphide DHBTs to Record Bandwidths

    Science.gov (United States)

    Lobisser, Evan

    Indium phosphide heterojunction bipolar transistors are able to achieve higher bandwidths at a given feature size than transistors in the Silicon material system for a given feature size. Indium phosphide bipolar transistors demonstrate higher breakdown voltages at a given bandwidth than both Si bipolars and field effect transistors in the InP material system. The high bandwidth of InP HBTs results from both intrinsic material parameters and bandgap engineering through epitaxial growth. The electron mobility in the InGaAs base and saturation velocity in the InP collector are both approximately three times higher than their counterparts in the SiGe material system. Resistance of the base can be made very low due to the large offset in the valence band between the InP emitter and the InGaAs base, which allows the base to be doped on the order of 1020 cm-3 with negligible reduction in emitter injection efficiency. This thesis deals with type-I, NPN dual-heterojunction bipolar transistors. The emitters are InP, and the base is InGaAs. There is a thin (˜ 10 nm) n-type InGaAs "setback" region, followed by a chirped superlattice InGaAs/InAlAs grade to the InP collector. The setback, grade, and collector are all lightly doped n-type. The emitter and collector are contacted through thin (˜ 5 nm) heavily doped n-type InGaAs layers to reduce contact resistivity. The primary focus of this work is increasing the bandwidth of InP HBTs through the proportional scaling of the device dimensions, both layer thicknesses and junction areas, as well as the reduction of the contact resistivities associated with the transistor. Essentially, all RC time constants and transit times must be reduced by a factor of two to double a transistor's bandwidth. Chapter 2 describes in detail the scaling laws and design principles for high frequency bipolar transistor design. A low-stress, blanket sputter deposited composite emitter metal process was developed. Refractory metal base contacts were

  2. Luminescent properties of dysprosium(Ⅲ) ions in LaAlO3 nanocrystallites

    Institute of Scientific and Technical Information of China (English)

    K. Lema(n)ski; P.J. Dere(n)

    2011-01-01

    The absorption and emission spectra as well as decay time profile of Dy3+ ions in LaAlO3 nanocrystals were analyzed.The crystal structure of LaAlO3 was confirmed from XRD measurement.The emission peaks from blue to red came from main emitting level of dysprosium 4F9/2 to the ground and other excited levels of Dy3+ ions.Cross relaxation process led to non-radiative quenching of luminescence,so that the lifetime of the 4F9/2 energy level ions decreased with increasing amount of doped Dy3+ ions.The cross relaxation transfer rates were experimentally determined as a function of Dy3+ concentration.

  3. Magnetic ordering temperatures in rare earth metal dysprosium under ultrahigh pressures

    Science.gov (United States)

    Samudrala, Gopi K.; Tsoi, Georgiy M.; Weir, Samuel T.; Vohra, Yogesh K.

    2014-04-01

    Magnetic ordering temperatures in heavy rare earth metal dysprosium (Dy) have been studied using an ultrasensitive electrical transport measurement technique in a designer diamond anvil cell to a pressure of 69 GPa and a temperature of 10 K. Previous studies using magnetic susceptibility measurements at high pressures were able to track magnetic ordering temperature only till 7 GPa in the hexagonal close packed (hcp) phase of Dy. Our studies indicate that the magnetic ordering temperature shows an abrupt drop of 80 K at the hcp-Sm phase transition followed by a gradual decrease that continues till 17 GPa. This is followed by a rapid increase in the magnetic ordering temperatures in the double hcp phase and finally leveling off in the distorted face centered cubic phase of Dy. Our studies reaffirm that 4f-shell remains localized in Dy and there is no loss of magnetic moment or 4f-shell delocalization for pressures up to 69 GPa.

  4. Electrochemical behaviour of dysprosium in the eutectic LiCl-KCl at W and Al electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Castrillejo, Y. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain)]. E-mail: ycastril@qa.uva.es; Bermejo, M.R. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Barrado, A.I. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Pardo, R. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Barrado, E. [Dpto de Quimica Analitica, Facultad de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Martinez, A.M. [Department of Materials Technology, Sem Saelands vei 6, 7491 Trondheim (Norway)

    2005-03-15

    The electrochemical behaviour of DyCl{sub 3} was studied in the eutectic LiCl-KCl at different temperatures. The cathodic reaction can be written:Dy(III)+3e-bar Dy(0)which can be divided in two very close cathodic steps:Dy(III)+1e-bar Dy(II)andDy(II)+2e-bar Dy(0)Transient electrochemical techniques, such as cyclic voltammetry, chronopotentiometry, and chronoamperometry were used in order to study the reaction mechanism and the transport parameters of electroactive species at a tungsten electrode. The results showed that in the eutectic LiCl-KCl, electrocrystallization of dysprosium seems to be the controlling electrochemical step. Chronoamperometric studies indicated instantaneous nucleation of dysprosium with three dimensional growth of the nuclei whatever the applied overpotential.Mass transport towards the electrode is a simple diffusion process, and the diffusion coefficient of the electroactive species, i.e. Dy(III), has been calculated. The validity of the Arrhenius law was also verified by plotting the variation of the logarithm of the diffusion coefficient versus 1/T.In addition, the electrode reactions of the LiCl-KCl-DyCl{sub 3} solutions at an Al wire were also investigated by cyclic voltammetry and open circuit chronopotentiometry. The redox potential of the Dy(III)/Dy couple at the Al electrode was observed at more positive potentials values than those at the inert electrode. This potential shift was thermodynamically analyzed by a lowering of activity of Dy in the metal phase due to the formation of intermetallic compounds.

  5. Structural, optical, thermal, mechanical and dielectric studies of Sulfamic acid single crystals: An influence of dysprosium (Dy3+) doping

    Science.gov (United States)

    Singh, Budhendra; Shkir, Mohd.; AlFaify, S.; Kaushal, Ajay; Nasani, Narendar; Bdikin, Igor; Shoukry, H.; Yahia, I. S.; Algarni, H.

    2016-09-01

    Sulfamic acid is a potential material that exhibits excellent optical properties. A good quality, pure and dysprosium (Dy3+) doped (2.5 and 5 mol %) Sulfamic acid (SA) single crystals were grown successfully by slow cooling method. Structural study revealed a slight change in its lattice parameters and volume, suggesting the successful incorporation of Dy3+ in crystal system. The existence of dysprosium in the system was also confirmed. Presence of various vibrational modes was confirmed. Optical transparency was found to have a significant effect with variation in the doping concentration. Furthermore, a marked enhancement in its mechanical parameters with doping was also identified by nanoindentation technique. Etching study was also performed on the grown crystals to study the etch-pit formation and growth mechanism. Effect of doping on the thermal stability was analysed. All the results were compared and discussed in detail to get insight of the effect of doping concentration on Sulfamic acid crystal.

  6. Optical trapping of ultracold dysprosium atoms: transition probabilities, dynamic dipole polarizabilities and van der Waals $C_6$ coefficients

    CERN Document Server

    Li, Hui; Dulieu, Olivier; Nascimbene, Sylvain; Lepers, Maxence

    2016-01-01

    The efficiency of optical trapping of ultracold atoms depend on the atomic dynamic dipole polarizability governing the atom-field interaction. In this article, we have calculated the real and imaginary parts of the dynamic dipole polarizability of dysprosium in the ground and first excited level. Due to the high electronic angular momentum of those two states, the polarizabilities possess scalar, vector and tensor contributions that we have computed, on a wide range of trapping wavelengths, using the sum-over-state formula. Using the same formalism, we have also calculated the $C_6$ coefficients characterizing the van der Waals interaction between two dysprosium atoms in the two lowest levels. We have computed the energies of excited states and the transition probabilities appearing in the sums, using a combination of \\textit{ab initio} and least-square-fitting techniques provided by the Cowan codes and extended in our group. Regarding the real part of the polarizability, for field frequencies far from atomic...

  7. Theoretical Study on Electronic, Optical Properties and Hardness of Technetium Phosphides under High Pressure

    Directory of Open Access Journals (Sweden)

    Shiquan Feng

    2017-06-01

    Full Text Available In this paper, the structural properties of technetium phosphides Tc3P and TcP4 are investigated by first principles at zero pressure and compared with the experimental values. In addition, the electronic properties of these two crystals in the pressure range of 0–40 GPa are investigated. Further, we discuss the change in the optical properties of technetium phosphides at high pressures. At the end of our study, we focus on the research of the hardness of TcP4 at different pressures by employing a semiempirical method, and the effect of pressure on the hardness is studied. Results show that the hardness of TcP4 increases with the increasing pressure, and the influence mechanism of pressure effect on the hardness of TcP4 is also discussed.

  8. Nickel Phosphide as a Copper Free Back Contact for CdTe-Based Solar Cells

    Science.gov (United States)

    Sunderland, Brian; Gupta, Akhlesh; Compaan, Alvin D.

    2002-03-01

    Nickel phosphide back contacts were deposited onto polycrystalline, thin-film, CdS/CdTe solar cells using DC magnetron sputtering. The effects of the etching procedure, substrate temperature, deposition duration, post-deposition diffusion temperature, and ambient on the initial performance and on the long term stability of the devices were studied. We found that the initial performance of nickel phosphide contacts was lower than typical Cu-based back contacts. However, the stability of the cells at open circuit under one-sun light soak for several months is better than for our standard contact with evaporated Cu and Au. The use of sputtered graphite as an interfacial layer improved the performance. Average efficiencies of over 8.6were achieved. The excellent stability makes Ni2P an attractive candidate for a Cu-free back contact to CdTe-based solar cells. Work supported by NREL and by NSF-REU.

  9. Femtosecond laser irradiation of indium phosphide in air: Raman spectroscopic and atomic force microscopic investigations

    Energy Technology Data Exchange (ETDEWEB)

    Bonse, J.; Wrobel, J.M.; Brzezinka, K.-W.; Esser, N.; Kautek, W

    2002-12-30

    Surface modification and ablation of crystalline indium phosphide was performed with single and double 130 fs pulses from a Ti:sapphire laser. The morphological features resulting from laser processing, have been investigated by means of micro Raman spectroscopy as well as by optical, atomic force and scanning electron microscopy. The studies indicate amorphous, ablated and recrystallized zones on the processed surface. In the single-pulse irradiation experimentsveral different threshold fluences could be assigned to the processes of melting, ablation and polycrystalline resolidification. Residual stress has been detected within the irradiated areas. Double-pulse exposure experiments have been analyzed in order to clarify the effect of cumulative damage in the ablation process of indium phosphide.

  10. Solid state synthesis and room temperature magnetic properties of iron phosphide nanoparticles

    Science.gov (United States)

    Singh, N.; Khanna, P. K.; Joy, P. A.

    2009-02-01

    Room temperature magnetic properties have been achieved for nano-crystalline iron phosphide synthesized from the direct solid state reaction of iron chloride and tri-octylphosphine (TOP). The magnetization continuously increased with higher magnetic fields, indicating a super-paramagnetic behavior. It is observed that room temperature magnetism is possible for the material showing antiferromagnetic nature at low temperatures. In the present synthesis, TOP acted as a source of phosphorus as well as a surfactant. X-ray diffraction (XRD) studies revealed that the black powder is a mixture of FeP and Fe2P. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed elongated as well spherical particles. Energy dispersion X-ray analysis (EDAX) confirmed a non-stoichiometric iron phosphide. Presence of TOP was confirmed by infra-red (IR) spectroscopy, and thermo-gravimetric analysis (TGA) indicated about 6% wt. loss due to presence of organics.

  11. Metal phosphide catalysts and methods for making the same and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Habas, Susan Ellen; Wang, Jun; Ruddy, Daniel A.; Baddour, Frederick Raymond Gabriel; Schaidle, Joshua

    2017-05-02

    The present disclosure relates to a method that includes heating a mixture that includes a metal phenylphosphine-containing precursor that includes at least one of Mo(PPh.sub.3).sub.2(CO).sub.4, Pd(PPh.sub.3).sub.4, Ru(PPh.sub.3).sub.3Cl.sub.2, Ru(PPh.sub.3).sub.2(CO).sub.2Cl.sub.2, Co(PPh.sub.3)(CO).sub.2(NO), and/or Rh(PPh.sub.3).sub.2(CO)Cl, a surfactant, and a solvent. The heating is to a target temperature to form a heated mixture containing a metal phosphide nanoparticle that includes at least one of MoP, Ru.sub.2P, Co.sub.2P, Rh.sub.2P, and/or Pd.sub.3P, and the metal phosphide nanoparticle is not hollow.

  12. Mixed (phthalocyaninato)(Schiff-base) di-dysprosium sandwich complexes. Effect of magnetic coupling on the SMM behavior.

    Science.gov (United States)

    Wang, Hailong; Liu, Chenxi; Liu, Tao; Zeng, Suyuan; Cao, Wei; Ma, Qi; Duan, Chunying; Dou, Jianmin; Jiang, Jianzhuang

    2013-11-21

    Reaction between Schiff-base ligand and half-sandwich complex M(Pc)(acac) led to the isolation of new sandwich-type mixed (phthalocyaninato)(Schiff-base) di-lanthanide compounds M2(Pc)2(L)H2O (M = Dy, Gd) (1, 2) [H2Pc = metal free phthalocyanine, Hacac = acetylacetone, H2L = N,N'-bis(3-methyloxysalicylidene)benzene-1,2-diamine] with the triple-decker molecular structure clearly revealed by single crystal X-ray diffraction analysis. For the comparative studies, sandwich triple-decker analogues with pure Schiff-base ligand M2(L)3H2O (M = Dy, Gd) (3, 4) were also prepared. Dynamic magnetic measurement result reveals the single-molecule magnet (SMM) nature of the di-dysprosium derivative 1, while the static magnetic investigation over both pure and the diamagnetic diluted samples of this compound discloses the interionic ferromagnetic coupling between the two dysprosium ions, which in turn effectively suppresses the QTM and enhances the energy barrier of this SMM. Nevertheless, comparative studies over the static magnetic properties of the di-dysprosium triple-decker complexes 1 and 3 indicate the stronger magnetic coupling between the two lanthanide ions in mixed (phthalocyaninato)(Schiff-base) species than in the pure Schiff-base triple-decker analogue, suggesting the special coordination sphere around the dysprosium ions in the former compound over the latter one on the more intense inter-ionic ferromagnetic coupling. As a very small step towards understanding the structure-property relationship, the present result will be surely helpful for the design and synthesis of the multinuclear lanthanide-based SMMs with good properties.

  13. Phosphide residue exposure as the cause of serum vitamin depletion in female Wistar rats

    Directory of Open Access Journals (Sweden)

    Ayobola Abolape Iyanda

    2013-04-01

    Full Text Available Background: Synthetic chemical preservatives have received much negative publicity in recent time, some of which include insect resistance and misapplication of fumigants as well as a myriad of clinical conditions that have been associated with grain consumption. Aluminum phosphide is widely employed for the fumigation of grains meant for both international and local markets. Although its manufacturers have discouraged contamination of grains with spent or unspent phosphide residue, contamination still does occur especially among many illiterate cowpea merchants. The objective of this study is to determine the impact of phosphide residue contaminated cowpea on serum vitamin levels. Methods: Female Wistar rats were divided into 3 experimental groups with each group consisting of 6 rats. They were fed unfumigated (control, fumigated-contaminated (group 1 and fumigated but uncontaminated (group 2 cowpea. Results: Vitamin analysis using high performance liquid chromatography technique showed significant differences in the levels of niacin, folic acid, thiamine, riboflavin, and vitamins A, C, D and E; but pantothenic acid and pyridoxine were not significantly different in group 1 rats compared with control. Moreover, compared with control none of the vitamins were significantly different in rats in group 2. Conclusion: Cowpea is a source of many vitamins among the teeming poor in many part of the developing world; therefore there is need to ensure its proper fumigation. The results of this study suggest that although proper phosphide fumigation of cowpea may not alter serum vitamin levels but improper handling of the fumigation process may result in vitamin depletion. [J Exp Integr Med 2013; 3(2.000: 159-163

  14. Ultra-fast mechanochemical synthesis of boron phosphides, BP and B12P2.

    Science.gov (United States)

    Mukhanov, Vladimir A; Vrel, Dominique; Sokolov, Petr S; Le Godec, Yann; Solozhenko, Vladimir L

    2016-06-21

    Here we propose a new approach to the synthesis of single-phase boron phosphides (BP and B12P2) by mechanochemical reactions between boron phosphate and magnesium/magnesium diboride in the presence of an inert diluent (sodium chloride). The proposed method is characterized by the simplicity of implementation, high efficiency, low cost of the product, and good perspectives for large-scale production.

  15. A new type of nonsulfide hydrotreating catalyst: nickel phosphide on carbon.

    Science.gov (United States)

    Shu, Yuying; Oyama, S Ted

    2005-03-07

    Nickel phosphide on carbon is successfully synthesized by temperature-programmed reduction as verified with X-ray diffraction and extended X-ray absorption fine structure measurements; it shows superior activity, selectivity, and stability for sulfur removal from the refractory compound 4,6-dimethyldibenzothiophene with a steady-state conversion of 99%, which is much higher than that of a commercial NiMoS/[gamma]-Al2O3 catalyst of 68%.

  16. Surface modification of gallium phosphide caused by swift (200 MeV) silver ions

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, S.K., E-mail: skdubey@physics.mu.ac.in

    2017-02-01

    Highlights: • Analysis of atomic force microscopic images of the gallium phosphide samples irradiated with different fluences showed the presence of hillocks at the surface of gallium phosphide. At higher fluences, the big size hillocks having arbitrary shape are formed. • Phonon confinement model employed to first order Raman scattering from longitudinal optical phonon mode revealed the decrease in phonon coherence length with the increase in ion fluence. • Stress induced in the sample and phonon coherence length saturate at lower ion fluence, suggests that the swift silver ion irradiation in gallium phosphide do not create the significant damage upon impact. - Abstract: In the present work, the effects of swift silver ion irradiation in crystalline gallium phosphide samples with various fluences ranging between 1 × 10{sup 11} and 2 × 10{sup 13} ions cm{sup −2} have been described. Atomic force microscopy images of the samples irradiated with different fluences showed the existence of hillocks at the surface, the diameter and density of these clusters were found to be depend on the ion fluence. As the ion fluence increased (⩾1 × 10{sup 13} ions cm{sup −2}), the big size hillocks having arbitrary shapes were observed due to outflow of the molten material to the sample surface or defect induced swelling of track areas accumulated during the track overlapping. Phonon confinement model employed to first order Raman scattering from longitudinal optical phonon mode revealed the decrease in phonon coherence length from 73.0 nm to 23.7 nm with the increase in ion fluence from 1 × 10{sup 12} to 2 × 10{sup 13} ion cm{sup −2}.

  17. Acetaminophen and zinc phosphide for lethal management of invasive lizards Ctenosaura similis

    Institute of Scientific and Technical Information of China (English)

    Michael L. AVERY; John D. EISEMANN; Kandy L. KEACHER; Peter J. SAVARIE

    2011-01-01

    Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective integrated management relies on a variety of tools,including toxicants.In Florida,using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis,we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species.Of the animals that received acetaminophen,none died except at the highest test dose,240 mg per lizard,which is not practical for field use.Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard,equivalent to about 0.5% in bait which is lower than currently used in commercial baits for eommensal rodent control.We conclude that zinc phosphide has potential as a useful tool for reducing populations of invasive lizards such as the black spiny-tailed iguana provided target-selective delivery methods are developed [Current Zoology 57 (5):625-629,2011].

  18. Orientation of Zn3P2 films via phosphidation of Zn precursors

    Science.gov (United States)

    Katsube, Ryoji; Nose, Yoshitaro

    2017-02-01

    Orientation of solar absorber is an important factor to achieve high efficiency of thin film solar cells. In the case of Zn3P2 which is a promising absorber of low-cost and high-efficiency solar cells, (110)/(001) orientation was only reported in previous studies. We have successfully prepared (101)-oriented Zn3P2 films by phosphidation of (0001)-oriented Zn films at 350 °C. The phosphidation mechanism of Zn is discussed through STEM observations on the partially-reacted sample and the consideration of the relationship between the crystal structures of Zn and Zn3P2 . We revealed that (0001)-oriented Zn led to nucleation of (101)-oriented Zn3P2 due to the similarity in atomic arrangement between Zn and Zn3P2 . The electrical resistivity of the (101)-oriented Zn3P2 film was lower than those of (110)/(001)-oriented films, which is an advantage of the phosphidation technique to the growth processes in previous works. The results in this study demonstrated that well-conductive Zn3P2 films could be obtained by controlling orientations of crystal grains, and provide a guiding principle for microstructure control in absorber materials.

  19. Analysis of uranium-bearing Fe-phosphide from a submerged arc furnace for phosphorus production

    Science.gov (United States)

    Voncken, J. H. L.; Scheepers, E.; Yang, Y.

    2006-10-01

    During a study on the Fe-phosphide phase formed during phosphorus production in a submerged arc furnace, a sample of ferrophosphorus was found which contains a so far unknown uranium-bearing Fe-phosphide. Uranium, as well as other trace metals like Mn, V, Cr, Ni, Zr, originates from the apatite ore used. Ti originates partly from the silica and coke used in the reduction process, but mainly from the clay used to produce ore pellets. In this paper the ferrophosphorus is described with respect to composition and crystalline compounds present. The crystallization sequence is discussed with respect to the FeP-phase diagram. The main phases found in the ferrophosphorus are FeP and Fe2P. With respect to trace and minor metals, it is observed that Si preferably enters the FeP-phase, whereas Ti, V, Cr, Mn and Ni preferably enter the Fe2P-phase, which is an analogue of the mineral barringerite. This study gives some insight into the behavior of impurities during crystallization of an iron-rich Fe-phosphide melt. The uranium-bearing phase has an overall Me2P-stoichiometry (Fe1.59, Ti0.06, V0.03, Cr0.02, Mn0.06, Ni0.02, U0.15, Zr0.09)2.02 (P0.96, Si0.02)0.98. An X-ray diffraction pattern of this phase is given for identification purposes.

  20. Ultrastable nitrogen-doped carbon encapsulating molybdenum phosphide nanoparticles as highly efficient electrocatalyst for hydrogen generation.

    Science.gov (United States)

    Pu, Zonghua; Amiinu, Ibrahim Saana; Liu, Xiaobo; Wang, Min; Mu, Shichun

    2016-10-06

    There is a crucial demand for cost-effective hydrogen evolution reaction (HER) catalysts towards future renewable energy systems, and the development of such catalysts operating under all pH conditions still remains a challenging task. In this work, a one-step facile approach to synthesizing nitrogen-doped carbon encapsulating molybdenum phosphide nanoparticles (MoP NPs@NC) is introduced by using ammonium molybdate, ammonium dihydrogen phosphate and melamine as precursor. Benefitting from structural advantages, including ultrasmall nanoparticles, large exposed surface area and fast charge transfer, MoP NPs@NC exhibits excellent HER catalytic activities with small overpotentials at all pH values (j = 10 mA cm(-2) at η = 115, 136 and 80 mV in 0.5 M H2SO4, 1.0 M phosphate buffer solution and 1.0 M KOH, respectively.). Meanwhile, the high catalytic activities of MoP NPs@NC under both neutral and basic conditions have never been achieved before for molybdenum phosphide-based catalysts. Additionally, the encapsulation by N-doped carbon effectively prevents the MoP NPs from corrosion, exhibiting nearly unfading stability after 100 h testing in 0.5 M H2SO4. Thus, our work could pave a new avenue for unprecedented design and fabrication of novel low-cost metal phosphide electrocatalysts encapsulated by N-doped carbon.

  1. Ingestion of gallium phosphide nanowires has no adverse effect on Drosophila tissue function.

    Science.gov (United States)

    Adolfsson, Karl; Schneider, Martina; Hammarin, Greger; Häcker, Udo; Prinz, Christelle N

    2013-07-19

    Engineered nanoparticles have been under increasing scrutiny in recent years. High aspect ratio nanoparticles such as carbon nanotubes and nanowires have raised safety concerns due to their geometrical similarity to asbestos fibers. III-V epitaxial semiconductor nanowires are expected to be utilized in devices such as LEDs and solar cells and will thus be available to the public. In addition, clean-room staff fabricating and characterizing the nanowires are at risk of exposure, emphasizing the importance of investigating their possible toxicity. Here we investigated the effects of gallium phosphide nanowires on the fruit fly Drosophila melanogaster. Drosophila larvae and/or adults were exposed to gallium phosphide nanowires by ingestion with food. The toxicity and tissue interaction of the nanowires was evaluated by investigating tissue distribution, activation of immune response, genome-wide gene expression, life span, fecundity and somatic mutation rates. Our results show that gallium phosphide nanowires applied through the diet are not taken up into Drosophila tissues, do not elicit a measurable immune response or changes in genome-wide gene expression and do not significantly affect life span or somatic mutation rate.

  2. Evaluating United States and world consumption of neodymium, dysprosium, terbium, and praseodymium in final products

    Science.gov (United States)

    Hart, Matthew

    This paper develops scenarios of future rare-earth-magnet metal (neodymium, dysprosium, terbium, and praseodymium) consumption in the permanent magnets used in wind turbines and hybrid electric vehicles. The scenarios start with naive base-case scenarios for growth in wind-turbine and hybrid-electric-vehicle sales over the period 2011 to 2020, using historical data for each good. These naive scenarios assume that future growth follows time trends in historical data and does not depend on any exogenous variable. Specifically, growth of each technological market follows historical time trends, and the amount of rare earths used per unit of technology remains fixed. The chosen reference year is 2010. Implied consumptions of the rare earth magnet metals are calculated from these scenarios. Assumptions are made for the material composition of permanent magnets, the market share of permanent-magnet wind turbines and vehicles, and magnet weight per unit of technology. Different scenarios estimate how changes in factors like the material composition of magnets, growth of the economy, and the price of a substitute could affect future consumption. Each scenario presents a different method for reducing rare earth consumption and could be interpreted as potential policy choices. In 2010, the consumption (metric tons, rare-earth-oxide equivalent) of each rare-earth-magnet metal was as follows. Total neodymium consumption in the world for both technologies was 995 tons; dysprosium consumption was 133 tons; terbium consumption was 50 tons; praseodymium consumption was zero tons. The base scenario for wind turbines shows there could be strong, exponential growth in the global wind turbine market. New U.S. sales of hybrid vehicles would decline (in line with the current economic recession) while non-U.S. sales increase through 2020. There would be an overall increase in the total amount of magnetic rare earths consumed in the world. Total consumption of each rare earth in the short

  3. Highly ordered horizontal indium gallium arsenide/indium phosphide multi-quantum-well in wire structure on (001) silicon substrates

    Science.gov (United States)

    Han, Yu; Li, Qiang; Lau, Kei May

    2016-12-01

    We report the characteristics of indium gallium arsenide stacked quantum structures inside planar indium phosphide nanowires grown on exact (001) silicon substrates. The morphological evolution of the indium phosphide ridge buffers inside sub-micron trenches has been studied, and the role of inter-facet diffusion in this process is discussed. Inside a single indium phosphide nanowire, we are able to stack quantum structures including indium gallium arsenide flat quantum wells, quasi-quantum wires, quantum wires, and ridge quantum wells. Room temperature photoluminescence measurements reveal a broadband emission spectrum centered at 1550 nm. Power dependent photoluminescence analysis indicates the presence of quasi-continuum states. This work thus provides insights into the design and growth process control of multiple quantum wells in wire structures for high performance nanowire lasers on a silicon substrate with 1550 nm band emission.

  4. Luminescence features of dysprosium and phosphorus oxide co-doped lithium magnesium borate glass

    Science.gov (United States)

    Hashim, S.; Mhareb, M. H. A.; Ghoshal, S. K.; Alajerami, Y. S. M.; Saripan, M. I.; Bradley, D. A.

    2017-08-01

    Lithium magnesium borate (LMB) glass system co-doped with the oxides of dysprosium (Dy2O3) and phosphorus (P2O5) were synthesized using melt-quenching method. Prepared samples were characterized using various techniques to determine the effects of co-dopants concentration variation on their thermoluminescence (TL) and photoluminescence (PL) properties. TL glow curves of LMB:0.5Dy sample revealed a single prominent peak at Tm=190 °C, where TL intensity was enhanced by a factor of 2.5 with the increase of P2O5 concentration up to 1 mol%. This enhancement was accompanied by a shift in Tm towards higher temperature. Good linearity in the range of 1-100 Gy with linear correlation coefficient of 0.998 was achieved. PL spectra displayed two significant peaks centred at 481 nm and 573 nm. These attractive luminescence features of the proposed glass system may be useful for the development of radiation dosimetry.

  5. Single-molecule magnet behavior for an antiferromagnetically superexchange-coupled dinuclear dysprosium(III) complex.

    Science.gov (United States)

    Long, Jérôme; Habib, Fatemah; Lin, Po-Heng; Korobkov, Ilia; Enright, Gary; Ungur, Liviu; Wernsdorfer, Wolfgang; Chibotaru, Liviu F; Murugesu, Muralee

    2011-04-13

    A family of five dinuclear lanthanide complexes has been synthesized with general formula [Ln(III)(2)(valdien)(2)(NO(3))(2)] where (H(2)valdien = N1,N3-bis(3-methoxysalicylidene)diethylenetriamine) and Ln(III) = Eu(III)1, Gd(III)2, Tb(III)3, Dy(III)4, and Ho(III)5. The magnetic investigations reveal that 4 exhibits single-molecule magnet (SMM) behavior with an anisotropic barrier U(eff) = 76 K. The step-like features in the hysteresis loops observed for 4 reveal an antiferromagnetic exchange coupling between the two dysprosium ions. Ab initio calculations confirm the weak antiferromagnetic interaction with an exchange constant J(Dy-Dy) = -0.21 cm(-1). The observed steps in the hysteresis loops correspond to a weakly coupled system similar to exchange-biased SMMs. The Dy(2) complex is an ideal candidate for the elucidation of slow relaxation of the magnetization mechanism seen in lanthanide systems.

  6. A comparative study of donor formation in dysprosium, holmium, and erbium implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Emtsev, V.V.; Emtsev, V.V. Jr.; Poloskin, D.S.; Shek, E.I.; Sobolev, N.A. [Division of Solid State Electronics, Ioffe Physicotechnical Institute, Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation)

    1998-12-01

    Formation of donor centers in Czochralski grown silicon doped with dysprosium, holmium, and erbium is discussed. Donor states of three kinds are introduced in the implanted layers after annealing at T=700C. Shallow donor states with ionization energies between 20 and 40 meV are attributed to oxygen -related thermal donors. Other donor centers in the energy range of E{sub C}-(60...70) meV and E{sub C}-(100...120) meV appear to be dependent on dopants. After a 900C anneal strong changes in the donor formation are observed only in silicon doped with erbium. Instead of donors at E{sub C}-(118{+-}5) meV, new donor centres at E{sub C}-(145{+-}5) meV are formed. Reportedly, the latter ones are involved in the excitation process of the Er{sup 3+} ions with a characteristic luminescence line at {approx}1.54 {mu}m. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Thermoluminescence properties of lithium magnesium borate glasses system doped with dysprosium oxide.

    Science.gov (United States)

    Mhareb, M H A; Hashim, S; Ghoshal, S K; Alajerami, Y S M; Saleh, M A; Razak, N A B; Azizan, S A B

    2015-12-01

    We report the impact of dysprosium (Dy(3+)) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+). An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O-MgO-B2O3 radiation dosimeters.

  8. Optical properties of zinc borotellurite glass doped with trivalent dysprosium ion

    Science.gov (United States)

    Ami Hazlin, M. N.; Halimah, M. K.; Muhammad, F. D.; Faznny, M. F.

    2017-04-01

    The zinc borotellurite doped with dysprosium oxide glass samples with chemical formula {[(TeO2) 0 . 7(B2O3) 0 . 3 ] 0 . 7(ZnO) 0 . 3 } 1 - x(Dy2O3)x (where x=0.01, 0.02, 0.03, 0.04 and 0.05 M fraction) were prepared by using conventional melt quenching technique. The structural and optical properties of the proposed glass systems were characterized by using X-ray diffraction (XRD) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and UV-VIS spectroscopy. The amorphous nature of the glass systems is confirmed by using XRD technique. The infrared spectra of the glass systems indicate three obvious absorption bands which are assigned to BO3 and TeO4 vibrational groups. Based on the absorption spectra obtained, the direct and indirect optical band gaps, as well as the Urbach energy were calculated. It is observed that both the direct and indirect optical band gaps increase with the concentration of Dy3+ ions. On the other hand, the Urbach energy is observed to decrease as the concentration of Dy3+ ions increases.

  9. Isolation of {sup 163}Ho from dysprosium target material by HPLC for neutrino mass measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mocko, Veronika; Taylor, Wayne A.; Nortier, Francois M.; Engle, Jonathan W.; Pollington, Anthony D.; Kunde, Gerd J.; Rabin, Michael W.; Birnbaum, Eva R. [Los Alamos National Laboratory, Los Alamos, NM (United States). Chemistry Div.; Barnhart, Todd E.; Nickles, Robert J. [Univ. Wisconsinn, Madison, WI (United States). Dept. of Medical Physics

    2015-07-01

    The rare earth isotope {sup 163}Ho is of interest for neutrino mass measurements. This report describes the isolation of {sup 163}Ho from a proton-irradiated dysprosium target and its purification. A Dy metal target was irradiated with 16 MeV protons for 10 h. After target dissolution, {sup 163}Ho was separated from the bulk Dy via cation-exchange high performance liquid chromatography using 70 mmol dm{sup -3} α-hydroxyisobutyric acid as the mobile phase. Subsequent purification of the collected Ho fraction was performed to remove the α-hydroxyisobutyrate chelating agent and to concentrate the Ho in a low ionic strength aqueous matrix. The final solution was characterized by MC-ICP-MS to determine the {sup 163}Ho/{sup 165}Ho ratio, {sup 163}Ho and the residual Dy content. The HPLC purification process resulted in a decontamination factor 1.4 x 10{sup 5} for Dy. The isolated Ho fraction contained 24.8 ± 1.3 ng of {sup 163}Ho corresponding to holmium recovery of 72 ± 3%.

  10. Engineering absorption and blackbody radiation in the far-infrared with surface phonon polaritons on gallium phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Streyer, W.; Law, S.; Rosenberg, A.; Wasserman, D. [Department of Electrical and Computer Engineering, University of Illinois Urbana Champaign, Urbana, Illinois 61801 (United States); Roberts, C.; Podolskiy, V. A. [Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts 01854 (United States); Hoffman, A. J. [Department of Electrical Engineering, University of Notre Dame, South Bend, Indiana 46556 (United States)

    2014-03-31

    We demonstrate excitation of surface phonon polaritons on patterned gallium phosphide surfaces. Control over the light-polariton coupling frequencies is demonstrated by changing the pattern periodicity and used to experimentally determine the gallium phosphide surface phonon polariton dispersion curve. Selective emission via out-coupling of thermally excited surface phonon polaritons is experimentally demonstrated. Samples are characterized experimentally by Fourier transform infrared reflection and emission spectroscopy, and modeled using finite element techniques and rigorous coupled wave analysis. The use of phonon resonances for control of emissivity and excitation of bound surface waves offers a potential tool for the exploration of long-wavelength Reststrahlen band frequencies.

  11. Cobalt phosphide nanowall array as an efficient 3D catalyst electrode for methanol electro-oxidation

    Science.gov (United States)

    Liu, Danni; Lu, Wenbo; Wang, Kunyang; Du, Gu; Asiri, Abdullah M.; Lu, Qun; Sun, Xuping

    2016-11-01

    In this letter, we report on the use of a cobalt phosphide nanowall array on conductive carbon cloth (CoP NA/CC) as an efficient catalyst electrode for methanol electro-oxidation under alkaline conditions. This CoP NA/CC achieves a current density of 96 mA cm-2 toward 0.5 M methanol at 0.5 V (versus a saturated calomel electrode (SCE)) in 1 M KOH. Moreover, this electrode exhibits superior stability and 93% of the initial anodic current density can be retained after 1000 cyclic voltammetry cycles when re-measured in new electrolyte.

  12. An efficient bifunctional electrocatalyst for water splitting based on cobalt phosphide

    Science.gov (United States)

    Yang, Libin; Qi, Honglan; Zhang, Chengxiao; Sun, Xuping

    2016-06-01

    The development of highly efficient electrocatalysts for water splitting is critical for various renewable-energy technologies. In this letter, we demonstrate a cobalt phosphide nanowire array grown on a Ti mesh (CoP/TM) behaving as a bifunctional electrocatalyst for water splitting. The CoP/TM electrode delivers 10 mA cm-2 at an overpotential of 72 mV for the hydrogen evolution reaction (HER) and 310 mV for the oxygen evolution reaction (OER) in 1.0 M KOH. Furthermore, its corresponding two-electrode alkaline electrolyzer displays 10 mA cm-2 at 1.64 V.

  13. Elastic Constants and Its Pressure Derivative of Boron Phosphide Using Higher-Order Perturbation Theory

    Directory of Open Access Journals (Sweden)

    A.R. Jivani

    2011-01-01

    Full Text Available The elastic constants, pressure derivative of bulk modulus and pressure derivative of elastic constants are investigated using the higher-order perturbation theory based on pseudopotential formalism and the application of our proposed model potential for Boron Phosphide. The parameter of the potential is derived using zero-pressure equilibrium condition. In the present study, Hartree and Sarkar et al screening functions are used to consider exchange and correlation effect. The good agreement of presently investigated numerical data is found with the available experiment data and other such theoretical values.

  14. Unusual complication of aluminum phosphide poisoning: Development of hemolysis and methemoglobinemia and its successful treatment

    Directory of Open Access Journals (Sweden)

    Kambiz Soltaninejad

    2011-01-01

    Full Text Available Methemoglobinemia and hemolysis are rare findings following phosphine poisoning. In this paper, a case of aluminum phosphide (AlP poisoning complicated by methemoglobinemia and hemolysis with a successful treatment is reported. A 28-year-old male patient presented following intentional ingestion of an AlP tablet. In this case, hematuria, hemolysis and methemoglobinemia were significant events. A methemoglobin level of 46% was detected by CO-oximetry. The patient was treated with ascorbic acid and methylene blue and he also received supportive care. Two weeks after admission, the patient was discharged from the hospital. Hemolysis and methemoglobinemia may complicate the course of phosphine poisoning.

  15. Theoretical investigations on the elastic and thermodynamic properties of rhenium phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Qun; Zhu, Xuanmin; Lin, Zhengzhe; Yao, Ronghui [Xidian Univ., Xi' an (China). School of Physics and Optoelectronic Engineering; Yan, Haiyan [Baoji Univ. of Arts and Sciences (China). Dept. of Chemistry and Chemical Engineering

    2016-04-01

    Structural, mechanical, and electronic properties of orthorhombic rhenium phosphide (Re{sub 2}P) are systematically investigated by using first principles calculations. The elastic constants and anisotropy of elastic properties are obtained. The metallic character of Re{sub 2}P is demonstrated by density of state calculations. The quasi-harmonic Debye model is applied to the study of the thermodynamic properties. The thermal expansion, heat capacities, and Grueneisen parameter on the temperature and pressure have been determined as a function of temperature and pressure in the pressure range from 0 to 100 GPa and the temperature range from 0 to 1600 K.

  16. Phosphides with zinc blende structure as anodes for lithium-ion batteries

    Science.gov (United States)

    Satya Kishore, M. V. V. M.; Varadaraju, U. V.

    The phosphides InP and GaP with a zinc blende structure are examined as anode materials for lithium-ion batteries. During discharge, X-ray diffraction phase analysis reveals the formation of Li-In/Li-Ga alloy and amorphous Li 3P. On charge, lithium is extracted from both Li xM (M = In, Ga) alloy and Li 3P. InP shows a reversible capacity of ∼475 mAh g -1 in the voltage range between 0.2 and 1.5 V, whereas GaP exhibits poor capacity retention compared with that of InP.

  17. Acute dysprosium toxicity to Daphnia pulex and Hyalella azteca and development of the biotic ligand approach.

    Science.gov (United States)

    Vukov, Oliver; Smith, D Scott; McGeer, James C

    2016-01-01

    The toxicological understanding of rare earth elements (REEs) in the aquatic environment is very limited but of increasing concern. The objective of this research is to compare the toxicological effect of the REE dysprosium to the freshwater invertebrates Daphnia pulex and Hyalella azteca and in the more sensitive organism, understand the toxicity modifying influence of Ca, Na, Mg, pH and dissolved organic matter (DOM). Standard methods (Environment Canada) were followed for testing and culture in media of intermediate hardness (60mg CaCO3 mg/L) at pH 7.8 with Ca at 0.5, Na 0.5, Mg 0.125 (mM) and 23°C. Acute toxicity tests were done with azteca and D. pulex revealed Hyalella to be 1.4 times more sensitive than Daphnia. Additions of Ca and Na but not Mg provided significant protection against Dy toxicity to Hyalella. Similarly, low pH was associated with reduction in toxicity. Exposures which were pH buffered with and without MOPS were significantly different and indicated that MOPS enhanced Dy toxicity. DOM also mitigated Dy toxicity. Biotic ligand based parameters (LogK values) were calculated based on free ion relationships as determined by geochemical equilibrium modeling software (WHAM ver. 7.02). The logK value for Dy(3+) toxicity to Hyalella was 7.75 while the protective influence of Ca and Na were 3.95 and 4.10, respectively. This study contributes data towards the development of site specific water quality guidelines and criteria for Dy and possibly REEs in general and offers insight into the complex bio-geochemical nature of this element.

  18. Silicon nanowire arrays coupled with cobalt phosphide spheres as low-cost photocathodes for efficient solar hydrogen evolution

    OpenAIRE

    Bao, Xiao-Qing; Cerqueira, M.F.; Alpuim, P.; Liu, Lifeng

    2015-01-01

    We demonstrate the first example of silicon nanowire array photocathodes coupled with hollow spheres of the emerging earth-abundant cobalt phosphide catalysts. Compared to bare silicon nanowire arrays, the hybrid electrodes exhibit significantly improved photoelectrochemical performance toward the solar-driven H2 evolution reaction. L. F. Liu acknowledges the financial support by the FCT Investigator grant (IF/01595/2014).

  19. Silicon nanowire arrays coupled with cobalt phosphide spheres as low-cost photocathodes for efficient solar hydrogen evolution.

    Science.gov (United States)

    Bao, Xiao-Qing; Fatima Cerqueira, M; Alpuim, Pedro; Liu, Lifeng

    2015-07-01

    We demonstrate the first example of silicon nanowire array photocathodes coupled with hollow spheres of the emerging earth-abundant cobalt phosphide catalysts. Compared to bare silicon nanowire arrays, the hybrid electrodes exhibit significantly improved photoelectrochemical performance toward the solar-driven H2 evolution reaction.

  20. Structure characterization and strain relief analysis in CVD growth of boron phosphide on silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guoliang [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Abbott, Julia K.C.; Brasfield, John D. [Department of Chemistry, The University of Tennessee, Knoxville, TN 37996 (United States); Liu, Peizhi [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Dale, Alexis [Department of Chemistry, The University of Tennessee, Knoxville, TN 37996 (United States); Duscher, Gerd [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Rack, Philip D. [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Feigerle, Charles S., E-mail: cfeigerl@tennessee.edu [Department of Chemistry, The University of Tennessee, Knoxville, TN 37996 (United States)

    2015-02-01

    Highlights: • Crystalline boron phosphide was grown on vicinal 4H (0 0 0 1)-SiC surfaces. • The microstructure evolution of defects generated at the interface was characterized by transmission electron microscopy. • The evolution of lattice distortion and strain are determined. - Abstract: Boron phosphide (BP) is a material of interest for development of a high-efficiency solid-state thermal neutron detector. For a thick film-based device, microstructure evolution is key to the engineering of material synthesis. Here, we report epitaxial BP films grown on silicon carbide with vicinal steps and provide a detailed analysis of the microstructure evolution and strain relief. The BP film is epitaxial in the near-interface region but deviates from epitaxial growth as the film develops. Defects such as coherent and incoherent twin boundaries, dislocation loops, stacking faults concentrate in the near-interface region and segment this region into small domains. The formation of defects in this region do not fully release the strain originated from the lattice mismatch. Large grains emerge above the near-interface region and grain boundaries become the main defects in the upper part of the BP film.

  1. Three-dimensional interconnected nickel phosphide networks with hollow microstructures and desulfurization performance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuna, E-mail: zhangshujuan@tust.edu.cn [College of Textile Engineering, Zhejiang Industry Polytechnic College, Shaoxing 312000 (China); Zhang, Shujuan [College of Science, Tianjin University of Science and Technology, Tianjin 300457 (China); Song, Limin, E-mail: tjpu2012@sohu.com [College of Environment and Chemical Engineering and State Key Laboratory of Hollow-Fiber Membrane Materials and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387 (China); Wu, Xiaoqing [Institute of Composite Materials and Ministry of Education Key Laboratory of Advanced Textile Composite Materials, Tianjin Polytechnic University, Tianjin 300387 (China); Fang, Sheng, E-mail: songlmnk@sohu.com [College of Environment and Chemical Engineering and State Key Laboratory of Hollow-Fiber Membrane Materials and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387 (China)

    2014-05-01

    Graphical abstract: Three-dimensional interconnected nickel phosphide networks with hollow microstructures and desulfurization performance. - Highlights: • Three-dimensional Ni{sub 2}P has been prepared using foam nickel as a template. • The microstructures interconnected and formed sponge-like porous networks. • Three-dimensional Ni{sub 2}P shows superior hydrodesulfurization activity. - Abstract: Three-dimensional microstructured nickel phosphide (Ni{sub 2}P) was fabricated by the reaction between foam nickel (Ni) and phosphorus red. The as-prepared Ni{sub 2}P samples, as interconnected networks, maintained the original mesh structure of foamed nickel. The crystal structure and morphology of the as-synthesized Ni{sub 2}P were characterized by X-ray diffraction, scanning electron microscopy, automatic mercury porosimetry and X-ray photoelectron spectroscopy. The SEM study showed adjacent hollow branches were mutually interconnected to form sponge-like networks. The investigation on pore structure provided detailed information for the hollow microstructures. The growth mechanism for the three-dimensionally structured Ni{sub 2}P was postulated and discussed in detail. To investigate its catalytic properties, SiO{sub 2} supported three-dimensional Ni{sub 2}P was prepared successfully and evaluated for the hydrodesulfurization (HDS) of dibenzothiophene (DBT). DBT molecules were mostly hydrogenated and then desulfurized by Ni{sub 2}P/SiO{sub 2}.

  2. Surface Roughening of Nickel Cobalt Phosphide Nanowire Arrays/Ni Foam for Enhanced Hydrogen Evolution Activity.

    Science.gov (United States)

    Wang, Xina; Tong, Rui; Wang, Yi; Tao, Hualong; Zhang, Zhihua; Wang, Hao

    2016-12-21

    Development of earth-abundant, efficient, and stable electrocatalysts for hydrogen evolution reactions (HER) in alkaline or even neutral pH electrolyte is very important for hydrogen production from water splitting. Construction of bimetal phosphides via tuning the bonding strength to hydrogen and increasing effective active sites through nanostructuring and surface engineering should lead to high HER activity. Here, ternary NiCoP nanowires (NWs) decorated by homogeneous nanoparticles have been obtained on Ni foam for a highly efficient HER property via long-term cyclic voltammetric (CV) sweeping. The electron density transfer between the positively charged Ni and Co and negatively charged P atoms, one-dimensional electron transfer channel of the NWs, and abundant active sites supplied by the nanoparticles and NWs endow the catalyst with low overpotentials of 43 and 118 mV to achieve the respective current densities of 10 and 100 mA cm(-2) together with long durability for at least 33 h in 1 M KOH. A cycled anodic dissolution-redeposition mechanism is disclosed for the formation of the NiCoP nanoparticles during the CV sweeping process. Such a surface roughening method is found to be adaptable to enhance the HER property of other phosphides, including Ni2P nanoplates/NF, NiCoP nanoparticles/NF, and CoP NW/NF.

  3. Optical trapping of ultracold dysprosium atoms: transition probabilities, dynamic dipole polarizabilities and van der Waals C 6 coefficients

    Science.gov (United States)

    Li, H.; Wyart, J.-F.; Dulieu, O.; Nascimbène, S.; Lepers, M.

    2017-01-01

    The efficiency of the optical trapping of ultracold atoms depends on the atomic dynamic dipole polarizability governing the atom-field interaction. In this article, we have calculated the real and imaginary parts of the dynamic dipole polarizability of dysprosium in the ground and first excited levels. Due to the high electronic angular momentum of those two states, the polarizabilities possess scalar, vector and tensor contributions that we have computed, on a wide range of trapping wavelengths, using the sum-over-state formula. Using the same formalism, we have also calculated the C 6 coefficients characterizing the van der Waals interaction between two dysprosium atoms in the two lowest levels. We have computed the energies of excited states and the transition probabilities appearing in the sums, using a combination of ab initio and least-square-fitting techniques provided by the Cowan codes and extended in our group. Regarding the real part of the polarizability, for field frequencies far from atomic resonances, the vector and tensor contributions are two-orders-of-magnitude smaller than the scalar contribution, whereas for the imaginary part, the vector and tensor contributions represent a noticeable fraction of the scalar contribution. Finally, our anisotropic C 6 coefficients are much smaller than those published in the literature.

  4. Acute dysprosium toxicity to Daphnia pulex and Hyalella azteca and development of the biotic ligand approach

    Energy Technology Data Exchange (ETDEWEB)

    Vukov, Oliver, E-mail: vuko3930@mylaurier.ca [Biology Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); Smith, D. Scott [Chemistry Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada); McGeer, James C. [Biology Department, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5 (Canada)

    2016-01-15

    The toxicological understanding of rare earth elements (REEs) in the aquatic environment is very limited but of increasing concern. The objective of this research is to compare the toxicological effect of the REE dysprosium to the freshwater invertebrates Daphnia pulex and Hyalella azteca and in the more sensitive organism, understand the toxicity modifying influence of Ca, Na, Mg, pH and dissolved organic matter (DOM). Standard methods (Environment Canada) were followed for testing and culture in media of intermediate hardness (60 mg CaCO{sub 3} mg/L) at pH 7.8 with Ca at 0.5, Na 0.5, Mg 0.125 (mM) and 23 °C. Acute toxicity tests were done with <24 h old neonates for 48 h in the case of D. pulex and with 2–9 days old offspring for 96 h tests with Hyalella. The potential protective effect of cationic competition was tested with Ca (0.5–2.0 mM), Na (0.5–2.0 mM) and Mg (0.125–0.5 mM). The effect of pH (6.5–8.0) and Suwannee River DOM complexation (at dissolved organic carbon (DOC) concentrations of 9 and 13 mg C/L) were evaluated. Dissolved Dy concentrations were lower than total (unfiltered) indicating precipitation, particularly at higher concentrations. Acute toxicity of Dy to H. azteca and D. pulex revealed Hyalella to be 1.4 times more sensitive than Daphnia. Additions of Ca and Na but not Mg provided significant protection against Dy toxicity to Hyalella. Similarly, low pH was associated with reduction in toxicity. Exposures which were pH buffered with and without MOPS were significantly different and indicated that MOPS enhanced Dy toxicity. DOM also mitigated Dy toxicity. Biotic ligand based parameters (Log K values) were calculated based on free ion relationships as determined by geochemical equilibrium modeling software (WHAM ver. 7.02). The log K value for Dy{sup 3+} toxicity to Hyalella was 7.75 while the protective influence of Ca and Na were 3.95 and 4.10, respectively. This study contributes data towards the development of site specific

  5. White light emission of dysprosium doped lanthanum calcium phosphate oxide and oxyfluoride glasses

    Science.gov (United States)

    Luewarasirikul, N.; Kim, H. J.; Meejitpaisan, P.; Kaewkhao, J.

    2017-04-01

    Lanthanum calcium phosphate oxide and oxyfluoride glasses doped with dysprosium oxide were prepared by melt-quenching technique with chemical composition 20La2O3:10CaO:69P2O5:1Dy2O3 and 20La2O3:10CaF2:69P2O5:1Dy2O3. The physical, optical and luminescence properties of the glass samples were studied to evaluate their potential to using as luminescence materials for solid-state lighting applications. The density, molar volume and refractive index of the glass samples were carried out. The optical and luminescence properties were studied by investigating absorption, excitation, and emission spectra of the glass samples. The absorption spectra were investigated in the UV-Vis-NIR region from 300 to 2000 nm. The excitation spectra observed under 574 nm emission wavelength showed the highest peak centered at 349 nm (6H15/2 → 6P7/2). The emission spectra, excited with 349 nm excitation wavelength showed two major peaks corresponding to 482 nm blue emission (4F9/2 → 6H15/2) and 574 nm yellow emission (4F9/2 → 6H13/2). The experimental lifetime were found to be 0.539 and 0.540 for oxide and oxyfluoride glass sample, respectively. The x,y color coordinates under 349 nm excitation wavelength were (0.38, 0.43) for both glass samples, that be plotted in white region of CIE 1931 chromaticity diagram. The CCT values obtained from the glass samples are 4204 K for oxide glass and 4228 K for oxyfluoride glass corresponding to the commercial cool white light (3100-4500 K). Judd-Ofelt theory had also been employed to obtain the J-O parameters (Ω2, Ω4 and Ω6), oscillator strength, radiative transition possibility, stimulated emission cross section and branching ratio. The Ω2 > Ω4 > Ω6 trend of J-O parameters of both glass samples may indicate the good quality of a glass host for using as optical device application. Temperature dependence of emission spectra was studied from 300 K to 10 K and found that the intensity of the emission peak was found to be increased with

  6. Transition Metal Phosphide Nanoparticles Supported on SBA-15 as Highly Selective Hydrodeoxygenation Catalysts for the Production of Advanced Biofuels.

    Science.gov (United States)

    Yang, Yongxing; Ochoa-Hernández, Cristina; de la Peña O'Shea, Víctor A; Pizarro, Patricia; Coronado, Juan M; Serrano, David P

    2015-09-01

    A series of catalysts constituted by nanoparticles of transition metal (M = Fe, Co, Ni and Mo) phosphides (TMP) dispersed on SBA-15 were synthesized by reduction of the corresponding metal phosphate precursors previously impregnated on the mesostructured support. All the samples contained a metal-loading of 20 wt% and with an initial M/P mole ratio of 1, and they were characterized by X-ray diffraction (XRD), N2 sorption, H2-TPR and transmission electron microscopy (TEM). Metal phosphide nanocatalysts were tested in a high pressure continuous flow reactor for the hydrodeoxygenation (HDO) of a methyl ester blend containing methyl oleate (C17H33-COO-CH3) as main component (70%). This mixture constitutes a convenient surrogate of triglycerides present in vegetable oils, and following catalytic hydrotreating yields mainly n-alkanes. The results of the catalytic assays indicate that Ni2P/SBA-15 catalyst presents the highest ester conversion, whereas the transformation rate is about 20% lower for MoP/SBA-15. In contrast, catalysts based on Fe and Co phosphides show a rather limited activity. Hydrocarbon distribution in the liquid product suggests that both hydrodeoxygenation and decarboxylation/decarbonylation reactions occur simultaneously over the different catalysts, although MoP/SBA-15 possess a selectivity towards hydrodeoxygenation exceeding 90%. Accordingly, the catalyst based on MoP affords the highest yield of n-octadecane, which is the preferred product in terms of carbon atom economy. Subsequently, in order to conjugate the advantages of both Ni and Mo phosphides, a series of catalysts containing variable proportions of both metals were prepared. The obtained results reveal that the mixed phosphides catalysts present a catalytic behavior intermediate between those of the monometallic phosphides. Accordingly, only marginal enhancement of the yield of n-octadecane is obtained for the catalysts with a Mo/Ni ratio of 3. Nevertheless, owing to this high selectivity

  7. Treatment of Aluminium Phosphide Poisoning with a Combination of Intravenous Glucagon, Digoxin and Antioxidant Agents

    Science.gov (United States)

    Oghabian, Zohreh; Mehrpour, Omid

    2016-01-01

    Aluminium phosphide (AlP) is used to protect stored grains from rodents. It produces phosphine gas (PH3), a mitochondrial poison thought to cause toxicity by blocking the cytochrome c oxidase enzyme and inhibiting oxidative phosphorylation, which results in cell death. AlP poisoning has a high mortality rate among humans due to the rapid onset of cardiogenic shock and metabolic acidosis, despite aggressive treatment. We report a 21-year-old male who was referred to the Afzalipour Hospital, Kerman, Iran, in 2015 after having intentionally ingested a 3 g AlP tablet. He was successfully treated with crystalloid fluids, vasopressors, sodium bicarbonate, digoxin, glucagon and antioxidant agents and was discharged from the hospital six days after admission in good clinical condition. For the treatment of AlP poisoning, the combination of glucagon and digoxin with antioxidant agents should be considered. However, evaluation of further cases is necessary to optimise treatment protocols. PMID:27606117

  8. Treatment of Aluminium Phosphide Poisoning with a Combination of Intravenous Glucagon, Digoxin and Antioxidant Agents

    Directory of Open Access Journals (Sweden)

    Zohreh Oghabian

    2016-08-01

    Full Text Available Aluminium phosphide (AlP is used to protect stored grains from rodents. It produces phosphine gas (PH3, a mitochondrial poison thought to cause toxicity by blocking the cytochrome c oxidase enzyme and inhibiting oxidative phosphorylation, which results in cell death. AlP poisoning has a high mortality rate among humans due to the rapid onset of cardiogenic shock and metabolic acidosis, despite aggressive treatment. We report a 21-yearold male who was referred to the Afzalipour Hospital, Kerman, Iran, in 2015 after having intentionally ingested a 3 g AlP tablet. He was successfully treated with crystalloid fluids, vasopressors, sodium bicarbonate, digoxin, glucagon and antioxidant agents and was discharged from the hospital six days after admission in good clinical condition. For the treatment of AlP poisoning, the combination of glucagon and digoxin with antioxidant agents should be considered. However, evaluation of further cases is necessary to optimise treatment protocols.

  9. High-efficiency indium tin oxide/indium phosphide solar cells

    Science.gov (United States)

    Li, X.; Wanlass, M. W.; Gessert, T. A.; Emery, K. A.; Coutts, T. J.

    1989-01-01

    Improvements in the performance of indium tin oxide (ITO)/indium phosphide solar cells have been realized by the dc magnetron sputter deposition of n-ITO onto an epitaxial p/p(+) structure grown on commercial p(+) bulk substrates. The highest efficiency cells were achieved when the surface of the epilayer was exposed to an Ar/H2 plasma before depositing the bulk of the ITO in a more typical Ar/O2 plasma. With H2 processing, global efficiencies of 18.9 percent were achieved. It is suggested that the excellent performance of these solar cells results from the optimization of the doping, thickness, transport, and surface properties of the p-type base, as well as from better control over the ITO deposition procedure.

  10. Surface modification of gallium phosphide caused by swift (200 MeV) silver ions

    Science.gov (United States)

    Dubey, S. K.

    2017-02-01

    In the present work, the effects of swift silver ion irradiation in crystalline gallium phosphide samples with various fluences ranging between 1 × 1011 and 2 × 1013 ions cm-2 have been described. Atomic force microscopy images of the samples irradiated with different fluences showed the existence of hillocks at the surface, the diameter and density of these clusters were found to be depend on the ion fluence. As the ion fluence increased (⩾1 × 1013 ions cm-2), the big size hillocks having arbitrary shapes were observed due to outflow of the molten material to the sample surface or defect induced swelling of track areas accumulated during the track overlapping. Phonon confinement model employed to first order Raman scattering from longitudinal optical phonon mode revealed the decrease in phonon coherence length from 73.0 nm to 23.7 nm with the increase in ion fluence from 1 × 1012 to 2 × 1013 ion cm-2.

  11. Molybdenum Disulfide as a Protection Layer and Catalyst for Gallium Indium Phosphide Solar Water Splitting Photocathodes.

    Science.gov (United States)

    Britto, Reuben J; Benck, Jesse D; Young, James L; Hahn, Christopher; Deutsch, Todd G; Jaramillo, Thomas F

    2016-06-02

    Gallium indium phosphide (GaInP2) is a semiconductor with promising optical and electronic properties for solar water splitting, but its surface stability is problematic as it undergoes significant chemical and electrochemical corrosion in aqueous electrolytes. Molybdenum disulfide (MoS2) nanomaterials are promising to both protect GaInP2 and to improve catalysis because MoS2 is resistant to corrosion and also possesses high activity for the hydrogen evolution reaction (HER). In this work, we demonstrate that GaInP2 photocathodes coated with thin MoS2 surface protecting layers exhibit excellent activity and stability for solar hydrogen production, with no loss in performance (photocurrent onset potential, fill factor, and light-limited current density) after 60 h of operation. This represents a 500-fold increase in stability compared to bare p-GaInP2 samples tested in identical conditions.

  12. Effect of hydrostatic pressure on the structural, elastic and electronic properties of (B3) boron phosphide

    Indian Academy of Sciences (India)

    Salah Daoud; Kamel Loucif; Nadhira Bloud; Noudjoud Lebgaa; Laarbi Belagraa

    2012-07-01

    In this paper we present the results obtained from first-principles calculations of the effect of hydrostatic pressure on the strucural, elastic and electronic properties of (B3) boron phosphide, using the pseudopotential plane-wave method (PP-PW) based on density functional theory within the Teter and Pade exchange-correlation functional form of the local density approximation (LDA). The lattice parameter, molecular and crystal densities, near-neighbour distances, independent elastic constant, bulk modulus, shear modulus, anisotropy factor and energy bandgaps of (B3) BP under high pressure are presented. The results showed a phase transition pressure from the zinc blende to rock-salt phase at around 1.56 Mbar, which is in good agreement with the theoretical data reported in the literature.

  13. Molybdenum Disulfide as a Protection Layer and Catalyst for Gallium Indium Phosphide Solar Water Splitting Photocathodes

    Energy Technology Data Exchange (ETDEWEB)

    Britto, Reuben J.; Benck, Jesse D.; Young, James L.; Hahn, Christopher; Deutsch, Todd G.; Jaramillo, Thomas F.

    2016-06-02

    Gallium indium phosphide (GaInP2) is a semiconductor with promising optical and electronic properties for solar water splitting, but its surface stability is problematic as it undergoes significant chemical and electrochemical corrosion in aqueous electrolytes. Molybdenum disulfide (MoS2) nanomaterials are promising to both protect GaInP2 and to improve catalysis since MoS2 is resistant to corrosion and also possesses high activity for the hydrogen evolution reaction (HER). In this work, we demonstrate that GaInP2 photocathodes coated with thin MoS2 surface protecting layers exhibit excellent activity and stability for solar hydrogen production, with no loss in performance (photocurrent onset potential, fill factor, and light limited current density) after 60 hours of operation. This represents a five-hundred fold increase in stability compared to bare p-GaInP2 samples tested in identical conditions.

  14. Band Discontinuities in Gallium Phosphide/Crystalline Silicon Heterojunctions Studied by Internal Photoemission

    Science.gov (United States)

    Sakata, Isao; Kawanami, Hitoshi

    2008-09-01

    We measured the band lineup of gallium phosphide (GaP) on crystalline silicon (c-Si) heterojunctions (HJs) by using internal photoemission (IPE), where the heterojunctions were prepared by using solid-source molecular beam epitaxy. It was found that the conduction-band and valence-band discontinuities, denoted by ΔEc and ΔEv, are 0.09+/-0.01 and 1.05+/-0.01 eV, respectively. By performing measurements on samples with different GaP layer thicknesses, we clarified that ΔEv of the present GaP-on-Si HJs is not affected by strain normal to the growth direction. The values of ΔEc and ΔEv obtained for the GaP-on-Si HJs are significantly different from those reported for thin Si-on-GaP HJs, and the implications of this discrepancy are briefly discussed.

  15. Effect of Reduction Temperature on Hydrofining Performance of Supported Molybdenum Phosphide Catalyst

    Institute of Scientific and Technical Information of China (English)

    Fengyan Li; Zhifang Zhao; Qingjie Li; Tianbo Zhao; Cuiqing Li; Guida Sun

    2005-01-01

    A series of supported molybdenum phosphide catalysts were prepared by impregnation method.XRD, TG-DTG, XPS and BET were used to study the phase, compositions and surface areas of the prepared catalysts. A model reactant containing thiophene, pyridine and cyclohexene was used for the measurements of catalytic activities. The effect of reduction temperature on catalytic activities was investigated. The analysis results by XRD and BET are very different when the reduction temperature is changed from 400 to 900 ℃. MoP/γ-Al2O3 catalysts and CoMoP/γ-Al2O3 catalysts prepared at the reduction temperature of 500 ℃ are the most active ones.

  16. Materials Development for Boron Phosphide Based Neutron Detectors: Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Edgar, James Howard [Kansas State Univ., Manhattan, KS (United States)

    2014-09-09

    The project goal was to improve the quality of boron phosphide (BP) by optimizing its epitaxial growth on single crystal substrates and by producing bulk BP single crystals with low dislocation densities. BP is potentially a good semiconductor for high efficiency solid state neutron detectors by combining neutron capture and charge creation within the same volume. The project strategy was to use newly available single crystal substrates, silicon carbide and aluminum nitride, engineered to produce the best film properties. Substrate variables included the SiC polytype, crystallographic planes, misorientation of the substrate surface (tilt direction and magnitude) from the major crystallographic plane, and surface polarity (Si and C). The best films were (111)BP on silicon-face (0001) 4H-SiC misoriented 4° in the [1-100] direction, and BP on (100) and (111) 3C-SiC/Si; these substrates resulted in films that were free of in-plane twin defects, as determined by x-ray topography. The impact of the deposition temperature was also assessed: increasing the temperature from 1000 °C to 1200 °C produced films that were more ordered and more uniform, and the size of individual grains increased by more than a factor of twenty. The BP films were free of other compounds such as icosahedral boron phosphide (B12P2) over the entire temperature range, as established by Raman spectroscopy. The roughness of the BP films was reduced by increasing the phosphine to diborane ratio from 50 to 200. Bulk crystals were grown by reacting boron dissolved in nickel with phosphorus vapor to precipitate BP. Crystals with dimensions up to 2 mm were produced.

  17. Limits on violations of Lorentz symmetry and the Einstein equivalence principle using radio-frequency spectroscopy of atomic dysprosium.

    Science.gov (United States)

    Hohensee, M A; Leefer, N; Budker, D; Harabati, C; Dzuba, V A; Flambaum, V V

    2013-08-02

    We report a joint test of local Lorentz invariance and the Einstein equivalence principle for electrons, using long-term measurements of the transition frequency between two nearly degenerate states of atomic dysprosium. We present many-body calculations which demonstrate that the energy splitting of these states is particularly sensitive to violations of both special and general relativity. We limit Lorentz violation for electrons at the level of 10(-17), matching or improving the best laboratory and astrophysical limits by up to a factor of 10, and improve bounds on gravitational redshift anomalies for electrons by 2 orders of magnitude, to 10(-8). With some enhancements, our experiment may be sensitive to Lorentz violation at the level of 9 × 10(-20).

  18. Nonlinear optical properties of lutetium and dysprosium bisphthalocyanines at 1550 nm with femto- and nanosecond pulse excitation

    Science.gov (United States)

    Plekhanov, A. I.; Basova, T. V.; Parkhomenko, R. G.; Gürek, A. G.

    2017-02-01

    In this work, the nonlinear optical properties of unsubstituted lutetium (LuPc2) and dysprosium (DyPc2) bisphthalocyanines as well as octasubstituted Lu(PcR8)2 derivative with R=-S(C6H13) were studied at a wavelength of 1550 nm with 10 ns and 300 fs pulses. Based on Z-scan measurements the nonlinear absorption and refraction coefficient as well as the nature of nonlinear optical properties were analyzed for these materials. Open aperture Z-scan indicates strong two-photon absorption in all three bisphthalocyanines in nano- and femtosecond regimes. With good nonlinear optical coefficients, bisphthalocyanines of rare earth elements are expected to be promising materials for the creation of optical limiters.

  19. Infrared spectroscopic investigation of CO adsorption on SBA-15- and KIT-6-supported nickel phosphide hydrotreating catalysts.

    Science.gov (United States)

    Korányi, Tamás I; Pfeifer, Eva; Mihály, Judith; Föttinger, Karin

    2008-06-12

    The infrared (IR) spectra of CO adsorbed on 10, 20, and 30 wt % nickel phosphide-containing reduced SBA-15 and KIT-6 mesoporous silica-supported catalysts have been studied at 300-473 K. On the catalysts containing a stoichiometric amount of phosphorus with 20 wt % loading, the most intense IR absorption band was observed at 2097-2099 cm(-1), which was assigned to CO terminally bonded to coordinatively unsaturated Ni(delta+) (0 hydrotreating catalytic activity. The modified Ni-P charge distribution, the mode of CO adsorption on surface nickel phosphide sites, as well as the acidity can be directly connected to the catalytic activity of these mesoporous silica-supported catalysts.

  20. Zinc phosphide toxicities among patients of the University of Benin Teaching Hospital, Benin city, Nigeria: A 10 year experience

    Directory of Open Access Journals (Sweden)

    S E Aghahowa

    2012-01-01

    Full Text Available Background: Due to the poor success rate associated with zinc phosphide ingestion, it became necessary to assess the incidence. Objective: To assess the incidence of zinc phosphide toxicities reported between June 2000 and June 2009 in the University of Benin Teaching Hospital, Benin City, Nigeria. Material and Method : Data were sourced from the archives of casualties of zinc phosphide poisoning. These were entered into a generated case data form after obtaining an ethical permission. Results: All the ages of the 23 casualties reported were within 37.74±13.20 years. The male-female ratio was 4.75:1. Nineteen [78.26%] died after reporting 13.52±11.34 hours following single ingestion. Twenty cases were due to suicidal tendencies; the most common reason given was because of frustration in life related to marital affairs. Among the three unintentional, two were accidental while the other was due to assassination. Postmortem was refused in all the patients that died. One attempted herbal medication. Oil and milk were the most frequent solvents used at home as first-aid care therapy. Three were unintentional. Nine came with empty sachets and containers brought by relatives. Sodium chloride intravenous infusion was the most frequently used. Duration of hospitalization was 13.38±15.60 hours. Intravenous ciprofloxacin and metronidazole were the most common antibiotics used. Oxygen was instituted in 78.26% of the victims during respiratory distress. One ate meal prepared from poisoned rodent and died after reporting. One had alcohol along with the Zinc Phosphide ingestion. Nine were reported at the drug and poison information centre. Conclusion: Attention is needed by all for proper regulation in the handling of poisons and related substances to reduce burden minimally.

  1. Comparative Efficacy of Bromadiolone, Cholecalciferol and Zinc Phosphide Against Short -Tailed Mole Rat Nesokia indica in Captivity

    OpenAIRE

    PERVEZ, Amjad; AHMAD, Syed M.; Waqar, S; RIZVI, A.

    1998-01-01

    We conducted no-choice and paired choice feeding trials with individually caged Nesokia indica to evaluate the efficacy of Bromadiolone, Cholecalciferol and Zinc phosphide baits. Under no-choice test (1 day and 3 day) male rats consumed less bromadiolone bait. However, sex-wise difference was observed non-significant. Under choice feeding test, difference between bromadiolone bait intake and sex was observed non-significant. Under cholecalciferol bait, treated bait was consumed more than ...

  2. Rodenticide Comparative Effect of Klerat® and Zinc Phosphide for Controlling Zoonotic Cutaneous Leishmaniasis in Central Iran

    Directory of Open Access Journals (Sweden)

    Arshad VEYSI

    2016-12-01

    Full Text Available Background: Zoonotic cutaneous leishmaniasis (ZCL is a neglected disease with public health importance that is common in many rural areas of Iran. In recent years, behavioral resistance and/or bait shyness against the common rodenticide among reservoir hosts of ZCL have been reported. The aim of this study was to evaluate the effectiveness of Klerat® and zinc phosphide against natural reservoir of ZCL.Methods: This survey was carried out in four villages located 45 to 95 km far from Esfahan City Esfahan province, central Iran from April to November 2011. The rodent burrows were counted destroyed and reopened holes baited around all villages. Effect of rodent control operation on the main vector density and incidence of ZCL were evaluated.Results: The reduction rate of rodent burrows after intervention calculated to be at 62.8% in Klerat® and 58.15% in zinc phosphide treated areas. Statistical analysis showed no difference between the densities of the vector in indoors and outdoors in intervention and control areas. The incidence of the disease between treated and control areas after intervention was statistically different (P< 0.05.Conclusion: Klerat® could be a suitable alternative for zinc phosphide in a specific condition such as behavior resistance or occurrence of bait shyness.

  3. A preliminary identification of insect successive wave in Egypt on control and zinc phosphide-intoxicated animals in different seasons

    Directory of Open Access Journals (Sweden)

    Marah Mohammad Abd El-Bar

    2016-09-01

    Full Text Available The presented study aimed primarily to document a baseline data of the decay process of rabbits and guinea pigs and their associated arthropod fauna, which are placed in an urban city: El Abbassyia, Cairo Governorate, Egypt, during winter and summer seasons, and to compare these data with the corresponding figure for zinc phosphide-intoxicated carrions. Generally, control rabbits and control guinea pigs were faster in their decay comparing the corresponding figure of the zinc phosphide–intoxicated group. A delay in colonization of insects was noticed either in the winter season for both groups, or additionally for the zinc phosphide groups. The associated insect fauna was represented in 6 orders, 20 families, and 36 genera and species. Necrophagous arthropods that supported decomposition of carcasses were mainly of orders Diptera and Coleoptera. Calliphoridae was the first insect family that colonized the different carcasses. The mean numbers of control immature dipterous maggots and similarly, the control coleopteran larvae significantly exceeded the corresponding mean numbers for the zinc phosphide-intoxicated groups in both winter and summer seasons in either rabbits or guinea pig groups. Moreover, the mean numbers of dipterous maggots or coleopteran larvae of rabbits significantly surpassed the corresponding figures for guinea pigs in both seasons. This study may add as a reference for the succession wave arthropod fauna in Cairo Governorate in winter and summer seasons. Moreover, it is the first record of the arthropod successive wave on zinc phosphide–intoxicated remains.

  4. Ensembles of indium phosphide nanowires: physical properties and functional devices integrated on non-single crystal platforms

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Nobuhiko P.; Lohn, Andrew; Onishi, Takehiro [University of California, Santa Cruz (United States). Baskin School of Engineering; NASA Ames Research Center, Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, Univ. of California Santa Cruz, Moffett Field, CA (United States); Mathai, Sagi; Li, Xuema; Straznicky, Joseph; Wang, Shih-Yuan; Williams, R.S. [Hewlett-Packard Laboratories, Information and Quantum Systems Laboratory, Palo Alto, CA (United States); Logeeswaran, V.J.; Islam, M.S. [University of California Davis, Electrical and Computer Engineering, Davis, CA (United States)

    2009-06-15

    A new route to grow an ensemble of indium phosphide single-crystal semiconductor nanowires is described. Unlike conventional epitaxial growth of single-crystal semiconductor films, the proposed route for growing semiconductor nanowires does not require a single-crystal semiconductor substrate. In the proposed route, instead of using single-crystal semiconductor substrates that are characterized by their long-range atomic ordering, a template layer that possesses short-range atomic ordering prepared on a non-single-crystal substrate is employed. On the template layer, epitaxial information associated with its short-range atomic ordering is available within an area that is comparable to that of a nanowire root. Thus the template layer locally provides epitaxial information required for the growth of semiconductor nanowires. In the particular demonstration described in this paper, hydrogenated silicon was used as a template layer for epitaxial growth of indium phosphide nanowires. The indium phosphide nanowires grown on the hydrogenerated silicon template layer were found to be single crystal and optically active. Simple photoconductors and pin-diodes were fabricated and tested with the view towards various optoelectronic device applications where group III-V compound semiconductors are functionally integrated onto non-single-crystal platforms. (orig.)

  5. A Plasma-Assisted Route to the Rapid Preparation of Transition-Metal Phosphides for Energy Conversion and Storage

    KAUST Repository

    Liang, Hanfeng

    2017-06-06

    Transition-metal phosphides (TMPs) are important materials that have been widely used in catalysis, supercapacitors, batteries, sensors, light-emitting diodes, and magnets. The physical and chemical structure of a metal phosphide varies with the method of preparation as the electronic, catalytic, and magnetic properties of the metal phosphides strongly depend on their synthesis routes. Commonly practiced processes such as solid-state synthesis and ball milling have proven to be reliable routes to prepare TMPs but they generally require high temperature and long reaction time. Here, a recently developed plasma-assisted conversion route for the preparation of TMPs is reviewed, along with their applications in energy conversion and storage, including water oxidation electrocatalysis, sodium-ion batteries, and supercapacitors. The plasma-assisted synthetic route should open up a new avenue to prepare TMPs with tailored structure and morphology for various applications. In fact, the process may be further extended to the synthesis of a wide range of transition-metal compounds such as borides and fluorides at low temperature and in a rapid manner.

  6. One-step synthesis of nickel and cobalt phosphide nanomaterials via decomposition of hexamethylenetetramine-containing precursors.

    Science.gov (United States)

    Yao, Zhiwei; Wang, Guanzhang; Shi, Yan; Zhao, Yu; Jiang, Jun; Zhang, Yichi; Wang, Haiyan

    2015-08-21

    Dispersed pure phases of Ni2P and Co2P nanoparticles with high surface areas were prepared from one-step decomposition of hexamethylenetetramine (HMT)-containing precursors under an inert atmosphere. The solids before and after decomposition and the evolution of gas during the processes were studied by various characterization techniques. The HMT precursors underwent three decomposition stages: low-, moderate- and high-temperature stages. The formation of phosphides was observed at the high-temperature decomposition stage, in which Ni (Co) and P species were reduced by the decomposition products (C, H2 and CH4) of HMT to yield Ni (Co) phosphides, with the release of COx and H2O. Note that in contrast to the traditional H2-temperature-programmed reduction (H2-TPR) method, the HMT-based method produced CO as a major gas product rather than H2O. The better dispersions and higher surface areas of the as-prepared phosphide nanoparticles were achieved probably due to the mitigation of hydrothermal sintering.

  7. Spectroscopic data of the 1.8-, 2.9-, and 4.3- mu m transitions in dysprosium-doped gallium lanthanum sulfide glass

    Science.gov (United States)

    Schweizer, T.; Hewak, D. W.; Samson, B. N.; Payne, D. N.

    1996-10-01

    Infrared emission at 1.8, 2.9, and 4.3 mu m is measured in dysprosium-doped gallium lanthanum sulfide (Ga:La:S) glass excited at 815 nm. Emission cross sections were calculated by Judd-Ofelt analysis, the Fuchtbauer-Ladenburg equation, and the theory of McCumber. The sigma tau value for the 4.3- mu m transition is \\similar 4000 times larger in the Ga:La:S glass than in a dysprosium-doped LiYF4 crystal, which has lased on this transition. The large sigma tau value and the recently reported ability of Ga:La:S glass to be fabricated into fiber form show the potential for an efficient, low-threshold mid-infrared fiber laser. The fluorescence peak at 4.3 mu m coincides with the fundamental absorption of atmospheric carbon dioxide, making the glass a potential laser source for gas-sensing applications.

  8. Spectroscopic data of the 1.8-, 2.9-, and 4.3-microm transitions in dysprosium-doped gallium lanthanum sulfide glass.

    Science.gov (United States)

    Schweizer, T; Hewak, D W; Samson, B N; Payne, D N

    1996-10-01

    Infrared emission at 1.8, 2.9, and 4.3 microm is measured in dysprosium-doped gallium lanthanum sulfide (Ga:La:S) glass excited at 815 nm. Emission cross sections were calculated by Judd-Ofelt analysis, the Füchtbauer- Ladenburg equation, and the theory of McCumber. The sigmatau value for the 4.3-microm transition is ~4000 times larger in the Ga:La:S glass than in a dysprosium-doped LiYF(4) crystal, which has lased on this transition. The large sigmatau value and the recently reported ability of Ga:La:S glass to be fabricated into fiber form show the potential for an efficient, low-threshold mid-infrared fiber laser. The f luorescence peak at 4.3 microm coincides with the fundamental absorption of atmospheric carbon dioxide, making the glass a potential laser source for gas-sensing applications.

  9. On-line complexation/cloud point preconcentration for the sensitive determination of dysprosium in urine by flow injection inductively coupled plasma-optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Claudia; Cerutti, Soledad; Silva, Maria F. [Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700, San Luis (Argentina); Olsina, Roberto A.; Martinez, Luis D. [Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700, San Luis (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Avda. Rivadavia 1917, CP C1033AAJJ, Buenos Aires (Argentina)

    2003-01-01

    An on-line dysprosium preconcentration and determination system based on the hyphenation of cloud point extraction (CPE) to flow injection analysis (FIA) associated with ICP-OES was studied. For the preconcentration of dysprosium, a Dy(III)-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex was formed on-line at pH 9.22 in the presence of nonionic micelles of PONPE-7.5. The micellar system containing the complex was thermostated at 30 C in order to promote phase separation, and the surfactant-rich phase was retained in a microcolumn packed with cotton at pH 9.2. The surfactant-rich phase was eluted with 4 mol L{sup -1} nitric acid at a flow rate of 1.5 mL min{sup -1}, directly in the nebulizer of the plasma. An enhancement factor of 50 was obtained for the preconcentration of 50 mL of sample solution. The detection limit value for the preconcentration of 50 mL of aqueous solution of Dy was 0.03 {mu}g L{sup -1}. The precision for 10 replicate determinations at the 2.0 {mu}g L{sup -1}Dy level was 2.2% relative standard deviation (RSD), calculated from the peak heights obtained. The calibration graph using the preconcentration system for dysprosium was linear with a correlation coefficient of 0.9994 at levels near the detection limits up to at least 100 {mu}g L {sup -1}. The method was successfully applied to the determination of dysprosium in urine. (orig.)

  10. Ellipsometric analysis and optical absorption characterization of gallium phosphide nanoparticulate thin film

    Institute of Scientific and Technical Information of China (English)

    Zhang Qi-Xian; Wei Wen-Sheng; Ruan Fang-Ping

    2011-01-01

    Gallium phosphide (GaP)nanoparticulate thin films were easily fabricated by colloidal suspension deposition via GaP nanoparticles dispersed in N,N-dimethylformamide. The microstructure of the film was performed by x-ray diffraction, high resolution transmission electron microscopy and field emission scanning electron microscopy. The film was further investigated by spectroscopic ellipsometry.After the model GaP+void|Si02 was built and an effective medium approximation was adopted, the values of the refractive index n and the extinction coefficient k were calculated for the energy range of 0.75 eV-4.0 eV using the dispersion formula in DeltaPsi2 software. The absorption coefficient of the film was calculated from its k and its energy gaps were further estimated according to the Tauc equation, which were further verified by its fluorescence spectrum measurement. The structure and optical absorption properties of the nanoparticulate films are promising for their potential applications in hybrid solar cells.

  11. Planar array antenna with director on indium phosphide substrate for 300GHz wireless link

    Science.gov (United States)

    Kanaya, Haruichi; Oda, Tomoki; Iizasa, Naoto; Kato, Kazutoshi

    2016-02-01

    This paper presents a design and fabrication of 1 x 4 one-sided directional slot array antenna with director metal layer on indium phosphide (InP) substrate for 300 GHz wireless link. The floating metal and polyimide dielectric layer are stacked on InP. Antenna is designed on the top metal layer. By optimizing the length of the bottom floating metal layer, one-sided directional radiation can be realized. The branched coplanar wave guide (CPW) transmission line is connected to each antenna element with the same electrical length. The size of the 1 x 4 array antenna is 2,550 µm x 1,217 µm x 18 µm. In order to enhance the gain of forward direction, director metal layer is placed over 83 µm from top metal layer. Simulated realized gain in peak direction of our antenna is 9.23 dBi. The measured center frequency is almost the same as that of the simulation results.

  12. Physical properties of new cerium palladium phosphide with C6Cr23-type structure

    Directory of Open Access Journals (Sweden)

    T. Abe

    2014-01-01

    Full Text Available We have found that a cerium palladium phosphide crystallizes into a C6Cr23-type structure with atomic disorder. Prepared polycrystalline samples show a homogeneity range in the ternary Ce–Pd–P phase diagram. The physical properties of the highest-quality sample of Ce2.4Pd20.7P5.9 were investigated by measuring the magnetization, electrical resistivity and specific heat. No pronounced phase transition was observed down to 0.5 K. The Kondo screening of localized 4f electrons in metallic Ce2.4Pd20.7P5.9 appears to be weaker than that in the isostructural compounds of Ce3Pd20Si6 and Ce3Pd20Ge6. By a comparative study of Ce2.4Pd20.7P5.9 and Ce3Pd20X6 (X = Si, Ge, the competition between the Kondo temperature and ordering temperatures including the quadrupolar ordering temperature is briefly discussed.

  13. V{sub 18}P{sub 9}C{sub 2}. A complex phosphide carbide

    Energy Technology Data Exchange (ETDEWEB)

    Boller, Herbert [Linz Univ. (Austria). Inst. fuer Anorganische Chemie; Effenberger, Herta [Wien Univ. (Austria). Inst. fuer Mineralogie und Kristallographie

    2016-08-01

    V{sub 18}P{sub 9}C{sub 2} crystallizes in the orthorhombic space group Pmma with the lattice parameters a = 17.044(3), b = 3.2219(7), and c = 13.030(2) Aa, Z = 2. The crystal structure is composed of 19 symmetry-independent atoms. The crystal structure is considered as a network formed by the transition metal atoms exhibiting cubic, trigonal prismatic, and octahedral voids centered by V, P, and C atoms, respectively. Vice versa, the V and P atoms form a three-dimensional network. The two CV{sub 6} octahedra are edge- and corner-connected to chains running parallel to [010]. The five unique P atoms are trigonal prismatically coordinated by V atoms with one to three faces capped again by a V atom. The V atoms have mainly cubic environments formed solely by V or by V and P atoms. V{sub 18}P{sub 9}C{sub 2} exhibits some structural relations to other compounds of the ternary system V-P-C as well as to other intermetallic phases. Despite the low carbon content, V{sub 18}P{sub 9}C{sub 2} is considered as a ternary compound rather than an interstitially stabilized (binary) phosphide in view of its special structural features.

  14. Effect of heat-treatment on the surface properties of gallium phosphide nanosolids by Raman spectroscopy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhaochun; YUE Longyi; GUO Jingkang

    2006-01-01

    Raman spectra of gallium phosphide (GaP) nanosolids (unheated and heat-treated at 598 and 723 K, respectively)were investigated. It was observed that both the longitudinal optical mode (LO) and the transverse optical mode (TO) displayed an asymmetry on the low-wavenumber side. The scattering bands were fitted to a sum of four Lorentzians which were assigned to the LO mode, surface phonon mode, TO mode, and a combination of Ga-O-P symmetric bending and sum band formed from the X-point TA + LA phonons, respectively. Analysis of the characteristic of surface phonon mode revealed that the surface phonon peak of the GaP nanosolids could be confirmed. In the infrared spectrum of the GaP nanoparticles, we observed the bands on account of symmetric stretching and bending of PO2, as well as stretching of Ga-O.The Raman scattering intensity arising from the Ga-O-P linkages increased as increasing the heat-treatment temperature.

  15. Growth and Photoelectrochemical Energy Conversion of Wurtzite Indium Phosphide Nanowire Arrays.

    Science.gov (United States)

    Kornienko, Nikolay; Gibson, Natalie A; Zhang, Hao; Eaton, Samuel W; Yu, Yi; Aloni, Shaul; Leone, Stephen R; Yang, Peidong

    2016-05-24

    Photoelectrochemical (PEC) water splitting into hydrogen and oxygen is a promising strategy to absorb solar energy and directly convert it into a dense storage medium in the form of chemical bonds. The continual development and improvement of individual components of PEC systems is critical toward increasing the solar to fuel efficiency of prototype devices. Within this context, we describe a study on the growth of wurtzite indium phosphide (InP) nanowire (NW) arrays on silicon substrates and their subsequent implementation as light-absorbing photocathodes in PEC cells. The high onset potential (0.6 V vs the reversible hydrogen electrode) and photocurrent (18 mA/cm(2)) of the InP photocathodes render them as promising building blocks for high performance PEC cells. As a proof of concept for overall system integration, InP photocathodes were combined with a nanoporous bismuth vanadate (BiVO4) photoanode to generate an unassisted solar water splitting efficiency of 0.5%.

  16. Bridging the Gap between Dielectric Nanophotonics and the Visible Regime with Effectively Lossless Gallium Phosphide Antennas.

    Science.gov (United States)

    Cambiasso, Javier; Grinblat, Gustavo; Li, Yi; Rakovich, Aliaksandra; Cortés, Emiliano; Maier, Stefan A

    2017-02-08

    We present all-dielectric gallium phosphide (GaP) nanoantennas as an efficient nanophotonic platform for surface-enhanced second harmonic generation (SHG) and fluorescence (SEF), showing negligible losses in the visible range. Employing single GaP nanodisks, we observe an increase of more than 3 orders of magnitude in the SHG conversion signal in comparison with the bulk. This constitutes an SHG efficiency as large as 0.0002%, which is to the best of our knowledge the highest yet achieved value for a single nano-object in the optical region. Furthermore, we show that GaP dimers with 35 nm gap can enhance up to 3600 times the fluorescence emission of dyes located in the gap of the nanoantenna. This is accomplished by a fluorescence lifetime reduction of at least 22 times, accompanied by a high-intensity field confinement in the gap region. These results open new avenues for low-loss nanophotonics in the optical regime.

  17. Two- versus three-dimensional quantum confinement in indium phosphide wires and dots.

    Science.gov (United States)

    Yu, Heng; Li, Jingbo; Loomis, Richard A; Wang, Lin-Wang; Buhro, William E

    2003-08-01

    The size dependence of the bandgap is the most identifiable aspect of quantum confinement in semiconductors; the bandgap increases as the nanostructure size decreases. The bandgaps in one-dimensional (1D)-confined wells, 2D-confined wires, and 3D-confined dots should evolve differently with size as a result of the differing dimensionality of confinement. However, no systematic experimental comparisons of analogous 1D, 2D or 3D confinement systems have been made. Here we report growth of indium phosphide (InP) quantum wires having diameters in the strong-confinement regime, and a comparison of their bandgaps with those previously reported for InP quantum dots. We provide theoretical evidence to establish that the quantum confinement observed in the InP wires is weakened to the expected extent, relative to that in InP dots, by the loss of one confinement dimension. Quantum wires sometimes behave as strings of quantum dots, and we propose an analysis to generally distinguish quantum-wire from quantum-dot behaviour.

  18. Photoluminescence blue shift of indium phosphide nanowire networks with aluminum oxide coating

    Energy Technology Data Exchange (ETDEWEB)

    Fryauf, David M.; Zhang, Junce; Norris, Kate J.; Diaz Leon, Juan J.; Oye, Michael M.; Kobayashi, Nobuhiko P. [Nanostructured Energy Conversion Technology and Research (NECTAR), Advanced Studies Laboratories, University of California, Santa Cruz, CA (United States); Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA (United States); NASA Ames Research Center, Moffett Field, CA (United States); Wei, Min [Baskin School of Engineering, University of California Santa Cruz, Santa Cruz, CA (United States); School of Micro-Electronics and Solid-Electronics, University of Electronic Science and Technology of China, Chengdu (China)

    2014-07-15

    This paper describes our finding that optical properties of semiconductor nanowires were modified by depositing a thin layer of metal oxide. Indium phosphide nanowires were grown by metal organic chemical vapor deposition on silicon substrates with gold catalyst resulting in three-dimensional nanowire networks, and optical properties were obtained from the collective nanowire networks. The networks were coated with an aluminum oxide thin film deposited by plasma-enhanced atomic layer deposition. We studied the dependence of the peak wavelength of photoluminescence spectra on the thickness of the oxide coatings. A continuous blue shift in photoluminescence spectra was observed when the thickness of the oxide coating was increased. The observed blue shift is attributed to the Burstein-Moss effect due to increased carrier concentration in the nanowire cores caused by repulsion from intrinsic negative fixed charges located at the inner oxide surface. Samples were further characterized by scanning electron microscopy, Raman spectroscopy, transmission electron microscopy, and selective area diffractometry to better understand the physical mechanisms for the blue shift. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Observation of three-component fermions in the topological semimetal molybdenum phosphide

    Science.gov (United States)

    Lv, B. Q.; Feng, Z.-L.; Xu, Q.-N.; Gao, X.; Ma, J.-Z.; Kong, L.-Y.; Richard, P.; Huang, Y.-B.; Strocov, V. N.; Fang, C.; Weng, H.-M.; Shi, Y.-G.; Qian, T.; Ding, H.

    2017-06-01

    In quantum field theory, Lorentz invariance leads to three types of fermion—Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.

  20. Submillimeter sources for radiometry using high power Indium Phosphide Gunn diode oscillators

    Science.gov (United States)

    Deo, Naresh C.

    1990-01-01

    A study aimed at developing high frequency millimeter wave and submillimeter wave local oscillator sources in the 60-600 GHz range was conducted. Sources involved both fundamental and harmonic-extraction type Indium Phosphide Gunn diode oscillators as well as varactor multipliers. In particular, a high power balanced-doubler using varactor diodes was developed for 166 GHz. It is capable of handling 100 mW input power, and typically produced 25 mW output power. A high frequency tripler operating at 500 GHz output frequency was also developed and cascaded with the balanced-doubler. A dual-diode InP Gunn diode combiner was used to pump this cascaded multiplier to produce on the order of 0.5 mW at 500 GHz. In addition, considerable development and characterization work on InP Gunn diode oscillators was carried out. Design data and operating characteristics were documented for a very wide range of oscillators. The reliability of InP devices was examined, and packaging techniques to enhance the performance were analyzed. A theoretical study of a new class of high power multipliers was conducted for future applications. The sources developed here find many commercial applications for radio astronomy and remote sensing.

  1. Heterogeneous Bimetallic Phosphide/Sulfide Nanocomposite for Efficient Solar-Energy-Driven Overall Water Splitting.

    Science.gov (United States)

    Xin, Yanmei; Kan, Xiang; Gan, Li-Yong; Zhang, Zhonghai

    2017-09-14

    Solar-driven overall water splitting is highly desirable for hydrogen generation with sustainable energy sources, which need efficient, earth-abundant, robust, and bifunctional electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, we propose a heterogeneous bimetallic phosphide/sulfide nanocomposite electrocatalyst of NiFeSP on nickel foam (NiFeSP/NF), which shows superior electrocatalytic activity of low overpotentials of 91 mV at -10 mA cm(-2) for HER and of 240 mV at 50 mA cm(-2) for OER in 1 M KOH solution. In addition, the NiFeSP/NF presents excellent overall water splitting performance with a cell voltage as low as 1.58 V at a current density of 10 mA cm(-2). Combining with a photovoltaic device of a Si solar cell or integrating into photoelectrochemical (PEC) systems, the bifunctional NiFeSP/NF electrocatalyst implements unassisted solar-driven water splitting with a solar-to-hydrogen conversion efficiency of ∼9.2% and significantly enhanced PEC performance, respectively.

  2. Low resistance silver contacts to indium phosphide - Electrical and metallurgical considerations

    Science.gov (United States)

    Weizer, Victor G.; Fatemi, Navid S.

    1993-03-01

    The electrical and metallurgical behavior of the Ag-InP contact system has been investigated. Specific contact resistivity (Rc) values in the low 10 exp -6 Ohm sq cm range are readily achieved on n-InP (Si: 1.7 x 10 exp 18/cu cm) after sintering at 400 C for several minutes. The low Rc values, however, are shown to be accompanied by dissolution of InP into the metallization, resulting in device degradation. An analysis of the sinter-induced metallurgical interactions shows this system to be similar to the well-characterized Au-InP system, albeit with fundamental differences. The similarities include the dissociative diffusion of In, the reaction-suppressing effect of SiO2 capping, and especially, the formation of a phosphide layer at the metal-InP interface. The low post-sinter Rc values in the Ag-InP system may be due to the presence of a AgP2 layer at the metal-InP interface; low values of Rc can be achieved without incurring device degrading metallurgical interactions by introducing a thin AgP2 layer between the InP and the current carrying metallization.

  3. ROLE OF C AND P SITES ON THE CHEMICAL ACTIVITY OF METAL CARBIDE AND PHOSPHIDES: FROM CLUSTERS TO SINGLE-CRYSTAL SURFACES

    Energy Technology Data Exchange (ETDEWEB)

    RODRIGUEZ,J.A.; VINES, F.; LIU, P.; ILLAS, F.

    2007-07-01

    Transition metal carbides and phosphides have shown tremendous potential as highly active catalysts. At a microscopic level, it is not well understood how these new catalysts work. Their high activity is usually attributed to ligand or/and ensemble effects. Here, we review recent studies that examine the chemical activity of metal carbide and phosphides as a function of size, from clusters to extended surfaces, and metal/carbon or metal/phosphorous ratio. These studies reveal that the C and P sites in these compounds cannot be considered as simple spectators. They moderate the reactivity of the metal centers and provide bonding sites for adsorbates.

  4. Synthesis and Crystal Structure of Tri-(2-mercaptopyridine N-oxide)bis(dimethyl sulfoxide) Dysprosium(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A range of rare earth metal complexes of 2-mercaptopyridine N-oxide (Hmpo) have been synthesized, and studied by elemental analysis and IR spectroscopic technique. Crystal structure of Dy(mpo)3(DMSO)2 (DMSO = dimethyl sulfoxide) has been determined. The complex crystallizes in the triclinic system, space group Pī with lattice parameters: a = 9.602(3), b = 9.803(3), c = 15.498(5)A, α= 89.51(1), β= 85.73(1), γ= 62.99(1)°, Dc = 1.787 g/cm3, C19H24N3O5S5Dy, Mr = 697.21, Z = 2, F(000) = 690, μ = 3.321mm-1, the final R = 0.0237 and wR = 0.0587 for 4116 reflections with I>σ2(I). The coordination number of dysprosium Ⅲ is eight, and its coordination geometry is a somewhat distorted square antiprism with O(3), O(4), O(5), S(3) and O(1), O(2), S(1), S(2) at the tetragonal bases (dihedral angle between their mean planes is 2.9(1)0). Around the Dy atom, three five-membered ring planes (Dy, O, N, C, S) make the dihedral angles of 74.42, 11.31 and 83.72, respectively.

  5. Photo-, cathodo- and thermoluminescent properties of dysprosium-doped HfO2 films deposited by ultrasonic spray pyrolysis.

    Science.gov (United States)

    Manríquez, R Reynoso; Góngora, J A I Díaz; Guzmán-Mendoza, J; Montalvo, T Rivera; Olguín, J C Guzmán; Ramírez, P V Cerón; García-Hipólito, M; Falcony, C

    2014-09-01

    In this work, the photoluminescent (PL), cathodoluminescent (CL) and thermoluminescent (TL) properties of hafnium oxide films doped with trivalent dysprosium ions are reported. The films were deposited on glass substrates at temperatures ranging from 300 to 600°C, using chlorides as precursor reagents. The surface morphology of films showed a veins shaped microstructure at low deposition temperatures, while at higher temperatures the formation of spherical particles was observed on the surface. X-ray diffraction showed the presence of HfO2 monoclinic phase in the films deposited at temperatures greater than 400°C. The PL and CL spectra of the doped films showed the highest emission band centered at 575nm corresponding to the transitions (4)F9/2→(6)H13/2, which is a characteristic transition of Dy(3+) ion. The greatest emission intensities were observed in samples doped with 1 atomic percent (at%) of DyCl3 in the precursor solution. Regarding the TL behavior, the glow curve of HfO2:Dy(+3) films exhibited spectrum with one broad band centered at about 150°C. The highest intensity TL response was observed on the films deposited at 500°C. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Workplace testing of the new single sphere neutron spectrometer based on Dysprosium activation foils (Dy-SSS)

    Science.gov (United States)

    Bedogni, R.; Gómez-Ros, J. M.; Esposito, A.; Gentile, A.; Chiti, M.; Palacios-Pérez, L.; Angelone, M.; Tana, L.

    2012-08-01

    A photon insensitive passive neutron spectrometer consisting of a single moderating polyethylene sphere with Dysprosium activation foils arranged along three perpendicular axes was designed by CIEMAT and INFN. The device is called Dy-SSS (Dy foil-based Single Sphere Spectrometer). It shows nearly isotropic response in terms of neutron fluence up to 20 MeV. The first prototype, previously calibrated with 14 MeV neutrons, has been recently tested in workplaces having different energy and directional distributions. These are a 2.5 MeV nearly mono-chromatic and mono-directional beam available at the ENEA Frascati Neutron Generator (FNG) and the photo-neutron field produced in a 15 MV Varian CLINAC DHX medical accelerator, located in the Ospedale S. Chiara (Pisa). Both neutron spectra are known through measurements with a Bonner Sphere Spectrometer. In both cases the experimental response of the Dy-SSS agrees with the reference data. Moreover, it is demonstrated that the spectrometric capability of the new device are independent from the directional distribution of the neutron field. This opens the way to a new generation of moderation-based neutron instruments, presenting all advantages of the Bonner sphere spectrometer without the disadvantage of the repeated exposures. This concept is being developed within the NESCOFI@BTF project of INFN (Commissione Scientifica Nazionale 5).

  7. Ferroelectric properties of dysprosium-doped Bi4Ti3O12 thin films crystallized in various atmospheres

    Institute of Scientific and Technical Information of China (English)

    CHENG Chuan-pin; TANG Ming-hua; YE Zhi; ZHOU Yic-hun; ZHENG Xue-jun; ZHONG Xiang-li; HU Zeng-shun

    2006-01-01

    Dysprosium-doped Bi4Ti3O12 (Bi3.4Dy0.6Ti3O12,BDT) ferroelectric thin films were deposited on Pt(111)/Ti/SiO2/Si(111) substrates by chemical solution deposition (CSD) and crystallized in nitrogen,air and oxygen atmospheres,respectively. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to identify the crystal structure,the surface and cross-section morphology of the deposited ferroelectric films. The results show that the crystallization atmosphere has significant effect on determining the crystallization and ferroelectric properties of the BDT films. The film crystallized in nitrogen at a relatively low temperature of 650 ℃,exhibits excellent crystallinity and ferroelectricity with a remanent polarization of 2Pr = 24.9 μC/cm2 and a coercive field of 144.5 kV/cm. While the films annealed in air and oxygen at 650 ℃ do not show good crystallinity and ferroelectricity until they are annealed at 700 ℃. The structure evolution and ferroelectric properties of BDT thin films annealed under different temperatures (600-750 ℃) were also investigated. The crystallinity of the BDT films is improved and the average grain size increases when the annealing temperature increases from 600 ℃ to 750 ℃ at an interval of 50 ℃. However,the polarization of the films is not monotonous function of the annealing temperature.

  8. A numerical simulation study of gallium-phosphide/silicon heterojunction passivated emitter and rear solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Hannes [Department of Solar Energy, Institute Solid-State Physics, Leibniz University of Hannover, Appelstr. 2, 30167 Hannover (Germany); ARC Photovoltaics Centre of Excellence, University of New South Wales (UNSW), Sydney, NSW 2052 (Australia); Ohrdes, Tobias [Institute for Solar Energy Research Hamelin (ISFH), 31860 Emmerthal (Germany); Dastgheib-Shirazi, Amir [Div. Photovoltaics, Department of Physics, University of Konstanz, 78457 Konstanz (Germany); Puthen-Veettil, Binesh; König, Dirk [ARC Photovoltaics Centre of Excellence, University of New South Wales (UNSW), Sydney, NSW 2052 (Australia); Altermatt, Pietro P. [Department of Solar Energy, Institute Solid-State Physics, Leibniz University of Hannover, Appelstr. 2, 30167 Hannover (Germany)

    2014-01-28

    The performance of passivated emitter and rear (PERC) solar cells made of p-type Si wafers is often limited by recombination in the phosphorus-doped emitter. To overcome this limitation, a realistic PERC solar cell is simulated, whereby the conventional phosphorus-doped emitter is replaced by a thin, crystalline gallium phosphide (GaP) layer. The resulting GaP/Si PERC cell is compared to Si PERC cells, which have (i) a standard POCl{sub 3} diffused emitter, (ii) a solid-state diffused emitter, or (iii) a high efficiency ion-implanted emitter. The maximum efficiencies for these realistic PERC cells are between 20.5% and 21.2% for the phosphorus-doped emitters (i)–(iii), and up to 21.6% for the GaP emitter. The major advantage of this GaP hetero-emitter is a significantly reduced recombination loss, resulting in a higher V{sub oc}. This is so because the high valence band offset between GaP and Si acts as a nearly ideal minority carrier blocker. This effect is comparable to amorphous Si. However, the GaP layer can be contacted with metal fingers like crystalline Si, so no conductive oxide is necessary. Compared to the conventional PERC structure, the GaP/Si PERC cell requires a lower Si base doping density, which reduces the impact of the boron-oxygen complexes. Despite the lower base doping, fewer rear local contacts are necessary. This is so because the GaP emitter shows reduced recombination, leading to a higher minority electron density in the base and, in turn, to a higher base conductivity.

  9. A numerical simulation study of gallium-phosphide/silicon heterojunction passivated emitter and rear solar cells

    Science.gov (United States)

    Wagner, Hannes; Ohrdes, Tobias; Dastgheib-Shirazi, Amir; Puthen-Veettil, Binesh; König, Dirk; Altermatt, Pietro P.

    2014-01-01

    The performance of passivated emitter and rear (PERC) solar cells made of p-type Si wafers is often limited by recombination in the phosphorus-doped emitter. To overcome this limitation, a realistic PERC solar cell is simulated, whereby the conventional phosphorus-doped emitter is replaced by a thin, crystalline gallium phosphide (GaP) layer. The resulting GaP/Si PERC cell is compared to Si PERC cells, which have (i) a standard POCl3 diffused emitter, (ii) a solid-state diffused emitter, or (iii) a high efficiency ion-implanted emitter. The maximum efficiencies for these realistic PERC cells are between 20.5% and 21.2% for the phosphorus-doped emitters (i)-(iii), and up to 21.6% for the GaP emitter. The major advantage of this GaP hetero-emitter is a significantly reduced recombination loss, resulting in a higher Voc. This is so because the high valence band offset between GaP and Si acts as a nearly ideal minority carrier blocker. This effect is comparable to amorphous Si. However, the GaP layer can be contacted with metal fingers like crystalline Si, so no conductive oxide is necessary. Compared to the conventional PERC structure, the GaP/Si PERC cell requires a lower Si base doping density, which reduces the impact of the boron-oxygen complexes. Despite the lower base doping, fewer rear local contacts are necessary. This is so because the GaP emitter shows reduced recombination, leading to a higher minority electron density in the base and, in turn, to a higher base conductivity.

  10. Exploiting the P L2,3 absorption edge for optics: spectroscopic and structural characterization of cubic boron phosphide thin films

    NARCIS (Netherlands)

    Huber, S.P.; Medvedev, V.V.; Meyer-Ilse, J.; Gullikson, E.; Padavala, B.; Edgar, J.H.; Sturm, J.M.; Kruijs, van de R.W.E.; Prendergast, D.; Bijkerk, F.

    2016-01-01

    The transmission of cubic boron phosphide (c-BP) thin films, prepared by chemical vapor deposition (CVD), was evaluated near the phosphorous L2,3 and boron K absorption edge. The c-BP films were analyzed with transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray ab

  11. Oxidation does not (always) kill reactivity of transition metals: solution-phase conversion of nanoscale transition metal oxides to phosphides and sulfides.

    Science.gov (United States)

    Muthuswamy, Elayaraja; Brock, Stephanie L

    2010-11-17

    Unexpected reactivity on the part of oxide nanoparticles that enables their transformation into phosphides or sulfides by solution-phase reaction with trioctylphosphine (TOP) or sulfur, respectively, at temperatures of ≤370 °C is reported. Impressively, single-phase phosphide products are produced, in some cases with controlled anisotropy and narrow polydispersity. The generality of the approach is demonstrated for Ni, Fe, and Co, and while manganese oxides are not sufficiently reactive toward TOP to form phosphides, they do yield MnS upon reaction with sulfur. The reactivity can be attributed to the small size of the precursor particles, since attempts to convert bulk oxides or even particles with sizes approaching 50 nm were unsuccessful. Overall, the use of oxide nanoparticles, which are easily accessed via reaction of inexpensive salts with air, in lieu of organometallic reagents (e.g., metal carbonyls), which may or may not be transformed into metal nanoparticles, greatly simplifies the production of nanoscale phosphides and sulfides. The precursor nanoparticles can easily be produced in large quantities and stored in the solid state without concern that "oxidation" will limit their reactivity.

  12. Sensitive search for the temporal variation of the fine structure constant using radio-frequency E1 transitions in atomic dysprosium

    CERN Document Server

    Nguyen, A T; Lamoreaux, S K; Torgerson, J R

    2003-01-01

    It has been proposed that the radio-frequency electric-dipole (E1) transition between two nearly degenerate opposite-parity states in atomic dysprosium should be highly sensitive to possible temporal variation of the fine structure constant ($\\alpha$) [V. A. Dzuba, V. V. Flambaum, and J. K. Webb, Phys. Rev. A {\\bf 59}, 230 (1999)]. We discuss here an experimental realization of the proposed search, which involves monitoring the E1 transition frequency over a period of time using direct frequency counting techniques. We estimate that a statistical sensitivity of $|\\adota| \\sim 10^{-18}$/yr may be achieved and discuss possible systematic effects in such a measurement.

  13. Surface-oxidized cobalt phosphide used as high efficient electrocatalyst in activated carbon air-cathode microbial fuel cell

    Science.gov (United States)

    Yang, Tingting; Wang, Zhong; Li, Kexun; Liu, Yi; Liu, Di; Wang, Junjie

    2017-09-01

    Herein, we report a simplistic method to fabricate the surface-oxidized cobalt phosphide (CoP) nanocrystals (NCs), which is used as electrocatalyst for oxygen reduction reaction (ORR) in microbial fuel cell (MFC) for the first time. The corallite-like CoP NCs are successfully prepared by a hydrothermal reaction following a phosphating treatment in N2 atmosphere. When used as an ORR catalyst, cobalt phosphide shows comparable onset potential, inferior resistance, as well as a small Tafel slope with long-term stability in neutral media. The maximum power density of MFC embellished with 10% CoP reached 1914.4 ± 59.7 mW m-2, which is 108.5% higher than the control. The four-electron pathway, observed by the RDE, plays a crucial role in electrochemical catalytic activity. In addition, material characterizations indicate that the surface oxide layer (CoOx) around the metallic CoP core is important and beneficial for ORR. Accordingly, it can be expected that the as-synthesized CoP will be a promising candidate of the non-precious metal ORR electrocatalysts for electrochemical energy applications.

  14. Electrocatalytic and photocatalytic hydrogen production from acidic and neutral-pH aqueous solutions using iron phosphide nanoparticles.

    Science.gov (United States)

    Callejas, Juan F; McEnaney, Joshua M; Read, Carlos G; Crompton, J Chance; Biacchi, Adam J; Popczun, Eric J; Gordon, Thomas R; Lewis, Nathan S; Schaak, Raymond E

    2014-11-25

    Nanostructured transition-metal phosphides have recently emerged as Earth-abundant alternatives to platinum for catalyzing the hydrogen-evolution reaction (HER), which is central to several clean energy technologies because it produces molecular hydrogen through the electrochemical reduction of water. Iron-based catalysts are very attractive targets because iron is the most abundant and least expensive transition metal. We report herein that iron phosphide (FeP), synthesized as nanoparticles having a uniform, hollow morphology, exhibits among the highest HER activities reported to date in both acidic and neutral-pH aqueous solutions. As an electrocatalyst operating at a current density of -10 mA cm(-2), FeP nanoparticles deposited at a mass loading of ∼1 mg cm(-2) on Ti substrates exhibited overpotentials of -50 mV in 0.50 M H2SO4 and -102 mV in 1.0 M phosphate buffered saline. The FeP nanoparticles supported sustained hydrogen production with essentially quantitative faradaic yields for extended time periods under galvanostatic control. Under UV illumination in both acidic and neutral-pH solutions, FeP nanoparticles deposited on TiO2 produced H2 at rates and amounts that begin to approach those of Pt/TiO2. FeP therefore is a highly Earth-abundant material for efficiently facilitating the HER both electrocatalytically and photocatalytically.

  15. Study of laboratory profile in patients with aluminium phosphide poisoning in the southwest of Iran from 2010 to 2015

    Directory of Open Access Journals (Sweden)

    Farkhonde Jamshidi

    2017-03-01

    Full Text Available Introduction : Aluminium phosphide or rice tablet is one of the most common pesticides around the world. The substance releases phosphine gas in the presence of water, steam or stomach acid which can lead to poisoning. Phosphine poisoning is more about suicide the number of which is increasing day by day. Two-thirds of patients lose their lives. The aim of this study was to evaluate the data on the clinical epidemiology and laboratory changes in patients poisoned with rice tablets. Material and methods : A total of 23 patients poisoned by aluminium phosphide who referred to Ahvaz Razi hospital within the period of 2010–2015 were studied. The data were analyzed using descriptive statistics and statistical tests. Results : The mean age of the patients was 27.2 ±7.3 years and 60.9% of the patients were male. 8.7% of the patients had hyponatremia and 21.7% of the patients had hypokalemia. In the majority of cases the amount of sodium and potassium was normal. 91% of patients had acidosis and serum bicarbonate was reduced in the majority of cases. The average interval between poisoning and admission was 1.48 ±0.76 hours. Conclusions : The pattern to change the electrolytes and other laboratory factors could be a good marker of the severity of the poisoning and the clinical conditions of the patient, which requires more specific research to prove the process.

  16. Dysprosium doping induced shape and magnetic anisotropy of Fe3-xDyxO4 (x=0.01-0.1) nanoparticles

    Science.gov (United States)

    Jain, Richa; Luthra, Vandna; Gokhale, Shubha

    2016-09-01

    The effect of dysprosium doping on evolution of structural and magnetic properties of magnetite (Fe3O4) nanoparticles is reported. A standard route of co-precipitation was used for the synthesis of undoped and doped magnetite nanoparticles Fe3-xDyxO4 (x=0.0-0.1). Transmission electron microscopy (TEM) shows formation of round shaped particles with diameter in the range of 8-14 nm for undoped sample. On doping beyond x=0.01, the formation of rod like structures is initiated along with the round shaped particles. The number of rods is found to increase with increasing doping concentration. Magnetic characterization using Vibrating Sample Magnetometer (VSM) revealed doping dependent magnetic properties which can be correlated with the crystallite size as determined from X-ray diffraction (XRD). Enhancement in the saturation magnetization in the initial stages of doping can be explained on the basis of incorporation of Dy3+ ions in the inverse spinel structure at the octahedral site in place of Fe3+ ions. Subsequent decrease in saturation magnetization observed beyond x=0.03 could be attributed to precipitation of excess Dy in form of dysprosium ferrite phase.

  17. Mössbauer Spectroscopy Investigation and Hydrodesulfurization Properties of Iron–nickel Phosphide Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Gaudette, Amy F.; Burns, Autumn W.; Hayes, John R.; Smith, Mica C.; Bowker, Richard H.; Seda, Takele; Bussell, Mark E.

    2010-05-25

    Unsupported and silica-supported FexNi2-xPy catalysts having a range of metal compositions (0 < x 6 2.0) were investigated using Mössbauer spectroscopy, and the results correlated with the surface and hydrodesulfurization (HDS) properties of the supported catalysts. Mössbauer spectroscopy permits determination of the relative site occupancy of Fe atoms in tetrahedral (M(1)) and pyramidal (M(2)) sites in the FexNi2-xPy materials. Fe atoms preferentially occupy M(2) sites for materials with significant Fe contents (x > ~0.60), but the Fe site preference reverses as the Fe content decreases (x < ~0.60). Similar occupation trends are observed for the unsupported and silica-supported FexNi2-xPy materials. Thiophene HDS measurements of the FexNi2-xPy/SiO2 catalysts revealed catalysts with high Fe contents (0.80 6 x 6 2.00) to have low activities, while the activities of Ni-rich catalysts increased dramatically with increased Ni content (0.03 6 x 6 0.60). The highest HDS activity was measured for a catalyst having a nominal precursor composition of Fe0.03Ni1.97P2.00/SiO2; this catalyst was 40% more active than a optimized nickel phosphide catalyst prepared from a precursor having a nominal composition of Ni2.00P1.60/SiO2. The 25 wt.% Fe0.03Ni1.97P2.00/SiO2 catalyst also had a dibenzothiophene HDS activity just over 10% higher than that of the 25 wt.% Ni2.00P1.60/SiO2 catalyst at 548 K. The trend of increasing HDS activity for the FexNi2-xPy/ SiO2 catalysts correlates with preferential Fe occupation of M(1) sites (and, therefore, Ni occupation of M(2) sites). Supported by X-ray photoelectron spectroscopy and oxygen chemisorption measurements, we conclude that the high activity of Ni-rich FexNi2-xPy/SiO2 catalysts can be traced to a high surface density of Ni in M(2) sites that are resistant to site blockage due to S incorporation.

  18. Aluminum phosphide poisoning known as rice tablet: A common toxicity in North Iran

    Directory of Open Access Journals (Sweden)

    A Hosseinian

    2011-01-01

    Full Text Available Background: Aluminum phosphide (ALP is a highly effective insecticide and rodenticide used frequently to protect stored grain. Acute poisoning with this compound is common in some countries including India and Iran, and is a serious health problem. Aim: The objective of this study was to survey ALP poisoning locally known as "Rice Tablet" and the outcome in a referral poisoning hospital in Mazandaran province, northern part of Iran. Materials and Methods: The study was a cross-sectional study from March 2007 to February 2008. Records of all patients admitted and hospitalized to a referral teaching hospital during the 2 year period were collected. Information including gender, age, cause of toxicity, amount of AIP consumed, route of exposure, time between exposure and hospital admission, signs and symptoms of toxicity at admission, therapeutic intervention, laboratory tests, and outcome were extracted from the patients′ notes. Patients who died and survived were compared using appropriate statistical tests. Results: During the two-year period, 102 patients, 46 men and 56 women with mean (±SD age 28.5 ± 12.4 year were admitted with ALP poisoning. The most common signs and symptoms at admission were nausea (79.4%, vomiting (76.5%, and abdominal pain (31.4%. 41.1% of the patients showed metabolic acidosis. Suicidal intention was the most common cause of poisoning (97% leading to 19 (18.6% deaths. Compared with the patients who survived, those who died had taken higher amount of ALP tablet (2.2 ± 2.4 vs. 1.4 ± 1.0, P < 0.05, had poor liver function test (P < 0.0001 and severe metabolic acidosis (pH: 7.17 ± 0.19 vs. 7.33 ± 0.08, P < 0.0001. Conclusion: ALP poisoning is a common toxicity in Iran causing high morality. This is a serious health problem in agricultural region where ALP is readily available. Withdrawal of ALP tablet from the market and introduction of safer products as rodenticides and insecticides is recommended.

  19. Characterization of the Absolute Crystal Polarity across Twin Boundaries in Gallium Phosphide Using Convergent-Beam Electron Diffraction.

    Science.gov (United States)

    Cohen; McKernan; Carter

    1999-05-01

    : The measurement of absolute crystal polarity is crucial to understanding the structural properties of many planar defects in compound semiconductors. Grain boundaries, including twin boundaries, in the sphalerite lattice are uniquely characterized by the crystallographic misorientation of individual grains and the direction of the crystal polarity in domains adjoining the grain boundary. To evaluate crystal polarity in gallium phosphide (GaP), asymmetrical interference contrast in convergent-beam electron-diffraction (CBED) patterns was used to ascertain the nature and direction of polar bonds. The direction of the asymmetry in the electron diffraction reflections was correlated with the crystal polarity of a sample with known polarity. The CBED technique was applied to determine the polar orientation of grains adjoining Sigma = 3 coherent and lateral twin boundaries in polycrystalline GaP.

  20. Facile synthesis of iron phosphide Fe{sub 2}P nanoparticle and its catalytic performance in thiophene hydrodesulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiang, E-mail: huangxianghd@gmail.com; Dong, Qing; Huang, He; Yue, Li; Zhu, Zhibin; Dai, Jinhui [Ocean University of China, Institute of Materials Science and Engineering (China)

    2014-12-15

    Nanosized iron phosphide (Fe{sub 2}P) was successfully synthesized under mild solvothermal conditions with environmental-friendly raw materials. The key synthetic parameters including the molar ratios of Fe/P in initial mixture, the solvothermal treatment temperature, and duration were systematically investigated, and the samples were characterized using X-ray diffraction, energy dispersive spectroscopy, and transmission electron microscopy. These measurements indicated that the nanoparticles are pure Fe{sub 2}P with an average particle size of about 20 nm. Furthermore, the catalytic performance of the as-synthesized Fe{sub 2}P/ZSM-5 in thiophene hydrodesulfurization was tested. The results showed that the desulfurization efficiency of thiophene can reach up to 88 % after 3 h with a stable catalytic activity during the whole examination process.

  1. In-situ potentiostatic activation to optimize electrodeposited cobalt-phosphide electrocatalyst for highly efficient hydrogen evolution in alkaline media

    Science.gov (United States)

    Wei, Mengmeng; Yang, Liming; Wang, Longlu; Liu, Tian; Liu, Chengbin; Tang, Yanhong; Luo, Shenglian

    2017-08-01

    We first report a novel cobalt-phosphide (Co-P) hybrid with flake-like structure by a facile one-step electrodeposition combined with in-situ potentiostatic activation technique. Exotic microstructure transformation of Co-P hybrid from microspheres to nanosheets has been noted during the activation process. The Co-P catalyst exhibits striking kinetic metrics with an overpotential of 85 mV (at 10 mA cm-2) and Tafel slope of 37 mV dec-1, performing among the best of all the HER catalysts in strong alkaline media (at pH 14). This study offers a new in-situ approach to optimize catalytic materials for high-performance electrocatalysts towards energy-related applications.

  2. 25th anniversary article: exploring nanoscaled matter from speciation to phase diagrams: metal phosphide nanoparticles as a case of study.

    Science.gov (United States)

    Carenco, Sophie; Portehault, David; Boissière, Cédric; Mézailles, Nicolas; Sanchez, Clément

    2014-01-22

    The notions of nanoscale "phase speciation" and "phase diagram" are defined and discussed in terms of kinetic and thermodynamic controls, based on the case of metal phosphide nanoparticles. After an overview of the most successful synthetic routes for these exotic nanomaterials, the cases of InP, Ni2 P, Ni12 P5 and Pdx Py are discussed in detail to highlight the relationship between composition, structure, and size at the nanoscale. The influence of morphology is discussed next by comparing the behavior of Cu3 P nanophases with those of Nix Py , FeP/Fe2 P, and CoP/Co2 P. Perspectives provide the reader with methodological guidelines for further investigation of nanoscale "phase diagrams", and their use for optimized synthesis of new functional nanomaterials.

  3. Probing hydrodesulfurization over bimetallic phosphides using monodisperse Ni2-xMxP nanoparticles encapsulated in mesoporous silica

    Science.gov (United States)

    Danforth, Samuel J.; Liyanage, D. Ruchira; Hitihami-Mudiyanselage, Asha; Ilic, Boris; Brock, Stephanie L.; Bussell, Mark E.

    2016-06-01

    Metal phosphide nanoparticles encapsulated in mesoporous silica provide a well-defined system for probing the fundamental chemistry of the hydrodesulfurization (HDS) reaction over this new class of hydrotreating catalysts. To investigate composition effects in bimetallic phosphides, the HDS of dibenzothiophene (DBT) was carried out over a series of Ni-rich Ni2-xMxP@mSiO2 (M = Co, Fe) nanocatalysts (x ≤ 0.50). The Ni2-xMxP nanoparticles (average diameters: 11-13 nm) were prepared by solution-phase arrested precipitation and encapsulated in mesoporous silica, characterized by a range of techniques (XRD, TEM, IR spectroscopy, BET surface area, CO chemisorption) and tested for DBT HDS activity and selectivity. The highest activity was observed for a Ni1.92Co0.08P@mSiO2 nanocatalyst, but the overall trend was a decrease in HDS activity with increasing Co or Fe content. In contrast, the highest turnover frequency (TOF) was observed for the most Co- and Fe-rich compositions based on sites titrated by CO chemisorption. IR spectral studies of adsorbed CO on the Ni2-xMxP@mSiO2 catalysts indicate that an increase in electron density occurs on Ni sites as the Co or Fe content is increased, which may be responsible for the increased TOFs of the catalytic sites. The Ni2-xMxP@mSiO2 nanocatalysts exhibit a strong preference for the direct desulfurization pathway (DDS) for DBT HDS that changes only slightly with increasing Co or Fe content.

  4. In situ X-ray absorption fine structure studies on the structure of nickel phosphide catalyst supported on K-USY

    CERN Document Server

    Kawai, T; Suzuki, S

    2003-01-01

    Local structure around Ni in a nickel phosphide catalyst supported on K-USY was investigated by an situ X-ray absorption fine structure (XAFS) method during the reduction process of the catalyst and the hydrodesulfurization (HDS) reaction of thiophene. In the passivated sample, Ni phosphide was partially oxidized but after the reduction, 1.1 nm diameter Ni sub 2 P particles were formed with Ni-P and Ni-Ni distances at 0.218 and 0.261 nm, respectively, corresponding to those of bulk Ni sub 2 P. In situ XAFS cleary revealed that the Ni sub 2 P structure was stable under reaction conditions and was an active structure for the HDS process.

  5. Proposing Boric Acid as an Antidote for Aluminium Phosphide Poisoning by Investigation of the Chemical Reaction Between Boric Acid and Phosphine

    OpenAIRE

    Motahareh Soltani; Seyed Farid Shetab-Boushehri; Hamidreza Mohammadi; Seyed Vahid Shetab-Boushehri

    2013-01-01

    Aluminium phosphide (AlP) is a storage fumigant pesticide, which is used to protect stored grains especially from insects and rodents. It releases phosphine (PH3) gas, a highly toxic mitochondrial poison, in contact with moisture, particularly if acidic. Although the exact mechanism of action is unknown so far, the major mechanism of PH3 toxicity seems to be the inhibition of cytochrome-c oxidase and oxidative phosphorylation which eventually results in adenosine triphosphate (ATP) depletion ...

  6. Comparative Study on the Effectiveness of Coumavec® and Zinc Phosphide in Controlling Zoonotic Cutaneous Leishmaniasis in a Hyperendemic Focus in Central Iran

    Directory of Open Access Journals (Sweden)

    A Veysi

    2012-06-01

    Full Text Available Background: Zoonotic cutaneous leishmaniasis (ZCL is an increasing health problems in many rural areas of Iran. The aim of this study was to introduce a new alternative rodenticide to control the reservoirs of ZCL, its effect on the vector density and the incidence of the disease in hyperendemic focus of Esfa­han County, central Iran.Methods: The study was carried out from January 2011 to Janu­ary 2012. In intervention areas, rodent control operation was conducted using zinc phosphide or Coumavec®. Active case findings were done by house-to-house visits once every season during 2011–2012. To evaluate the effect of rodent control operation on the vector density, sand flies were collected twice a month using sticky traps.Results: The reduction rate of rodent holes in intervention areas with Coumavec® and zinc phosphide were 48.46% and 58.15% respectively, whereas in control area results showed 6.66 folds intensification. The Incidence of ZCL significantly reduced in the treated areas. Totally, 3200 adult sand flies were collected and identified in the inter­vention and control areas. In the treated area with zinc phosphide, the density of Phlebotomus papatasi was higher in outdoors in contrast with the treated area by Coumavec® which the density of the sand fly was higher in indoors. Conclusion: Both rodenticides were effective on the incidence of ZCL and the population of the reservoirs as well. Coumavec® seems to be effective on the outdoor density of the vector. This combination of rodenticide-insecticide could be a suitable alternative for zinc phosphide while bait shyness or behavioral resistance is occurred.

  7. Single-molecule magnet behavior in an octanuclear dysprosium(iii) aggregate inherited from helical triangular Dy3 SMM-building blocks.

    Science.gov (United States)

    Zhang, Li; Zhang, Peng; Zhao, Lang; Wu, Jianfeng; Guo, Mei; Tang, Jinkui

    2016-06-28

    An unprecedented octanuclear dysprosium(iii) cluster with the formula [Dy8L6(μ3-OH)4(μ2-CH3O)2(CH3OH)6(H2O)2]·6H2O·10CH3OH·2CH3CN () based on a nonlinearly tritopic aroylhydrazone ligand H3L has been isolated, realizing the successful linking of pairwise interesting triangular Dy3 SMMs. It is noteworthy that two enantiomers (Λ and Δ configurations) individually behaving as a coordination-induced chirality presented in the Dy3 helicate are connected in the meso Dy8 cluster. Remarkably, alternating-current magnetic susceptibility measurements revealed that the Dy8 cluster shows typical SMM behavior inherited from its Dy3 helical precursor. It is one of the rare polynuclear Lnn SMMs (n > 7) under zero dc field.

  8. Another challenge to paramagnetic relaxation theory: a study of paramagnetic proton NMR relaxation in closely related series of pyridine-derivatised dysprosium complexes.

    Science.gov (United States)

    Rogers, Nicola J; Finney, Katie-Louise N A; Senanayake, P Kanthi; Parker, David

    2016-02-14

    Measurements of the relaxation rate behaviour of two series of dysprosium complexes have been performed in solution, over the field range 1.0 to 16.5 Tesla. The field dependence has been modelled using Bloch-Redfield-Wangsness theory, allowing estimates of the electronic relaxation time, T1e, and the size of the magnetic susceptibility, μeff, to be made. Changes in relaxation rate of the order of 50% at higher fields were measured, following variation of the para-substituent in the single pyridine donor. The magnetic susceptibilities deviated unexpectedly from the free-ion values for certain derivatives in each series examined, in a manner that was independent of the electron-releasing/withdrawing ability of the pyridine substituent, suggesting that the polarisability of just one pyridine donor in octadenate ligands can play a significant role in defining the magnetic susceptibility anisotropy.

  9. Studies of high temperature ternary phases in mixed-metal-rich early transition metal sulfide and phosphide systems

    Energy Technology Data Exchange (ETDEWEB)

    Marking, G.A.

    1994-01-04

    Investigations of ternary mixed early transition metal-rich sulfide and phosphide systems resulted in the discovery of new structures and new phases. A new series of Zr and Hf - group V transition metal - sulfur K-phases was synthesized and crystallographically characterized. When the group V transition metal was Nb or Ta, the unit cell volume was larger than any previously reported K-phase. The presence of adventitious oxygen was determined in two K-phases through a combination of neutron scattering and X-ray diffraction experiments. A compound Hf{sub 10}Ta{sub 3}S{sub 3} was found to crystallize in a new-structure type similar to the known gamma brasses. This structure is unique in that it is the only reported {open_quotes}stuffed{close_quotes} gamma-brass type structure. The metal components, Hf and Ta, are larger in size and more electropositive than the metals found in normal gamma brasses (e.g. Cu and Zn) and because of the larger metallic radii, sulfur can be incorporated into the structure where it plays an integral role in stabilizing this phase relative to others. X-ray single-crystal, X-ray powder and neutron powder refinements were performed on this structure. A new structure was found in the ternary Nb-Zr-P system which has characteristics in common with many known early transition metal-rich sulfides, selenides, and phosphides. This structure has the simplest known interconnection of the basic building blocks known for this structural class. Anomalous scattering was a powerful tool for differentiating between Zr and Nb when using Mo K{alpha} X-radiation. The compounds ZrNbP and HfNbP formed in the space group Prima with the simple Co{sub 2}Si structure which is among the most common structures found for crystalline solid materials. Solid solution compounds in the Ta-Nb-P, Ta-Zr-P, Nb-Zr-P, Hf-Nb-P, and Hf-Zr-S systems were crystallographically characterized. The structural information corroborated ideas about bonding in metal-rich compounds.

  10. Mid-infrared tunable, narrow-linewidth difference-frequency laser based on orientation-patterned gallium phosphide

    Science.gov (United States)

    Insero, G.; Clivati, C.; D’Ambrosio, D.; De Natale, P.; Santambrogio, G.; Schunemann, P. G.; Borri, S.; Zondy, J. J.

    2017-01-01

    We report on the first characterization of orientation-patterned gallium phosphide (OP-GaP) crystals used to generate narrow-linewidth, coherent mid-infrared (MIR) radiation at 5.85 μm by difference frequency generation (DFG) of continuous-wave (cw) Nd:YAG laser at 1064nm and diode-laser at 1301nm. By comparison of the experimental absolute MIR efficiency versus focusing to Gaussian beam DFG theory, we derive an effective nonlinear coefficient for first-order quasi-phase-matched OP-GaP at the generated DFG wavelength. Using d = (2/π)d 14 and taking into account Miller’s delta rule, we retrieve an absolute value of the d 14 quadratic nonlinear susceptibility coefficient of GaP of d 14 = 27.2(3) pm/V at 5.85 μm, in good agreement with the latest absolute measurement of this nonlinear coefficient from non-phase-matched second-harmonic generation (1.32 μm → 0.66 μm) taking into account multiple reflection effects [Shoji et al 1997 J. Opt. Soc. Am. B 14 2268]. The temperature and signal-wave tuning curves are also in qualitative agreement with a recently proposed temperature-dependent Sellmeier equation for OP-GaP when focusing effects are taken into account.

  11. Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning

    Science.gov (United States)

    Soltani, Motahareh; Shetab-Boushehri, Seyed F.; Shetab-Boushehri, Seyed V.

    2016-01-01

    Objectives: Aluminium phosphide (AlP) is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3), a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. Methods: This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Results: Activated charcoal significantly reduced the volume of released gas (P <0.01). Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01). A gaseous adduct was formed in the reaction between pure AlP and boric acid. Conclusion: These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning. PMID:27606109

  12. Pure and carbon-doped boron phosphide (6,0) zigzag nanotube: A computational NMR study

    Energy Technology Data Exchange (ETDEWEB)

    Arshadi, S., E-mail: sattar_arshadi@yahoo.com [Department of Chemistry, Payame Noor University, 19395-4697, I.R. of Iran (Iran, Islamic Republic of); Bekhradnia, A.R., E-mail: abekhradnia@gmail.com [Pharmaceutical Sciences Research Center, Department of Medicinal Chemistry, Mazandaran University of Medical Sciences, Sari (Iran, Islamic Republic of); Department of Chemistry and Molecular Biology, Gothenburg University, Gothenburg (Sweden); Alipour, F.; Abedini, S. [Department of Chemistry, Payame Noor University, 19395-4697, I.R. of Iran (Iran, Islamic Republic of)

    2015-11-15

    Calculations were performed for investigation of the properties of the electronic structure of Carbon- Doped Boron Phosphide Nanotube (CDBPNT). Pristine and three models of C-doped structures of (6,0) zigzag BPNT were studied at density functional theory (DFT) in combination with 6-311G* basis set using Gaussian package of program. The calculated parameters reveal that various {sup 11}B and {sup 31}P nuclei are divided into some layers with equivalent electrostatic properties. The electronic structure properties are highly influenced by replacement of {sup 11}B and {sup 31}P atoms by {sup 12}C atoms in pristine model. Furthermore, the HOMO−LUMO gap energy for suggested doped models (I), (II) and (III) were lower than pure BPNT pristine systems. The dipole moment values of models (II) and (III) were decreased to 1.788 and 1.789, respectively while the dipole moments of model (I) were enhanced to 4.373, in compare to pure pristine one (2.586). The magnitude of changes in Chemical Shielding (CS) tensor parameters revealed that the electron density at the site of {sup 31}P was higher than that at the site of {sup 11}B due to carbon doping.

  13. Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning.

    Science.gov (United States)

    Soltani, Motahareh; Shetab-Boushehri, Seyed F; Shetab-Boushehri, Seyed V

    2016-08-01

    Aluminium phosphide (AlP) is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3), a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Activated charcoal significantly reduced the volume of released gas (P boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P boric acid. These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning.

  14. Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Motahareh Soltani

    2016-08-01

    Full Text Available Objectives: Aluminium phosphide (AlP is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3, a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. Methods: This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Results: Activated charcoal significantly reduced the volume of released gas (P <0.01. Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01. A gaseous adduct was formed in the reaction between pure AlP and boric acid. Conclusion: These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning.

  15. Cobalt phosphide nanowall arrays supported on carbon cloth: an efficient monolithic non-noble-metal hydrogen evolution catalyst

    Science.gov (United States)

    Yang, Libin; Wang, Kunyang; Du, Gu; Zhu, Wenxin; Cui, Liang; Zhang, Chengxiao; Sun, Xuping; Asiri, Abdullah M.

    2016-11-01

    Hydrogen has been considered as an ideal energy carrier for replacing fossil fuels to mitigate global energy crises. Hydrolysis of sodium borohydride (NaBH4) is simple and effective for hydrogen production but needs active and durable catalysts to accelerate the kinetics. In this paper, we demonstrate that cobalt phosphide nanowall arrays supported on carbon cloth (CoP NAs/CC) efficiently catalyze the hydrolytic dehydrogenation of NaBH4 with an activation energy of 42.1 kJ mol-1 in alkaline media. These monolithic CoP NAs/CC show a maximum hydrogen generation rate of 5960 {{ml}} {{{\\min }}}-1 {{{{g}}}-1}({{CoP})} and are robust with superior durability and reusability. They are also excellent in activity and durability for electrochemical hydrogen evolution in 1.0 M KOH, with the need of an overpotential of only 80 mV to drive 10 mA cm-2. They offer us a promising low-cost hydrogen-generating catalyst for applications.

  16. Indium phosphide all air-gap Fabry-Pérot filters for near-infrared spectroscopic applications

    Science.gov (United States)

    Ullah, A.; Butt, M. A.; Fomchenkov, S. A.; Khonina, S. N.

    2016-08-01

    Food quality can be characterized by noninvasive techniques such as spectroscopy in the Near Infrared wavelength range. For example, 930 -1450 nm wavelength range can be used to detect diseases and differentiate between meat samples. Miniaturization of such NIR spectrometers is useful for quick and mobile characterization of food samples. Spectrometers can be miniaturized, without compromising the spectral resolution, using Fabry-Pérot (FP) filters consisting of two highly reflecting mirrors with a central cavity in between. The most commonly used mirrors in the design of FP filters are Distributed Bragg Reflections (DBRs) consisting of alternating high and low refractive index material pairs, due to their high reflectivity compared to metal mirrors. However, DBRs have high reflectivity for a selected range of wavelengths known as the stopband of the DBR. This range is usually much smaller than the sensitivity range of the spectrometer detector. Therefore, a bandpass filter is usually required to restrict wavelengths outside the stopband of the FP DBRs. Such bandpass filters are difficult to design and implement. Alternatively, high index contrast materials must be can be used to broaden the stopband width of the FP DBRs. In this work, Indium phosphide all air-gap filters are proposed in conjunction with InGaAs based detectors. The designed filter has a wide stopband covering the entire InGaAs detector sensitivity range. The filter can be tuned in the 950-1450 nm with single mode operation. The designed filter can hence be used for noninvasive meat quality control.

  17. Peapod-like composite with nickel phosphide nanoparticles encapsulated in carbon fibers as enhanced anode for li-ion batteries.

    Science.gov (United States)

    Zhang, Huijuan; Feng, Yangyang; Zhang, Yan; Fang, Ling; Li, Wenxiang; Liu, Qing; Wu, Kai; Wang, Yu

    2014-07-01

    Herein, we introduce a peapod-like composite with Ni12 P5 nanoparticles encapsulated in carbon fibers as the enhanced anode in Li-ion batteries for the first time. In the synthesis, NiNH4 PO4 ⋅H2 O nanorods act as precursors and sacrificial templates, and glucose molecules serve as the green carbon source. With the aid of hydrogen bonding between the precursor and carbon source, a polymer layer is hydrothermally formed and then rationally converted into carbon fibers upon inert calcination at elevated temperatures. Meanwhile, NiNH4 PO4 ⋅H2 O nanorods simultaneously turn into Ni12 P5 nanoparticles encapsulated in carbon fibers by undergoing a decomposition and reduction process induced by high temperature and the carbon fibers. The obtained composite performs excellently as a Li-ion batteries anode relative to pure-phase materials. Specific capacity can reach 600 m Ah g(-1) over 200 cycles, which is much higher than that of isolated graphitized carbon or phosphides, and reasonably believed to originate from the synergistic effect based on the combination of Ni12 P5 nanoparticles and carbon fibers. Due to the benignity, sustainability, low cost, and abundance of raw materials of the peapod-like composite, numerous potential applications, in fields such as optoelectronics, electronics, specific catalysis, gas sensing, and biotechnology can be envisaged.

  18. Tuning the composition and magnetostructure of dysprosium iron garnets by Co-substitution: An XRD, FT-IR, XPS and VSM study

    Energy Technology Data Exchange (ETDEWEB)

    Tholkappiyan, R.; Vishista, K., E-mail: raovishista@gmail.com

    2015-10-01

    Graphical abstract: - Highlights: • Garnet type Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} (x = 0–0.06) nanoparticles were synthesized by glycine assisted combustion method. • To investigate and confirm the phases in the synthesized ferrite nanoparticles by FT-IR and XRD analysis. • To investigate the compositional and oxidation state of the samples by X-ray photoelectron spectroscopy. • The detailed core level spectra of Dy 4d, Fe 2p, Co 2p and O 1s were analyzed using XPS. • The magnetic property was studied by VSM technique. - Abstract: We report the Co-substituting on the synthesis and properties of garnet type dysprosium ferrite nanoparticles by basic composition Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} (x = 0–0.06) synthesized through glycine assisted combustion method. A possible formation mechanism of synthesized Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} samples by controlling the synthesis process has been proposed. XRD, FT-IR, XPS and VSM studies were used to investigate the compositional and magnetostructural properties of the prepared nanoparticles. XRD results confirm that all the samples are single-phase cubic garnet structure with mean crystallite size of 97–105 nm obtained from Scherrer method and 95–102 nm from W–H method. FT-IR analysis shows the presence of three expected bands in the frequency limit of 450–600 cm{sup −1} attributed to metal–O stretching vibration in tetrahedral site of garnet structure. A typical survey spectrum from XPS results confirmed the presence of Dy, Fe, Co and O elements in the samples. This study also to characterize the different oxidation states of the samples by fitting the parameters of high resolution Dy 4d, Fe 2p, Co 2p and O 1s XPS spectra. The XPS data of Dy 4d spectrum show that Dy{sup 3+} ion occupy in dodecahedral (D) site. The XPS analysis of Fe 2p and Co 2p data suggests that (Fe{sup 3+} and Fe{sup 2+}), (Co{sup 3+} and Co{sup 2+}) are distributed in tetrahedral and octahedral sites

  19. Molecular fingerprint-region spectroscopy from 5 to 12  μm using an orientation-patterned gallium phosphide optical parametric oscillator.

    Science.gov (United States)

    Maidment, Luke; Schunemann, Peter G; Reid, Derryck T

    2016-09-15

    We report a femtosecond optical parametric oscillator (OPO) based on the new semiconductor gain material orientation-patterned gallium phosphide (OP-GaP), which enables the production of high-repetition-rate femtosecond pulses spanning 5-12 μm with average powers in the few to tens of milliwatts range. This is the first example of a broadband OPO operating across the molecular fingerprint region, and we demonstrate its potential by conducting broadband Fourier-transform spectroscopy using water vapor and a polystyrene reference standard.

  20. Molecular fingerprint-region spectroscopy from 5 to 12 μm using an orientation-patterned gallium phosphide optical parametric oscillator

    Science.gov (United States)

    Maidment, Luke; Schunemann, Peter G.; Reid, Derryck T.

    2016-09-01

    We report a femtosecond optical parametric oscillator (OPO) based on the new semiconductor gain material orientation patterned gallium phosphide (OP-GaP), which enables the production of high-repetition-rate femtosecond pulses spanning 5-12 \\mu m with average powers in the few to tens of milliwatts range. This is the first example of a broadband OPO operating across the molecular fingerprint region, and we demonstrate its potential by conducting broadband Fourier-transform spectroscopy using water vapor and a polystyrene reference standard.

  1. Molecular fingerprint-region spectroscopy from 5-12 \\mu m using an orientation-patterned gallium phosphide optical parametric oscillator

    CERN Document Server

    Maidment, Luke; Reid, Derryck T

    2016-01-01

    We report a femtosecond optical parametric oscillator (OPO) based on the new semiconductor gain material orientation patterned gallium phosphide (OP-GaP), which enables the production of high-repetition-rate femtosecond pulses spanning 5-12 \\mu m with average powers in the few to tens of milliwatts range. This is the first example of a broadband OPO operating across the molecular fingerprint region, and we demonstrate its potential by conducting broadband Fourier-transform spectroscopy using water vapor and a polystyrene reference standard.

  2. A dysprosium-based metal-organic framework: Synthesis, characterization, crystal structure and interaction with calf thymus-DNA and bovine serum albumin

    Indian Academy of Sciences (India)

    Biplab Mondal; Buddhadeb Sen; Ennio Zangrando; Pabitra Chattopadhyay

    2014-07-01

    A dysprosium-based metallo-organic framework (MOF) containing calcium ions formulated as {Dy(pyda)3Ca1.5(H2O)6} · 5.5H2O (1) (H2pyda = pyridine-2,6-dicarboxylic acid) was solvothermally synthesized in ethanolic medium and characterized by physico-chemical and spectroscopic tools. A detailed structural analysis of the solid state structure of 1 by single crystal X-ray diffraction study showed a tricapped trigonal prism geometry for lanthanide in the [Dy(pyda)3]3− fragment. The mode of interaction of 1 with calf thymus- DNA and with protein bovine serum albumin (BSA) was investigated by using absorption and emission spectroscopic tools. The apparent association constant of complex 1 with CT-DNA was deduced from an absorption spectral study (b = 4.08 × 104 M-1). Spectral and viscosity measurements indicated a groove-binding mode of 1 with CT-DNA, and from spectroscopic study the formation of a metal complex-BSA adduct was assumed to be the result of the interaction of 1 with BSA.

  3. Dual-mode T1 and T2 magnetic resonance imaging contrast agent based on ultrasmall mixed gadolinium-dysprosium oxide nanoparticles: synthesis, characterization, and in vivo application

    Science.gov (United States)

    Tegafaw, Tirusew; Xu, Wenlong; Wasi Ahmad, Md; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong; Lee, Gang Ho

    2015-09-01

    A new type of dual-mode T1 and T2 magnetic resonance imaging (MRI) contrast agent based on mixed lanthanide oxide nanoparticles was synthesized. Gd3+ (8S7/2) plays an important role in T1 MRI contrast agents because of its large electron spin magnetic moment resulting from its seven unpaired 4f-electrons, and Dy3+ (6H15/2) has the potential to be used in T2 MRI contrast agents because of its very large total electron magnetic moment: among lanthanide oxide nanoparticles, Dy2O3 nanoparticles have the largest magnetic moments at room temperature. Using these properties of Gd3+ and Dy3+ and their oxide nanoparticles, ultrasmall mixed gadolinium-dysprosium oxide (GDO) nanoparticles were synthesized and their potential to act as a dual-mode T1 and T2 MRI contrast agent was investigated in vitro and in vivo. The D-glucuronic acid coated GDO nanoparticles (davg = 1.0 nm) showed large r1 and r2 values (r2/r1 ≈ 6.6) and as a result clear dose-dependent contrast enhancements in R1 and R2 map images. Finally, the dual-mode imaging capability of the nanoparticles was confirmed by obtaining in vivo T1 and T2 MR images.

  4. Experimental and molecular dynamics studies of dysprosium(III) salt solutions for a better representation of the microscopic features used within the binding mean spherical approximation theory.

    Science.gov (United States)

    Ruas, Alexandre; Guilbaud, Philippe; Den Auwer, Christophe; Moulin, Christophe; Simonin, Jean-Pierre; Turq, Pierre; Moisy, Philippe

    2006-10-19

    This work is aimed at a predictive description of the thermodynamic properties of actinide(III) salt solutions at high concentration and 25 degrees C. A new solution of the binding mean spherical approximation (BIMSA) theory, based on the Wertheim formalism, for taking into account 1:1 and also 1:2 complex formation, is used to reproduce, from a simple procedure, experimental osmotic coefficient variation with concentration for three binary salt solutions of the same lanthanide(III) cation: dysprosium(III) perchlorate, nitrate, and chloride. The relevance of the fitted parameters is discussed, and their values are compared with available literature values. UV-vis/near-IR, time-resolved laser-induced fluorescence spectroscopy experiments, and molecular dynamics (MD) calculations were conducted for dilute to concentrated solutions (ca. 3 mol.kg-1) for a study of the microscopic behavior of DyCl3 binary solutions. Coupling MD calculations and extended X-ray absorption fine structure led to the determination of reliable distances. The MD results were used for a discussion of the parameters used in the BIMSA.

  5. Experimental and molecular dynamics studies of dysprosium(III) salt solutions for a better representation of the microscopic features used within the binding mean spherical approximation theory

    Energy Technology Data Exchange (ETDEWEB)

    Ruas, Alexandre; Guilbaud, Philippe; Den Auwer, Christophe; Moulin, Christophe; Simonin, Jean-Pierre; Turq, Pierre; Moisy, Philippe [DEN/DRCP/SCPS, CEA-Valrho Marcoule, BP 17171, 30207 Bagnols-sur-Ceze Cedex, DEN/DPC/SECR/LSRM, CEA-Saclay, Bat 391, BP 91191 Gif sur Yvette, Cedex (France); Laboratoire LI2C (UMR 7612), Universite Pierre et Marie Curie-Paris 6, Boite No. 51, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2006-07-01

    This work is aimed at a predictive description of the thermodynamic properties of actinide (III) salt solutions at high concentration and 25 deg. C. A new solution of the binding mean spherical approximation (BIMSA) theory, based on the Wertheim formalism, for taking into account 1: 1 and also 1: 2 complex formation, is used to reproduce, from a simple procedure, experimental osmotic coefficient variation with concentration for three binary salt solutions of the same lanthanide (III) cation: dysprosium (III) perchlorate, nitrate, and chloride. The relevance of the fitted parameters is discussed, and their values are compared with available literature values. UV-vis/near-IR, time-resolved laser-induced fluorescence spectroscopy experiments, and molecular dynamics (MD) calculations were conducted for dilute to concentrated solutions (ca. 3 mol, kg{sup -1}) for a study of the microscopic behavior of DyCl{sub 3} binary solutions. Coupling MD calculations and extended X-ray absorption fine structure led to the determination of reliable distances. The MD results were used for a discussion of the parameters used in the BIMSA. (authors)

  6. Elucidation of Dual Magnetic Relaxation Processes in Dinuclear Dysprosium(III) Phthalocyaninato Triple-Decker Single-Molecule Magnets Depending on the Octacoordination Geometry.

    Science.gov (United States)

    Katoh, Keiichi; Aizawa, Yu; Morita, Takaumi; Breedlove, Brian K; Yamashita, Masahiro

    2017-08-07

    When applying single-molecule magnets (SMMs) to spintronic devices, control of the quantum tunneling of the magnetization (QTM) as well as a spin-lattice interactions are important. Attempts have been made to use not only coordination geometry but also magnetic interactions between SMMs as an exchange bias. In this manuscript, dinuclear dysprosium(III) (Dy(III) ) SMMs with the same octacoordination geometry undergo dual magnetic relaxation processes at low temperature. In the dinuclear Dy(III) phthalocyaninato (Pc(2-) ) triple-decker type complex [(Pc)Dy(ooPc)Dy(Pc)] (1) (ooPc(2-) =2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato) with a square-antiprismatic (SAP) geometry, the ground state is divided by the Zeeman effect, and level intersection occurs when a magnetic field is applied. Due to the ground state properties of 1, since the Zeeman diagram where the levels intersect in an Hdc of 2500 Oe, two kinds of QTM and direct processes occur. However, dinuclear Dy(III) -Pc systems with C4 geometry, which have a twist angle (ϕ) of less than 45° do not undergo dual magnetic relaxation processes. From magnetic field and temperature dependences, the dual magnetic relaxation processes were clarified. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Annealing behaviour and crystal structure of RF-sputtered Bi-substituted dysprosium iron-garnet films having excess co-sputtered Bi-oxide content

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, M; Nur-E-Alam, M; Alameh, K [Electron Science Research Institute, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027 (Australia); Premchander, P; Lee, Y T [Department of Information and Communications, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712 (Korea, Republic of); Kotov, V A [Institute of Radio Engineering and Electronics, Russian Academy of Sciences, 11 Mohovaya St, Moscow, 125009 (Russian Federation); Lee, Y P, E-mail: m.vasiliev@ecu.edu.au [Quantum Photonic Science Research Center, Department of Physics, Hanyang University, 133-791 (Korea, Republic of)

    2011-02-23

    We investigate the magneto-optic properties, crystal structure and annealing behaviour of nano-composite media with record-high magneto-optic quality exceeding the levels reported so far in sputtered iron-garnet films. Bi-substituted dysprosium-gallium iron-garnet films having excess bismuth oxide content are deposited using RF co-sputtering, and a range of garnet materials are crystallized using conventional oven-annealing processes. We report, for the first time ever, the results of optimization of thermal processing regimes for various high-performance magneto-optic iron-garnet compositions synthesized and describe the evolution of the optical and magneto-optical properties of garnet-Bi-oxide composite-material films occurring during the annealing processes. The crystallization temperature boundaries of the system (BiDy){sub 3}(FeGa){sub 5}O{sub 12} : Bi{sub 2}O{sub 3} are presented. We also report the results of x-ray diffraction and energy-dispersive x-ray spectroscopy studies of this recently developed class of high-performance magneto-optic composites. Our hypothesis of iron oxides being the cause of excess optical absorption in sputtered Bi-iron-garnet films is confirmed experimentally.

  8. Oxidative stress determined through the levels of antioxidant enzymes and the effect of N-acetylcysteine in aluminum phosphide poisoning

    Directory of Open Access Journals (Sweden)

    Avinash Agarwal

    2014-01-01

    Full Text Available Introduction: The primary objective of this study was to determine the serum level of antioxidant enzymes and to correlate them with outcome in patients of aluminum phosphide (ALP poisoning and, secondly, to evaluate the effect of N-acetylcysteine (NAC given along with supportive treatment of ALP poisoning. Design: We conducted a cohort study in patients of ALP poisoning hospitalized at a tertiary care center of North India. The treatment group and control group were enrolled during the study period of 1 year from May 2011 to April 2012. Interventions: Oxidative stress was evaluated in each subject by estimating the serum levels of the enzymes, viz. catalase, superoxide dismutase (SOD and glutathione reductase (GR. The treatment group comprised of patients who were given NAC in addition to supportive treatment (magnesium sulfate and vasopressors, if required, while in the control group, only supportive treatment was instituted. The primary endpoint of the study was the survival of the patients. Measurements and Results: The baseline catalase (P = 0.008 and SOD (P < 0.01 levels were higher among survivors than non-survivors. Of the total patients in the study, 31 (67.4% expired and 15 (32.6% survived. Among those who expired, the mean duration of survival was 2.92 ± 0.40 days in the test group and 1.82 ± 0.33 days in the control group (P = 0.043. Conclusions: This study suggests that the baseline level of catalase and SOD have reduced in ALP poisoning, but baseline GR level has not suppressed but is rather increasing with due time, and more so in the treatment group. NAC along with supportive treatment may have improved survival in ALP poisoning.

  9. Tailored surface structure of LiFePO4/C nanofibers by phosphidation and their electrochemical superiority for lithium rechargeable batteries.

    Science.gov (United States)

    Lee, Yoon Cheol; Han, Dong-Wook; Park, Mihui; Jo, Mi Ru; Kang, Seung Ho; Lee, Ju Kyung; Kang, Yong-Mook

    2014-06-25

    We offer a brand new strategy for enhancing Li ion transport at the surface of LiFePO4/C nanofibers through noble Li ion conducting pathways built along reduced carbon webs by phosphorus. Pristine LiFePO4/C nanofibers composed of 1-dimensional (1D) LiFePO4 nanofibers with thick carbon coating layers on the surfaces of the nanofibers were prepared by the electrospinning technique. These dense and thick carbon layers prevented not only electrolyte penetration into the inner LiFePO4 nanofibers but also facile Li ion transport at the electrode/electrolyte interface. In contrast, the existing strong interactions between the carbon and oxygen atoms on the surface of the pristine LiFePO4/C nanofibers were weakened or partly broken by the adhesion of phosphorus, thereby improving Li ion migration through the thick carbon layers on the surfaces of the LiFePO4 nanofibers. As a result, the phosphidated LiFePO4/C nanofibers have a higher initial discharge capacity and a greatly improved rate capability when compared with pristine LiFePO4/C nanofibers. Our findings of high Li ion transport induced by phosphidation can be widely applied to other carbon-coated electrode materials.

  10. In situ XRD, XAS, and magnetic susceptibility study of the reduction of ammonium nickel phosphate NiNH4PO4 x H2O into nickel phosphide.

    Science.gov (United States)

    Berhault, Gilles; Afanasiev, Pavel; Loboué, Hermione; Geantet, Christophe; Cseri, Tivadar; Pichon, Christophe; Guillot-Deudon, Catherine; Lafond, Alain

    2009-04-06

    The reduction of the ammonium nickel phosphate NiNH(4)PO(4) x H(2)O precursor into nickel phosphide (Ni(2)P), a highly active phase in hydrotreating catalysis, was studied using a combination of magnetic susceptibility and in situ X-ray diffraction and X-ray absorption spectroscopy (XAS) techniques. The transformation of NiNH(4)PO(4) x H(2)O into Ni(2)P could be divided into three distinguishable zones: (1) from room temperature to 250 degrees C, the NiNH(4)PO(4) x H(2)O structure was essentially retained; (2) from 300 to 500 degrees C, only an amorphous phase was observed; (3) above 500 degrees C, a crystallization process occurred with the formation of Ni(2)P. An in situ XAS study and magnetic susceptibility measurements clearly revealed for the first time that the amorphous region corresponds to the nickel pyrophosphate phase alpha-Ni(2)P(2)O(7). The phosphate reduction into phosphide did not start before 550 degrees C and led to the selective formation of Ni(2)P at 650 degrees C.

  11. Global use structures of the magnetic materials neodymium and dysprosium. A scenario-based analysis of the effect of the diffusion of electromobility on the demand for rare earths; Globale Verwendungsstrukturen der Magnetwerkstoffe Neodym und Dysprosium. Eine szenariobasierte Analyse der Auswirkung der Diffusion der Elektromobilitaet auf den Bedarf an Seltenen Erden

    Energy Technology Data Exchange (ETDEWEB)

    Gloeser-Chahoud, Simon; Kuehn, Andre; Tercero Espinoza, Luis

    2016-06-15

    Neodymium-iron-boron magnets (NdFeB) have experienced a significant demand as the most powerful permanent magnet in recent years, especially for the manufacture of compact electric servomotors with high efficiency and high power density, especially for mobile applications in hybrid traction motors and electric vehicles or for electric bikes. However, NdFeB magnets are also increasingly being used in general mechanical engineering (conveying and pumping systems, tools, air conditioning systems, lift motors, etc.), in the small electric motors of conventional passenger cars or in the generators of large wind power plants with permanent magnetic direct drive. Nevertheless, there is still high uncertainty in the use structures of NdFeB magnets and the contained rare earth elements neodymium and dysprosium. An effective instrument for increasing the market transparency and the understanding of complex anthropogenic material cycles is the dynamic material flow modeling. In the present work paper, this instrument is used for an in-depth analysis of the use structures of NdFeB magnets and the contained rare earths on a global scale. The dynamic modeling of product usage cycles reveals today's usage structures and quantifies future magnetic quantities in obsolete product flows. It could be shown that the magnets in today's scrap volume are mainly contained in obsolete electronics applications such as hard disks (HDD), CD and DVD drives, which makes the recycling hardly seem to be economical due to the small magnets and the high material spread, but in the foreseeable future with larger magnetic quantities from synchronous servomotors and generators can be expected, which significantly increases the recycling potential. In a further step, the effect of the diffusion of alternative drives in the automotive market on the dysprosium requirement is analyzed using a system dynamics model and possible adaptation mechanisms in the form of different substitution effects in

  12. The role of dysprosium on the structural and magnetic properties of (Nd1-xDyx)2Fe14B nanoparticles

    Science.gov (United States)

    Rahimi, Hamed; Ghasemi, Ali; Mozaffarinia, Reza; Tavoosi, Majid

    2017-02-01

    In current work, Nd2Fe14B nanoparticles was synthesized by sol-gel method. Dysprosium powders were added into Nd2Fe14B nanoparticles by mechanical alloying process in order to enhancement of coercivity. The phase analysis, structure, and magnetic properties of annealed (Nd1-xDyx)2Fe14B nanoparticles with different Dy-content (x=0.1, 0.2, 0.3, 0.4, 0.5, 0.6) were investigated by employing X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, field emission scanning electron microscope, transmission electron microscope and vibrating sample magnetometer techniques. The results showed that with an increase in Dy amounts, the coercivity of particles increased from 2.9 kOe to 13.4 kOe and then decreased to 5.6 kOe. By adding an optimum amount of Dy (x=0.4), the coercivity was significantly increased from 2.9 kOe to 13.4 kOe. The average particle size of annealed (Nd1-xDyx)2Fe14B nanoparticles was below 10 nm. Magnetization reversal studies indicate that the coercivity of milled and annealed (Nd1-xDyx)2Fe14B nanoparticles is controlled by the nucleation of reversed magnetic domains. The experimental results in the angular dependence of coercivity for (Nd1-xDyx)2Fe14B permanent magnets showed that the normalized coercivity of the permanent magnets Hc(θ)/Hc(0) increases from 1 to about 1.2-1.5 with increasing θ from 0 to about π/3, for x=0.4-0.6.

  13. Design and fabrication of anti-reflection coating on Gallium Phosphide, Zinc Selenide and Zinc Sulfide substrates for visible and infrared application

    Directory of Open Access Journals (Sweden)

    Mokrý P.

    2013-05-01

    Full Text Available Results of design and fabrication of a dual-band anti-reflection coating on a gallium phosphide (GaP, zinc selenide (ZnSe and zinc sulfide (ZnS substrates are presented. A multilayer stack structure of antireflection coatings made of zinc sulfide and yttrium fluoride (YF3 was theoretically designed for optical bands between 0.8 and 0.9 μm and between 9.5 and 10.5 μm. This stack was designed as efficient for these materials (GaP, ZnS, ZnSe together. Multilayer stack structure was deposited using thermal evaporation method. Theoretically predicted transmittance spectra were compared with transmitted spectra measured on coated substrates. Efficiency of anti-reflection coating is estimated and discrepancies are analyzed and discussed.

  14. Thermal expansion, heat capacity and Grüneisen parameter of iridium phosphide Ir2P from quasi-harmonic Debye model

    Science.gov (United States)

    Liu, Z. J.; Song, T.; Sun, X. W.; Ma, Q.; Wang, T.; Guo, Y.

    2017-03-01

    Thermal expansion coefficient, heat capacity, and Grüneisen parameter of iridium phosphide Ir2P are reported by means of quasi-harmonic Debye model for the first time in the current study. This model combines with first-principles calculations within generalized gradient approximation using pseudopotentials and a plane-wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. The Debye temperature as a function of volume, the Grüneisen parameter, thermal expansion coefficient, constant-volume and constant-pressure heat capacities, and entropy on the temperature T are also successfully obtained. All the thermodynamic properties of Ir2P in the whole pressure range from 0 to 100 GPa and temperature range from 0 to 3000 K are summarized and discussed in detail.

  15. Results from Coupled Optical and Electrical Sentaurus TCAD Models of a Gallium Phosphide on Silicon Electron Carrier Selective Contact Solar Cell

    Energy Technology Data Exchange (ETDEWEB)

    Limpert, Steven; Ghosh, Kunal; Wagner, Hannes; Bowden, Stuart; Honsberg, Christiana; Goodnick, Stephen; Bremner, Stephen; Green, Martin

    2014-06-09

    We report results from coupled optical and electrical Sentaurus TCAD models of a gallium phosphide (GaP) on silicon electron carrier selective contact (CSC) solar cell. Detailed analyses of current and voltage performance are presented for devices having substrate thicknesses of 10 μm, 50 μm, 100 μm and 150 μm, and with GaP/Si interfacial quality ranging from very poor to excellent. Ultimate potential performance was investigated using optical absorption profiles consistent with light trapping schemes of random pyramids with attached and detached rear reflector, and planar with an attached rear reflector. Results indicate Auger-limited open-circuit voltages up to 787 mV and efficiencies up to 26.7% may be possible for front-contacted devices.

  16. First-Principles Study of Structural, Electronic, Mechanical, Thermal, and Phonon Properties of III-Phosphides (BP, AlP, GaP, and InP)

    Science.gov (United States)

    Ehsanfar, S.; Kanjouri, F.; Tashakori, H.; Esmailian, A.

    2017-10-01

    Based on first-principles calculations with generalized gradient approximation as exchange-correlation functional, the structural, electronic, mechanical, thermal, and phonon properties of III-phosphide binary compounds, namely BP, AlP, GaP, and InP, with cubic zincblende structure have been investigated. The calculations were performed in the framework of density functional theory and density functional perturbation theory (DFPT) implemented in the Quantum ESPRESSO package. The results obtained for the structural and electronic properties are in good agreement with available theoretical and experimental results. The results of our electronic calculations indicate semiconducting properties for these binary compounds. Furthermore, the frequency bandgaps and phonon density of states were also investigated. The computed mechanical constants predict that BP, AlP, GaP, and InP are elastically stable. Finally, we determined the heat capacity and entropy for these binary compounds within a quasiharmonic Debye model using DFPT for comparison.

  17. Dysprosium(III) complexes with a square-antiprism configuration featuring mononuclear single-molecule magnetic behaviours based on different β-diketonate ligands and auxiliary ligands.

    Science.gov (United States)

    Zhang, Sheng; Ke, Hongshan; Shi, Quan; Zhang, Jangwei; Yang, Qi; Wei, Qing; Xie, Gang; Wang, Wenyuan; Yang, Desuo; Chen, Sanping

    2016-03-28

    Three mononuclear dysprosium(III) complexes derived from three β-diketonate ligands, 4,4,4-trifluoro-1-(4-methylphenyl)-1,3-butanedione (tfmb), 4,4,4-trifluoro-1-(4-fluorophenyl)-1,3-butanedione (tffb) and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (tfnb) as well as auxiliary ligands, 5-nitro-1,10-phenanthroline (5-NO2-Phen), DMF and 2,2'-bipyridine (bpy) have been synthesized and structurally characterized, namely [Dy(5-NO2-Phen)(tfmb)3] (1), [Dy(DMF)2(tffb)3] (2) and [Dy(bpy)2(tfnb)3]·0.5(1,4-dioxane) (3). The metal ions in 1-3 adopt an approximately square-antiprismatic (SAP) coordination environment with D4d axial symmetry. The magnetic properties of 1-3 have been investigated, displaying weak out-of-phase AC signals under a zero-DC field. With an applied DC field of 1200 Oe, the quantum tunnelling of the magnetization was suppressed in 1-3 with the pre-exponential factor τ0 = 5.3 × 10(-7) s and the effective barrier ΔE/kB = 83 K for 1 as well as the pre-exponential factor τ0 = 3.09 × 10(-7) s and the effective barrier ΔE/kB = 39 K for 3. Interestingly, for the frequency dependence of the out-of-phase (χ'') of the AC susceptibility of 2, two slow relaxation of the magnetization processes occurred under the applied magnetic field of 1200 Oe, corresponding to the fast relaxation (FR) phase and slow relaxation (SR) phase, respectively. Arrhenius analysis gave the effective energy barrier (ΔE/kB) of 55 K and the pre-exponential factor (τ0) of 8.23 × 10(-12) for the SR. It is thus very likely that the FR process in complex 2 results from QTM enhanced by dipolar interactions between the Dy ions or the presence of the applied field. The structure-property relationship of some Dy(III) based mononuclear SMMs with the SAP configuration was further discussed.

  18. Magnetic Phase Transition of Nanocrystalline Bulk Metal Gadolinium and Dysprosium%纳米块体金属钆和镝的磁性相变分析

    Institute of Scientific and Technical Information of China (English)

    刘凤艳; 侯碧辉; 岳明; 王克军

    2011-01-01

    The magnetic properties of bulk nanocrystalline metal gadolinium (Gd) and dysprosium (Dy)samples were studied.The magnetization and Curie temperature TC of nanocrystalline Gd and Dy decreased usually as compared with the polycrystal.However,when the mean grain size was 10 nm, the Curie temperature Tc of nanocrystalline Dy increased to 100 K instead and there was an antiferromagnetic phase in nanocrystalline Gd.According to the calculation based on Ruderman-Kittel-Kasuya-Yosida exchange interaction, the exchange integral of the grain boundary atoms and crystalline surface atoms had its sign changed from plus to minus or vice versa, and there were three orderly phases in the steady state with the lowest energy, ferromagnetic phase, antiferromagnetic phase and fan phase.For the nanocrystals with mean grain size of 10 nm, the proportion of grain boundary to crystalline surface atoms was high, and as the result of superposition of the three phases, and there appeared a peak near the phase transition temperature for the nanocrystalline Gd.While for the Dy, the magnetization decreased gently with temperature, and showing a higher Curie temperature than in the case of the polycrystal.%对纳米晶钆(Gd)和镝(Dy)块体材料的磁性进行了研究.与多晶比较,通常纳米晶的磁化强度减小,居里温度TC降低,但平均粒径为10 nm的纳米晶Dy的居里温度TC反而升高到100 K,平均粒径为10 nm的纳米晶Gd中还存在明显的反铁磁相.通过RKKY交换作用的计算知道,晶面晶界处原子的交换积分会发生正负号的变化,能量最低的稳定状态对应三种有序相:铁磁相、反铁磁相和扇相,晶粒中在一定条件下出现三相共存.对于平均粒径为10 nm的纳米晶,晶面晶界处原子所占比例很大,三相叠加的结果,对于Gd,即是在相变点附近出现磁化强度尖峰;对于Dy,则是磁化强度随温度升高下降缓慢,表现为居里温度TC比多晶升高.

  19. Synthesis of the nickel selenophosphinates [Ni(Se(2)PR(2))(2)] (R = (i)Pr, (t)Bu and Ph) and their use as single source precursors for the deposition of nickel phosphide or nickel selenide nanoparticles.

    Science.gov (United States)

    Maneeprakorn, Weerakanya; Nguyen, Chinh Q; Malik, Mohammad A; O'Brien, Paul; Raftery, James

    2009-03-28

    Nickel phosphide (Ni(2)P and Ni(12)P(5)) or nickel selenide (NiSe) nanoparticles were prepared from the single molecule precursor, dialkyldiselenophosphinato nickel(II), [Ni(Se(2)PR(2))(2)] (R = (i)Pr, (t)Bu and Ph) by thermolysis in trioctylphosphine oxide (TOPO) or hexadecylamine (HDA). The chemical composition of these nanoparticles depends on the precursors, capping agents, and reaction temperature.

  20. Synthesis and characterization of low-valence actinide phosphide tellurides and ternary selenium-halide iridium complexes; Synthese und Charakterisierung niedervalenter Actinoidphosphidtelluride und ternaerer Selen-Halogenid-Komplexe des Iridiums

    Energy Technology Data Exchange (ETDEWEB)

    Stolze, Karoline

    2016-04-07

    The thesis on the synthesis and characterization of low-valence actinide phosphide tellurides and ternary selenium-halide iridium complexes includes two parts: a description of the experimental synthesis of UPTe and U2PTe2O and ThPTe and the synthesis of selenium-chloride iridium complexes and selenium-bromide iridium complexes. The characterization included X-ray diffraction and phase studies.

  1. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65 MeV

    CERN Document Server

    Tárkányi, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2016-01-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65 MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides $^{159}$Dy, $^{157}$Dy, $^{155}$Dy, $^{161}$Tb, $^{160}$Tb, $^{156}$Tb, $^{155}$Tb, $^{154m2}$Tb, $^{154m1}$Tb, $^{154g}$Tb, $^{153}$Tb, $^{152}$Tb and $^{151}$Tb are reported in the 36-65 MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013.

  2. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65MeV.

    Science.gov (United States)

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-04-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides (159)Dy, (157)Dy, (155)Dy, (161)Tb, (160)Tb, (156)Tb, (155)Tb, (154m2)Tb, (154m1)Tb, (154g)Tb, (153)Tb, (152)Tb and (151)Tb are reported in the 36-65MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013. Copyright © 2015. Published by Elsevier Ltd.

  3. Dysprosium selective potentiometric membrane sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Faridbod, Farnoush; Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2013-03-01

    A novel Dy(III) ion-selective PVC membrane sensor was made using a new synthesized organic compound, 3,4-diamino-N Prime -((pyridin-2-yl)methylene)benzohydrazide (L) as an excellent sensing element. The electrode showed a Nernstian slope of 19.8 {+-} 0.6 mV per decade in a wide concentration range of 1.0 Multiplication-Sign 10{sup -6}-1.0 Multiplication-Sign 10{sup -2} mol L{sup -1}, a detection limit of 5.5 Multiplication-Sign 10{sup -7} mol L{sup -1}, a short conditioning time, a fast response time (< 10 s), and high selectivity towards Dy(III) ion in contrast to other cations. The proposed sensor was successfully used as an indicator electrode in the potentiometric titration of Dy(III) ions with EDTA. The membrane sensor was also applied to the F{sup -} ion indirect determination of some mouth washing solutions and to the Dy{sup 3+} determination in binary mixtures. Highlights: Black-Right-Pointing-Pointer The novelty of this work is based on the high affinity of the ionophore toward the Dy{sup 3+} ions. Black-Right-Pointing-Pointer This technique is very simple, fast and inexpensive and it is not necessary to use sophisticated equipment. Black-Right-Pointing-Pointer The newly developed sensor is superior to the formerly reported Dy{sup 3+} sensors in terms of selectivity.

  4. The magnetocaloric effect in dysprosium

    Science.gov (United States)

    Benford, S. M.

    1979-01-01

    The magnetocaloric effect in polycrystalline Dy was measured in the 84-280-K range in measuring fields from 1 to 7 T. These adiabatic temperature changes reflect structural changes in Dy with applied field and temperature, and include the first magnetocaloric data for a helical antiferromagnet. Above the Neel point (179 K) a field increase always caused heating; below the Neel point fields less than about 2 T cause cooling for some values of initial temperature. The largest temperature increase with a 7 T field occurs at the Neel point and at fields below 2 T near the Curie point. For refrigeration purposes the optimal working region for a Dy cooling element is field dependent.

  5. A Mechanistic Study of CO2 Reduction at the Interface of a Gallium Phosphide (GaP) Surface using Core-level Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Kristen [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-18

    Carbon dioxide (CO2) emission into the atmosphere has increased tremendously through burning of fossil fuels, forestry, etc.. The increased concentration has made CO2 reductions very attractive though the reaction is considered uphill. Utilizing the sun as a potential energy source, CO2 has the possibility to undergo six electron and four proton transfers to produce methanol, a useable resource. This reaction has been shown to occur selectively in an aqueous pyridinium solution with a gallium phosphide (GaP) electrode. Though this reaction has a high faradaic efficiency, it was unclear as to what role the GaP surface played during the reaction. In this work, we aim to address the fundamental role of GaP during the catalytic conversion, by investigating the interaction between a clean GaP surface with the reactants, products, and intermediates of this reaction using X-ray photoelectron spectroscopy. We have determined a procedure to prepare atomically clean GaP and our initial CO2 adsorption studies have shown that there is evidence of chemisorption and reaction to form carbonate on the clean surface at LN2 temperatures (80K), in contrast to previous theoretical calculations. These findings will enable future studies on CO2 catalysis.

  6. New Intermetallic Ternary Phosphide Chalcogenide AP2-xXx (A = Zr, Hf; X = S, Se) Superconductors with PbFCl-Type Crystal Structure

    Science.gov (United States)

    Kitô, Hijiri; Yanagi, Yousuke; Ishida, Shigeyuki; Oka, Kunihiko; Gotoh, Yoshito; Fujihisa, Hiroshi; Yoshida, Yoshiyuki; Iyo, Akira; Eisaki, Hiroshi

    2014-07-01

    We have synthesized a series of intermetallic ternary phosphide chalcogenide superconductors, AP2-xXx (A = Zr, Hf; X = S, Se), using the high-pressure synthesis technique. These materials have a PbFCl-type crystal structure (space group P4/nmm) when x is greater than 0.3. The superconducting transition temperature Tc changes systematically with x, yielding dome-like phase diagrams. The maximum Tc is achieved at approximately x = 0.7, at which point the Tc is 6.3 K for ZrP2-xSex (x = 0.75), 5.5 K for HfP2-xSex (x = 0.7), 5.0 K for ZrP2-xSx (x = 0.675), and 4.6 K for Hfp2-xSx (x = 0.5). They are typical type-II superconductors and the upper and lower critical fields are estimated to be 2.92 T at 0 K and 0.021 T at 2 K for ZrP2-xSex (x = 0.75), respectively.

  7. Effect of multilayer structure, stacking order and external electric field on the electrical properties of few-layer boron-phosphide.

    Science.gov (United States)

    Chen, Xianping; Tan, Chunjian; Yang, Qun; Meng, Ruishen; Liang, Qiuhua; Jiang, Junke; Sun, Xiang; Yang, D Q; Ren, Tianling

    2016-06-28

    Development of nanoelectronics requires two-dimensional (2D) systems with both direct-bandgap and tunable electronic properties as they act in response to the external electric field (E-field). Here, we present a detailed theoretical investigation to predict the effect of atomic structure, stacking order and external electric field on the electrical properties of few-layer boron-phosphide (BP). We demonstrate that the splitting of bands and bandgap of BP depends on the number of layers and the stacking order. The values for the bandgap show a monotonically decreasing relationship with increasing layer number. We also show that AB-stacking BP has a direct-bandgap, while ABA-stacking BP has an indirect-bandgap when the number of layers n > 2. In addition, for a bilayer and a trilayer, the bandgap increases (decreases) as the electric field increases along the positive direction of the external electric field (E-field) (negative direction). In the case of four-layer BP, the bandgap exhibits a nonlinearly decreasing behavior as the increase in the electric field is independent of the electric field direction. The tunable mechanism of the bandgap can be attributed to a giant Stark effect. Interestingly, the investigation also shows that a semiconductor-to-metal transition may occur for the four-layer case or more layers beyond the critical electric field. Our findings may inspire more efforts in fabricating new nanoelectronics devices based on few-layer BP.

  8. Proposing Boric Acid as an Antidote for Aluminium Phosphide Poisoning by Investigation of the Chemical Reaction Between Boric Acid and Phosphine

    Directory of Open Access Journals (Sweden)

    Motahareh Soltani

    2013-01-01

    Full Text Available Aluminium phosphide (AlP is a storage fumigant pesticide, which is used to protect stored grains especially from insects and rodents. It releases phosphine (PH3 gas, a highly toxic mitochondrial poison, in contact with moisture, particularly if acidic. Although the exact mechanism of action is unknown so far, the major mechanism of PH3 toxicity seems to be the inhibition of cytochrome-c oxidase and oxidative phosphorylation which eventually results in adenosine triphosphate (ATP depletion and cell death. Death due to AlP poisoning seems to be as a result of myocardial damage. No efficient antidote has been found for AlP poisoning so far, and unfortunately, most of the poisoned human cases die. PH3, like ammonia (NH3, is a Lewis base with a lone-pair electron. However, boric acid (B(OH3 is a Lewis acid with an empty p orbital. It is predicted that lone-pair electron from PH3 is shared with the empty p orbital from B(OH3 and a compound forms in which boron attains its octet. In other words, PH3 is trapped and neutralised by B(OH3. The resulting polar reaction product seems to be excretable by the body due to hydrogen bonding with water molecules. The present article proposes boric acid as a non-toxic and efficient trapping agent and an antidote for PH3 poisoning by investigating the chemical reaction between them.

  9. Analysis of radiation-damaged and annealed gallium arsenide and indium phosphide solar cells using deep-level transient spectroscopy techniques. Master's thesis

    Energy Technology Data Exchange (ETDEWEB)

    Pinzon, D.

    1991-03-01

    Degradation of solar cell performance from radiation damage was found to be reversed through annealing processes. The mechanisms behind the degradation and recovery is based on deep-level traps, or defects, in the lattice structure of the solar cell. Through a process known as Deep Level Transient Spectroscopy (DLTS), a correlation can be made between damage/recovery and trap energy level/concentration of the cell. Gallium Arsenide (GaAs) and Indium Phosphide (InP) solar cells were subjected to 1 MeV electron irradiation by a Dynamitron linear acceleration at two fluence levels of 1E1r and 1E15 electrons/cm sq. The process of annealing included thermal annealing at 90 c with forward bias current and thermal annealing alone for (GaAs). After each cycle, DLTS measurements were taken to determine the energy level of the traps and their concentration. Multiple cycles of irradiation, annealing and DLTS were performed to observe the correlation between degradation and recovery to trap energy level and concentration. The results show that the lower energy level traps are associated with the recovery of the cells while the higher level traps are associated with the overall permanent degradation of the cells.

  10. Interaction between F2 gas with the pristine and 3C-doped(4, 4 armchair boron phosphide nanotubes: a DFT study

    Directory of Open Access Journals (Sweden)

    M Rezaei-Sameti

    2015-12-01

    Full Text Available In this research, the structure, quantum and NQR (Nuclear quadrupole resonanceparameters of F2 gas adsorption on the pristine and 3C-doped (4,4 armchair models of boron phosphide nanotubes (BPNTs have been investigated in the framework of density functional theory. For this purpose, at the first step, four models for F2 adsorption on the inner and outer surfaces of pristine and 3C-doped BPNTS are considered and then all structures are optimized by using Gaussian 03 program package. The optimized structures are used to calculate the quantum and NQR parameters. The calculated results reveal that the adsorption energy of pristine and 3C-doped models of BPNTs are exothermic and adsorption process is a physisorption process due to the weak Van der Waals interaction. The substitution of three carbons with three B atoms of nanotube decreases significantly the adsorption energies. The F2 adsorption and 3C-doping decrease the band gap, global hardness, and ionization potential of the pristine BPNTs. The calculated NQR parameters of all the models show that CQ and &etaQ values of the first layer are larger than those of the other layers.

  11. A Mechanistic Study of CO2 Reduction at the Interface of a Gallium Phosphide (GaP) Surface using Core-level Spectroscopy - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Kristen [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-19

    Carbon dioxide (CO2) emission into the atmosphere has increased tremendously through burning of fossil fuels, forestry, etc.. The increased concentration has made CO2 reductions very attractive though the reaction is considered uphill. Utilizing the sun as a potential energy source, CO2 has the possibility to undergo six electron and four proton transfers to produce methanol, a useable resource. This reaction has been shown to occur selectively in an aqueous pyridinium solution with a gallium phosphide (GaP) electrode. Though this reaction has a high faradaic efficiency, it was unclear as to what role the GaP surface played during the reaction. In this work, we aim to address the fundamental role of GaP during the catalytic conversion, by investigating the interaction between a clean GaP surface with the reactants, products, and intermediates of this reaction using X-ray photoelectron spectroscopy. We have determined a procedure to prepare atomically clean GaP and our initial CO2 adsorption studies have shown that there is evidence of chemisorption and reaction to form carbonate on the clean surface at LN2 temperatures (80K), in contrast to previous theoretical calculations. These findings will enable future studies on CO2 catalysis.

  12. Phosphorus K β X-Ray Emission Spectra and Valence-Band Structures of Transition-Metal Phosphides and GaAs 1-xPx

    Science.gov (United States)

    Sugiura, Chikara

    1996-07-01

    The P Kβ emission spectra in fluorescence from ZrP, NbP, MoP,HfP, TaP, WP, AgP2, CdP2, Mn3P2, Cd3P2 and GaAs1-xPxfor 0.2 ≤ x ≤ 1 are measured with a high-resolutiontwo-crystal vacuum spectrometer equipped with Ge(111) crystals. Theinfluence of metal atoms appears distinctly in the P Kβemission spectra of transition-metal phosphides. The effect ofarsenic atoms appears slightly in the P Kβ emission spectraof GaAs1-xPx. The P Kβ emission spectra of AgP2,CdP2, Cd3P2 and GaAs0.6 P0.4 are compared withavailable P L2,3 emission and XPS valence-band spectra ona common energy scale. It is shown that the P 3p electronsinteract fairly with the metal d electrons in the upper partof the valence band for MP ( M = Zr, Nb, Mo, Hf, Ta, W) and Mn3P2;considerable p-d, s mixing occurs in the middle part for AgP2and in the lower part for CdP2 and Cd3P2; and the Ga 3dstates mix fairly with the P 3s states in GaAs0.6P0.4.

  13. Aqueous-solution growth of GaP and InP nanowires: a general route to phosphide, oxide, sulfide, and tungstate nanowires.

    Science.gov (United States)

    Xiong, Yujie; Xie, Yi; Li, Zhengquan; Li, Xiaoxu; Gao, Shanmin

    2004-02-06

    A general synthetic route has been developed for the growth of metal phosphide, oxide, sulfide, and tungstate nanowires in aqueous solution. In detail, cetyltrimethylammonium cations (CTA(+)) can be combined with anionic inorganic species along a co-condensation mechanism to form lamellar inorganic-surfactant intercalated mesostructures, which serve as both microreactors and reactants for the growth of nanowires. For example, GaP, InP, gamma-MnO(2), ZnO, SnS(2), ZnS, CdWO(4), and ZnWO(4) nanowires have been grown by this route. To the best of our knowledge, this is the first time that the synthesis of GaP and InP nanowires in aqueous solution has been achieved. This strategy is expected to extend to grow nanowires of other materials in solution or by vapor transport routes, since the nanowire growth of any inorganic materials can be realized by selecting an appropriate reaction and its corresponding lamellar inorganic-surfactant precursors.

  14. Effects of Aluminum Phosphide on Soil Microbial Population and Enzyme Activities%磷化铝对土壤微生物数量和酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    仉欢; 朱玉坤; 乔康; 王开运

    2012-01-01

    Effects of aluminum phosphide (0.1, 1 mg·g-1 and 10 mg·g-1) on soil microbial population and enzyme activities were studied under laboratory control condition. The results indicated that, all concentrations of aluminum phosphide had inhibitory effect on soil bacteria, fungi and actinomyces and the inhibitory effect was more obvious with concentration increased. However, the effect caused by low concentration (0.1 mg·g-1) returned to the control level after a period of treatment. Aluminum phosphide had inhibitory effect on soil urease, and the inhibitory effect increased with the increasing concentration. Low concentration of aluminum phosphide had no significant inhibitory effect on soil invertase, while the treatment with the highest concentration (10 mg·g-1) had the greatest inhibition all the time. All concentrations of aluminum phosphide had inhibitory or stimulatory effect on soil hydrogen peroxidase in the early stage, while the effect returned to the control level on 30 days after treatment. The present data supported the conclusion that aluminum phosphide at the routine dose had certain effect on soil microbial population and enzyme activities, but the effect disappeared and recovered to the control level after a period.%为明确磷化铝对土壤微生物数量和酶活性的影响,采用室内培养的方法,研究了经0.1、1 mg? g4和10 mg?g-1 3个浓度磷化铝熏蒸处理后,供试土壤中微生物数量和土壤酶活性的变化.结果表明,磷化铝处理土壤后,各个浓度的磷化铝对土壤细菌、真菌和放线菌数量具有抑制作用,浓度越高,抑制作用越强,但一段时间后低浓度(0.1 mg?g-1)处理对土壤微生物数量的影响恢复至对照水平.磷化铝对土壤脲酶表现为抑制作用,并随浓度升高而增强;低浓度处理对土壤中的蔗糖酶活性抑制作用不明显,而高浓度(10mg?g-1)处理表现为强烈的抑制作用;各浓度处理初期对土壤过氧化氢酶表现为

  15. Silicon dioxide with a silicon interfacial layer as an insulating gate for highly stable indium phosphide metal-insulator-semiconductor field effect transistors

    Science.gov (United States)

    Kapoor, V. J.; Shokrani, M.

    1991-01-01

    A novel gate insulator consisting of silicon dioxide (SiO2) with a thin silicon (Si) interfacial layer has been investigated for high-power microwave indium phosphide (InP) metal-insulator-semiconductor field effect transistors (MISFETs). The role of the silicon interfacial layer on the chemical nature of the SiO2/Si/InP interface was studied by high-resolution X-ray photoelectron spectroscopy. The results indicated that the silicon interfacial layer reacted with the native oxide at the InP surface, thus producing silicon dioxide, while reducing the native oxide which has been shown to be responsible for the instabilities in InP MISFETs. While a 1.2-V hysteresis was present in the capacitance-voltage (C-V) curve of the MIS capacitors with silicon dioxide, less than 0.1 V hysteresis was observed in the C-V curve of the capacitors with the silicon interfacial layer incorporated in the insulator. InP MISFETs fabricated with the silicon dioxide in combination with the silicon interfacial layer exhibited excellent stability with drain current drift of less than 3 percent in 10,000 sec, as compared to 15-18 percent drift in 10,000 sec for devices without the silicon interfacial layer. High-power microwave InP MISFETs with Si/SiO2 gate insulators resulted in an output power density of 1.75 W/mm gate width at 9.7 GHz, with an associated power gain of 2.5 dB and 24 percent power added efficiency.

  16. Microstructure and dielectric properties of dysprosium-doped barium titanate ceramics Microestrutura e propriedades dielétricas de cerâmicas de titanato de bário dopado com disprósio

    Directory of Open Access Journals (Sweden)

    Y. Pu

    2005-09-01

    Full Text Available The substitution behavior and lattice parameter of barium titanate between solid_solubility with a dopant concentration in the range of 0.25 to 1.5 mol% are studied. The influences of dysprosium-doped fraction on the grain size and dielectric properties of barium titanate ceramic, including dielectric constant and breakdown electric field strength, are investigated via scanning electronic microscopy, X-ray diffraction and electric property tester. The results show that, at a dysprosium concentration of 0.75 mol%, the abnormal grain growth is inhibited and the lattice parameters of grain rise up to the maximum because of the lowest vacancy concentration. In addition, the finegrain and high density of barium titanate ceramic result in its excellent dielectric properties. The relative dielectric constant (25 °C reaches to 4100. The temperature coefficient of the capacitance varies from -10 to 10% within the temperature range of -15 °C -100 °C, and the breakdown electric field strength (alternating current achieves 3.2 kV/mm. These data suggest that our barium titanate could be used in the manufacture of high voltage ceramic capacitors.Foram estudados o comportamento da substituição e o parâmetro de rede de titanato de bário da solubilidade sólida com uma concentração de dopante na faixa 0,25-1,5 mol%. As influências da fração do dopante disprósio no tamanho de grão e nas propriedades dielétricas da cerâmica de titanato de bário, incluindo constante dielétrica e rigidez dielétrica foram investigadas por meio de microscopia eletrônica de varredura, difração de raios X e teste de propriedades elétricas. Os resultados mostram que a uma concentração de disprósio de 0,75 mol% o crescimento anormal de grão é inibido e os parâmetros de rede aumentam até um máximo devido a menor concentração de vacâncias. Além disso, as cerâmicas de grãos pequenos e alta densidade resultam em excelentes propriedades dielétricas. A

  17. Neodymium Dysprosium Modified Starch- coated Magnetic Fluid Preparation of Ferrite%淀粉包覆镝钕改性铁氧体磁性液体的制备

    Institute of Scientific and Technical Information of China (English)

    林穗云; 周育辉

    2011-01-01

    In this paper, in order to obtain the ferrite magnetic fluids of higher saturation magnetic intensity with simple technology, nanometer magnetite ( Fe3O4 ) particles ware prepared by chemical co - precipitation. And to a certain proportion of Dysprosium Neodymium ferrite magnetic fluids on the modification, we selected starch prepara- tion for the relief of water - based coating of rare earth iron oxide magnetic fluid composites. We also investigated the amount of Nd - Dy, the amount of coating agent, reaction temperature, coating temperature on the performance of the products and the effects of particle size, and its preliminary characterization was also performed . Through experiment,we summed up, under n (Fe) : [ n ( Nd3+ ) + n ( Dy3+ ) ] = 30:1 and n ( Fe3 + ) : n ( Fe2 + ) = 1.70 ~ 1. 75, the ratio for use of dysprosium and neodymium is n(Dy3+ ) : n(Nd3+ ) =4:1, 25%NH3 · H2O(A. R. ) as precipitating agent and pH value conditioner; the reacting system temperature was controlled in 35 ℃, and the pH value was adjusted to 9 ~ 11 ; the best dosage of starch as the relief is O. 0050g each 6OraL magnetic fluids, the temperature of surfactant was controlled in 50℃ and the pH value was adjusted to 2 ~ 3. In such system under the conditions of a water - based rare - earth compound Nd Dy Fe Magnetic, fluid magnetic oxygen was higher than or- dinary water- based ferrite.%为制备工艺简单且饱和磁化强度高的磁流体,本文采用化学共沉淀法制得了纳米磁性Fe304粒子.然后以一定比例的镝钕对铁氧体磁流体改性,选择淀粉为包覆剂制备水基稀土复合铁氧磁流体.考察了镝钕的用量、包覆剂的用量、反应温度、包覆温度等因素对产物粒径及性能的影响,并对其进行了初步的性能表征.实验总结出适宜的条件:在n(Fe):[n(Nd3+)+n(Dy3+)]=30:1,n(Fe3+):n(Fe2+)=1.70~1.75

  18. An Improved Study of Electronic Band Structure and Optical Parameters of X-Phosphides (X--B, AL, Ga, In) by Modified Becke-Johnson Potential%An Improved Study of Electronic Band Structure and Optical Parameters of X-Phosphides (X--B, AL, Ga, In) by Modified Becke-Johnson Potential

    Institute of Scientific and Technical Information of China (English)

    Masood Yousaf; M.A. Saeed; R. Ahmed; M.M. Alsardia; Ahmad Radzi Mat Isa; A. Shaari

    2012-01-01

    We report the electronic band structure and optical parameters of X-Phosphides (X=B, AI, Ga, In) by first-principles technique based on a new approximation known as modified Becke-Johnson (roB J). This potential is considered more accurate in elaborating excited states properties of insulators and semiconductors as compared to LDA and GGA. The present calculated band gaps values of BP, AlP, GaP, and InP are 1.867 eV, 2.268 eV, 2.090 eV, and 1.377 eV respectively, which are in close agreement to the experimental results. The band gap values trend in this study is as: E9 (mBJ-GGA/LDA) 〉 E9 (GGA) 〉 Eg (LDA). Optical parametric quantities (dielectric constant, refractive index, reflectivity and optical conductivity) which based on the band structure are aiso presented and discussed. BP, AlP, GaP, and InP have strong absorption in between the energy range 4-9 eV, 4-7 ev, 3-7 eV, and 2-7 eV respectively. Static dielectric constant, static refractive index and coefficient of reflectivity at zero frequency, within mBJ-GGA, are also calculated. BP, AIP, GaP, and InP show significant optical conductivity in the range 5.2-10 eV, 4.3-8 eV, 3.5- 7.2 eV, and 3.2-8 eV respectively. The present study endorses that the said compounds can be used in opto-electronic applications, for different energy ranges.

  19. Bimetallic Cobalt-Based Phosphide Zeolitic Imidazolate Framework: CoP x Phase-Dependent Electrical Conductivity and Hydrogen Atom Adsorption Energy for Efficient Overall Water Splitting

    Energy Technology Data Exchange (ETDEWEB)

    Song, Junhua [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Zhu, Chengzhou [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Xu, Bo Z. [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Fu, Shaofang [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Engelhard, Mark H. [Pacific Northwest National Laboratory, Richland WA 99352 USA; Ye, Ranfeng [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Du, Dan [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Beckman, Scott P. [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Lin, Yuehe [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Pacific Northwest National Laboratory, Richland WA 99352 USA

    2016-10-25

    Cobalt-based bimetallic phosphide encapsulated in carbonized zeolitic imadazolate frameworks has been successfully synthesized and showed excellent activities toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Density functional theory calculation and electrochemical measurements reveal that the electrical conductivity and electrochemical activity are closely associated with the Co2P/CoP mixed phase behaviors upon Cu metal doping. This relationship is found to be the decisive factor for enhanced electrocatalytic performance. Moreover, the precise control of Cu content in Co-host lattice effectively alters the Gibbs free energy for H* adsorption, which is favorable for facilitating reaction kinetics. Impressively, an optimized performance has been achieved with mild Cu doping in Cu0.3Co2.7P/nitrogen-doped carbon (NC) which exhibits an ultralow overpotential of 0.19 V at 10 mA cm–2 and satisfying stability for OER. Cu0.3Co2.7P/NC also shows excellent HER activity, affording a current density of 10 mA cm–2 at a low overpotential of 0.22 V. In addition, a homemade electrolyzer with Cu0.3Co2.7P/NC paired electrodes shows 60% larger current density than Pt/ RuO2 couple at 1.74 V, along with negligible catalytic deactivation after 50 h operation. The manipulation of electronic structure by controlled incorporation of second metal sheds light on understanding and synthesizing bimetallic transition metal phosphides for electrolysis-based energy conversion.

  20. Gallium phosphide high temperature diodes

    Science.gov (United States)

    Chaffin, R. J.; Dawson, L. R.

    1981-01-01

    High temperature (300 C) diodes for geothermal and other energy applications were developed. A comparison of reverse leakage currents of Si, GaAs, and GaP was made. Diodes made from GaP should be usable to 500 C. A Liquid Phase Epitaxy (LPE) process for producing high quality, grown junction GaP diodes is described. This process uses low vapor pressure Mg as a dopant which allows multiple boat growth in the same LPE run. These LPE wafers were cut into die and metallized to make the diodes. These diodes produce leakage currents below ten to the -9th power A/sq cm at 400 C while exhibiting good high temperature rectification characteristics. High temperature life test data is presented which shows exceptional stability of the V-I characteristics.

  1. 表面修饰对镝铁氧体纳米磁粒子的合成及其磁性能的影响%Effect of Surface Modification on Formation and Magnetic Property of Dysprosium Ferrite Nanomagnetic Particles

    Institute of Scientific and Technical Information of China (English)

    陈静; 张茂润; 邓真娟

    2011-01-01

    利用湿化学法制备镝铁氧体纳米磁粒子时,用适量的阴离子表面活性剂进行表面修饰,能够有效地控制磁粒子的粒径,同时避免干燥时产生硬团聚.文章介绍了用月桂酸、月桂酸钠、正十二烷基硫酸钠对磁粒子进行表面修饰的研究结果,探讨了三者及其用量对磁粒子的形成及磁性能的影响.借助X射线衍射仪(XRD)、透射电镜(TEM)、振动样品磁强计(VSM)、红外光谱仪(IR)对产物的性能进行了表征.结果表明,用月桂酸修饰后的产物具有Fe3O4磁粒子的晶型结构且结晶度高、磁性能优异、平均粒径约16nm;用月桂酸钠、正十二烷基硫酸钠修饰后的产物不具有Fe3O4磁粒子的晶型结构,结晶度低且磁性能差.%When wet chemical method are use to prepare dysprosium-doped ferrite magnetic nanoparticles, right a-mount of anionic surfactant were doped as surface modification, which can effectively control the size of magnetic particles, and avoid producing hard reunion when dry out. This paper introduces the research results of magnetic particle surface modification by using lauric acid, laurel acid sodium and lauryl sodium sulfate, discusses the effect of lauric acid, laurel acid sodium and lauryl sodium sulfate and their dosages on the formation of magnetic and its magnetic property. The properties of the product can be characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), infrared spectrometer (IR). The results showed that the product modified with lauric acid have a crystalline structure of Fe3O4 magnetic particles and high crystallin-ity, excellent magnetic properties. The average particle size is about 16 nm; the product modified with laurel acid sodium and lauryl sodium sulfate does not have the crystalline structure of Fe3O4 magnetic particles, with low crystal-linity and low magnetic property.

  2. Structure and properties of a new family of ceramic phosphides: AgZnLaP sub 2 , AgZnSmP sub 2 , and CuZnSmP sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Tejedor, P.; Stacy, A.M. (Univ. of California, Berkeley (USA))

    1990-12-01

    Three new quaternary phosphides, AgZnLaP{sub 2}, AgZnSmP{sub 2}, and CuZnSmP{sub 2}, were synthesized by direct reaction of the elements. Recrystallization by isothermal chemical vapor transport, using iodine as the transporting agent, yielded single crystals. The structure of AgZnSmP{sub 2} was refined from single crystal X-ray data in the space group P{bar 3}m1 to an R value of 2.11%. The lattice parameters are a = 4.1247(4) {angstrom} and c = 6.6920(6) {angstrom}. The other two compounds were found to be isostructural, with lattice parameters a = 4.194(2) {angstrom} and c = 6.817(2) {angstrom} for AgZnLaP{sub 2} and a = 4.016(2) {angstrom} and c = 6.592(2) {angstrom} for CuZnSmP{sub 2}. These new materials sinter at temperatures near 800C, have melting points above 1,100C, and do not react with water at room temperature. Diffuse reflectance spectra and the temperature dependence of the resistivity indicate that these materials are heavily doped semiconductors.

  3. Structure and behavior of the barringerite Ni end-member, Ni[subscript 2]P, at deep Earth conditions and implications for natural Fe-Ni phosphides in planetary cores

    Energy Technology Data Exchange (ETDEWEB)

    Dera, P.; Lavina, B.; Borkowski, L.A.; Prakapenka, V.B.; Sutton, S.R.; Rivers, M.L.; Downs, R.T.; Boctor, N.Z.; Prewitt, C.T.; (UNLV); (CIW); (UC); (Ariz)

    2009-06-01

    High pressure and high temperature behavior of synthetic Ni{sub 2}P has been studied in a laser-heated diamond anvil cell up to 50 GPA and 2200 K. Incongruent melting associated with formation of pyrite-type NiP{sub 2} and amorphous Ni-P alloy was found at an intermediate pressure range, between 6.5 and 40 GPa. Above GPa, Ni{sub 2}P melts congruently. At room conditions, Ni{sub 2}P has hexagonal C22-type structure, and without heating it remains in this structure to at least 50 GPa. With a bulk modulus K{sub 0} = 201(8) GPa and K' = 4.2(6), Ni{sub 2}P is noticeable less compressible than hcp Fe, as well as all previously described iron phosphides, and its presence in the Earth core would favorable lower the core density. In contrast to Fe{sub 2}P, the c/a ratio in Ni{sub 2}P decreases on compression because of the lack of ferromagnetic interaction along the c direction. Lack of the C22{yields}C23 transition in the Ni{sub 2}P rules out a stabilizing effect of Ni on the orthorhombic phase of natural (Fe{sub 1-x}Ni{sub x}){sub 2}P allabogdanite.

  4. GeP and (Ge{sub 1−x}Sn{sub x})(P{sub 1−y}Ge{sub y}) (x≈0.12, y≈0.05): Synthesis, structure, and properties of two-dimensional layered tetrel phosphides

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kathleen; Synnestvedt, Sarah; Bellard, Maverick; Kovnir, Kirill, E-mail: kkovnir@ucdavis.edu

    2015-04-15

    GeP and Sn-doped GeP were synthesized from elements in bismuth and tin flux, respectively. The layered crystal structures of these compounds were characterized by single crystal X-ray diffraction. Both phosphides crystallize in a GaTe structure type in the monoclinic space group C2/m (No. 12) with GeP: a=15.1948(7) Å, b=3.6337(2) Å, c=9.1941(4) Å, β=101.239(2)°; Ge{sub 0.93(3)}P{sub 0.95(1)}Sn{sub 0.12(3)}: a=15.284(9) Å, b=3.622(2) Å, c=9.207(5) Å, β=101.79(1)°. The crystal structure of GeP consists of 2-dimensional GeP layers held together by weak electron lone pair interactions between the phosphorus atoms that confine the layer. Each layer is built of Ge–Ge dumbbells surrounded by a distorted antiprism of phosphorus atoms. Sn-doped GeP has a similar structural motif, but with a significant degree of disorder emphasized by the splitting of all atomic positions. Resistivity measurements together with quantum-chemical calculations reveal semiconducting behavior for the investigated phosphides. - Graphical abstract: Layered phosphides GeP and Sn-doped GeP were synthesized from elements in bismuth and tin flux, respectively. The crystal structure of GeP consists of 2-dimensional GeP layers held together by weak electron lone pair interactions between the phosphorus atoms that confine the layer. Sn-doped GeP has a similar structural motif with a significant degree of disorder emphasized by the splitting of all atomic positions. Resistivity measurements together with quantum-chemical calculations reveal semiconducting behavior for the investigated phosphides. - Highlights: • GeP crystallizes in a layered crystal structure. • Doping of Sn into GeP causes large structural distortions. • GeP is narrow bandgap semiconductor. • Sn-doped GeP exhibits an order of magnitude higher resistivity due to disorder.

  5. Phase equilibria in the Mo-Fe-P system at 800 °C and structure of ternary phosphide (Mo(1-x)Fe(x))3P (0.10 ≤ x ≤ 0.15).

    Science.gov (United States)

    Oliynyk, Anton O; Lomnytska, Yaroslava F; Dzevenko, Mariya V; Stoyko, Stanislav S; Mar, Arthur

    2013-01-18

    Construction of the isothermal section in the metal-rich portion (<67 atom % P) of the Mo-Fe-P phase diagram at 800 °C has led to the identification of two new ternary phases: (Mo(1-x)Fe(x))(2)P (x = 0.30-0.82) and (Mo(1-x)Fe(x))(3)P (x = 0.10-0.15). The occurrence of a Co(2)Si-type ternary phase (Mo(1-x)Fe(x))(2)P, which straddles the equiatomic composition MoFeP, is common to other ternary transition-metal phosphide systems. However, the ternary phase (Mo(1-x)Fe(x))(3)P is unusual because it is distinct from the binary phase Mo(3)P, notwithstanding their similar compositions and structures. The relationship has been clarified through single-crystal X-ray diffraction studies on Mo(3)P (α-V(3)S-type, space group I42m, a = 9.7925(11) Å, c = 4.8246(6) Å) and (Mo(0.85)Fe(0.15))(3)P (Ni(3)P-type, space group I4, a = 9.6982(8) Å, c = 4.7590(4) Å) at -100 °C. Representation in terms of nets containing fused triangles provides a pathway to transform these closely related structures through twisting. Band structure calculations support the adoption of these structure types and the site preference of Fe atoms. Electrical resistivity measurements on (Mo(0.85)Fe(0.15))(3)P reveal metallic behavior but no superconducting transition.

  6. The first-principle study of N2O gas interaction on the surface of pristine and Si-, Ga-, SiGa-doped of armchair boron phosphide nanotube using DFT method

    Directory of Open Access Journals (Sweden)

    M Rezaei-Sameti

    2016-12-01

    Full Text Available In present research,  the electrical, structural, quantum and Nuclear Magnetic Resonance (NMR parameters of interaction of N2O gas on the B and P sites of pristine, Ga-, Si- and SiGa-doped (4,4 armchair models of boron phosphide nanotubes (BPNTs are investigated by using density functional theory (DFT.  For this purpose, seven models for adsorption of N2O gas on the exterior surfaces of BPNTs have been considered and then all structures are optimized by B3LYP level of theory and 6–31G (d base set. The optimized structures are used to calculate the electrical, structural, quantum and NMR parameters. The computational results revealed that the adsorption energy of all studied models of BPNTs is negative; all processes are exothermic and favorable in thermodynamic approach. When N2O gas is adsorbed from its O atom head on the B site of nanotube, N2O gas is dissociated to O atom and N2 molecule. The adsorption energy of this process is more than those of other models and more stable than other models. In A, B and C models, the global hardness decreases significantly from original values and so the activity of nanotube increases from original state. On the other hand, the electrophilicity index (ω, electronic chemical potential (μ, electronegativity (χ and global softness (S of the A, B and C models increase significantly from original value and CSI values of the C model are larger than those of other models. The results demonstrate that the Ga-, Si- and SiGa- doped BPNTs are good candidates to adsorb N2O and make N2O gas sensor

  7. 烟草熏蒸过程中仓库内外环境磷化氢浓度检测%Air phosphine concentration of aluminum phosphide fumigated warehouse

    Institute of Scientific and Technical Information of China (English)

    张建中; 陈发明; 叶青; 彭言群

    2011-01-01

    Objective To investigate the variation of air phosphine (PH3) concentrations in the internal and external environment of warehouse after aluminum phosphide (AlP) fumigation and natural air ventilation.Methods Air PH3 concentrations inside and outside fumigated warehouse were measured using synchronous sampling method according to the GBZ159 air collection standard during the process of fumigation and ventilation.Results PH3 concentrations were 30.36 ~ 182.14 g/m3 inside the warehouse when it was fumigated with 0.2~0.5 g/m3 AlP.Air PH3 concentrations were 3.12~17.9 mg/m3 and 27.3~ 162.4 g/m3 respectively at the fumigation operation position andbefore the ventilation of fumigated warehouse.PH3 concentrations gradually decreased to occupationally acceptable level in 90 % of the air samples inside the warehouse after 48 hrs of natural ventilation.Conclusion Air PH3 concentrations outside the fumigated warehouse were within the occupational acceptable levels in the whole process of fumigation.The safe level of air PH3 concentrations inside the fumigated warehouse was achieved after 72 hrs of natural air ventilation.%目的 探讨某烟草仓储基地磷化铝熏蒸过程中库内及周围环境空气中磷化氢(PH3)浓度变化规律,以及熏蒸后开仓通风散气工作场所达到安全浓度所需排放时间,为烟草熏蒸安全作业提供依据.方法 按GBZ-159采样规范,采用与熏蒸和散气过程同步等时采样方法,对某烟草仓储基地1号储烟库烟草熏蒸和开仓散气过程仓库内外环境空气中PH3浓度进行现场检测,监测不同时段库内外空气中PH3浓度.结果 库内磷化铝投放量为0.2~0.5 mg/m3;库内磷化氢熏蒸浓度为30.36~182.14 mg/m3;熏蒸时操作岗位磷化氢浓度范围为3.12~17.9 mg/m3;开仓散气前库内磷化氢浓度范围为27.3~162.4 mg/m3;在开仓散气48 h后库内pH3氢浓度逐步降至职业接触限值;库外磷化氢浓度在散气时同步检测91%

  8. Indium phosphide based photonic integrated circuits

    Science.gov (United States)

    Mason, Thomas Gordon Beck

    The continued advancement of growth and processing technology in compound semiconductor materials has opened up new possibilities for the creation of complex photonic devices and circuits. This dissertation discusses the design and development of a photonic circuit based on the monolithic integration of a widely tunable laser with an on chip wavelength monitor. The widely tunable laser is a four-section device with a pair of sampled grating distributed Bragg reflector mirrors. This enables it to use a Vernier effect tuning mechanism to overcome the Deltan/n characteristic which limits the wavelength range of conventional injection tuned semiconductor lasers. Index tuning in the laser is improved by using a thick low band gap waveguide with an optimized grating etch and regrowth technique. A record 22 nm quasi-continuous tuning range has been demonstrated for a ridge waveguide device. For even greater tuning range, a buried heterostructure device was developed that is capable of tuning over more than 47 nm, enabling it to cover almost 60 DWDM wavelength channels. The complexity of the tuning mechanism in these devices makes it desirable to have a wavelength monitor to provide feedback for control of the laser. In this work, we have developed a compact integrated wavelength monitor that can be fabricated on chip with the tunable sampled grating DBR laser. The wavelength monitor takes advantage of two-mode interference in a semiconductor waveguide to create a wavelength dependent splitter. Monitors based on this principle have been successfully integrated with both ridge waveguide and buried heterostructure sampled grating DBR lasers. This dissertation reviews all of the aspects of the design, growth, processing and packaging of these devices.

  9. Efficient water reduction with gallium phosphide nanowires

    NARCIS (Netherlands)

    Standing, A.; Assali, S.; Gao, L.; Verheijen, M.A.; Van Dam, D.; Cui, Y.; Notten, P.H.L.; Haverkort, J.E.M.; Bakkers, E.P.A.M.

    2015-01-01

    Photoelectrochemical hydrogen production from solar energy and water offers a clean and sustainable fuel option for the future. Planar III/V material systems have shown the highest efficiencies, but are expensive. By moving to the nanowire regime the demand on material quantity is reduced, and new m

  10. Multiple light scattering in porous gallium phosphide

    OpenAIRE

    Bret, Boris Paul Jean

    2005-01-01

    This thesis presents an experimental study on multiple light scattering, with the necessary introductions: theoretical background and sample preparation. The emphasis is put on the effects of the multiple scattering of waves, i.e., where interference effects exist and are significant, in the search for Anderson localization. In ensemble-averaged random media, there exists a cone of light, superimposed on the diffuse background, in the exact backscattering direction, due to the constructive in...

  11. Electrical properties of donors in gallium phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Poedoer, B. (Hungarian Academy of Sciences, Budapest. Research Lab. for Inorganic Chemistry); Pfeiffer, J.; Csontos, L.; Nador, N. (Hungarian Academy of Sciences, Budapest. Research Inst. for Technical Physics); Deak, F. (Eoetvoes Lorand Tudomanyegyetem, Budapest (Hungary). Atomfizikai Tanszek)

    1983-04-16

    The thermal ionization energies of S, Te, and Si donors in GaP and their dependences on impurity concentration are determined from an anlysis of Hall effect data. An ellipsoidal six-valley model is used incorporating the effects of valley-orbit splitting of the ground state of the P-site donors. A careful characterization of the samples ensures that results are obtained on samples containing only one type of dominant donor. The thermal ionization energies of the above donors extrapolated to infinite dilution are (105.0 +- 5.7), (94.1 +- 2.6), and (83.5 +- 1.7) meV, respectively. The valley-orbit splitting energies of S and Te donors are also obtained, amounting to (34 +- 9) and (23.5 +- 9) meV, respectively.

  12. [Suicide attempt with aluminum phosphide poisoning].

    Science.gov (United States)

    Reyna-Medina, Mauricio; Vázquez-de Anda, Gilberto Felipe; García-Monroy, Jesús; Valdespino-Salinas, Eduardo Alfredo; Vicente-Cruz, Dante Carlos

    2013-01-01

    Introducción: la tentativa suicida con el fumigante denominado fosfuro de aluminio tiene elevada mortalidad. El objetivo fue determinar la frecuencia del consumo de fosfuro de aluminio por tentativa suicida. Métodos: estudio retrospectivo de serie de casos, realizado en el Hospital General de Tejupilco durante los años 2009 a 2011. De 32 pacientes con tentativa suicida, solo se incluyeron 18 que utilizaron fosfuro de aluminio. El riesgo de rescate se calificó de acuerdo con la escala de Weisman. Resultados: de los 18 pacientes suicidas que utilizaron fosfuro de aluminio, 83 % era del sexo femenino (n = 15) y la edad media era de 17.7 ± 4.4 años, 89 % (n = 16) tenía = 23 años de edad y 89 % (n = 16) cursaba con depresión. El motivo detonante del intento suicida fue el abandono de la pareja en 56 % (n = 10). La letalidad del fosfuro de aluminio fue de 78 % (n = 14). Las defunciones sucedieron en 4 ± 2 horas. Conclusiones: el fosfuro de aluminio es el tóxico más usado con intención suicida en el medio rural; su uso predomina en las mujeres abandonadas por su pareja y se relaciona con depresión emocional y seguridad de morir.

  13. Minority carrier lifetime in indium phosphide

    Science.gov (United States)

    Jenkins, Phillip; Landis, Geoffrey A.; Weinberg, Irving; Kneisel, Keith

    1991-01-01

    Transient photoluminescence is used to measure the minority carrier lifetime on n-type and p-type InP wafers. The measurements show that unprocessed InP wafers have very high minority carrier lifetimes. Lifetimes of 200 ns and 700 ns were observed for lightly-doped p- and n-type material respectively. Lifetimes over 5 ns were found in heavily doped n-type material.

  14. 磷化铝中毒抑制大鼠胆碱酯酶及阿托品和氯解磷啶的作用%Cholinesterase inhibition by aluminium phosphide poisoning in rats and effects of atropine and pralidoxime chloride

    Institute of Scientific and Technical Information of China (English)

    Shivani MHrRA; Sharda Shah PESHIN; Shyam Bala LALL

    2001-01-01

    AIM: To investigate the cholinesterase inhibition and effect of atropine and pralidoxime (PAM) treatment on the survival time in the rat model of aluminium phosphide (ALP) poisoning. METHODS: The rats were treated with AlP (10 mg/kg; 5.55×LD50; ig) and the survival time was noted. The effect of atropine (1 mg/kg, ip) and PAM (5 mg/kg, ip) was noted on the above. Atropine and PAM were administered 5 min after AlP. Plasma cholinesterase levels were measured spectrophotometrically in the control and AlP treated rats 30 min after administration. RESULTS: Treaanent with atropine and PAM increased the survival time by 2.5 fold (1.4 h ±0.3 h vs 3.4 h±2.5 h, P<0.01) in9 out of 15 animals and resulted in total survival of the 6 remaining animals. Plasma cholinesterase levels were inhibited by 47%, (438±74) U/L in AlP treated rats as compared tocontrol (840±90) U/L (P<0.01). CONCLUSION: This preliminary study concludes that AlP poisoning causes cholinesterase inhibition and responds to treatment with atropine and PAM.

  15. Dysprosium-free melt-spun permanent magnets.

    Science.gov (United States)

    Brown, D N; Wu, Z; He, F; Miller, D J; Herchenroeder, J W

    2014-02-12

    Melt-spun NdFeB powders can be formed into a number of different types of permanent magnet for a variety of applications in electronics, automotive and clean technology industries. The melt-spinning process produces flake powder with a fine uniform array of nanoscale Nd2Fe14B grains. These powders can be net-shape formed into isotropic polymer-bonded magnets or hot formed into fully dense magnets. This paper discusses the influence of heavy rare earth elements and microstructure on the magnetic performance, thermal stability and material cost of NdFeB magnets. Evidence indicates that melt-spun nanocrystalline NdFeB magnets are less dependent on heavy rare earth elements for high-temperature performance than the alternative coarser-grained sintered NdFeB magnets. In particular, hot-pressed melt-spun magnets are an attractive low-cost solution for applications that require thermal stability up to 175-200 °C.

  16. Structural and magnetic study of dysprosium substituted cobalt ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Hemaunt, E-mail: hvatsal@gmail.com [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Srivastava, R.C. [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Pal Singh, Jitendra [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of); Negi, P. [Department of Physics, Govind Ballabh Pant University of Agr. & Technology, Pantnagar, Uttarakhand 263145 (India); Agrawal, H.M. [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of); Das, D. [UGC-DAE CSR Kolkata Centre, Kolkata 700098 (India); Hwa Chae, Keun [Advanced Analysis Centre, Korea Institute of Science and Technology, Seoul 02792 (Korea, Republic of)

    2016-03-01

    The present work investigates the magnetic behavior of Dy{sup 3+} substituted cobalt ferrite nanoparticles. X-ray diffraction studies reveal presence of cubic spinel phases in these nanoparticles. Raman spectra of these nanoparticles show change in intensity of Raman bands, which reflects cation redistribution in cubic spinel lattice. Saturation magnetization and coercivity decrease with increase of Dy{sup 3+}concentration in these nanoparticles. Room temperature Mössbauer measurements show the cation redistribution in these nanoparticles and corroborates the results obtained from Raman Spectroscopic measurements. Decrease in magnetization of Dy{sup 3+} substituted cobalt ferrite is attributed to the reduction in the magnetic interaction and cation redistribution. - Highlights: • Slight decrease in crystallite size after Dy{sup 3+} doping. • Saturation magnetization and coercivity decrease after Dy{sup 3+} doping. • Mössbauer measurements show the cation redistribution in the samples.

  17. Dysprosium Acetylacetonato Single-Molecule Magnet Encapsulated in Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ryo Nakanishi

    2016-12-01

    Full Text Available Dy single-molecule magnets (SMMs, which have several potential uses in a variety of applications, such as quantum computing, were encapsulated in multi-walled carbon nanotubes (MWCNTs by using a capillary method. Encapsulation was confirmed by using transmission electron microscopy (TEM. In alternating current magnetic measurements, the magnetic susceptibilities of the Dy acetylacetonato complexes showed clear frequency dependence even inside the MWCNTs, meaning that this hybrid can be used as magnetic materials in devices.

  18. Microscopic study of neutron-rich dysprosium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Carlos E. [Universidad Veracruzana, Facultad de Fisica e Inteligencia Artificial, Xalapa (Mexico); Universidad Nacional Autonoma de Mexico, Facultad de Ciencias, Apartado Postal 70-542, Mexico D.F. (Mexico); Velazquez, Victor [Universidad Nacional Autonoma de Mexico, Facultad de Ciencias, Apartado Postal 70-542, Mexico D.F. (Mexico); Lerma, Sergio [Universidad Veracruzana, Facultad de Fisica e Inteligencia Artificial, Xalapa (Mexico)

    2013-01-15

    Microscopic studies in heavy nuclei are very scarce due to large valence spaces involved. This computational problem can be avoided by means of the use of symmetry-based models. Ground-state, {gamma} and {beta} bands, and their B(E2) transition strengths in {sup 160-168}Dy isotopes, are studied in the framework of the pseudo-SU(3) model which includes the preserving symmetry Q . Q term and the symmetry-breaking Nilsson and pairing terms, systematically parametrized. Additionally, three rotor-like terms are considered, whose free parameters, fixed for all members of the chain, are used to fine tune the moment of inertia of rotational bands and the band head of {gamma} and {beta} bands. The model succesfully describes in a systematic way rotational features in these nuclei and allows to extrapolate toward the midshell nucleus {sup 170}Dy. The results presented show that it is possible to study a full chain of isotopes or isotones in the region with the present model. (orig.)

  19. Photodissociation spectroscopy of the dysprosium monochloride molecular ion

    CERN Document Server

    Dunning, Alexander; Showalter, Steven J; Puri, Prateek; Kotochigova, Svetlana; Hudson, Eric R

    2015-01-01

    We have performed a combined experimental and theoretical study of the photodissociation cross section of the molecular ion DyCl$^+$. The cross section for the photon energy range 35,500 cm$^{-1}$ to 47,500 cm$^{-1}$ is measured using an integrated ion trap and time-of-flight mass spectrometer, and we observe a broad, asymmetric profile that is peaked near 43,000 cm$^{-1}$. The theoretical cross section is determined from electronic potentials and transition dipole moments calculated using the relativistic configuration-interaction valence-bond and coupled-cluster methods. The electronic structure of DyCl$^+$ is unprecedentedly complex due to the presence of multiple open electronic shells, including 4f$^{10}$ orbitals. The molecule has nine attractive potentials with ionically-bonded electrons and 99 repulsive potentials dissociating to a ground state Dy$^+$ ion and Cl atom. We explain the lack of symmetry in the cross section as due to multiple contributions from one-electron-dominated transitions between t...

  20. FTIR and Electrical Study of Dysprosium Doped Cobalt Ferrite Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hemaunt Kumar

    2014-01-01

    Full Text Available We have studied the role of Dy3+ doping on the XRD, TEM, FTIR, and dielectric and electrical properties of CoFe2O4 at room temperature. Cubic spinel phase of CoFe2−xDyxO4 (x = 0.00, 0.05, 0.10, and 0.15 was synthesized by using different sintering temperatures (300, 500, 700, and 900°C. The two absorption bands ν1 and ν2 are observed in Fourier transform infrared spectroscopy (FTIR spectra corresponding to the tetrahedral and octahedral sites, which show signature of spinel structure of the sample. For the sample sintered at 300°C, the dielectric constant is almost unchanged with the frequency at the particular concentrations of x = 0.00 and 0.05. Similar result is obtained for the sample sintered at 500°C (x = 0.10, 0.15, 700°C (x = 0.05, 0.10, and 0.15, and 900°C (x = 0.05, 0.10. An increase in the dielectric constant was observed for the undoped cobalt ferrite sintered at 500, 700, and 900°C. The values of electrical resistivity of the materials vary from ~105 to 109 Ω-cm.

  1. Adsorption of D113 Resin for Dysprosium(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The adsorption behavior and mechanism of D113 resin for Dy(Ⅲ) was investigated by using the method of resin adsorption. Experimental results show that the optimum medium pH of adsorption of D113 resin for Dy3+ is pH=6.00 in the HAc-NaAc medium. The static adsorption capacity of D113 resin for Dy3+chemical analysis and IR spectra.

  2. 1300-nm gain obtained with dysprosium-doped chloride crystals

    Energy Technology Data Exchange (ETDEWEB)

    Page, R.H.; Schaffers, K.I.; Beach, R.J.; Payne, S.A.; Krupke, W.F.

    1996-03-01

    Dy{sup 3+} - doped chloride crystals have high 1300-nm emission quantum yields. Pump - probe experiments on La Cl{sub 3}:Dy{sup 3+} demonstrate optical gain consistent with predictions based on spectroscopic cross sections and lifetimes.

  3. Microscopic study of neutron-rich Dysprosium isotopes

    CERN Document Server

    Vargas, Carlos E; Lerma, Sergio; 10.1140/epja/i2013-13004-1

    2013-01-01

    Microscopic studies in heavy nuclei are very scarce due to large valence spaces involved. This computational problem can be avoided by means of the use of symmetry based models. Ground-state, gamma and beta-bands, and their B(E2) transition strengths in 160-168Dy isotopes, are studied in the framework of the pseudo-SU(3) model which includes the preserving symmetry Q.Q term and the symmetry-breaking Nilsson and pairing terms, systematically parametrized. Additionally, three rotor-like terms are considered whose free parameters, fixed for all members of the chain are used to fine tune the moment of inertia of rotational bands and the band-head of gamma and beta-bands. The model succesfully describes in a systematic way rotational features in these nuclei and allows to extrapolate toward the midshell nucleus 170Dy. The results presented show that it is possible to study full chain of isotopes or isotones in the region with the present model.

  4. Visible luminescence of dysprosium ions in oxyhalide lead borate glasses

    Science.gov (United States)

    Pisarska, Joanna; Żur, Lidia; Pisarski, Wojciech A.

    2011-08-01

    Visible luminescence of Dy 3+ ions in oxyhalide lead borate glasses was examined. Luminescence spectra show two intense bands at 480 nm and 573 nm due to 4F 9/2 → 6H 15/2 (blue) and 4F 9/2 → 6H 13/2 (yellow) transitions of Dy 3+. Luminescence decays from 4F 9/2 state and yellow-to-blue luminescence intensity ratios (Y/B) were analysed with PbX 2 (X = F, Cl) content. An introduction of PbX 2 to the borate glass results in the increasing of 4F 9/2 lifetime and the decreasing of yellow-to-blue luminescence intensity ratio, which is due to reduction of covalency between Dy 3+ and O 2-/X - ions.

  5. MAGNETIC FIELD INDUCED FIRST-ORDER TRANSITIONS IN DYSPROSIUM ORTHOFERRITE

    OpenAIRE

    Eremenko, V.; Gnatchenko, S.; Kharchenko, N.; Lebedev, P.; Piotrowski, K; Szymczak, H.; Szymczak, R.

    1988-01-01

    New type of magnetic first-order phase transition induced by external magnetic field applied in the ab-plane in DyFeO3 is investigated using different magnetooptic techniques. The phenomenological model of this transition is proposed. The phase diagram in H-T plane has been obtained for various H orientation in the ab-plane.

  6. Preparation, Characterization, Hydrodesulfurization and Hydrodenitrogenation Activities of Alumina-supported Tungsten Phosphide Catalysts%WP/γ-Al2O3催化剂的制备、表征及加氢脱硫和加氢脱氮活性

    Institute of Scientific and Technical Information of China (English)

    李翠清; 孙桂大; 李成岳; 宋亚娟

    2006-01-01

    Two series of WP/Al2O3 catalyst precursors with WP mass loading in the range 18.5%-37.1% were prepared using the impregnation method and mixing method, respectively, and the catalysts were then obtained by temperature-programmed reduction of supported tungsten phosphate (precursor of WP/Al2O3 catatlysts) in H2 at 650℃ for 4h. The catalysts were characterized by XRD, BET, TG/DTA, XPS and 31p MAS-NMR. The activities of these catalysts were tested in the hydrodenitrogenation (HDN) of pyridine and hydrodesulfurization (HDS) of thiophene at 340℃ and 3.0MPa. The results showed that owing to the stronger interaction of the support with the active species, the precursor of WP/Al2O3 catalyst was more difficultly phosphided and a greater amount of W species was in a high valence state W6+ on the surface of the catalyst prepared by the impregnation method than that by the mixing method. 31p MAS-NMR results indicated that 31p shift from 85% H3PO4 of 2.55 × 10-4 for WP and 2.57 × 10-4 for WP/γ-Al2O3 catalysts prepared by mixing method. Such WP/Al2O3 catalysts showed higher HDN activities and lower HDS activities than those prepared by the impregnation method under the same loading of WP.WP/γ-Al2O3 catalysts with weak interaction between support and active species were favorable for HDN reaction while the WP/γ-Al2O3 catalysts with strong interaction were favorable for HDS reaction.

  7. Effect of N-acetylcysteine and L-NAME on aluminium phosphide induced cardiovascular toxicity in rats%N-乙酰半胱氨酸和L-NAME对磷化铝诱导的大鼠心血管毒性的作用

    Institute of Scientific and Technical Information of China (English)

    Archana AZAD; Shyam Bala LALL; Shivani MITTRA

    2001-01-01

    AIM: To investigate the protective effects of N-acetyl- cysteine (NAC) and Nω-Nitro-L-arginine methyl ester (L-NAME) on aluminium phosphide (AlP) poisoning induced hemodynamic changes, myocardial oxygen free radical injury and on survival time in rats. METH- ODS: AlP (12.5 mg/kg) was administered intragastri cally under urethane anaesthesia. The effect of pre- and post-treatment with NAC and L-NAME alone and in combination was studied on haemodynamic parameters [blood pressure (BP), heart rate (HR), and electrocar- diogram (ECG) ] and biochemical parameters ( malonyl- dialdehyde, catalase, and glutathione peroxidase). RE SULTS: AlP caused significant hypotension, tachycar dia, ECG abnormalities, and finally marked bradycardia. The mean survival time was (90 ± 10) min. There was significant increase in myocardial malonyldialdehyde (MDA), and decrease in catalase and glutathione peroxi dase (GSH Px) levels. NAC infusion (6.25 mg·kg-1· min-1, iv for 30 min) caused insignificant hemodynamic and biochemical changes. Pre- and post-treatment of NAC with AlP significantly increased the survival time, stabilized BP, HR, and ECG, decreased MDA and in creased GSH Px levels compared to AlP group. L- NAME infusion ( 1 mg· kg- 1· min- 1, iv for 60 min) as such caused significant rise in BP but precipitated ECG abnormalities. Pre- and post-treatment of L-NAME with AlP neither improved the survival time nor the biochemi cal parameters despite significant rise in BP. Co-admin- istration of both the drugs with AlP worsened the hemo dynamic and biochemical parameters with reduction in the survival time as compared to AlP. CONCLUSION: NAC increased the survival time by reducing myocardial oxidative injury whereas L-NAME showed no such pro tective effects in rats exposed to AlP.

  8. Measurement of surface recombination velocity on heavily doped indium phosphide

    Science.gov (United States)

    Jenkins, Phillip; Ghalla-Goradia, Manju; Faur, Mircea; Faur, Maria; Bailey, Sheila

    1990-01-01

    Surface recombination velocity (SRV) on heavily doped n-type and p-type InP was measured as a function of surface treatment. For the limited range of substrates and surface treatments studied, SRV and surface stability depend strongly on the surface treatment. SRVs of 100,000 cm/sec in both p-type and n-type InP are obtainable, but in n-type the low-SRV surfaces were unstable, and the only stable surfaces on n-type had SRVs of more than 10to the 6th cm/sec.

  9. Analysis of indium-phosphide/indium tin oxide solar cells

    Science.gov (United States)

    Coutts, T. J.; Pearsall, N. M.; Nottenburg, R.; Ireland, P. J.; Kazmerski, L. L.

    1981-05-01

    The mechanisms that underlie the operation of p-InP/N-ITO solar cells fabricated by depositing thin films of ITO onto InP substrates by both RF sputtering and ion-beam sputtering were investigated. The RF sputtered devices behave like SIS or heterojunction cells. The ion-beam sputtered cells behave more like buried homojunction devices. It is sown that the properties of these cells depend not only on the method of fabrication, but also on several other complicating effects which occur before, during and after deposition of the ITO.

  10. Strategic Review of Arsenide, Phosphide and Nitride MOSFETs

    OpenAIRE

    Gourab Dutta; Palash Das; Partha Mukherjee; Dhrubes Biswas

    2011-01-01

    Metal oxide semiconductor field effect transistor used as an amplifier and switch uses Si primarily as a channel material for its very stable oxide SiO2. In-spite of many advantages there are some restrictions for Si MOS, so the world is approaching towards compound semiconductor for higher frequency and current. The development of compound semiconductor metal oxide semiconductor is also facing critical problems due to the lack of availability of proper gate oxide material. Research is being ...

  11. Spectroscopic properties of colloidal indium phosphide quantum wires

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lin-Wang; Wang, Fudong; Yu, Heng; Li, Jingbo; Hang, Qingling; Zemlyanov, Dmitry; Gibbons, Patrick C.; Wang, Lin-Wang; Janes, David B.; Buhro, William E.

    2008-07-11

    Colloidal InP quantum wires are grown by the solution-liquid-solid (SLS) method, and passivated with the traditional quantum dots surfactants 1-hexadecylamine and tri-n-octylphosphine oxide. The size dependence of the band gaps in the wires are determined from the absorption spectra, and compared to other experimental results for InP quantum dots and wires, and to the predictions of theory. The photoluminescence behavior of the wires is also investigated. Efforts to enhance photoluminescence efficiencies through photochemical etching in the presence of HF result only in photochemical thinning or photo-oxidation, without a significant influence on quantum-wire photoluminescence. However, photo-oxidation produces residual dot and rod domains within the wires, which are luminescent. The results establish that the quantum-wire band gaps are weakly influenced by the nature of the surface passivation, and that colloidal quantum wires have intrinsically low photoluminescence efficiencies.

  12. 40 CFR 180.284 - Zinc phosphide; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... agricultural commodities as follows: Commodity Parts per million Alfalfa, forage 0.2 Alfalfa, hay 0.2 Barley, grain 0.05 Barley, hay 0.2 Barley, straw 0.2 Bean, dry, seed 0.05 Beet, sugar, roots 0.05 Beet, sugar... Expiration/Revocation Date Alfalfa, forage 1.0 12/31/05 Alfalfa, hay 1.0 12/31/05 Clover, forage 0.1...

  13. Hydrodechlorination of polychlorinated molecules using transition metal phosphide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Cecilia, J.A.; Infantes-Molina, A., E-mail: ainfantes@uma.es; Rodríguez-Castellón, E.

    2015-10-15

    Highlights: • Ni{sub 2}P catalyst is much more active than CoP one for Cl-removal. • Benzene is the main reaction product for Ni{sub 2}P catalyst. • The activity followed the order ClB > 1,4-DClB ≈ 1,2,4-TClB > 1,3-DClB > 1,2-DClB for Ni{sub 2}P. • The activity followed the order ClB > 1,4-DClB > 1,3-DClB > 1,2-DClB > 2,4-TClB for CoP. • Active phase dispersion, P-concentration on the surface and H-species on the surface explain the results. - Abstract: Ni{sub 2}P and CoP catalysts (5 wt.% of metal) supported on a commercial SiO{sub 2} were tested in the gas phase catalytic hydrodechlorination (HDCl) of mono (chlorobenzene-ClB) and polychlorobenzenes (PCBs) (1,2- dichlorobenzene (1,2-DClB), 1,3-dichlorobenzene (1,3-DClB), 1,4-dichlorobenzene (1,4-DClB), and 1,2,4-trichlorobenzene (1,2,4-TClB)) at atmospheric pressure. It was investigated how the number and position of chlorine atoms in the molecule influence the HDCl activity. The prepared catalysts were characterized by X-ray diffraction (XRD), CO chemisorption, N{sub 2} adsorption–desorption at −196 °C, and X-ray photoelectron spectroscopy (XPS). Characterization results indicated better active phase dispersion and greater amount of P on the Ni{sub 2}P catalyst surface. Catalytic results showed that the Ni{sub 2}P was more active and stable in this type of reactions. The hydrodechlorination activity decreased by increasing the number of chlorine atoms in the molecule and chlorine substituents in close proximity. The observed trend in the HDCl activity was: ClB > 1,4-DClB > 1,3-DClB > 1,2-DClB > 1,2,4-TClB. The exception was the catalytic response after 24 h on stream observed for the Ni{sub 2}P in the HDCl reaction of 1,2,4-TClB, which was equal to that observed for the 1,4-DClB molecule, and also yielding benzene as the main reaction product.

  14. X-ray photoelectron spectroscopy of FeP phosphide

    Energy Technology Data Exchange (ETDEWEB)

    Teterin, Yu. A.; Sobolev, A. V., E-mail: salex12@rambler.ru, E-mail: alex@radio.chem.msu.ru; Presnyakov, I. A.; Maslakov, K. I. [Moscow State University (Russian Federation); Teterin, A. Yu. [National Research Center “Kurchatov Institute,” (Russian Federation); Morozov, I. V.; Chernyavskii, I. O. [Moscow State University (Russian Federation); Ivanov, K. E. [National Research Center “Kurchatov Institute,” (Russian Federation); Shevel’kov, A. V. [Moscow State University (Russian Federation)

    2017-02-15

    The structure of the outer and inner electron spectra of iron (2p, 3p, 3s, and 3d) and phosphorus (3s and 3p) atoms in FeP monophosphide is studied in detail by the X-ray photoelectron spectroscopy (XPS) method. On the basis of the analysis of the binding energy of electrons, as well as the parameters characterizing the structure of experimental spectra, a conclusion is made that Fe{sup 3+} (d{sup 5}) cations in FeP are stabilized in a state with intermediate value of the total spin (IS, S = 3/2). The range of values of intra-atomic parameters (10Dq, J{sub H}) is established in which the consideration of the high degree of covalence of Fe–P bonds may lead to the stabilization of (FeP{sub 6}){sup 15–} clusters in the IS state.

  15. A review of indium phosphide space solar cell fabrication technology

    Science.gov (United States)

    Spitzer, M. B.; Dingle, B.; Dingle, J.; Morrison, R.

    1990-01-01

    A review of the status of InP cell efficiency and of approaches to the reduction of cell cost is presented. The use of heteroepitaxial techniques such as InP-on-GaAs and InP-on-Si is discussed along with the use of chemical and mechanical techniques for removal and recovery of the substrate. The efficiency ultimately obtainable with designs made possible by such an approach is calculated.

  16. Electron and hole transfer from indium phosphide quantum dots.

    Science.gov (United States)

    Blackburn, J L; Selmarten, D C; Ellingson, R J; Jones, M; Micic, O; Nozik, A J

    2005-02-24

    Electron- and hole-transfer reactions are studied in colloidal InP quantum dots (QDs). Photoluminescence quenching and time-resolved transient absorption (TA) measurements are utilized to examine hole transfer from photoexcited InP QDs to the hole acceptor N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) and electron transfer to nanocrystalline titanium dioxide (TiO2) films. Core-confined holes are effectively quenched by TMPD, resulting in a new approximately 4-ps component in the TA decay. It is found that electron transfer to TiO2 is primarily mediated through surface-localized states on the InP QDs.

  17. Spectroscopic properties of colloidal indium phosphide quantum wires.

    Science.gov (United States)

    Wang, Fudong; Yu, Heng; Li, Jingbo; Hang, Qingling; Zemlyanov, Dmitry; Gibbons, Patrick C; Wang, Lin-Wang; Janes, David B; Buhro, William E

    2007-11-21

    Colloidal InP quantum wires are grown by the solution-liquid-solid (SLS) method, and passivated with the traditional quantum dots surfactants 1-hexadecylamine and tri-n-octylphosphine oxide. The size dependence of the band gaps in the wires are determined from the absorption spectra, and compared to other experimental results for InP quantum dots and wires, and to the predictions of theory. The photoluminescence behavior of the wires is also investigated. Efforts to enhance photoluminescence efficiencies through photochemical etching in the presence of HF result only in photochemical thinning or photooxidation, without a significant influence on quantum-wire photoluminescence. However, photooxidation produces residual dot and rod domains within the wires, which are luminescent. The results establish that the quantum-wire band gaps are weakly influenced by the nature of the surface passivation and that colloidal quantum wires have intrinsically low photoluminescence efficiencies.

  18. Third-Order Nonlinear Optical Susceptibility of Indium Phosphide Nanocrystals

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-Li; WANG Dong; CHEN Guang-De; LIU Hui

    2007-01-01

    InP nanocrystals synthesized by refluxing and annealing of organic solvent are determined from XRD measurements to have an average granularity of 25 nm. The nonlinear optical properties of the InP nanocrystals studied by using laser Z-scan technique with 50ps pulses at 532nm are found to reveal strong nonlinear optical properties and two-photon absorption phenomenon. Also, the nonlinear absorption coefficient, the nonlinear refractive index and the third-order nonlinear optical susceptibility are determined by experiments, in which the nonlinear refractive index is three orders of magnitude larger than that of bulk InP.

  19. Observation of Weyl nodes and Fermi arcs in tantalum phosphide.

    Science.gov (United States)

    Xu, N; Weng, H M; Lv, B Q; Matt, C E; Park, J; Bisti, F; Strocov, V N; Gawryluk, D; Pomjakushina, E; Conder, K; Plumb, N C; Radovic, M; Autès, G; Yazyev, O V; Fang, Z; Dai, X; Qian, T; Mesot, J; Ding, H; Shi, M

    2016-03-17

    A Weyl semimetal possesses spin-polarized band-crossings, called Weyl nodes, connected by topological surface arcs. The low-energy excitations near the crossing points behave the same as massless Weyl fermions, leading to exotic properties like chiral anomaly. To have the transport properties dominated by Weyl fermions, Weyl nodes need to locate nearly at the chemical potential and enclosed by pairs of individual Fermi surfaces with non-zero Fermi Chern numbers. Combining angle-resolved photoemission spectroscopy and first-principles calculation, here we show that TaP is a Weyl semimetal with only a single type of Weyl fermions, topologically distinguished from TaAs where two types of Weyl fermions contribute to the low-energy physical properties. The simple Weyl fermions in TaP are not only of fundamental interests but also of great potential for future applications. Fermi arcs on the Ta-terminated surface are observed, which appear in a different pattern from that on the As-termination in TaAs and NbAs.

  20. Synthesis of actinide nitrides, phosphides, sulfides and oxides

    Science.gov (United States)

    Van Der Sluys, William G.; Burns, Carol J.; Smith, David C.

    1992-01-01

    A process of preparing an actinide compound of the formula An.sub.x Z.sub.y wherein An is an actinide metal atom selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, x is selected from the group consisting of one, two or three, Z is a main group element atom selected from the group consisting of nitrogen, phosphorus, oxygen and sulfur and y is selected from the group consisting of one, two, three or four, by admixing an actinide organometallic precursor wherein said actinide is selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, a suitable solvent and a protic Lewis base selected from the group consisting of ammonia, phosphine, hydrogen sulfide and water, at temperatures and for time sufficient to form an intermediate actinide complex, heating said intermediate actinide complex at temperatures and for time sufficient to form the actinide compound, and a process of depositing a thin film of such an actinide compound, e.g., uranium mononitride, by subliming an actinide organometallic precursor, e.g., a uranium amide precursor, in the presence of an effectgive amount of a protic Lewis base, e.g., ammonia, within a reactor at temperatures and for time sufficient to form a thin film of the actinide compound, are disclosed.

  1. Hybrid indium phosphide-on-silicon nanolaser diode

    Science.gov (United States)

    Crosnier, Guillaume; Sanchez, Dorian; Bouchoule, Sophie; Monnier, Paul; Beaudoin, Gregoire; Sagnes, Isabelle; Raj, Rama; Raineri, Fabrice

    2017-04-01

    The most-awaited convergence of microelectronics and photonics promises to bring about a revolution for on-chip data communications and processing. Among all the optoelectronic devices to be developed, power-efficient nanolaser diodes able to be integrated densely with silicon photonics and electronics are essential to convert electrical data into the optical domain. Here, we report a demonstration of ultracompact laser diodes based on one-dimensional (1D) photonic crystal (PhC) nanocavities made in InP nanoribs heterogeneously integrated on a silicon-waveguide circuitry. The specific nanorib design enables an efficient electrical injection of carriers in the nanocavity without spoiling its optical properties. Room-temperature continuous-wave (CW) single-mode operation is obtained with a low current threshold of 100 µA. Laser emission at 1.56 µm in the silicon waveguides is obtained with wall-plug efficiencies greater than 10%. This result opens up exciting avenues for constructing optical networks at the submillimetre scale for on-chip interconnects and signal processing.

  2. Nanoimprinted DWDM laser arrays on indium phosphide substrates

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Nørregaard, Jesper; Mironov, Andrej

    2014-01-01

    shift in the grating, and are single mode with high side-mode suppression. Typically, such lasers are patterned using e-beam lithography (EBL). We present a fabrication method based on patterning by thermal nanoimprint lithography, which is potentially less costly and faster than EBL. Thermal...

  3. A Semiconductor Under Insulator Technology in Indium Phosphide

    CERN Document Server

    Mnaymneh, Khaled; Frédérick, Simon; Lapointe, Jean; Poole, Philip J; Williams, Robin L

    2012-01-01

    This Letter introduces a Semiconductor-Under-Insulator (SUI) technology in InP for designing strip waveguides that interface InP photonic crystal membrane structures. Strip waveguides in InP-SUI are supported under an atomic layer deposited insulator layer in contrast to strip waveguides in silicon supported on insulator. We show a substantial improvement in optical transmission when using InP-SUI strip waveguides interfaced with localized photonic crystal membrane structures when compared with extended photonic crystal waveguide membranes. Furthermore, SUI makes available various fiber-coupling techniques used in SOI, such as sub-micron coupling, for planar membrane III-V systems.

  4. Luminescence of divalent europium activated spinels synthesized by combustion and the enhanced afterglow by dysprosium incorporation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Haoyi, E-mail: manofchina@gmail.com; Jin, Yahong

    2016-05-01

    Herein we report a luminescent phenomenon of Eu{sup 2+} in the spinel MgAl{sub 2}O{sub 4} and ZnAl{sub 2}O{sub 4} samples which are successfully synthesized via a combustion method. The XRD shows cubic spinel structure is obtained from the prepared samples. The mean crystal sizes estimated from XRD data are 30 and 10 nm for MgAl{sub 2}O{sub 4} and ZnAl{sub 2}O{sub 4} respectively, and the large grain particles are the agglomeration of crystallites. The Eu{sup 2+} ions show a blue emission at around 480 nm and an afterglow phenomenon is observed after the removal of excitation. The afterglow spectrum of MgAl{sub 2}O{sub 4}: Eu{sup 2+}, Dy{sup 3+} shows two emissions at 480 and 520 nm while only one at 480 nm is observed in ZnAl{sub 2}O{sub 4}: Eu{sup 2+}, Dy{sup 3+}. The afterglow intensity and the persisting duration can be substantially enhanced by the Dy{sup 3+} incorporation because the trapping ability of the electron traps is reinforced. This is confirmed by the TL curves of the samples.

  5. Energy level decay and excited state absorption processes in dysprosium-doped fluoride glass

    Science.gov (United States)

    Gomes, Laércio; Librantz, André Felipe Henriques; Jackson, Stuart D.

    2010-03-01

    The primary excited state decay processes relating to the H613/2→H615/2˜3 μm laser transition in singly Dy3+-doped fluoride (ZBLAN) glass have been investigated in detail using time-resolved fluorescence spectroscopy. Selective laser excitation of the F69/2, H67/2 energy levels at 1125 nm and F611/2, H69/2 energy levels at 1358 nm established that the energy levels above the H611/2 level, excluding the F49/2 level, are entirely quenched by multiphonon emission in ZBLAN glass. The H611/2 and H613/2 energy levels emit luminescence with peaks at ˜1700 and ˜2880 nm, respectively, but at low quantum (luminescence) efficiencies. The quantum efficiency of the H611/2 level and H613/2 level is ˜9×10-5 and ˜1.3×10-2, respectively, for [Dy3+]=0.5 mol % based on calculations of the radiative lifetimes using the Judd-Ofelt theory. Excited state absorption (ESA) was detected by monitoring the rise time of the 1700 nm luminescence after tuning the probe wavelength across the spectral range from 1100 to 1400 nm. As a result of nonradiative decay of the higher excited states, ESA contributes to the heating of ˜3 μm fiber lasers based on Dy3+-doped fluoride glass. For [Dy3+] up to 4 mol %, we found no evidence of energy transfer processes between Dy3+ ions that influence the decay characteristics of the H611/2 and H613/2 energy levels.

  6. A naproxen complex of dysprosium intercalates into calf thymus DNA base pairs

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Mengsi; Jin, Jianhua; Xu, Guiqing [School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang 453007 (China); Cui, Fengling, E-mail: fenglingcui@hotmail.com [School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang 453007 (China); Luo, Hongxia [Department of Chemistry, Renmin University of China, Beijing 100872 (China)

    2014-01-15

    Highlights: • Binding mode to ctDNA was studied by various methods. • Intercalation is the most possible binding mode. • Dynamic and static quenching occurred simultaneously. • Hydrophobic force played a major role. • Binding characteristic of rare earth complexes to DNA are dependent on the element. - Abstract: The binding mode and mechanism of dysprosium–naproxen complex (Dy–NAP) with calf thymus deoxyribonucleic acid (ctDNA) were studied using UV–vis and fluorescence spectra in physiological buffer (pH 7.4). The results showed that more than one type of quenching process occurred and the binding mode between Dy–NAP with ctDNA might be intercalation. In addition, ionic strength, iodide quenching and fluorescence polarization experiments corroborated the intercalation binding mode between Dy–NAP and ctDNA. The calculated thermodynamic parameters ΔG, ΔH and ΔS at different temperature demonstrated that hydrophobic interaction force played a major role in the binding process.

  7. Connecting mononuclear dysprosium single-molecule magnets to form dinuclear complexes via in situ ligand oxidation.

    Science.gov (United States)

    Yutronkie, Nathan J; Kühne, Irina A; Korobkov, Ilia; Brusso, Jaclyn L; Murugesu, Muralee

    2016-01-14

    A Dy2 complex, exhibiting SMM behaviour, and its Y analogue were prepared via in situ oxidation of Py2TTA, a pincer type ligand, followed by dimerisation. This unique metal complexation and subsequent dimerization were followed by solution NMR studies.

  8. A Linear Tetranuclear Dysprosium(III) Compound Showing Single-Molecule Magnet Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Hongshan; Xu, Gong Feng; Guo, Yun-Nan; Gamez, Patrick; Beavers, Christine M; Teat, Simon J; Tang, Jinkui

    2010-04-20

    Although magnetic measurements reveal a single-relaxation time for a linear tetranuclear Dy(III) compound, the wide distribution of the relaxation time observed clearly suggests the presence of two slightly different anisotropic centres, therefore opening new avenues for investigating the relaxation dynamics of lanthanide aggregates.

  9. A Novel (4,6)-Connected Net Based on Dysprosium Benzenedicarboxylate, [Dy(OAc)(BDC)]n

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; LI Zhao-Ji; QIN Ye-Yan; CHENG Jian-Kai; YAO Yuan-Gen

    2008-01-01

    A new lanthanide coordination polymer, [Dy(OAc)(BDC)]n 1 (OAc= acetate, BDC = 1,4-benzenediacarboxylate), has been synthesized under hydrothermal conditions. Single-crystal X-ray diffraction analysis reveals that complex 1 has infinite zigzag Dy-OAc chains, which are further connected by BDC to form a 3D metal-organic framework. According to topology analysis, this framework can be characterized as (4,6)-connected (3.4.54)(32.4.56.66) net that has never been reported before. Crystal structure for 1: space group Pbca, a = 13.314(3), b = 8.0269(18), c = 20.275(5) A, V = 2166.8(9) A3, C10H7O6Dy, Mr= 385.66, Z = 8, Dc = 2.364 g/cm3, μ = 6.910 mm-1, F(000) = 1448, the final R = 0.0181 and wR = 0.0520.

  10. Photoluminescence and thermoluminescence properties of tricalcium phosphate phosphors doped with dysprosium and europium

    Indian Academy of Sciences (India)

    K Madhukumar; H K Varma; Manoj Komath; T S Elias; V Padmanabhan; C M K Nair

    2007-10-01

    The suitability of calcium phosphate crystals for thermoluminescence dosimetry (TLD) applications is investigated, owing to their equivalence to bone mineral. The and phases of tricalcium phosphate (TCP) were synthesized through wet precipitation and high temperature solid state routes and doped with Dy and Eu. The photoluminescence and thermoluminescence studies of the phosphors have been carried out. The TL properties were found to be highly dependent on the method of preparation of the material. Eu doping gave good PL emission, whereas Dy doping was more efficient in TL emission. -TCP was found to be less TL sensitive than -TCP, yet it was identified as a better phosphor material owing to its better fading characteristics. The dependence of TL of -TCP : Dy on the energy and dose of radiation, and on the doping concentration were studied. The TL intensity was observed to fade exponentially during a storage period of 20 days, but it stabilized at 70% of the initial value after 30 days. The optimum doping concentration was found to be 0.5 mol%.

  11. Extraction liquide-solide de Dysprosium(III) par le charbon actif ferromagnétique

    OpenAIRE

    khiri, khaira

    2014-01-01

    L’extraction liquide-solide de Dy(III) a été faite par le charbon actif ferromagnétique, dans un milieu nitré. L’effet de pH initial, concentration initial en ion Dy(III), le temps de contact, la force ionique, la température, la masse et l’élution ont été étudiés. La capacité de sorption augmente avec l’augmentation de la concentration initiale en Dy(III), le pH et la température. L’isotherme de Freundlich décrit mieux le processus d’extraction, ainsi que le modèle cinétique de p...

  12. Geometric and electronic structure of dysprosium thin films on tungsten surfaces Structural and magnetic properties

    CERN Document Server

    Moslemzadeh, N

    2001-01-01

    The rare earth thin films are frequently the focus of investigators due to their unusual structural and magnetic properties. Despite the potential interest of Dy/W systems to the surface/rare earth community, they have been little studied. This study is the first try of growing Dy on W(100) and W(112) and W(110) in which almost a complete set of information about film morphology and electronic structure of the surface and interface have been achieved. A set of different experiments have been done for this purpose including LEED, XPS, UPS (with synchrotron radiation) and STM. The growth modes of Dy on different W substrates (W(100), W(112) and W(110)) at RT and at elevated temperatures have been determined by XPS of Dy 3d sub 3 sub / sub 2 and W 4f intensities. Crystallographic ordering and the epitaxial relationship between adsorbate Dy and different W substrates have been studied with LEED and the effect of annealing temperature on the resultant superstructures was investigated. As a complementary study to t...

  13. Cerium: an unlikely replacement of dysprosium in high performance Nd-Fe-B permanent magnets.

    Science.gov (United States)

    Pathak, Arjun K; Khan, Mahmud; Gschneidner, Karl A; McCallum, Ralph W; Zhou, Lin; Sun, Kewei; Dennis, Kevin W; Zhou, Chen; Pinkerton, Frederick E; Kramer, Matthew J; Pecharsky, Vitalij K

    2015-04-24

    Replacement of Dy and substitution of Nd in NdFeB-based permanent magnets by Ce, the most abundant and lowest cost rare earth element, is important because Dy and Nd are costly and critical rare earth elements. The Ce, Co co-doped alloys have excellent high-temperature magnetic properties with an intrinsic coercivity being the highest known for T ≥ 453 K.

  14. Studies on Preparation of Dysprosium - 165 Metallic Macroaggregates for the Treatment of Rheumatoid Arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyung Bae; Kim, Jae Rok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    1994-07-15

    Irradiation of 20 mg of natural Dy(NO{sub 3})3 in a neutron flux of 2 X10{sup 13} n/cm{sup 2} sec for 4 hours gave 5.76 Ci of {sup 165}Dy (specific activity, 610 mCi/mg Dy) with high radionuclidic purity (>99.9%). {sup 165}Dy-MA was prepared in a quantitative yield by reacting the aqueous solution of {sup 165}Dy(NO{sub 3})3 with sodium borohydride solution in 0.2N NaOH. Coulter particle analyzer exhibited mean particle size of 2.6 mum (range 1 approx 6 mum). Even though the {sup 165}Dy-MA suspension in saline was stored at 37 .deg. C for 24 hours of autoclaved at 121 .deg. C for 30 minutes, there was no significant change in particle size and leakage problem indicating the prepared {sup 165}Dy-MA is sufficiently stable. In-vivo retention studies were carried out by administering {sup 165}Dy-MA into the knee joint space of normal rabbits. Gamma camera analysis showed high retention in joint space of normal rabbits. Gamma camera analysis showed high retention in joining space even at 24 hours after administration (>99.9%) The ease with which the{sup 165}Dy-MA can be made in the narrow size range and their high in vitro and vivo stability make them attractive agents for radiation synovectomy.

  15. Dysprosium sorption by polymeric composite bead: robust parametric optimization using Taguchi method.

    Science.gov (United States)

    Yadav, Kartikey K; Dasgupta, Kinshuk; Singh, Dhruva K; Varshney, Lalit; Singh, Harvinderpal

    2015-03-06

    Polyethersulfone-based beads encapsulating di-2-ethylhexyl phosphoric acid have been synthesized and evaluated for the recovery of rare earth values from the aqueous media. Percentage recovery and the sorption behavior of Dy(III) have been investigated under wide range of experimental parameters using these beads. Taguchi method utilizing L-18 orthogonal array has been adopted to identify the most influential process parameters responsible for higher degree of recovery with enhanced sorption of Dy(III) from chloride medium. Analysis of variance indicated that the feed concentration of Dy(III) is the most influential factor for equilibrium sorption capacity, whereas aqueous phase acidity influences the percentage recovery most. The presence of polyvinyl alcohol and multiwalled carbon nanotube modified the internal structure of the composite beads and resulted in uniform distribution of organic extractant inside polymeric matrix. The experiment performed under optimum process conditions as predicted by Taguchi method resulted in enhanced Dy(III) recovery and sorption capacity by polymeric beads with minimum standard deviation.

  16. Dysprosium(III)-diethylenetriaminepentaacetate complexes of aminocyclodextrins as chiral NMR shift reagents.

    Science.gov (United States)

    Wenzel, T J; Miles, R D; Zomlefer, K; Frederique, D E; Roan, M A; Troughton, J S; Pond, B V; Colby, A L

    2000-01-01

    A metal chelating ligand is bonded to alpha-, beta-, and gamma-cyclodextrin by the reaction of diethylenetraminepentaacetic dianhydride with the corresponding 6-mono- and 2-mono(amine)cyclodextrin. Adding Dy(III) to the cyclodextrin derivatives causes shifts in the (1)H-NMR spectra of substrates such as propranolol, tryptophan, aspartame, carbinoxamine, pheniramine, doxylamine, and 1-anilino-8-naphthalenesulfonate. The Dy(III)-induced shifts enhance the enantiomeric resolution in the NMR spectra of several substrates. Enhancements in enantiomeric resolution using cyclodextrin derivatives with the amine tether are compared to previously described compounds in which the chelating ligand is attached through an ethylenediamine tether. In general, the Dy(III) complex of the 6-beta-derivative with the amine tether is a more effective chiral resolving agent than the complex with the ethylenediamine tether. The opposite trend is observed with the 2-beta-derivatives. The presence of the chelating ligand in the 2-beta-derivative hinders certain substrates from entering the cavity. For cationic substrates, evidence suggests that a cooperative association involving inclusion in the cavity and association with the Dy(III) unit occurs. Enhancements in enantiomeric resolution in the spectrum of tryptophan are greater for the secondary alpha- and gamma-derivatives than the beta-derivative.

  17. The Separation of Dysprosium and Holmium for Production of n.c.a. Ho-166

    Energy Technology Data Exchange (ETDEWEB)

    Choi, K. H.; Kim, J. B.; Park, U. J.; Nam, S. S.; Jang, K. D.; Yoo, K. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The uses of radiolanthanide series are increasing in these days because of target therapy which does not require surgery. Certain radiolanthanides is very useful since they have the ability of simultaneous diagnosis and therapeutic effect in nuclear medicine. But this conventional therapeutic method has often limited by specific activity which is important things to affect labeling yield such as radiommunoconjugation and peptide labeling. There are two approaches to produce radiolanthanide in nuclear reactor. One is direct method using (n, γ) reaction and the other is indirect method using (n, γ)β reaction. Among the radiolanthanides, Ho-166 can be produced with two methods. Some radiolanthanides show the good theranostic effect in that they have proper LET (Linear Energy Transfer) to induce apoptosis for cancer treatment and gamma ray to use as a tracer for cancer diagnosis. The aim of this project based on this view is to get the carrier free radioisotopes for applying the nuclear medicine.

  18. Thermal expansion in dysprosium tungstate Dy10W2O21

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The complex oxide Dy10W2O21 was synthesized by a solid-state reaction and isolated in cubic symmetry by an X-ray diffractometry (XRD) method. Differential scanning calorimetry (DSC) measurements show that the compound is thermodynamically stable. The intrinsic thermal expansion coefficients were determined by extra-power powder Xray diffractometry from room temperature to 1000 ℃: linear coefficient α = 1.07 × 10-5 ℃-1 and bulk coefficient β=3.20 × 10-5℃-1. Dilatometry was used to measure the extrinsic thermal expansion coefficient (9.2 × 10-6℃-1).

  19. Magnetic Properties of Some Gadolinium, Erbium, Dysprosium, Manganese Substituted Samarium-2 Cobalt-17 Intermetallic Compounds.

    Science.gov (United States)

    1979-08-01

    S K AREA B WORK UNIT NUMBERSElect ronic Materials Research Division 61102AUS Army Electronics Technology & Devices Laborator) 1-rrr~ -rrd2An47 02 031...permanent magnet materials having intrinsically temperature compensated magneti- zations. The properties investigated were saturation magnetization...that excellent temperature compensation could be achieved in these compounds in the teinper~ture (cont’d) ~‘ DD I ? ) 1Q3 L°’TI°M °’ INOV BI

  20. Recycling of waste Nd-Fe-B sintered magnets by doping with dysprosium hydride nanoparticles

    Institute of Scientific and Technical Information of China (English)

    刘卫强; 李超; ZAKOTNIK Miha; 岳明; 张东涛; 黄秀莲

    2015-01-01

    Recycling of waste sintered Nd-Fe-B permanent magnets by doping DyH3 nanoparticles was investigated. The effect of the DyH3 nanoparticles on the microstructure and magnetic properties of the recycled magnets was studied. As the DyH3 nanoparticles additive increased, the coercivity of recycled magnet increased gradually. The recycled magnets with DyH3 nanoparticle content be-tween 0.0 wt.% and 1.0 wt.% maintained the remanence (Br), but, with higher additions, theBr began to decrease rapidly. The best recycled magnet produced contained 1.0 wt.% of DyH3 nanoparticles when compared to the properties of the starting waste sintering magnet. TheHcj,Br and (BH)max values of 101.7%, 95.4%, and 88.58%, respectively, were recovered.

  1. Photo and cathodoluminescence characteristics of dysprosium doped yttrium oxide nanoparticles prepared by Polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Balderas-Xicohténcatl, R., E-mail: rbalderas@fis.cinvestav.mx [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07360, México, D.F. (Mexico); Martínez-Martínez, R. [Instituto de Física y Matemáticas, Universidad Tecnológica de la Mixteca, Carretera a Acatlima Km. 2.5, Huajuapan de León, Oaxaca 69000 (Mexico); Rivera-Alvarez, Z.; Santoyo-Salazar, J.; Falcony, C. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07360, México, D.F. (Mexico)

    2014-02-15

    The luminescent characteristics of Dy{sup 3+}-doped Y{sub 2}O{sub 3} nanopowders synthesized using the polyol method are reported. The Y{sub 2}O{sub 3} nanoparticles presented a cubic phase crystalline structure of Y{sub 2}O{sub 3} after an annealing treatment in oxygen ambient at temperatures above 600 °C. The averaged crystallite size determined from the X-ray diffraction peaks width was in the 20–32 nm range depending on the annealing temperature. Scanning and transmission electron microscopy studies indicate the formation of nanoparticle aggregates up to 175 nm in diameter. Photoluminescence and cathodoluminescence measurements show a predominant emission at 573 nm, which is attributed to the {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} of the Dy{sup 3+} ion. The luminescence emission dependence with the dopant concentration and post-annealing temperatures is discussed. -- Highlights: • Nanoparticles of Y{sub 2}O{sub 3}:Dy{sup 3+} have been successfully synthesized by the polyol method. • XRD shows a grain size from 20 to 32 nm which is in agreement with SEM and TEM. • Electronic micrographs indicate the formation agglomerates of ∼175 nm. • The method used in the synthesis is industrial scalable and a low cost. • CL emission is observed at naked eye.

  2. Naval Research Laboratory's programs in advanced indium phosphide solar cell development

    Science.gov (United States)

    Summers, Geoffrey P.

    1996-01-01

    The Naval Research Laboratory (NRL) has been involved in the development of solar cells for space applications since the 1960s. It quickly became apparent in this work that radiation damage caused to solar cells by electrons and protons trapped by the earth's magnetic field would seriously degrade the power output of photovoltaic arrays in extended missions. Techniques were therefore developed to harden the cells by shielding them with coverglass, etc. Ultimately, however, there is a limit to such approaches, which is determined by the radiation response of the semiconductor material employed. A desire for high efficiency and radiation resistance led to the development of alternative cell technologies such as GaAs, which has since become the technology of choice for many applications. InP cells are currently the most radiation resistant, high efficiency, planar cells known. NRL first sponsored InP solar cell technology in 1986, when Arizona State University was contracted to grow p/n cells by liquid phase epitaxy. NRL's interest in InP cells was generated by the results presented by Yamaguchi and his co-workers in the early 1980s on the remarkable radiation resistance of cells grown by diffusion of S into Zn doped p-type InP substrates. These cells also had beginning of life (BOL) efficiencies approximately 16%(AM0). Related to the radiation resistance of the cells was the fact that radiation-induced damage could be optically annealed by sunlight. Relatively large quantities of 1 x 2 cm(exp 2) diffused junction cells were made and were used on the MUSES-A and the EXOS-D satellites. These cells were also available in the U.S. through NIMCO, and were studied at NRL and elsewhere. Workers at NASA Lewis became involved in research in InP cells about the same time as NRL.

  3. Non-Epitaxial Thin-Film Indium Phosphide Photovoltaics: Growth, Devices, and Cost Analysis

    Science.gov (United States)

    Zheng, Maxwell S.

    In recent years, the photovoltaic market has grown significantly as module prices have continued to come down. Continued growth of the field requires higher efficiency modules at lower manufacturing costs. In particular, higher efficiencies reduce the area needed for a given power output, thus reducing the downstream balance of systems costs that scale with area such as mounting frames, installation, and soft costs. Cells and modules made from III-V materials have the highest demonstrated efficiencies to date but are not yet at the cost level of other thin film technologies, which has limited their large-scale deployment. There is a need for new materials growth, processing and fabrication techniques to address this major shortcoming of III-V semiconductors. Chapters 2 and 3 explore growth of InP on non-epitaxial Mo substrates by MOCVD and CSS, respectively. The results from these studies demonstrate that InP optoelectronic quality is maintained even by growth on non-epitaxial metal substrates. Structural characterization by SEM and XRD show stoichiometric InP can be grown in complete thin films on Mo. Photoluminescence measurements show peak energies and widths to be similar to those of reference wafers of similar doping concentrations. In chapter 4 the TF-VLS growth technique is introduced and cells fabricated from InP produced by this technique are characterized. The TF-VLS method results in lateral grain sizes of >500 mum and exhibits superior optoelectronic quality. First generation devices using a n-TiO2 window layer along with p-type TF-VLS grown InP have reached ˜12.1% power conversion efficiency under 1 sun illumination with VOC of 692 mV, JSC of 26.9 mA/cm2, and FF of 65%. The cells are fabricated using all non-epitaxial processing. Optical measurements show the InP in these cells have the potential to support a higher VOC of ˜795 mV, which can be achieved by improved device design. Chapter 5 describes a cost analysis of a manufacturing process using an InP cell as the active layer in a monolithically integrated module. Importantly, TF-VLS growth avoids the hobbles of traditional growth: the epitaxial wafer substrate, low utilization efficiency of expensive metalorganic precursors, and high capital depreciation costs due to low throughput. Production costs are projected to be 0.76/W(DC) for the benchmark case of 12% efficient modules and would decrease to 0.40/W(DC) for the long-term potential case of 24% efficient modules.

  4. Excitons into one-axis crystals of zinc phosphide (Zn3P2

    Directory of Open Access Journals (Sweden)

    D.M. Stepanchikov

    2009-01-01

    Full Text Available Theoretical study of excitons spectra is offered in this report as for Zn3P2 crystals. Spectra are got in the zero approach of the theory of perturbations with consideration of both the anisotropy of the dispersion law and the selection rules. The existence of two exciton series was found, which corresponds to two valence bands (hh, lh and the conductivity band (c. It is noteworthy that anisotropy of the dispersion law plus the existence of crystalline packets (layers normal to the main optical axis, both will permit the consideration of two-dimensional excitons too. The high temperature displaying of these 2D-exciton effects is not eliminated even into bulk crystals. The calculated values of the binding energies as well as the oscillator's strength for the optical transitions are given for a volume (3D and for two-dimensional (2D excitons. The model of energy exciton transitions and four-level scheme of stimulated exciton radiation for receiving laser effect are offered.

  5. The structural evolution and diffusion during the chemical transformation from cobalt to cobalt phosphide nanoparticles

    KAUST Repository

    Ha, Don-Hyung

    2011-01-01

    We report the structural evolution and the diffusion processes which occur during the phase transformation of nanoparticles (NPs), ε-Co to Co 2P to CoP, from a reaction with tri-n-octylphosphine (TOP). Extended X-ray absorption fine structure (EXAFS) investigations were used to elucidate the changes in the local structure of cobalt atoms which occur as the chemical transformation progresses. The lack of long-range order, spread in interatomic distances, and overall increase in mean-square disorder compared with bulk structure reveal the decrease in the NP\\'s structural order compared with bulk structure, which contributes to their deviation from bulk-like behavior. Results from EXAFS show both the Co2P and CoP phases contain excess Co. Results from EXAFS, transmission electron microscopy, X-ray diffraction, and density functional theory calculations reveal that the inward diffusion of phosphorus is more favorable at the beginning of the transformation from ε-Co to Co2P by forming an amorphous Co-P shell, while retaining a crystalline cobalt core. When the major phase of the sample turns to Co 2P, the diffusion processes reverse and cobalt atom out-diffusion is favored, leaving a hollow void, characteristic of the nanoscale Kirkendall effect. For the transformation from Co2P to CoP theory predicts an outward diffusion of cobalt while the anion lattice remains intact. In real samples, however, the Co-rich nanoparticles continue Kirkendall hollowing. Knowledge about the transformation method and structural properties provides a means to tailor the synthesis and composition of the NPs to facilitate their use in applications. © 2011 The Royal Society of Chemistry.

  6. High Sensitivity Indium Phosphide Based Avalanche Photodiode Focal Plane Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — nLight has demonstrated highly-uniform APD arrays based on the highly sensitive InGaAs/InP material system. These results provide great promise for achieving the...

  7. High Sensitivity Indium Phosphide Based Avalanche Photodiode Focal Plane Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to build a monolithically integrated FPA of densely packed APDs (70-um pitch) operating at or around 1500 nm wavelength that is suitable for the solicited...

  8. Polycrystalline indium phosphide on silicon by indium assisted growth in hydride vapor phase epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Metaferia, Wondwosen; Sun, Yan-Ting, E-mail: yasun@kth.se; Lourdudoss, Sebastian [Laboratory of Semiconductor Materials, Department of Materials and Nano Physics, KTH—Royal Institute of Technology, Electrum 229, 164 40 Kista (Sweden); Pietralunga, Silvia M. [CNR-Institute for Photonics and Nanotechnologies, P. Leonardo da Vinci, 32 20133 Milano (Italy); Zani, Maurizio; Tagliaferri, Alberto [Department of Physics Politecnico di Milano, P. Leonardo da Vinci, 32 20133 Milano (Italy)

    2014-07-21

    Polycrystalline InP was grown on Si(001) and Si(111) substrates by using indium (In) metal as a starting material in hydride vapor phase epitaxy (HVPE) reactor. In metal was deposited on silicon substrates by thermal evaporation technique. The deposited In resulted in islands of different size and was found to be polycrystalline in nature. Different growth experiments of growing InP were performed, and the growth mechanism was investigated. Atomic force microscopy and scanning electron microscopy for morphological investigation, Scanning Auger microscopy for surface and compositional analyses, powder X-ray diffraction for crystallinity, and micro photoluminescence for optical quality assessment were conducted. It is shown that the growth starts first by phosphidisation of the In islands to InP followed by subsequent selective deposition of InP in HVPE regardless of the Si substrate orientation. Polycrystalline InP of large grain size is achieved and the growth rate as high as 21 μm/h is obtained on both substrates. Sulfur doping of the polycrystalline InP was investigated by growing alternating layers of sulfur doped and unintentionally doped InP for equal interval of time. These layers could be delineated by stain etching showing that enough amount of sulfur can be incorporated. Grains of large lateral dimension up to 3 μm polycrystalline InP on Si with good morphological and optical quality is obtained. The process is generic and it can also be applied for the growth of other polycrystalline III–V semiconductor layers on low cost and flexible substrates for solar cell applications.

  9. UV-sensitive optical sensors based on ITO-gallium phosphide heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Oleksandr; Hidalga-Wade, F. Javier de la; Zuniga-Islas, Carlos; Abundis Patino, Jesus H. [National Institute for Astrophysics, Optics, and Electronics (INAOE), Puebla (Mexico)

    2010-04-15

    Design and characteristics of wide-band UV sensors based on ITO/GaP heterostructures are discussed. Such sensors have perfect electrical parameters and high UV-visible sensitivity in comparison with surface-barrier structures using a semi-transparent thin metal film as an electrode. Many applications require UV sensors with an effective rejection of visible radiation and a wide temperature operating interval. For this aim, the theoretical modelling of extreme selective optical sensors with a double Ag/ITO thin film on the GaP surface, in which the thin silver film serves as a narrow bandpass filter at 320 nm, has been conducted. With this modelling the optimal thickness combination for the silver and ITO films was found for the maximum rejection of the sensitivity to visible radiation (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Indium phosphide solar cell research in the United States: Comparison with non-photovoltaic sources

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

    1989-01-01

    Highlights of the InP solar cell research program are presented. Homojunction cells with efficiencies approaching 19 percent are demonstrated, while 17 percent is achieved for ITO/InP cells. The superior radiation resistance of the two latter cell configurations over both Si and GaAs cells has been shown. InP cells aboard the LIPS3 satellite show no degradation after more than a year in orbit. Computed array specific powers are used to compare the performance of an InP solar cell array to solar dynamic and nuclear systems.

  11. Determination of the rod-wire transition length in colloidal indium phosphide quantum rods.

    Science.gov (United States)

    Wang, Fudong; Buhro, William E

    2007-11-21

    Colloidal InP quantum rods (QRs) having controlled diameters and lengths are grown by the solution-liquid-solid method, from Bi nanoparticles in the presence of hexadecylamine and other conventional quantum dot surfactants. These quantum rods show band-edge photoluminescence after HF photochemical etching. Photoluminescence efficiency is further enhanced after the Bi tips are selectively removed from the QRs by oleic acid etching. The QRs are anisotropically 3D confined, the nature of which is compared to the corresponding isotropic 3D confinement in quantum dots and 2D confinement in quantum wires. The 3D-2D rod-wire transition length is experimentally determined to be 25 nm, which is about 2 times the bulk InP exciton Bohr radius (of approximately 11 nm).

  12. Junction characteristics of indium tin oxide/indium phosphide solar cells

    Science.gov (United States)

    Sheldon, P.; Ahrenkiel, R. K.; Hayes, R. E.; Russell, P. E.; Nottenburg, R. N.; Kazmerski, L. L.

    Efficient indium tin oxide (ITO)/p-InP solar cells have been fabricated. Typical uncorrected efficiencies range from 9-12 percent at AM1 intensities. It is shown that deposition of ITO causes a semi-insulating layer at the InP surface as determined by C-V measurements. The thickness of this layer is approximately 750 A. We believe that this high resistivity region is due to surface accumulation of Fe at the ITO/InP interface.

  13. Grain boundary resistance in p- and n-type indium phosphide

    Science.gov (United States)

    Shieh, C.-L.; Wagner, S.; Kazmerski, L. L.

    1985-08-01

    The zero-bias resistance between grains in p- and n-type InP was measured as a function of temperature. Among bulk n-type, bulk p-type and thin-film p-type samples, only the first exhibited a temperature-dependent resistance. Auger electron and secondary ion mass spectrometries of grain boundaries fractured in vacuo showed pronounced segregation of In, P and of foreign impurities. An impurity-induced grain boundary defect located close to the conduction band edge appears to account best for the experimental results.

  14. Synthesis of Indium Nitride Epitaxial Layers on a Substrate of Porous Indium Phosphide

    Directory of Open Access Journals (Sweden)

    J.A. Suchikova

    2015-10-01

    Full Text Available The paper presents a technique to obtain InN films on porous InP substrates by radical-beam gettering epitaxy. According to the results of the Auger spectroscopy, InN film thickness ranged from 100 nm to 0.5 microns depending on the etching conditions.

  15. Advanced indium phosphide based monolithic integration using quantum well intermixing and MOCVD regrowth

    Science.gov (United States)

    Raring, James W.

    The proliferation of the internet has fueled the explosive growth of telecommunications over the past three decades. As a result, the demand for communication systems providing increased bandwidth and flexibility at lower cost continues to rise. Lightwave communication systems meet these demands. The integration of multiple optoelectronic components onto a single chip could revolutionize the photonics industry. Photonic integrated circuits (PIC) provide the potential for cost reduction, decreased loss, decreased power consumption, and drastic space savings over conventional fiber optic communication systems comprised of discrete components. For optimal performance, each component within the PIC may require a unique epitaxial layer structure, band-gap energy, and/or waveguide architecture. Conventional integration methods facilitating such flexibility are increasingly complex and often result in decreased device yield, driving fabrication costs upward. It is this trade-off between performance and device yield that has hindered the scaling of photonic circuits. This dissertation presents high-functionality PICs operating at 10 and 40 Gb/s fabricated using novel integration technologies based on a robust quantum-well-intermixing (QWI) method and metal organic chemical vapor deposition (MOCVD) regrowth. We optimize the QWI process for the integration of high-performance quantum well electroabsorption modulators (QW-EAM) with sampled-grating (SG) DBR lasers to demonstrate the first widely-tunable negative chirp 10 and 40 Gb/s EAM based transmitters. Alone, QWI does not afford the integration of high-performance semiconductor optical amplifiers (SOA) and photodetectors with the transmitters. To overcome this limitation, we have developed a novel high-flexibility integration scheme combining MOCVD regrowth with QWI to merge low optical confinement factor SOAs and 40 Gb/s uni-traveling carrier (UTC) photodiodes on the same chip as the QW-EAM based transmitters. These high-saturation power receiver structures represent the state-of-the-art technologies for even discrete components. Using the novel integration technology, we present the first widely-tunable single-chip device capable of transmit and receive functionality at 40 Gb/s. This device monolithically integrates tunable lasers, EAMs, SOAs, and photodetectors with performance that rivals optimized discrete components. The high-flexibility integration scheme requires only simple blanket regrowth steps and thus breaks the performance versus yield trade-off plaguing conventional fabrication techniques employed for high-functionality PICs.

  16. [Zinc phosphide poisoning in pediatric patients from a Toxicology Center at Mexico City].

    Science.gov (United States)

    Sánchez-Villegas, María Carmen Socorro; Bárcena-Ruiz, Alejandro

    2017-01-01

    Introducción: el fosfuro de zinc es usado para exterminar roedores; es un producto altamente tóxico, no crea resistencias y es de uso popular. Debido a que es un plaguicida altamente comercializado de elevada toxicidad que no cuenta con un antídoto disponible, es imperativo precisar e identificar con oportunidad las manifestaciones clínicas de la intoxicación. El objetivo fue describir el perfil epidemiológico y clínico de los niños intoxicados con fosfuro de zinc atendidos en un centro toxicológico de tercer nivel de atención. Métodos: estudio retrospectivo, observacional y trasversal del 2005 al 2015, con 36 registros de pacientes pediátricos atendidos en el Centro de Información y Atención Toxicológica del Hospital General “Dr. Gaudencio González Garza” del Centro Médico Nacional La Raza del Instituto Mexicano del Seguro Social. Resultados: el estudio no demostró predominio de algún género. El 66% de los pacientes se encontraba entre 1 y 2 años de edad. El 96% de los pacientes eran sanos y tres adolescentes utilizaron el producto con fines suicidas. La exposición ocurrió en el hogar. La toxicidad se caracterizó por hipotensión arterial, hipoglucemia, acidosis metabólica, dolor abdominal, náuseas, vómitos; ninguno de los pacientes falleció ni requirió de asistencia ventilatoria ni de hemodiálisis. Conclusión: la falta de conocimiento del potencial tóxico y la accesibilidad al producto en el interior del domicilio de los pacientes facilita su exposición; se trata de un riesgo 100% prevenible.

  17. Histopathological effect of sub-lethal concentration of aluminum phosphide (phostoxin on Clarias gariepinus juveniles

    Directory of Open Access Journals (Sweden)

    Kayode B. Olurin

    Full Text Available Abtsract: The study evaluated the effect of sub-lethal concentration of phostoxin on Clarias gariepinus juveniles. C. gariepinus juveniles belonging to the same cohort (40.1±1.2g; 18.1±1.1cm from a commercial fish farm were randomly placed ten in each of 15 plastic tanks containing 15 liters of water. They were exposed for 96 hrs to three sub-lethal concentrations (treatments of phostoxin (0.125, 0.250, 0.5mg L-1 and a phostoxin free control. At the end of 96 hrs exposure, they were dissected and the tissues need for histopathology removed and fixed in Bouin's fluid. The gill filament exhibited fusion at the secondary lamella that was progressive with concentration. At the highest concentration of exposure, the secondary lamellae showed marked pyknotic and necrotic changes characterized by epithelia detachment. The hepatic tissue showed mild inflammatory changes at lower concentrations while at the highest concentration of exposure there was marked inflammation with observed hydropic degeneration. In the kidney, an inflammatory change was only observed in the interstices at the highest dose of exposure with the convoluted tubules showing partial shrinkage. Phostoxin showed to have significantly caused alterations in cyto-architecture of the gills and to a considerable extent liver and kidney of C. gariepinus.

  18. DWDM laser arrays fabricated using thermal nanoimprint lithography on Indium Phosphide substrates

    DEFF Research Database (Denmark)

    Smistrup, K.; Nørregaard, J.; Mironov, A.;

    Dense Wavelength Division Multiplexing (DWDM) lasers play a major role in today’s long-haul broadband communication. Typical distributed feedback (DFB) laser cavities consist of long half-pitch gratings in InGaAsP on InP substrates with pitches around 240 nm. Lasers are made reliably single mode ....... The fabricated lasers were cleaved and measured. Laser arrays exhibited >40mW optical power in all 12 channels. Figure 3 shows the overlaid spectra of a 12-channel array laser chip with uniform (~3nm) wavelength spacing and good sidemode suppression....

  19. Aminophosphines: A Double Role in the Synthesis of Colloidal Indium Phosphide Quantum Dots.

    Science.gov (United States)

    Tessier, Mickael D; De Nolf, Kim; Dupont, Dorian; Sinnaeve, Davy; De Roo, Jonathan; Hens, Zeger

    2016-05-11

    Aminophosphines have recently emerged as economical, easy-to-implement precursors for making InP nanocrystals, which stand out as alternative Cd-free quantum dots for optoelectronic applications. Here, we present a complete investigation of the chemical reactions leading to InP formation starting from InCl3 and tris(dialkylamino)phosphines. Using nuclear magnetic resonance (NMR) spectroscopy and single crystal X-ray diffraction, we demonstrate that injection of the aminophosphine in the reaction mixture is followed by a transamination with oleylamine, the solvent of the reaction. In addition, mass spectrometry and NMR indicate that the formation of InP concurs with that of tetra(oleylamino)phosphonium chloride. The chemical yield of the InP formation agrees with this 4 P(+III) → P(-III) + 3 P(+V) disproportionation reaction occurring, since full conversion of the In precursor was only attained for a 4:1 P/In ratio. Hence it underlines the double role of the aminophosphine as both precursor and reducing agent. These new insights will guide further optimization of high quality InP quantum dots and might lead to the extension of synthetic protocols toward other pnictide nanocrystals.

  20. Epitaxially Grown Indium Phosphide Quantum Dots on a Virtual Ge Substrate Realized on Si(001)

    Science.gov (United States)

    Wiesner, Michael; Bommer, Moritz; Schulz, Wolfgang-Michael; Etter, Martin; Werner, Jens; Oehme, Michael; Schulze, Jörg; Jetter, Michael; Michler, Peter

    2012-04-01

    An ultrathin virtual Ge substrate (GeVS) with low defect density was realized on CMOS-compatible Si(001) by molecular beam epitaxy. On top, III-V layers were deposited by metal-organic vapor-phase epitaxy, at which diffusion of Ge was successfully suppressed. Nonclassical light emitters, based on InP quantum dots (QDs), were realized on a thin GaAs buffer (thickness ≈ 1 µm). The quantum dots show emission in the red spectral region, meeting the range of the highest detection efficiency of silicon avalanche photodiodes. The decay dynamics and emission characteristics of single QDs were investigated. Autocorrelation measurements prove single-photon emission with a value of g(2)(0)=0.32.

  1. Undoped semi-insulating indium phosphide (InP) and its applications

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ During the past several years, the research and development of InP material has made great progress due to serving as the substrate for most optoelectronic devices operating at the communications wavelength of 1.31 and 1.55 (m. At present, InP has become an important semiconductor material together with Si and GaAs. When compared to GaAs, InP has higher electron velocity, higher radiation hardness and better heat-conducting property. The advantage of InP crystal material allows higher frequency operation and lower power requirements. Therefore, InPis widely being used for the manufacture of microwave devices, high-frequency devices and optoelectronic integrated circuits (OEICs) which are indispensable for wireless technology, satellite communications[1-3]. Although n-type and p-type InP can meet actual needs, semi-insulating InP substrates remain to be improved due to their poor uniformity and consistency. For this reason, several possible approaches have been reported to the preparation of SI InP by wafer annealing under different conditions[4-9].

  2. Gallium phosphide as a new material for anodically bonded atomic sensors

    Directory of Open Access Journals (Sweden)

    Nezih Dural

    2014-08-01

    Full Text Available Miniaturized atomic sensors are often fabricated using anodic bonding of silicon and borosilicate glass. Here we describe a technique for fabricating anodically bonded alkali-metal cells using GaP and Pyrex. GaP is a non-birefringent semiconductor that is transparent at alkali-metal resonance wavelengths, allowing new sensor geometries. GaP also has a higher thermal conductivity and lower He permeability than borosilicate glass and can be anodically bonded below 200 °C, which can also be advantageous in other vacuum sealing applications.

  3. Gallium phosphide as a new material for anodically bonded atomic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Dural, Nezih; Romalis, Michael V., E-mail: romalis@princeton.edu [Physics Department, Princeton University, Princeton, New Jersey 08540 (United States)

    2014-08-01

    Miniaturized atomic sensors are often fabricated using anodic bonding of silicon and borosilicate glass. Here we describe a technique for fabricating anodically bonded alkali-metal cells using GaP and Pyrex. GaP is a non-birefringent semiconductor that is transparent at alkali-metal resonance wavelengths, allowing new sensor geometries. GaP also has a higher thermal conductivity and lower He permeability than borosilicate glass and can be anodically bonded below 200 °C, which can also be advantageous in other vacuum sealing applications.

  4. Gallium phosphide as a new material for anodically bonded atomic sensors

    Science.gov (United States)

    Dural, Nezih; Romalis, Michael V.

    2014-08-01

    Miniaturized atomic sensors are often fabricated using anodic bonding of silicon and borosilicate glass. Here we describe a technique for fabricating anodically bonded alkali-metal cells using GaP and Pyrex. GaP is a non-birefringent semiconductor that is transparent at alkali-metal resonance wavelengths, allowing new sensor geometries. GaP also has a higher thermal conductivity and lower He permeability than borosilicate glass and can be anodically bonded below 200 °C, which can also be advantageous in other vacuum sealing applications.

  5. Studies of Electrical Activation and Impurity Migration in Ion Implanted Indium Phosphide.

    Science.gov (United States)

    1986-09-01

    diffused with Fe (7). Fe acts as an acceptor in n-type material by the reaction ES:2 3%>e~ 2 FeGa 3 + + e < ------- > FeGa [151 .?. ,*% "S whereas in p...type material the Fermi level is below the FeGa2+ energy level so that Fe is . seen only as FeGa 3+. In this case, the Fe atom does not have to change

  6. Modifications of gallium phosphide single crystals using slow highly charged ions and swift heavy ions

    Science.gov (United States)

    El-Said, A. S.; Wilhelm, R. A.; Heller, R.; Akhmadaliev, Sh.; Schumann, E.; Sorokin, M.; Facsko, S.; Trautmann, C.

    2016-09-01

    GaP single crystals were irradiated with slow highly charged ions (HCI) using 114 keV 129Xe(33-40)+ and with various swift heavy ions (SHI) of 30 MeV I9+ and 374 MeV-2.2 GeV 197Au25+. The irradiated surfaces were investigated by scanning force microscopy (SFM). The irradiations with SHI lead to nanohillocks protruding from the GaP surfaces, whereas no changes of the surface topography were observed after the irradiation with HCI. This result indicates that a potential energy above 38.5 keV is required for surface nanostructuring of GaP. In addition, strong coloration of the GaP crystals was observed after irradiation with SHI. The effect was stronger for higher energies. This was confirmed by measuring an increased extinction coefficient in the visible light region.

  7. Heterodyne pump probe measurements of nonlinear dynamics in an indium phosphide photonic crystal cavity

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Combrié, S.; Lehoucq, G.

    2013-01-01

    Using a sensitive two-color heterodyne pump-probe technique, we investigate the carrier dynamics of an InP photonic crystal nanocavity. The heterodyne technique provides unambiguous results for all wavelength configurations, including the degenerate case, which cannot be investigated with the wid...... with the widely used homodyne technique. A model based on coupled mode theory including two carrier distributions is introduced to account for the relaxation dynamics, which is assumed to be governed by both diffusion and recombination.......Using a sensitive two-color heterodyne pump-probe technique, we investigate the carrier dynamics of an InP photonic crystal nanocavity. The heterodyne technique provides unambiguous results for all wavelength configurations, including the degenerate case, which cannot be investigated...

  8. Electronic structure and optical properties of doped gallium phosphide: A first-principles simulation

    Science.gov (United States)

    Lu, Xuefeng; Gao, Xu; Li, Cuixia; Ren, Junqiang; Guo, Xin; La, Peiqing

    2017-09-01

    Using DFT-GGA-PW91 calculations we investigate the electronic structures and optical properties of doped GaP. It is found that the lattice constants and volume increase slightly for Al, In, As and Sb doped systems and EG distinctly decrease after doping. The formation energies are 0.587 and 0.273 eV for As and Sb doped systems, respectively, and lower remarkably than those in other systems, indicating that the stability of the two systems is higher. The direct band gap transition occurs when doped with In, As and Sb elements. The charge density difference images reveal that electron loss near Al atom is observed accompanying the enhancement of covalent bond feature, and then electron enrichment is present around N atom demonstrating that the ionic bond characteristic is obvious. The Sb-doped system has the higher static dielectric constant illustrating the applications in semiconductor devices. The absorption peak value is located at 194.7 nm for Al-doped system and this shows that the system can absorb a large amount of light and displays ;Barrier-type; characteristics in UV region. In the visible region, the doped systems have lower reflectivity coefficient, indicating that the systems all have ;clear-type; properties. This is conducive to fundamentally insights to a tunable band gap semiconductor with enormous potential in device fields.

  9. Characterization of high-temperature oxide films on dysprosium-doped Fe-20Cr alloys by electrochemical techniques

    Institute of Scientific and Technical Information of China (English)

    GUO Pingyi; ZENG Chaoliu; SHAO Yong; QIN Zeshang

    2012-01-01

    The oxidation propegies of Fe-20Cr,Fe-20Cr-0.2Dy and Fe-20Cr-1Dy alloys were studied using gravimetric and electrochemical techniques.The high-temperature oxide films of Dy-doped Fe-20Cr alloys were prepared in air at 900 ℃ for 24,48 and 100 h,respectively.The electrochemical experiment was performed by a three-electrode electrochemical cell and in 0.1 mol/L Na2SO4 aqueous solution.Proper models were built for describing electrochemical impedance spectroscopy of the different oxide layers and the spectra were interpreted in terms of a two-layer model of the films.The results revealed that the oxide films of Dy-doped Fe-20Cr alloys became compacter than that of undoped alloys and retained their good protective ability for a relatively long time.With increasing content of Dy,the protection of the oxide films slightly decreased.Mott-Schottky curves indicated that all the oxides were n-type semi-conductors,and the Nd value of oxide film on Fe-20Cr was much larger than that of Dy-doped Fe-20Cr alloys.The results of kinetic curves and SEM were in agreement with electrochemical impedance spectroscopy and Mott-Schottky data.

  10. Reexamination of Nuclear Shape Transitions in Gadolinium and Dysprosium Isotopes Chains by Using the Geometric Collective Model

    Directory of Open Access Journals (Sweden)

    Khalaf A. M.

    2014-01-01

    Full Text Available The critical points of potential energy surface (PES’s of the limits of nuclear struc- ture harmonic oscillator, axially symmetric rotor and deformed -soft and discussed in framework of the general geometric collective model (GCM. Also the shape phase transitions linking the three dynamical symmetries are studied taking into account only three parameters in the PES’s. The model is tested for the case of 238 92 U , which shows a more prolate behavior. The optimized model parameters have been adjusted by fit- ting procedure using a simulated search program in order to reproduce the experimental excitation energies in the ground state band up to 6 + and the two neutron separation energies.

  11. Critical Rare Earths, National Security, and U.S.-China Interactions: A Portfolio Approach to Dysprosium Policy Design

    Science.gov (United States)

    2015-01-01

    yttrium are often used for pigmentation for consumer products such as paint and sunglasses. REE-based lasers are used for cosmetic, epidermal, and... bacterial cell walls (Takahashi 2005). In acidic solutions, from an initial concentration of 100 micrograms of an REE mixture per liter, the bacteria...Logistics Agency Justification Book , Research, Development, Test, and Evaluation, Defense-Wide,” U.S. Department of Defense, Washington, DC: 2013

  12. Influence of dysprosium addition on the structural, morphological, electrical and magnetic properties of nano-crystalline W-type hexaferrites

    Indian Academy of Sciences (India)

    Ali-Sharbati; Javad-Mola Verdi Khani; G R Amiri; R Mousarezaei

    2015-02-01

    Dysporium (Dy)-substituted W-type barium hexaferrites were prepared by the citrate sol–gel-method. Crystalline structure, morphology, magnetic properties, DC resistivity and microwave absorption properties of BaNi2DyFe16−O27 ( = 0-0.9) were studied using X-ray diffraction, transmission electron microscope (TEM), vibrating sample magnetometer and vector network analyzer and sensitive source meter, respectively. Single-phase W-type barium hexaferrites, with a chemical composition of BaNi2DyFe16−O27 ( = 0-0.9), were formed by being heated at 1250°C for 4 h in air. The magnetic properties such as saturation magnetization (s), and coercivity (c) were calculated from hysteresis loops. Hysteresis loop measurements show that the coercivity values lie in the range of 530–560 Oe with increasing Dy content. It was also observed that magnetization decreases with the increase of Dy content. The DC resistivity was observed to increase from 0.83 × 107 to 6.92 × 107 cm with increasing Dy contents due to the unavailability of Fe3+ ions. Microwave absorption properties of hexaferrite (70 wt%)–acrylic resin (30 wt%) composites were measured by the standing-wave-ratio (SWR) method in the range from 12 to 20 GHz. For sample with = 0.6, a minimum reflection loss of −40 dB was obtained at 16.2 GHz for a layer of 1.7 mm in thickness. Sample with = 0.9 had wide bandwidth absorption in the frequency range of 13.5–18 GHz with reflection losses less than −15 dB. Meanwhile the minimum reflection point shifts toward higher frequency with the increase of Dy content.

  13. L-Shell Ionization Cross Section Measurements of Dysprosium and Samarium by Low-Energy Electron Impact

    Institute of Scientific and Technical Information of China (English)

    GOU Cheng-Jun; WU Zhang-Wen; YANG Dai-Lun; HE Fu-Qing; PENG Xiu-Feng; AN Zhu; LUO Zheng-Ming

    2005-01-01

    @@ The Lα, Lβ and Lγ x-ray production cross sections of Dy and Sm by electron impact are measured at energies from near threshold to tens of keV. In the experiments, thin targets with thick substrates are used. Meanwhile,the electron transport bipartition model is used to eliminate the influence of electrons reflected from the thick substrates on measurements. The measured x-ray production cross sections are also compared with the theoretical predictions by Gryzinski and McGuire.

  14. Generation of White Light from Dysprosium-Doped Strontium Aluminate Phosphor by a Solid-State Reaction Method

    Science.gov (United States)

    Sahu, Ishwar Prasad; Bisen, D. P.; Brahme, N.; Tamrakar, Raunak Kumar

    2016-04-01

    A single-host lattice, white light-emitting SrAl2O4:Dy3+ phosphor was synthesized by a solid-state reaction method. The crystal structure of prepared SrAl2O4:Dy3+ phosphor was in a monoclinic phase with space group P21. The chemical composition of the sintered SrAl2O4:Dy3+ phosphor was confirmed by the energy dispersive x-ray spectroscopy technique. Under ultra-violet excitation, the characteristic emissions of Dy3+ are peaking at 475 nm, 573 nm and 660 nm, originating from the transitions of 4F9/2 → 6H15/2, 4F9/2 →&!nbsp; 6H13/2 and 4F9/2 → 6H11/2 in the 4f9 configuration of Dy3+ ions. Commission International de I'Eclairage color coordinates of SrAl2O4:Dy3+ are suitable for white light-emitting phosphor. In order to investigate the suitability of the samples as white color light sources for industrial uses, correlated color temperature (CCT) and color rendering index (CRI) values were calculated. Values of CCT and CRI were found well within the defined acceptable range. Mechanoluminescence (ML) intensity of SrAl2O4:Dy3+ phosphor increased linearly with increasing impact velocity of the moving piston. Thus, the present investigation indicates piezo-electricity was responsible for producing ML in sintered SrAl2O4:Dy3+ phosphor. Decay rates of the exponential decaying period of the ML curves do not change significantly with impact velocity. The photoluminescence and ML results suggest that the synthesized SrAl2O4:Dy3+ phosphor was useful for the white light-emitting diodes and stress sensor respectively.

  15. Significant enhancement of energy barriers in dinuclear dysprosium single-molecule magnets through electron-withdrawing effects.

    Science.gov (United States)

    Habib, Fatemah; Brunet, Gabriel; Vieru, Veacheslav; Korobkov, Ilia; Chibotaru, Liviu F; Murugesu, Muralee

    2013-09-11

    The effect of electron-withdrawing ligands on the energy barriers of Single-Molecule Magnets (SMMs) is investigated. By introducing highly electron-withdrawing atoms on targeted ligands, the energy barrier was significantly enhanced. The structural and magnetic properties of five novel SMMs based on a dinuclear {Dy2} phenoxo-bridged motif are explored and compared with a previously studied {Dy2} SMM (1). All complexes share the formula [Dy2(valdien)2(L)2]·solvent, where H2valdien = N1,N3-bis(3-methoxysalicylidene) diethylenetriamine, the terminal ligand L = NO3(-) (1), CH3COO(-) (2), ClCH2COO(-) (3), Cl2CHCOO(-) (4), CH3COCHCOCH3(-) (5), CF3COCHCOCF3(-) (6), and solvent = 0.5 MeOH (4), 2 CH2Cl2 (5). Systematic increase of the barrier was observed for all complexes with the most drastic increase seen in 6 when the acac ligand of 5 was fluorinated resulting in a 7-fold enhancement of the anisotropic barrier. Ab initio calculations reveal more axial g tensors as well as higher energy first excited Kramers doublets in 4 and 6 leading to higher energy barriers for those complexes.

  16. Slow Magnetic Relaxation Observed in Dysprosium Compounds Containing Unsupported Near-Linear Hydroxo- and Fluoro-Bridges.

    Science.gov (United States)

    Brunet, Gabriel; Habib, Fatemah; Korobkov, Ilia; Murugesu, Muralee

    2015-07-06

    The encapsulating N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) ligand was employed to isolate two novel Dy(III) compounds which contain rare bridging pathways for lanthanide systems. Compound 1, [Na2Dy(III)2(valdien)2(μ-OH)(dbm)2(H2O)2][Na2Dy(III)2(valdien)2(μ-OH)(NO3)2(dbm)2], where dbm(-) is dibenzoylmethanido, and compound 2, [Na3Dy(III)2(valdien)2(μ-F)(μ3-F)2(Cl)2(MeOH)2]n·0.5(MeOH)·(H2O), both exhibit linear lone hydroxo- and fluoro-bridges, respectively, between the metal centers. The unit cell of 1 comprises two discrete dinuclear molecules, which differ slightly, forming a cation-anion pair, while 2 forms a coordination polymer. The magnetic investigations indicate that both compounds display ferromagnetic coupling between the Dy(III) ions. Magnetic susceptibility measurements in the temperature range 1.8-300 K reveal that the Dy(III) ions in 1 are weakly coupled, resulting in a mononuclear single-molecule magnet-like behavior under an applied field. In the case of 2, the stronger coupling arising from the fluoride-bridge, leads to zero-field single-molecule magnet (SMM) behavior with a non-negligible anisotropy barrier (Ueff) of 42 K.

  17. Effect of Ligand Field Tuning on the SMM Behavior for Three Related Alkoxide-Bridged Dysprosium Dimers.

    Science.gov (United States)

    Peng, Yan; Mereacre, Valeriu; Baniodeh, Amer; Lan, Yanhua; Schlageter, Martin; Kostakis, George E; Powell, Annie K

    2016-01-04

    The synthesis and characterization of three Dy2 compounds, [Dy2(HL1)2(NO3)4] (1), [Dy2(L2)2(NO3)4] (2), and [Dy2(HL3)2(NO3)4] (3), formed using related tripodal ligands with a central tertiary amine bearing picolyl and alkoxy arms, 2-[(2-hydroxy-ethyl)-pyridin-2-ylmethylamino]-ethanol (H2L1), 2-(bis-pyridin-2-ylmethylamino)-ethanol (HL2), and 2-(bis-pyridin-2-ylmethylamino)-propane-1,3-diol (H2L3), are reported. The compounds are rare examples of alkoxide-bridged {Dy2} complexes and display capped square antiprism coordination geometry around each Dy(III) ion. Changes in the ligand field environment around the Dy(III) ions brought about through variations in the ligand donors can be gauged from the magnetic properties, with compounds 1 and 2 showing antiparallel coupling between the Dy(III) ions and 3 showing parallel coupling. Furthermore, slow relaxation of the magnetization typical of SMM behavior could be observed for compounds 2 and 3, suggesting that small variations in the ligand field can have a significant influence on the slow relaxation processes responsible for SMM behavior of Dy(III)-based systems.

  18. Effects of magnetic annealing on structure and multiferroic properties of pure and dysprosium substituted BiFeO 3

    KAUST Repository

    Zhang, Shuxia

    2012-07-01

    In this work, the effects of magnetic annealing on crystal structure and multiferroic properties of BiFeO 3 and Bi 0.85Dy 0.15FeO 3 have been investigated. It is found that the X-ray diffraction patterns of pure BiFeO 3 samples are obviously broadened after magnetic annealing, whereas those of Bi 0.85Dy 0.15FeO 3 samples are almost unchanged. Magnetic field annealing did not affect the magnetic properties of these two kinds of samples much. However, ferroelectric properties of the two materials exhibited different behaviors after magnetic field annealing. For pure BiFeO 3 samples, the remnant polarizations (P r) are suppressed; in contrast, for Bi 0.85Dy 0.15FeO 3 samples, P r is greatly enhanced. Possible mechanisms for the effects of magnetic field annealing have been discussed. © 2012 Elsevier B.V. All rights reserved.

  19. Dielectric relaxation in double potassium yttrium orthophosphate K 3Y(PO 4) 2 doped by praseodymium and dysprosium ions

    Science.gov (United States)

    Szulia, S.; Kosmowska, M.; Kołodziej, H. A.; Mizer, D.; Czupińska, G.

    2011-12-01

    We report the paper presents the results of electric properties of double potassium yttrium orthophosphates doped by lanthanide ions K 3Y( 1-x)Ln x(PO 4) 2 ( x = 0.01, 0.05, Ln = Pr 3+, Dy 3+). Electric permittivity and dielectric loss measurements have been performed on polycrystalline samples in the temperature range -50-120 °C and frequency range 1 kHz-1 MHz by means of HP 4282A impedance meter. The frequency and temperature dependence of electric properties were analyzed by theoretical models of dielectric relaxation in order to obtain information abut molecular dynamic of our solids in external electric field.

  20. Dilution-induced slow magnetic relaxation and anomalous hysteresis in trigonal prismatic dysprosium(III) and uranium(III) complexes.

    Science.gov (United States)

    Meihaus, Katie R; Rinehart, Jeffrey D; Long, Jeffrey R

    2011-09-05

    Magnetically dilute samples of complexes Dy(H(2)BPz(Me2)(2))(3) (1) and U(H(2)BPz(2))(3) (3) were prepared through cocrystallization with diamagnetic Y(H(2)BPz(Me2)(2))(3) (2) and Y(H(2)BPz(2))(3). Alternating current (ac) susceptibility measurements performed on these samples reveal magnetic relaxation behavior drastically different from their concentrated counterparts. For concentrated 1, slow magnetic relaxation is not observed under zero or applied dc fields of several hundred Oersteds. However, a 1:65 (Dy:Y) molar dilution results in a nonzero out-of-phase component to the magnetic susceptibility under zero applied dc field, characteristic of a single-molecule magnet. The highest dilution of 3 (1:90, U:Y) yields a relaxation barrier U(eff) = 16 cm(-1), double that of the concentrated sample. These combined results highlight the impact of intermolecular interactions in mononuclear single-molecule magnets possessing a highly anisotropic metal center. Finally, dilution elucidates the previously observed secondary relaxation process for concentrated 3. This process is slowed down drastically upon a 1:1 molar dilution, leading to butterfly magnetic hysteresis at temperatures as high as 3 K. The disappearance of this process for higher dilutions reveals it to be relaxation dictated by short-range intermolecular interactions, and it stands as the first direct example of an intermolecular relaxation process competing with single-molecule-based slow magnetic relaxation.

  1. Challenging lanthanide relaxation theory: erbium and thulium complexes that show NMR relaxation rates faster than dysprosium and terbium analogues.

    Science.gov (United States)

    Funk, Alexander M; Harvey, Peter; Finney, Katie-Louise N A; Fox, Mark A; Kenwright, Alan M; Rogers, Nicola J; Senanayake, P Kanthi; Parker, David

    2015-07-07

    Measurements of the proton NMR paramagnetic relaxation rates for several series of isostructural lanthanide(III) complexes have been performed in aqueous solution over the field range 1.0 to 16.5 Tesla. The field dependence has been modeled using Bloch-Redfield-Wangsness theory, allowing values for the electronic relaxation time, Tle and the magnetic susceptibility, μeff, to be estimated. Anomalous relaxation rate profiles were obtained, notably for erbium and thulium complexes of low symmetry 8-coordinate aza-phosphinate complexes. Such behaviour challenges accepted theory and can be interpreted in terms of changes in Tle values that are a function of the transient ligand field induced by solvent collision and vary considerably between Ln(3+) ions, along with magnetic susceptibilities that deviate significantly from free-ion values.

  2. Distance determination from dysprosium induced relaxation enhancement: a case study on membrane-inserted WALP23 polypeptides

    NARCIS (Netherlands)

    Lueders, P.; Razzaghi, S.; Jäger, H.; Tschaggelar, R.; Hemminga, M.A.; Yulikov, M.; Jeschke, G.

    2013-01-01

    Membrane incorporated synthetic a-helical polypeptides labelled with Dy(III) chelate complexes and nitroxide radicals were studied by the inversion recovery (IR) technique and Dy(III)-nitroxide distances were obtained. A comparison of obtained distances with the previously reported Gd(III)-nitroxide

  3. Controlled Synthesis of Uniform Cobalt Phosphide Hyperbranched Nanocrystals Using Tri- n -octylphosphine Oxide as a Phosphorus Source

    KAUST Repository

    Zhang, Haitao

    2011-01-12

    A new method to produce hyperbranched Co 2P nanocrystals that are uniform in size, shape, and symmetry was developed. In this reaction tri-n-octylphosphine oxide (TOPO) was used as both a solvent and a phosphorus source. The reaction exhibits a novel monomer-saturation-dependent tunability between Co metal nanoparticle (NP) and Co 2P NP products. The morphology of Co 2P can be controlled from sheaflike structures to hexagonal symmetric structures by varying the concentration of the surfactant. This unique product differs significantly from other reported hyperbranched nanocrystals in that the highly anisotropic shapes can be stabilized as the majority shape (>84%). This is the first known use of TOPO as a reagent as well as a coordinating background solvent in NP synthesis. © 2011 American Chemical Society.

  4. Optical and Electrical Characterization of Melt-Grown Bulk Indium Gallium Arsenide and Indium Arsenic Phosphide Alloys

    Science.gov (United States)

    2011-03-01

    constant match and mismatch effects on the quality of crystal. Bulk crystal growth typically uses the Czochralski Method (melt). In this method , a...deviation and Michelson Fabry-Perot interferometry methods . The measured results of refractive indices, transport properties, bandgap energies, and...exhibit some random compositional fluctuations across the sample. A practical method of extracting bandgap energies directly from the FTIR

  5. Chemical mechanical polishing of Indium phosphide, Gallium arsenide and Indium gallium arsenide films and related environment and safety aspects

    Science.gov (United States)

    Matovu, John Bogere

    As scaling continues with advanced technology nodes in the microelectronic industry to enhance device performance, the performance limits of the conventional substrate materials such as silicon as a channel material in the front-end-of-the-line of the complementary metal oxide semiconductor (CMOS) need to be surmounted. These challenges have invigorated research into new materials such as III-V materials consisting of InP, GaAs, InGaAs for n-channel CMOS and Ge for p-channels CMOS to enhance device performance. These III-V materials have higher electron mobility that is required for the n-channel while Ge has high hole mobility that is required for the p-channel. Integration of these materials in future devices requires chemical mechanical polishing (CMP) to achieve a smooth and planar surface to enable further processing. The CMP process of these materials has been associated with environment, health and safety (EH&S) issues due to the presence of P and As that can lead to the formation of toxic gaseous hydrides. The safe handling of As contaminated consumables and post-CMP slurry waste is essential. In this work, the chemical mechanical polishing of InP, GaAs and InGaAs films and the associated environment, health and safety (EH&S) issues are discussed. InP removal rates (RRs) and phosphine generation during the CMP of blanket InP films in hydrogen peroxide-based silica particle dispersions in the presence and absence of three different multifunctional chelating carboxylic acids, namely oxalic acid, tartaric acid, and citric acid are reported. The presence of these acids in the polishing slurry resulted in good InP removal rates (about 400 nm min-1) and very low phosphine generation (slurry compositions consisting of 3 wt % silica, 1 wt % hydrogen peroxide and 0.08 M oxalic acid or citric acid that provided the best results on blanket InP films were used to evaluate their planarization capability of patterned InP-STI structures of 200 mm diameter wafers. Cross sectional scanning electron microscope (SEM) images showed that InP in the shallow trench isolation structures was planarized and scratches, slurry particles and smearing of InP were absent. Additionally, wafers polished at pH 6 showed very low dishing values of about 12-15 nm, determined by cross sectional SEM. During the polishing of blanket GaAs, GaAs RRs were negligible with deionized water or with silica slurries alone. They were relatively high in aq. solutions of H2O2 alone and showed a strong pH dependence, with significantly higher RRs in the alkaline region. The addition of silica particles to aq. H2O2 did not increase the GaAs RRs significantly. The evolution of arsenic trihydride (AsH3) during the dissolution of GaAs in aq. H2O2 solution was similarly higher in the basic pH range than in neutral pH or in the acidic pH range. However, no AsH3 was measured during polishing, evidently because of the relatively high water solubility of AsH3. The work done on InGaAs polishing shows that InGaAs RR trends are different from those observed for InP or GaAs. InGaAs RRs at pH 2 are higher than those at pH 10 and highest at pH 4. Dissolution rates (DRs), Fourier Transform Infrared Spectroscopy (FTIR), contact angles, X-Ray Photoelectron Spectroscopy (XPS), X-Ray Fluorescence Spectroscopy (XRF), zeta potential measurements and calculated Gibbs free energy changes of the reactions involved during polishing and gas formation were used to discuss the observed RRs and hydride gas generation trends and to propose the reaction pathways involved in the material removal and in hydride gas generation mechanisms.

  6. Synthesis of Cobalt Phosphide Nanoparticles Supported on Pristine Graphene by Dynamically Self-Assembled Graphene Quantum Dots for Hydrogen Evolution.

    Science.gov (United States)

    Wang, Xiaoyan; Yuan, Weiyong; Yu, Yanan; Li, Chang Ming

    2017-03-09

    A highly active, durable, and low-cost hydrogen evolution reaction (HER) catalyst is desirable for energy storage through water splitting but its fabrication presents great challenges. Herein, mediated by dynamically self-assembled graphene quantum dots (GQDs), small, uniform, high-density, and well-dispersed CoP nanoparticles were grown in situ on pristine graphene for the first time. This hybrid nanostructure was then employed as HER electrocatalyst, showing an onset potential of 7 mV, an overpotential of 91.3 mV to achieve 10 mA cm(-2) , a Tafel slope of 42.6 mV dec(-1) , and an exchange current density of 0.1225 mA cm(-2) , all of which compare favorably to those of most reported non-noble-metal catalysts. The developed catalyst also exhibits excellent durability with negligible current loss after 2000 cyclic voltammetry cycles (+0.01 to -0.17 V vs. RHE) or 34 h of chronoamperometric measurement at an overpotential of 91.3 mV. This work not only develops a new strategy for the fabrication of high-performance and inexpensive electrocatalysts for HER but also provides scientific insight into the mechanism of the dynamically self-assembled GQDsmediated synthesis process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Theoretical Studies of High Energy Transport of Electrons and Holes in Gallium Arsenide, Indium Phosphide, Indium Arsenide, and Gallium Antimonide.

    Science.gov (United States)

    1984-06-01

    interest and support in many aspects of this work. The author would also like to thank Professors N. Holonyak Jr., G. * Stillman, and B. Wheeler for...York, 1958. [321 R. P. Feynman , Statistical Mechanics, A Set of Lectures, W. A. * -. Benjamin, Reading Ma., 1972. [33] G. 3. lafrate, "Quantum transport

  8. Heavy-Fermion Compound of the Ternary Phosphide Ce2Pt8P with a Non-Centrosymmetric Structure

    Science.gov (United States)

    Kase, Naoki; Furukawa, Shoh; Nakano, Tomohito; Takeda, Naoya

    2017-01-01

    The low-temperature properties of Ce2Pt8P are studied by magnetic susceptibility χ(T), electrical resistivity ρ(T), and specific heat C(T) measurements. The crystal structure is considered to be analogs of the CePt3Si-type structure. From the magnetic susceptibility χ(T), the effective paramagnetic moment μeff is estimated to be 2.30 μB/Ce, suggesting that the valence state of Ce ions is expected to be close to trivalent (Ce3+). The paramagnetic Curie-Weiss temperature θcw is determined to be 12 K. The electrical resistivity ρ(T) shows -ln T dependence with a small slope from 10 to 3 K, which indicates a weak Kondo anomaly. The specific heat exhibits a λ-type anomaly at around T* = 1.0 K, while the magnetic entropy at T* is reduced to 80% of R ln 2. The linear coefficient of specific heat is determined to be 145 mJ/(mol-Ce·K2). From several measurements, Ce2Pt8P can be classified as a moderate heavy-fermion compound. The ground state is far from the quantum-critical point (QCP) compared with CePt3Si. La2Pt8P shows normal metallic behavior and no superconductivity is observed above 0.28 K.

  9. Nickel phosphide nanoparticles-nitrogen-doped graphene hybrid as an efficient catalyst for enhanced hydrogen evolution activity

    Science.gov (United States)

    Pan, Yuan; Yang, Na; Chen, Yinjuan; Lin, Yan; Li, Yanpeng; Liu, Yunqi; Liu, Chenguang

    2015-11-01

    Development of hybrid catalysts with high activity, good stability and low cost is extremely desirable for hydrogen production by electrolysis of water. In this work, a hybrid composed of Ni2P nanoparticles (NPs) on N-doped reduced graphene oxide (NRGO) is synthesized via an in situ thermal decomposition approach for the first time and investigated as a catalyst for the hydrogen evolution reaction (HER). The as-synthesized Ni2P/NRGO hybrid exhibits an enhanced catalytic activity with low onset overpotential (37 mV), a small Tafel slope (59 mV dec-1), a much larger exchange current density (4.9 × 10-5 A cm-2), and lower HER activation energy (46.9 kJ mol-1) than Ni2P/RGO hybrid. In addition, the Ni2P/NRGO hybrid maintains its catalytic activity for at least 60‧000 s in acidic media. The enhanced catalytic activity is attributed to the synergistic effect of N-doped RGO and Ni2P NPs, the charged natures of Ni and P, as well as the high electrical conductivity of Ni2P/NRGO hybrid. This study may offer a new strategy for improving the electrocatalytic activity for hydrogen production.

  10. International Conference on Indium Phosphide and Related Materials, Held in Cape Cod, Massachusetts, on 11 - 15 May 1997.

    Science.gov (United States)

    1998-01-14

    Lasers Fabricated Using Photo-Absorption Induced Disordering .................. 288 TuP6 Comparison of InGaAs Absorptive Grating Structures in 1.55pm...Pistol, L. Samuelson, and R. Wallenberg , Progr. Crystal Growth Charact. 33, 423 (1996). [5] K. Deppert, J.-O. Bovin, J.-O. Malm, and L. Fig. 5: Electron...temperatures will increase the overall mobility of the surface atoms, tending to slightly disorder the alloy and counteract the lateral composition

  11. Influence of dysprosium substitution on magnetic and mechanical properties of high intrinsic coercivity Nd-Fe-B magnets prepared by double-alloy powder mixed method

    Institute of Scientific and Technical Information of China (English)

    胡志华; 瞿海锦; 马冬威; 罗成; 王会杰

    2016-01-01

    The double-alloy powder mixed method is very proper for developing new small-mass products by changing the composi-tion of sintered Nd-Fe-B magnets, and there is little research on this aspect. The variation on magnetic and mechanical properties of high intrinsic coercivity Nd-Fe-B magnets prepared by double-alloy powder mixed method was discussed, which is a method blend-ing two-type main phase alloy powders with different components. The results showed that the intrinsic coercivity and density of sin-tered Nd-Fe-B magnets increased gradually with the increase in Dy content, and the double-alloy powder mixed method could obtain high intrinsic coercivity Nd-Fe-B magnets with good crystallographic alignment and microstructure. The bending strength of sintered Nd-Fe-B magnets declined, and the Rockwell hardness of sintered Nd-Fe-B magnets first declined, and then increased with the in-crease in Dy content. The microstructure showed that there existed the phenomenon that the Dy element diffused into main phase dur-ing sintering process, and the distribution of Dy content in main phase had some variation in homogeneity as a result of incomplete reaction between the double-alloy powder types.

  12. Effect of dysprosium substitution on electrical properties of SrBi{sub 4}Ti{sub 4}O{sub 15}

    Energy Technology Data Exchange (ETDEWEB)

    Mamatha, B., E-mail: boinanemamatha@gmail.com; Sarah, P.

    2014-10-15

    SrBi{sub 4−x}Dy{sub x}Ti{sub 4}O{sub 15} (with x = 0.02, 0.04, 0.06 and 0.08) powders have been synthesized using the stoichiometric amounts of nitrates and oxides of the constituent materials through sol–gel method. The compound so formed is characterized using X-ray diffraction. The density and lattice parameters are calculated. The impedance and electrical conductivity properties are investigated. The imaginary part of impedance as a function of frequency shows Debye like relaxation. Impedance data presented in the Nyquist plot which is used to identify an equivalent circuit and the fundamental circuit parameters are determined at different temperatures. The results of bulk a.c. conductivity as a function of frequency at different temperatures are presented. The dielectric behavior was investigated. Permittivity was calculated based on the relaxation frequency using an alternative approach based on the variation of the imaginary impedance component as a function of reciprocal angular frequency. The frequency dependence of real and imaginary permittivities was also investigated. - Highlights: • SrBi{sub 4−x}Dy{sub x}Ti{sub 4}O{sub 15} (x = 0.02, 0.04, 0.06 and 0.08) powders are produced by sol–gel method. Phase formation is confirmed by XRD analysis. • Frequency dependent imaginary part of impedance shows distribution of relaxation in system. • Broadness of Z″ peak shows distribution of relaxation frequency. • Increase in peak width at ½ maxima of Z″ with increase of temperature shows increase of relaxation frequency distribution. • Cole–Cole plots are resolved into two different circles, ascribed to different mechanisms of polarization and relaxation phenomena.

  13. Hexanuclear, heterometallic, Ni₃Ln₃ complexes possessing O-capped homo- and heterometallic structural subunits: SMM behavior of the dysprosium analogue.

    Science.gov (United States)

    Goura, Joydeb; Guillaume, Rogez; Rivière, Eric; Chandrasekhar, Vadapalli

    2014-08-04

    The reaction of hetero donor chelating mannich base ligand 6,6'-{(2-(dimethylamino)ethylazanediyl)bis(methylene)}bis(2-methoxy-4-methylphenol) with Ni(ClO4)2·6H2O and lanthanide(III) salts [Dy(III) (1); Tb(III) (2); Gd (III) (3); Ho(III) (4); and Er(III) (5)] in the presence of triethylamine and pivalic acid afforded a series of heterometallic hexanuclear Ni(II)-Ln(III) coordination compounds, [Ni3Ln3(μ3-O)(μ3-OH)3(L)3(μ-OOCCMe3)3]·(ClO4)·wCH3CN·xCH2Cl2·yCH3OH·zH2O [for 1, w = 8, x = 3, y = 0, z = 5.5; for 2, w = 0, x = 5, y = 0, z = 6.5; for 3, w = 15, x = 18, y = 3, z = 7.5; for 4, w = 15, x = 20, y = 6, z = 9.5; and for 5, w = 0, x = 3, y = 2, z = 3]. The molecular structure of these complexes reveals the presence of a monocationic hexanuclear derivative containing one perchlorate counteranion. The asymmetric unit of each of the hexanuclear derivatives comprises the dinuclear motif [NiLn(L)(μ3-O)(μ3-OH)(μ-Piv)]. The cation contains three interlinked O-capped clusters: one Ln(III)3O and three Ni(II)Ln(III)2O. Each of the lanthanide centers is eight- coordinated (distorted trigonal-dodecahedron), while the nickel centers are hexacoordinate (distorted octahedral). The study of the magnetic properties of all compounds are reported and suggests single molecule magnet behavior for the Dy(III) derivative (1).

  14. Two-dimensional dysprosium(III triiodate(V dihydrate, Dy(IO33(H2O·H2O

    Directory of Open Access Journals (Sweden)

    Laishun Qin

    2009-08-01

    Full Text Available During our research into novel nonlinear optical materials using 1,10-phenanthroline as an appending ligand on lanthanide iodates, crystals of an infinite layered DyIII iodate compound, Dy(IO33(H2O·H2O, were obtained under hydrothermal conditions. The DyIII cation has a dicapped trigonal prismatic coordination environment consisting of one water O atom and seven other O atoms from seven iodate anions. These iodate anions bridge the DyIII cations into a two-dimensional structure. Through O—H...O hydrogen bonds, all of these layers stack along [111], giving a supramolecular channel, with the solvent water molecules filling the voids.

  15. Two-dimensional dysprosium(III) triiodate(V) dihydrate, Dy(IO3)3(H2O)·H2O

    Science.gov (United States)

    Chai, Wenxiang; Song, Li; Shi, Hongsheng; Qin, Laishun; Shu, Kangying

    2009-01-01

    During our research into novel nonlinear optical materials using 1,10-phenanthroline as an appending ligand on lanthanide iodates, crystals of an infinite layered DyIII iodate compound, Dy(IO3)3(H2O)·H2O, were obtained under hydro­thermal conditions. The DyIII cation has a dicapped trigonal prismatic coordination environment consisting of one water O atom and seven other O atoms from seven iodate anions. These iodate anions bridge the DyIII cations into a two-dimensional structure. Through O—H⋯O hydrogen bonds, all of these layers stack along [111], giving a supra­molecular channel, with the solvent water mol­ecules filling the voids. PMID:21583297

  16. 吡罗昔康镝配合物的合成与表征%Synthesis and characterization of the complex of piroxicam and dysprosium

    Institute of Scientific and Technical Information of China (English)

    张艳军; 石俊; 孙体健; 徐隋意; 曹晓峰

    2009-01-01

    利用热乙醇搅拌法合成吡罗昔康和稀土金属镝的配合物,通过紫外光谱、红外光谱、元素分析、电导率、差热-热重等方法对其进行表征,最后确定其组成为Dy(pir)2C2H5OHCl3·2H2O.

  17. Multicolor photoluminescence and energy transfer properties of dysprosium and europium-doped Gd{sub 2}O{sub 3} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanxia; Liu, Guixia, E-mail: liuguixia22@163.com; Wang, Jinxian; Dong, Xiangting; Yu, Wensheng

    2015-11-15

    In this study, a series of Gd{sub 2}O{sub 3}: Ln{sup 3+} (Ln = Dy, Eu) submicrospheres were successfully prepared by a hydrothermal method and a subsequent higher temperature pyrolysis. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectrometer (EDS), photoluminescence (PL) spectra and vibrating sample magnetometer (VSM) were utilized to characterize the as-prepared samples. The precursor sample thoroughly decomposed into Gd{sub 2}O{sub 3} submicrospheres with a diameter of about 550 nm after calcination. Under UV excitation, the samples exhibit multicolor emissions including yellow-green, yellow, red as well as white, moreover, the Dy{sup 3+} ions acted as donors can transfer the energy to Eu{sup 3+} served as acceptors in Gd{sub 2}O{sub 3}: Dy{sup 3+}, Eu{sup 3+} system. The interaction between Dy{sup 3+} ions and Eu{sup 3+} ions is verified to be phonon-assisted electric quadrupole–quadrupole interaction. Multicolor luminescence including white light emission can be obtained through varying the content of Eu{sup 3+} or adopting different excitation wavelengths in Dy{sup 3+} and Eu{sup 3+} co-doped Gd{sub 2}O{sub 3} system. The energy transfer efficiency reaches 88.2% when the doped concentration of Eu{sup 3+} is 0.035. The CIE chromaticity diagram directly reveals the variability of the hue of the as-prepared samples. Besides, the as-prepared samples exhibit paramagnetic properties at room temperature. This type of color-tunable luminescence phosphors has promising applications in the fields of photoelectronic devices and biomedical science. - Graphical abstract: Tunable multicolor emissions and energy transfer properties of lanthanides (Ln{sup 3+}, Ln{sup 3+} = Dy{sup 3+}, Eu{sup 3+}) doped cubic Gd{sub 2}O{sub 3} submicrospheres prepared by hydrothermal method and a subsequent calcination. - Highlights: • The as-prepared samples can exhibit multicolor emissions. • Dy{sup 3+} transfer energy to Eu{sup 3+} in Dy{sup 3+} and Eu{sup 3+} co-doped Gd{sub 2}O{sub 3}. • The as-prepared phosphor has promising applications in the fields of photoelectronic devices and biomedical science.

  18. Emission from Divalent Dysprosium (Dy2+ )in Crystalline Strontium Tetraborate%晶态四硼酸锶中二价镝的发射

    Institute of Scientific and Technical Information of China (English)

    许武; Peterson; J; R

    2001-01-01

    Emission spectra from SrB4O7 doped with Dy2O3 and heated in air have been recorded at room temperature. A change in oxidation state from Dy3+ to Dy2+ was observed. Optimum production of Dy2+ ion occurs when the sample is heated in air at about 650℃. Two broad emission bands centered in the vicinity of 550 and 660nm have been observed from the sample under the excitation of 457.9nm. It is suggested that these bands are due to Dy2 + ion emission from the 5d band into the ground state 4f level (5I8). Several conditions promoting the reduction of Dy3+ion in this matrix are discussed. To aid the reduction of Dy3+ ion, we have also prepared SrB4O7 doped with Dy2O3 in Ar/H2 (4 % ) atmosphere and compared the optical characteristics of Dy2 + ion in these samples with those from the samples prepared in air. The range of g-element reducibility and stabilization in SrB4O7 has been extended from Tm2+[ E0 (Tm3+/Tm2+) = -2.3V] to Dy2+ [E0(Dy3+/Dy2 +) = -2.6V] in the present work; however, the limit of this facile reduction process has not been determined yet.%在室温下测量了在空气中灼烧掺杂Dy2O3的SrB4O7的发射光谱.观测到了由Dy3+到Dy2+氧化态的变化.经优化,当在空气中灼烧温度为650℃时为产生Dy2+的最佳温度.在457.9nm的激发下测出了两个峰位分别位于550和660nm的宽发射带.我们认为这两个宽发射带是由Dy2+离子由5d态向4f基态能级(5I8)跃迁产生的.讨论了几个有益于在这种基质中还原Dy3+离子的条件.为了实现Dy3+离子的还原,我们还在Ar/H2(4%)气氛中制备了Dy2O3掺杂的SrB4O7,比较了这种样品和在空气中所制备的样品的光学特性.本文还对标志SrB4O7还原性和稳定性的g-因子由Tm2+的[Eo(Tm3+/Tm2+=-2.3V]推导出Dy2+的[E0(Dy3+/Dy2+)=-2.6V],但对这种还原过程的局限性尚未确定.

  19. CCDC 1402057: Experimental Crystal Structure Determination : pentakis(tetra-n-butylammonium) tetrakis(mu-oxalato)-dodecachloro-tetranitrosyl-ethanol-tetra-ruthenium-dysprosium sesquihydrate

    KAUST Repository

    Kuhn, Paul-Steffen

    2015-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  20. Electron emitting device and method of making the same

    Science.gov (United States)

    Olsen, Gregory Hammond; Martinelli, Ramon Ubaldo; Ettenberg, Michael

    1977-04-19

    A substrate of single crystalline gallium arsenide has on a surface thereof a layer of single crystalline indium gallium phosphide. A layer of single crystalline gallium arsenide is on the indium gallium phosphide layer and a work function reducing material is on the gallium arsenide layer. The substrate has an opening therethrough exposing a portion of the indium gallium phosphide layer.

  1. Oxidative formation of phosphinyl radicals from a trigonal pyramidal terminal phosphide Rh(i) complex, with an unusually long Rh-P bond.

    Science.gov (United States)

    Fischbach, Urs; Trincado, M; Grützmacher, Hansjörg

    2017-03-14

    A rhodium complex containing a tetrapodal triolefin ligand (trop3P) and a phosphanyl ligand (PPh2(-)) has been prepared and characterised. The special structural confinements of the tetradentate ligand impose an unusually long Rh-PPh2 bond. Chemical oxidation of the complex with FcOTf affords [Rh(OTf)(trop3P)] and plausibly phosphanyl radicals, which react instantly with a spin trap reagent forming a nitroxide-based persistent radical, undergo HAT with silanes or dimerise to the corresponding diphosphine (PPh2)2. Chemical oxidation with a peroxide leads to complex [Rh(POPh2)(trop3P)] which is photolabile and loses the Ph2PO moiety upon irradiation with UV/Vis light in CH2Cl2.

  2. Design of a Three-Layer Antireflection Coating for High Efficiency Indium Phosphide Solar Cells Using a Chemical Oxide as First Layer

    Science.gov (United States)

    Moulot, Jacques; Faur, Mircea; Faur, Maria; Goradia, Chandra; Goradia, Manju; Bailey, Sheila

    1995-01-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 microns of the illuminated surface of the cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with the p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally, a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown, thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3- layer AR coating for thermally diffused p(+)n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p(+) emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as a fairly efficient antireflective layer yielding a measured record high AM0, 25 C, open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3, MgF2 or ZnS, MgF2 as the second and third layers respectively, so as to yield an overall theoretical reflectance of less than 2%. Since chemical oxides are readily grown on III-V semiconductor materials, the technique of using the grown oxide layer to both passivate the surface as well as serve as the first of a multilayer AR coating, should work well for essentially all III-V compound-based solar cells.

  3. Electronic Properties of III-V Semiconductors under [111] Uniaxial Strain; a Tight-Binding Approach: I. Arsenides and Gallium Phosphide

    Directory of Open Access Journals (Sweden)

    Miguel E. Mora-Ramos

    2009-01-01

    Full Text Available Empleando un esquema de cálculo tight-binding que usa una base de orbitales sp3s*d5, se estudian propiedades de la estructura electrónica de un grupo de materiales semiconductores IIIV los cuales son de notable interés para la tecnología de dispositivos electrónicos y optoelectrónicos. En específico, se analiza la influencia sobre estas propiedades de una tensión aplicada según la dirección cristalográfica [111], haciendo uso de una formulación basada en la teoría de la elasticidad para establecer las posiciones relativas de los iones vecinos más próximos. Especial atención se presta a la inclusión del efecto de deformación interna de la red cristalina. Para cada material de los estudiados presentamos las dependencias de las brechas energéticas asociadas a los puntos L, X y L de la zona de Brillouin como funciones de la tensión uniaxial en AlAs, GaAs, InAs y GaP. Asimismo, reportamos expresiones de ajuste para los valores de las masas efectivas de conducción en esos cuatro materiales. La comparación de la variación de la brecha de energía en X para el GaP, calculada con nuestro modelo, y recientes resultados experimentales para la transición indirecta entre la banda de huecos pesados y la banda X de conducción arroja una muy buena concordancia.

  4. Materials Integration and Metamorphic Substrate Engineering from Silicon to Gallium Arsenide to Indium Phosphide for Advanced III-V/Silicon Photovoltaics

    Science.gov (United States)

    Carlin, Andrew M.

    Lattice-mismatched epitaxy in the III-V compound semiconductor system based on III-AsP and related alloys are of enormous importance, and considerable research interest, for many years. The reason is straightforward if one considers the limitations placed on available materials properties for devices dictated by lattice matching to the dominant substrate technologies - Si, GaAs (and/or Ge) and InP. For III-V epitaxy, the lattice constants of these substrates have defined a generation or more of device advances since growth of heterostructures possessing the same equilibrium lattice constants as the substrate yields essentially defect-free (specifically extended defect-free) materials and devices. Removing the restriction of lattice matching to current substrate technology opens a rich spectrum of bandgaps, bandgap combinations, conduction and valence band offsets, etc., that are desirable and exploitable for advancing device technologies for new functionality and greater performance. However successful exploitation of these properties requires mitigation of a variety of extended defects that result from the lattice mismatch between substrate and epitaxial heterostructures. A well known method to achieve this solution is through the use of compositionally (lattice constant-graded) buffer interlayers, in which the equilibrium lattice constants of interlayers are slowly altered by controlled changes in layer composition so that the mismatch strain between the initial substrate and the final device layers is spread across a thickness of buffer. The research accomplished has yielded success for both lattice constant ranges Si - GaAs and GaAs - InP. For the Si - GaAs system, a three step GaP nucleation process on Si has been developed and demonstrated, which maintains total avoidance of creating coalescence-related defects such as antiphase domains and stacking faults resulting from the initial III-V/IV interfaces while reducing overall threading dislocation density by ~10x, to a range of 1×107 cm-2, compared to current state of the art. This reduction can now enable future III-V/Si solar cells based on GaAsP metamorphic buffers in which the underlying Si substrate can participate as an active sub-cell, and such buffers have been demonstrated in this research. Second, in this same lattice constant range, novel GaP/SiGe interfaces on Si were grown and demonstrated to eliminate the small, but not negligible lattice misfit between GaP and Si, and provides a second pathway for future III-V/Si solar cell integration through subsequent metamorphic buffer growth. For the GaAs-InP range of lattice constants, multiple metamorphic buffer strategies, including those based on anion-specific quaternary GaInAsP, combinations of step and linearly-graded buffers, and buffers with multiple ternary alloys were all investigated. Micro-scale phase separation within quaternary anion-graded GaInAsP was identified as a mechanism to significantly inhibit proper lattice misfit strain relaxation, which was explained by thermodynamic arguments consistent with theoretical phase separation. This led to the creation of hybrid step and linearly graded InGaAs/InGaP metamorphic buffers through which phase separation was totally eliminated by avoiding specific compositions that were identified as sources for phase separation. These findings have enabled a realistic path for accessing the full range of bandgaps needed for future high efficiency III-V solar cells through optimized metamorphic III-V grading strategies.

  5. The effect of bulk traps on the InP (Indium Phosphide) accumulation type MISFET (Metal-Insulator-Semiconductor Field-Effect Transistor)

    Science.gov (United States)

    Meiners, L. G.

    The enclosed reports represent work performed at USCD on Contract N00014-82-K-2032 entitled Surface and Interfacial Properties of InP and provides a full account of the results obtained during the contract period: May 1, 1984 through April 31, 1985. The paper, Space charge-limited currents and trapping in semi-insulating InP, has now been published in Electron. Device Letters, volume EDL-6, page 356 (1985). The manuscript, Effect of bulk traps on the InP accumulation type MISFET, will be presented as an invited talk at the fall meeting in the Journal of the Electrochemical Society.

  6. Modeling and Real-Time Process Monitoring of Organometallic Chemical Vapor Deposition of III-V Phosphides and Nitrides at Low and High Pressure

    Science.gov (United States)

    Bachmann, K. J.; Cardelino, B. H.; Moore, C. E.; Cardelino, C. A.; Sukidi, N.; McCall, S.

    1999-01-01

    The purpose of this paper is to review modeling and real-time monitoring by robust methods of reflectance spectroscopy of organometallic chemical vapor deposition (OMCVD) processes in extreme regimes of pressure. The merits of p-polarized reflectance spectroscopy under the conditions of chemical beam epitaxy (CBE) and of internal transmission spectroscopy and principal angle spectroscopy at high pressure are assessed. In order to extend OMCVD to materials that exhibit large thermal decomposition pressure at their optimum growth temperature we have designed and built a differentially-pressure-controlled (DCP) OMCVD reactor for use at pressures greater than or equal to 6 atm. We also describe a compact hard-shell (CHS) reactor for extending the pressure range to 100 atm. At such very high pressure the decomposition of source vapors occurs in the vapor phase, and is coupled to flow dynamics and transport. Rate constants for homogeneous gas phase reactions can be predicted based on a combination of first principles and semi-empirical calculations. The pressure dependence of unimolecular rate constants is described by RRKM theory, but requires variational and anharmonicity corrections not included in presently available calculations with the exception of ammonia decomposition. Commercial codes that include chemical reactions and transport exist, but do not adequately cover at present the kinetics of heteroepitaxial crystal growth.

  7. Preparation of Unsupported Molybdenum Phosphide Hydrofining Catalysts%非负载型磷化钼加氢精制催化剂的研制

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ Hydrofining catalysts contain Mn-Ni, Ni-Mo, Ni-W, Co-Mo, Mo, W, Ni, Co, etc and many studies of these catalysts are concerned with the addition of phosphorus or compounds containing phosphorus to give Ni-Mo-P, W-Ni-P, Mo-P, Ni-P, W-P, Co-Mo-P, NiPS3, and Mo-Ni-W-P[1,2].

  8. Pulse-reverse electrodeposition of transparent nickel phosphide film with porous nanospheres as a cost-effective counter electrode for dye-sensitized solar cells.

    Science.gov (United States)

    Wu, Mao-Sung; Wu, Jia-Fang

    2013-12-01

    A Ni2P nanolayer with porous nanospheres was directly coated on fluorine-doped tin oxide glass by pulse-reverse deposition as a low-cost counter electrode catalyst for dye-sensitized solar cells, and the photoelectron conversion efficiency of the cell was increased to 7.32% by using a porous nanosphere catalyst due to the significantly improved ion transport.

  9. Synthesis of MnP nanocrystals by treatment of metal carbonyl complexes with phosphines: a new, versatile route to nanoscale transition metal phosphides.

    Science.gov (United States)

    Perera, Susanthri C; Tsoi, Georgy; Wenger, Lowell E; Brock, Stephanie L

    2003-11-19

    The reaction of Mn2(CO)10 with P(SiMe3)3 in coordinating solvents at T >/= 220 degrees C yields low polydispersity, highly crystalline MnP nanoparticles for the first time. The effect of dimensional limiting has resulted in the stabilization of a ferromagnetic ground state at low temperatures, rather than the metamagnetic state observed in bulk (microcrystalline) MnP. The synthetic methodology reported here is demonstrated to be general for a number of different metals and phosphine sources.

  10. International Conference on Indium Phosphide and Related Materials (22nd) (IPRM) held on 31 May-4 Jun 2010, at Takamatsu Symbol Tower, Kagawa, Japan

    Science.gov (United States)

    2010-08-13

    E. Patten, R. Coussa, K. Kosai, W. Radford, J. Edwards, S. Johnson, S. Baur, J. Roth , B. Nosho, J. Jensen and R. Longshore, "Materials for Infrared... Roth . IEEE J. Sel. Top. Quantum Electron, Vol. 4. pp. 741-745, July/August 1998. 5. S. Gozu. T. Mozume. R. Akimoto. K. Akita. G.W. Cong, and H...13 (1974) 2886. [2] T. Tsuchiya, T. Kitatani, and M. Aoki: Proc. 17th Int. Conf. InP and Related Materials, Glasgow. Scotland , 2005, p. 256. [3] C

  11. Temperature and chemical bonding-directed self-assembly of cobalt phosphide nanowires in reaction solutions into vertical and horizontal alignments.

    Science.gov (United States)

    Zhang, Shuang-Yuan; Ye, Enyi; Liu, Shuhua; Lim, Suo Hon; Tee, Si Yin; Dong, Zhili; Han, Ming-Yong

    2012-08-22

    The preparation of vertically or horizontally aligned self-assemblies of CoP nanowires is demonstrated for the first time by aging them in the reaction solution for a sufficient time at 20 or 0 °C. This strategy opens up a way for exploring the controlled self-assembly of various highly anisotropic nanostructures into long-range ordered structures with collective properties.

  12. Measurement of the Two-photon Absorption Coefficient of Gallium Phosphide (GaP) Using a Dispersion-minimized Sub-10 Femtosecond Z-scan Measurement System

    Science.gov (United States)

    2012-09-01

    samples of semiconductors and thin films of organic materials on substrates. The use of dispersive media in the optical path has been eliminated...other semiconductors such as cadmium sulfide (CdS) and zinc selenide (ZnSe). We will also begin measuring the two-photon absorption coefficient for...organic thin - film materials deposited on various substrates. 15 6. References 1. Sheik-Bahae, M.; Said, A. A.; Van Stryland, E. W. High

  13. Sugar Blowing-induced Porous Cobalt Phosphide/nitrogen-doped Carbon Nanostructures With Enhanced Electrochemical Oxidation Performance Towards Water And Other Small Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chengzhou; Fu, Shaofang; Xu, Bo; Song, Junhua; Shi, Qiurong; Engelhard, Mark H.; Li, Xiaolin; Beckman, Scott P.; Sun, Junming; Du, Dan; Lin, Yuehe

    2017-09-06

    Finely controlled synthesis of high active and robust nonprecious metal catalysts with excellent catalytic efficiency in oxygen evolution reaction (OER) is extremely vital for making the water splitting process more energy-efficient and economical. Among these noble metal-free catalysts, transition-metal-based nanomaterials are considered as one of the most promising OER catalysts due to their relatively low-cost intrinsic activities, high abundance and diversity in terms of structure and morphology. In this work, we reported a facile sugar-blowing technique and low-temperature phosphorization to generate 3D self-supported metal involved carbon nanostructures, which termed as Co2P@Co/nitrogen-doped carbon (Co2P@Co/N-C). By capitalizing on the 3D porous nanostructures with high surface area, generously dispersed active sites, the intimate interaction between active sites and 3D N-doped carbon, the resultant Co2P@Co/N-C exhibited satisfying OER performance superior to CoO@Co/N-C, delivering 10 mA cm-2 at overpotential of 0.32 V. It is noting that in contrast to the substantial current density loss of RuO2, Co2P@Co/N-C showed much enhanced catalytic activity during the stability test and the 1.8-fold increase in current density was observed after stability test. Furthermore, the obtained Co2P@Co/N-C can also be served as an excellent nonprecious metal catalyst for methanol and glucose electrooxidation in alkaline media, further extending their potential applications.

  14. Activation of Small Molecules by DyI_2 and Dy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results The reactivities of dysprosium diiodide and metallic dysprosium toward small molecules are discussed.For instance,DyI2-induced silyl radical reactions are described.The combination of dysprosium diiodide and dichloromethane can serve as an effective methylene transfer reagent for cyclopropanation of unfunctionalized alkenes beyond that possible with other metal-dichloromethane systems.Furthermore,we report that the combination of chlorosilane and metallic Dy can also serve as an effective prom...

  15. Heterometallic octanuclear RE(III)3Ni(II)5 (RE = Dy(III), Gd(III) and Y(III)) clusters with slow magnetic relaxation for the dysprosium derivative.

    Science.gov (United States)

    Wang, Huiyu; Ke, Hongshan; Lin, Shuang-Yan; Guo, Yang; Zhao, Lang; Tang, Jinkui; Li, Yun-Hui

    2013-04-21

    Reactions of rare earth benzoate and nickel perchlorate with a Schiff-base ligand, 2-([(2-hydroxyphenyl)imino]methyl) phenol (H2L), in the presence of triethylamine yielded three heterobimetallic octanuclear clusters of general formula [RE3Ni5L5(PhCOO)3(μ3-OH)5(μ3-OCH3)(CH3OH)4(H2O)]·xCH3OH·yH2O (RE = Dy(III), x = 4, y = 4 (1), RE = Gd(III), x = 5, y = 4 (2), RE = Y(III), x = 5, y = 3 (3)). Single-crystal X-ray diffraction reveals that the metal core of each cluster consists of two distorted [RE2Ni2O4] cubane-like moieties and a heterobimetallic triangular [RE2NiO2] unit, with RE ions arranged in a typical triangular fashion. Variable-temperature solid state magnetic susceptibilities of these complexes were measured in the temperature range 2-300 K and the results indicate that an overall ferromagnetic interaction among the metal ions is operative for compounds 2 and 3. Under zero external field, the Dy3Ni5 compound shows a frequency dependence of the out-of-phase (χ'') signals, which indicates slow relaxation of the magnetization.

  16. Poly[(6-carboxypicolinato-κ3O2,N,O6(μ3-pyridine-2,6-dicarboxylato-κ5O2,N,O6:O2′:O6′dysprosium(III

    Directory of Open Access Journals (Sweden)

    Xu Li

    2009-11-01

    Full Text Available In the title complex, [Dy(C7H3NO4(C7H4NO4]n, one of the ligands is fully deprotonated while the second has lost only one H atom. Each DyIII ion is coordinated by six O atoms and two N atoms from two pyridine-2,6-dicarboxylate and two 6-carboxypicolinate ligands, displaying a bicapped trigonal-prismatic geometry. The average Dy—O bond distance is 2.40 Å, some 0.1Å longer than the corresponding Ho—O distance in the isotypic holmium complex. Adjacent DyIII ions are linked by the pyridine-2,6-dicarboxylate ligands, forming a layer in (100. These layers are further connected by π–π stacking interactions between neighboring pyridyl rings [centroid–centroid distance = 3.827 (3 Å] and C—H...O hydrogen-bonding interactions, assembling a three-dimensional supramolecular network. Within each layer, there are other π–π stacking interactions between neighboring pyridyl rings [centroid–centroid distance = 3.501 (2 Å] and O—H...O and C—H...O hydrogen-bonding interactions, which further stabilize the structure.

  17. 10 CFR Appendix B to Part 30 - Quantities 1 of Licensed Material Requiring Labeling

    Science.gov (United States)

    2010-01-01

    ... Cesium-135 10 Cesium-136 10 Cesium-137 10 Chlorine-36 10 Chlorine-38 10 Chromium-51 1,000 Cobalt-58m 10 Cobalt-58 10 Cobalt-60 1 Copper-64 100 Dysprosium-165 10 Dysprosium-166 100 Erbium-169 100 Erbium-171...

  18. 10 CFR 33.100 - Schedule A.

    Science.gov (United States)

    2010-01-01

    ... .1 Cesium-137 .1 .001 Chlorine-36 1 .01 Chlorine-38 100 1. Chromium-51 100 1. Cobalt-57 10 0.1 Cobalt-58m 100 1. Cobalt-58 1 .01 Cobalt-60 .1 .001 Copper-64 10 .1 Dysprosium-165 100 1. Dysprosium-166...

  19. Generation of phosphine gas for the control of grain storage pests

    OpenAIRE

    Zhao, B.X.

    2010-01-01

    The phosphine generator is a device for rapid production of phosphine (PH₃) gas to be introduced into grain storage. The aluminum phosphide (ALP) tablets are used as raw material and its effective constituent is 56%. When the aluminum phosphide and water are brought into contact a hydrolyzation reaction takes place to produce the phosphine gas. Controlling the reaction temperature, reaction pressure and the dosage of aluminum phosphide immersed in the water, the hydrolyzation reaction can be ...

  20. Effect of integrated pest management on controlling zoonotic cutaneous leishmaniasis in Emamzadeh Agha Ali Abbas (AS) District, Isfahan province, 2006-2009

    National Research Council Canada - National Science Library

    Nilforoushzadeh, Mohammad Ali; Shirani-Bidabadi, Leila; Saberi, Sedigheh; Hosseini, Seyed Mohsen; Jaffary, Fariba

    2014-01-01

    ... (Isfahan Province, Iran). Subsequently, three methods of controlling the disease, including, spraying residential buildings with Baygon, baiting with zinc phosphide poisons, changing the vegetative cover of the region...

  1. Ni2P/Al-MCM-41催化剂的制备及其加氢脱硫性能%Preparation and hydrodesulfurization performance of Al-MCM-41 supported nickel phosphide catalysts

    Institute of Scientific and Technical Information of China (English)

    匡志敏; 龚建议; 杨运泉; 王威燕; 陈来福; 贺恒

    2011-01-01

    A1-MCM-41 mesoporous molecular sieves were prepared by the azeotropic distillation and ultrasonic dispersive technology using sodium silicate as silica source , aluminum sulfate as aluminum source and cetyltrimethyl ammonium bromide as structure-directing agent. By using A1-MCM-41 as support, nickel nitrate and diammonium hydrogen phosphate as raw materials, a series of supported Ni2P catalysts on A1-MCM-41 was prepared via the method of temperature-programmed reduction under ultrasonic oscillation. The catalysts were characterized by FT1R, BET, XRD and SEM.Hydrodesulfurization of thiophene catalyzed by Ni2P/Al-MCM-41 was carried out in a high pressure autoclave reactor. The experimental results showed that Al-MCM-41 prepared by ultrasonic dispersive technology had a much higher specific surface area, larger pore volume and pore diameter than that prepared by conventional mechanical mixing. The Al-MCM-41 prepared by azeotropic distillation with ultrasonic dispersive technology was also better than that using only ultrasonic dispersive technology.The Ni2P/A1-MCM-41 catalysts, hydrodesulfurization conversion of thiophene nearly reached 100% at the reaction time 5 h, reaction temperature 548 K, and reaction pressure 3.5 MPa.%以硅酸钠为硅源、硫酸铝为铝源、十六烷基三甲基溴化铵(CTAB)作模板剂,采用共沸蒸馏与超声波分散技术相结合的方法制备了介孔分子筛Al-MCM-41.以Al-MCM-41为载体,硝酸镍和磷酸氢二氨为原料,采用超声波振荡、程序升温还原法制备了Ni2P/Al-MCM-41催化剂,并对Al-MCM-41和Ni2P/Al-MCM-41进行了傅里叶变换红外光谱、比表面积测定、X射线衍射、扫描电镜表征.考察了Ni2P/Al-MCM-41催化剂对噻吩加氢脱硫的催化性能.结果表明:采用超声波制得的Al-MCM-41其比表面积,孔容和孔径明显高于常规搅拌制得的Al-MCM-41,共沸蒸馏制得的Al-MCM-41其比表面积、孔容和孔径高于未共沸蒸馏的Al-MCM-41;在反应时间为5h、548K、3.5MPa条件下,Ni2P/Al-MCM-41催化剂对噻吩加氢脱硫的转化率接近100%.

  2. Study on Magnetic Responsibility of Rare Earth Ferrite/Polyacrylamide Magnetic Microsphere

    Institute of Scientific and Technical Information of China (English)

    Zhang Ming; Wang Zhifeng; Zhang Hong; Dai Shaojun; Qiu Guanming; Okamoto Hiroshi

    2005-01-01

    In inverse microemulsion, rare earth ferrite/polyacrylamide magnetic microsphere were prepared and their magnetic responsibility were studied by magnetic balance. Results indicate that the magnetic responsibility of microsphere relates to magnetic moment of rare earth ion, and it can be improved by the addition of dysprosium ion of high magnetic moment. Dysprosium content has an effect on magnetic responsibility of dysprosium ferrite/polyacrylamide magnetic microsphere. The microsphere displays strong magnetic responsibility when the molar ratio of Dy3+/iron is 0.20.

  3. Poly[hexaaquatri-μ-malonato-didysprosium(III

    Directory of Open Access Journals (Sweden)

    Mei Yang

    2008-07-01

    Full Text Available The title compound, [Dy2(C3H2O43(H2O6]n, forms a coordination polymeric structure comprising hydrated dysprosium ions and malonate ligands. In the asymmetric unit, there are one dysprosium ion, one and a half malonate ligands, and three water molecules. Each DyIII atom is coordinated by six O atoms from four malonate ligands and by three water molecules, and displays a tricapped trigonal–prismatic coordination geometry. The malonate ligands adopt two types of coordination mode, linking dysprosium centres to form a three-dimensional coordination polymer. The extensive network of hydrogen bonds in this polymer enhances the structural stability.

  4. A Thermally Actuated Flux Pump for Energizing YBCO Pucks

    Science.gov (United States)

    2016-05-01

    antiferromagnetic, so heat pulses that go above and below 85 K should create a wave of magnetism across the face of the YBCO puck. The YBCO and dysprosium...temperature sensors were located at the centre and the outer perimeter on the surface of the dysprosium closest to the cold head, and on the side of the YBCO...outer perimeter of the dysprosium, the edge of the YBCO and the coldhead. In the following figures various curves are removed to give a clear picture of

  5. Methods for Estimating Physicochemical Properties of Inorganic Chemicals of Environmental Concern.

    Science.gov (United States)

    1984-06-01

    Herbicides, Fumigants , Growth Regulators, Repellents, and Rodenticides 102 17. Organometallics Listed as TSCA Section 4 Chemicals 103 18. Organometallics...Na and K Tetrasodium Pyrophosphate Phosphine 0 Phosphorus Pentachloride Aluminum Phosphide Lead Phosphate Zinc Phosphide A Arthur Utdet Inc. 960 TABLE...acid) 101 * i Arthur D. Linke, imc TABLE 16 ORGANOMETALLICS USED AS INSECTICIDES, FUNGICIDES, 0 HERBICIDES, FUMIGANTS , GROWTH REGULATORS, REPELLENTS

  6. Maximum Permissible Concentrations and Negligible Concentrations for Rare Earth Elements (REEs)

    NARCIS (Netherlands)

    Sneller FEC; Kalf DF; Weltje L; Wezel AP van; CSR

    2000-01-01

    In dit rapport worden maximaal toelaatbare risiconiveaus (MTR) en verwaarloosbare risiconiveaus (VR) afgeleid voor zeldzame aardmetalen (ZAM). De geselecteerde ZAMs zijn Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), en Dysprosium (Dy

  7. Atomic physics: A strange kind of liquid

    Science.gov (United States)

    Laburthe-Tolra, Bruno

    2016-11-01

    Interactions between the magnetic dipoles of dysprosium atoms in an ultracold gas can produce a 'self-bound' droplet. This provides a useful isolated system for probing the quantum-mechanical properties of ultracold gases. See Letter p.259

  8. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Active demands from downstream industry drove the price rise of rare earth products in Chinese domestic marketrecently, particularly didymium and dysprosium products. Prices of other rare earth products remained stable.

  9. Luminescence investigation of Dy2O2S and Dy2O2SO4 obtained by thermal decomposition of sulfate hydrate

    Institute of Scientific and Technical Information of China (English)

    RV Rodrigues; L Marciniak; LU Khan; JR Matos; HF Brito; W Strk

    2016-01-01

    The yellow emitting dysprosium oxysulfide (Dy2O2S) and dysprosium oxysulfate (Dy2O2SO4) compounds were prepared from the thermal decomposition of hydrated dysprosium sulphate. The materials were characterized by using thermogravimetry (TG/DTG), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopies. The thermal stability temperatures at around 1151 and 1313 K were determined for the Dy2O2S and Dy2O2SO4 materials, respectively. The photolumines-cence properties of the dysprosium oxysulfide were investigated, showing narrow emission bands assigned to the 4F9/2→6HJ intracon-figurational transitions of the Dy3+ion. The yellow emission color of this phosphor suggests that the Dy2O2S is a promising material for applications in LEDs.

  10. Sinterless Fabrication Of Contact Pads On InP Devices

    Science.gov (United States)

    Weizer, Victor G.; Fatemi, Navid S.; Korenyi-Both, Andras L.

    1995-01-01

    Research has shown that with proper choice of material, low-resistance contact pads deposited on solar cells and other devices by improved technique that does not involve sintering. Research directed at understanding mechanisms involved in contact-sintering process has resulted in identification of special group of materials that includes phosphides of gold, silver, and nickel; specifically, Au(2)P(3), AgP(2), and Ni(3)P. Incorporation of phosphide interlayer substantially reduces resistivity between gold current-carrying layer and indium phosphide substrate. Further research indicated only very thin interlayer of any of these compounds needed to obtain low contact resistance, without subjecting contact to destructive sintering process.

  11. Syntheses, structures, and magnetic properties of a family of tetranuclear hydroxido-bridged Ni(II)2Ln(III)2 (Ln = La, Gd, Tb, and Dy) complexes: display of slow magnetic relaxation by the zinc(II)-dysprosium(III) analogue.

    Science.gov (United States)

    Abtab, Sk Md Towsif; Maity, Manoranjan; Bhattacharya, Kisholoy; Sañudo, E Carolina; Chaudhury, Muktimoy

    2012-10-01

    A new family of [2 × 2] tetranuclear 3d-4f heterometallic complexes have been synthesized. These are [Zn(2)Dy(2)L(2)(μ(3)-OH)(2)(μ(4)-OH)(dbm)(2)(MeOH)(2)](NO(3))·2H(2)O·MeOH (3), [Ni(2)Dy(2)L(2)(μ(3)-OH)(2)(μ(4)-OH)(dbm)(2)(MeOH)(2)](NO(3))·MeOH (4), [Ni(2)La(2)L(2)(μ(3)-OH)(2)(μ(4)-OH)(dbm)(2)(MeOH)(2)](ClO(4))·H(2)O·2MeOH (5), [Ni(2)Tb(2)L(2)(μ(3)-OH)(2)(μ(4)-OH)(dbm)(2) (MeOH)(2)](NO(3))·MeOH (6), and [Ni(2)Gd(2)L(2)(μ(3)-OH)(2)(μ(4)-OH)(dbm)(2)(MeOH)(2)](NO(3))·MeOH (7), [H(2)L = N,N'-dimethyl-N,N'-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine and Hdbm = dibenzoylmethane] obtained through a single-pot synthesis using [Zn(HL)(dbm)] (for 3)/[Ni(HL)(dbm)]·2CH(3)OH (for 4, 5, 6, and 7) as 3d-metal ion precursors. Single-crystal X-ray diffraction analysis and electrospray ionization (ESI) mass spectroscopy have been used to establish their identities. Compounds are isostructural, in which the metal ions are all connected together by a bridging hydroxido ligand in a rare μ(4)-mode. In complexes 3-7, the metal ions are antiferromagnetically coupled. Taking a cue from the results of 3 and 5, precise estimations have been made for the antiferromagnetic Ni···Ni (J(Ni) = -50 cm(-1)), Ni···Gd (J(NiGd) = -4.65 cm(-1)), and Gd···Gd (J(Gd) = -0.02 cm(-1)) exchange interactions in 7, involving the gadolinium(III) ions. The Zn(II)(2)Dy(III)(2) compound 3 has shown the tail of an out-of-phase signal in alternating current (AC) susceptibility measurement, indicative of slow relaxation of magnetization. Interestingly, the Ni(II)(2)Dy(III)(2) compound 4 in which both the participating metal ions possess large single ion anisotropy, has failed to show up any slow magnetic relaxation.

  12. 镝与二甘醇酸的配位聚合物的水热合成、晶体结构及荧光性质%Hydrothermal Synthesis, Crystal Structure and Fluorescence Property of Dysprosium Coordination Polymer with Diglycolic Acid

    Institute of Scientific and Technical Information of China (English)

    张艳斌; 鞠艳玲; 李艳秋; 李夏

    2007-01-01

    A new lanthanide coordination polymer {[Dy2(dga)3(H2O)4]·2H2O}n was prepared by hydrothermal method with DyCl3·6H2O and diglycolic acid (H2dga), and structurally characterized by single-crystal X-ray diffraction technique. The complex crystallizes in Orthorhombic system, C2221 space group with a=1.773 5(11) nm, b =0.875 2(6) nm, c=1.504 3(9) nm, V=2.335 0(3) nm3, Dc=2.359 Mg·m-3, Z=4,μ=6.447 mm-1, F(000)=1 584.0, R=0.0507, wR=0.121 6. In the complex, there are two types of coordination environments for Dy3+ ion. One Dy1 ion is nine-coordinated by three diglycolato groups via six carboxyl oxygen atoms and three ether oxygen atoms. The Dy1 ion is in a distorted monocapped square-antiprism coordination geometry. Whereas the other Dy2 ion is eight-coordinated and the coordination sphere around each Dy2 ion consists of four carboxyl oxygen atoms from four diglycolato ligands and four oxygen atoms from four coordinated water molecules. The coordination polyhedron of Dy2 ion can be described as a distorted square-antiprism. Eight- and nine-coordinate Dy3+ ions are linked by diglycolato ligands to form a 2D network structure. The fluorescence spectral of the complex in solid state at room temperature shows that the diglycolic acid is suitable for the sensitization on the luminescence of Dy3+ ion. CCDC: 660435.%DyCl3·6H2O与二甘醇酸(H2dga)在水热条件下反应得到配位聚合物{[Dy2(dga)3(H2O)4]·2H2O}n,用X-射线衍射单晶结构分析方法确定了其晶体结构.该配合物的晶体属于正交晶系,C2221空间群.在配合物中,Dy3+离子存在两种类型的配位环境.九配位的Dy1离子与3个二甘醇酸根的6个羧基氧原子和3个醚氧原子配位,其配位多面体可描述为一个扭曲的单帽四方反棱柱;八配位的Dy2离子周围的8个配位氧原子形成一个扭曲的四方反棱柱配位多面体,其中4个氧原子来自4个二甘醇酸根,另外4个氧原子由4个配位水分子提供.二甘醇酸配体的2个羧基和其醚氧原子同时与Dy3+离子配位而形成2D网状结构.该配合物在室温下的固体荧光光谱显示了中心Dy3+离子的特征荧光,位于483 nm和574 nm的发射峰分别对应于Dy3+离子的4F9/2→6H15/2和4F9/2→6H13/2跃迁.

  13. 稀土金属 Dy 掺杂 TiO2光催化剂的制备及其对孔雀石绿降解性能的研究%Study on preparation of rare earth element dysprosium doped with TiO2 photocatalyst and its degradation property to malachite green

    Institute of Scientific and Technical Information of China (English)

    高航; 高梅; 李松田; 马威; 吴晓兵

    2015-01-01

    To improve the oxidation efficiency of heterogeneous photocatalysis,TiO2 doped by rare-earth elements was adopted. The results indicate that:there was red-shift adsorption spectra of synthetic product which could enhance malachite green oxidative decolorization effectively under the action of normal visible light. Due to Dy3 + -TiO2 doped photocatalyst,activation energy of photooxidation was decreased so that the efficiency of photolysis could be improved significantly. What’s more,the treatment of malachite green model wastewater with Dy3 + -TiO2 was studied and optimal conditions has been determined as follows:the concentration of malachite green is 20 mg / L,molar ratio of Dy-doping is 1. 5% . Under that reaction con-dition,after 150 min,the decolorization rates of malachite green will be over 60% .%采用稀土元素掺杂法制备改性的二氧化钛,以改善非均相光催化的氧化效率。研究结果表明,在掺杂镝元素之后,产物的吸收光谱发生了红移,在可见光作用下,可以有效地促进孔雀石绿的氧化脱色。引入掺杂型光催化剂 Dy3+-TiO2后,可降低光氧化体系所需的能量,提高光解效率。以孔雀石绿溶液作为模拟废水,考察了 Dy3+离子掺杂量、底物浓度等因素的影响,确定了优化的实验条件:在孔雀石绿的浓度为20 mg/ L,稀土元素 Dy 掺杂量为1.5%(摩尔比)时,反应150 min 后孔雀石绿脱色率达到60%以上。

  14. N-对甲苯磺酰β-丙氨酸镝配合物的合成、晶体结构及抑菌活性%Synthesis crystal structure and antibacterial activity of dysprosium complex with N-p-tolysulfonyl-β-Alanine

    Institute of Scientific and Technical Information of China (English)

    李森兰; 马录芳; 王利亚; 黄世稳; 韦启后; 梁福沛; 张漫波

    2005-01-01

    稀土由于其特殊的电子结构,容易与一些中性、酸性和碱性生物配体形成配合物。本文合成并测定了对甲苯磺酰β-丙氨酸与稀土镝配合物的晶体结构及抑菌活性。

  15. Bis[μ-2-(4-hydroxyphenylacetato]-κ3O,O′:O;κ3O:O,O′-bis{aqua(4,4′-bipyridine-κNbis[2-(4-hydroxyphenylacetato-κ2O,O′]dysprosium(III} monohydrate

    Directory of Open Access Journals (Sweden)

    Jia-Lu Liu

    2010-12-01

    Full Text Available In the title dinuclear complex, [Dy2(C8H7O36(C10H8N22(H2O2]·H2O, the DyIII atoms are coordinated by eight O atoms from four 2-(4-hydroxyphenylacetate (HPAA ligands and a water molecule, and one N atom from a 4,4′-bipyridine (bipy ligand in a distorted tricapped trigonal prismatic geometry. Whereas four HPAA ligands coordinate to just two DyIII atoms, the remaining two ligands bridge the two DyIII atoms. In the crystal, O—H...O and O—H...N hydrogen bonds link the molecules into a three-dimensional network.

  16. Low Cost Automated Module Assembly for 180 GHz Devices Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Emergence of Indium Phosphide IC's has made possible devices operating at frequencies up to 200GHZ and beyond. Building modules using these devices opens a goldmine...

  17. Rice tablet: An overview to common material in Iran

    Directory of Open Access Journals (Sweden)

    Hassan Amiri

    2016-05-01

    Full Text Available Rice tablets or Aluminum phosphide (ALP poisoning is one of the most lethal poisoning cases in the country, leading to high mortality, especially in youths every year. The management of aluminum phosphide poisoning remains purely supportive because no specific antidote exists. Although in various studies mortality rates has been reported ranged 40-80%. In many cases it marked too late, suspected to consume of Botanical rice tablets (garlic compound and caused delay in aggressive treatment. Aluminium phosphide, is an effective insecticide and rodenticide, which is used widely in the storage place and transportation of grain as a fumigant to control rodents and pests. For many years, Aluminum and zinc phosphide have been strong insecticides and rodenticides, which are cheap and effective, and their residues are not toxic

  18. Optical Processing and Control

    Science.gov (United States)

    1994-01-01

    interfaces(7]. The effect has been used to provide evidence for surface states on semiconductors using germanium and silicon surfaces(8]. 3.1 References...8f, c ndr where Sf& is the beat frequency of the ring laser due to the moving medium, f is the frequency of the propagating beam, c is the velocity...Tantalate Gallium Arsenide Phosphide Tantalum Pentoxide Gallium Aluminum Nitride Niobium Pentoxide Indium Phosphide Silicon Other III-V, II-VI, etc

  19. Poly[hexa-aqua-tri-μ-malonato-didysprosium(III)].

    Science.gov (United States)

    Fang, Zhan-Qiang; Zeng, Rong-Hua; Song, Zhao-Feng; Yang, Mei

    2008-06-07

    The title compound, [Dy(2)(C(3)H(2)O(4))(3)(H(2)O)(6)](n), forms a coordination polymeric structure comprising hydrated dysprosium ions and malonate ligands. In the asymmetric unit, there are one dysprosium ion, one and a half malonate ligands, and three water mol-ecules. Each Dy(III) atom is coordinated by six O atoms from four malonate ligands and by three water mol-ecules, and displays a tricapped trigonal-prismatic coordination geometry. The malonate ligands adopt two types of coordination mode, linking dysprosium centres to form a three-dimensional coordination polymer. The extensive network of hydrogen bonds in this polymer enhances the structural stability.

  20. Poly[hexa­aqua­tri-μ-malonato-didysprosium(III)

    Science.gov (United States)

    Fang, Zhan-Qiang; Zeng, Rong-Hua; Song, Zhao-Feng; Yang, Mei

    2008-01-01

    The title compound, [Dy2(C3H2O4)3(H2O)6]n, forms a coordination polymeric structure comprising hydrated dysprosium ions and malonate ligands. In the asymmetric unit, there are one dysprosium ion, one and a half malonate ligands, and three water mol­ecules. Each DyIII atom is coordinated by six O atoms from four malonate ligands and by three water mol­ecules, and displays a tricapped trigonal–prismatic coordination geometry. The malonate ligands adopt two types of coordination mode, linking dysprosium centres to form a three-dimensional coordination polymer. The extensive network of hydrogen bonds in this polymer enhances the structural stability. PMID:21202748

  1. Poly[hexa­aqua­tri-μ-malonato-didysprosium(III)

    OpenAIRE

    2008-01-01

    The title compound, [Dy2(C3H2O4)3(H2O)6]n, forms a coordination polymeric structure comprising hydrated dysprosium ions and malonate ligands. In the asymmetric unit, there are one dysprosium ion, one and a half malonate ligands, and three water molecules. Each DyIII atom is coordinated by six O atoms from four malonate ligands and by three water molecules, and displays a tricapped trigonal–prismatic coordination geometry. The malonate ligands adopt two types of coordination mode, linkin...

  2. Photoluminescence, trap states and thermoluminescence decay process study of Ca2MgSi2O7 : Eu2+, Dy3+ phosphor

    Indian Academy of Sciences (India)

    Ravi Shrivastava; Jagjeet Kaur; Vikas Dubey; Beena Jaykumar

    2014-06-01

    Europium and dysprosium-doped calcium magnesium silicate powder with different concentrations of dysprosium were synthesized using solid-state reaction. The Fourier transform infrared (FT–IR) spectra confirmed the proper preparation of the sample. The prepared phosphors were characterized using photoluminescence excitation and emission spectra. Prominent green colour emission was obtained under ultraviolet excitation. The thermoluminescence glow curves of the samples were measured at various delay times. With increased delay time, the intensity of the thermoluminescence peak decays and the position of the thermoluminescence peak shifts towards higher temperature, indicating the considerable retrapping associated with general order kinetics.

  3. 补药控制偏高磷化氢浓度熏蒸锈赤扁谷盗生产试验%FIELD TRAIL OF CRYPTOLESTES FERRUGINEUS (STEPHENS)FUMIGATED WITH HIGHER LEVEL OF PHOSPHINE CONCENTRATION MAINTAINED BY ALUMINIUM PHOSPHIDE SUPPLEMENT

    Institute of Scientific and Technical Information of China (English)

    黄子法; 王殿轩; 汪灵广; 王公勤

    2012-01-01

    The field trial of phosphine fumigation was carried out that was focus on the Cryptolestes ferrugineus (Stephens)control completely in a horizontal storage of paddy rice, in which the population of the insect was similarly high both monitored by the method of sieving and light trap attracting. The gastightness of the warehouse was 30 seconds of half time decreased from 500 Pa to 250 Pa. The results involved in that the phosphine concentration reached to 130-170 mL/m3 in 20h after aluminium powder and tablet application. The peak concentration, 800 mL/m3 was monitored in three days. And then the concentration went down quickly. The maintaining time of phosphine was six days above 400 mL/m3, nine days in 300-400 mL/m3, seven days in 200?00 mL/m3. Total time of more than 300 mL/m3 was 15 days. Through the process of phosphine concentration maintaining the insect population was killed fully and successfully.%针对灯光诱捕和取样检查都发现锈赤扁谷盗发生数量较多的储藏稻谷,实仓进行了补充施药控制偏高磷化氢浓度杀虫试验,试验仓房的气密性为500 Pa正压半衰期为30 s.试验结果为:在粮面施用磷化铝粉剂和通风口施用磷化铝片剂后,环流20 h仓内磷化氢浓度可达130 mL/m3~170 mL/m3,施药3d后两种剂型药剂都达到了释放磷化氢的高峰(800 mL/m3),随后磷化氢浓度较快地下降.通过分别2次补充施药后,保持磷化氢浓度在400 mL/m3以上的时间达6d,300 mL/m~400 mL/m3的时间达9d,200 mL/m3~300 mL/m3的时间7d.试验仓熏蒸中磷化氢控制偏高浓度(大于300 mL/m3)的时间达到了15 d.在此偏高浓度下,9d后大部分害虫死亡,整个熏蒸过程实现了完全杀死锈赤扁谷盗.

  4. Cyclopentadiene Elimination Reaction as a Route to Bis(Neopentyl)Gallium Phosphides, Crystal and Molecular Structures of (Me3CCh2)2GaPEt22 and (Me3CCH2)2GaP(C6H11)22.

    Science.gov (United States)

    1997-05-12

    Code: 4135002 8. PERFORMING ORGANIZATION REPORT NUMBER Technical Report No. 46 10. SPONSORING ’ MONITORING AGENCY REPORT NUMBER N/A 11...585 (sh), 456 (w), 446 (w), 350 (w), 290 (w). Synthesis of (Me3CCH2)2GaP(C6Hu)2 by a Metathesis Reaction. A side-arm dumper charged with 1.07 g

  5. Perovskite catalysts for oxidative coupling

    Science.gov (United States)

    Campbell, Kenneth D.

    1991-01-01

    Perovskites of the structure A.sub.2 B.sub.2 C.sub.3 O.sub.10 are useful as catalysts for the oxidative coupling of lower alkane to heavier hydrocarbons. A is alkali metal; B is lanthanide or lanthanum, cerium, neodymium, samarium, praseodymium, gadolinium or dysprosium; and C is titanium.

  6. Rare Earths; The Fraternal Fifteen (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Gschneidner, Jr., Karl A. [Iowa State University; Ames Laboratory

    1966-01-01

    Rare earths are a set of 15 elements: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. They are not rare and not earths; they are metals and quite abundant. They are studied to develop commercial products which are beneficial to mankind, and because some rare earths are important to fission products.

  7. An organometallic sandwich lanthanide single-ion magnet with an unusual multiple relaxation mechanism.

    Science.gov (United States)

    Jeletic, Matthew; Lin, Po-Heng; Le Roy, Jennifer J; Korobkov, Ilia; Gorelsky, Serge I; Murugesu, Muralee

    2011-12-07

    A dysprosium(III) sandwich complex, [Dy(III)(COT″)(2)Li(THF)(DME)], was synthesized using 1,4-bis(trimethylsilyl)cyclooctatetraenyl dianion (COT″). The complex behaves as a single-ion magnet and demonstrates unusual multiple relaxation modes. The observed relaxation pathways strongly depend on the applied static dc fields.

  8. On the use of Liouville relaxation supermatrices in Mössbauer studies. III : Application to Mössbauer relaxation in superconductors

    OpenAIRE

    Hartmann-Boutron, F.

    1980-01-01

    Wagner et al. recently studied the Mössbauer relaxation of paramagnetic dysprosium as an impurity in superconducting thorium. In connection with this study, we have derived simple formulas for interpreting relaxation effects in 2+ 0+ Mössbauer transitions of rare earth ions in superconductors.

  9. High-pressure synthesis of {nu}-DyBO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Emme, H.; Huppertz, H. [Dept. Chemie und Biochemie, Ludwig-Maximilians-Univ. Muenchen, Muenchen (Germany)

    2004-12-01

    {nu}-Dysprosium borate ({nu}-DyBO{sub 3}) was synthesized under conditions of high temperature and pressure in a Walker-type multi-anvil apparatus at 3 GPa and 1323 K. The compound is isotypic with the already known {nu}-samarium and {nu}-europium orthoborates. (orig.)

  10. Note: Simple means for selective removal of the 365 nm line from the Hg spectrum using Dy

    DEFF Research Database (Denmark)

    Vesborg, Peter Christian Kjærgaard; Chorkendorff, Ib; Brock-Nannestad, T.

    2011-01-01

    The emission spectrum of mercury has a notable line at about 365 nm under both low and medium-high pressure conditions. A simple filter based on a solution of dysprosium ions, Dy3+, is shown to be very useful for applications of Hg-light sources where this line is unwanted. The presented filter i...

  11. Benzoxazole-based heterometallic dodecanuclear complex [Dy(III)4Cu(II)8] with single-molecule-magnet behavior.

    Science.gov (United States)

    Iasco, Olga; Novitchi, Ghenadie; Jeanneau, Erwann; Wernsdorfer, Wolfgang; Luneau, Dominique

    2011-08-15

    Three Cu-Ln (Ln = Dy, Gd, Y) dodecanuclear clusters assembled by a novel ligand of the benzoxazole type are reported. The dysprosium cluster exhibits a frequency dependence of the alternating-current susceptibility and hysteresis loop at low temperature, indicating single-molecule-magnet behavior.

  12. Market Review

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ RE Market Dec. 10-20 Price of Pr-Nd oxide and Pr-Nd mischrnetal kept on rising in domestic market recently due to the tight supply of RE carbonate. Short supply of ion adsorption clay in southern China did not affect the prices of dysprosium and terbium obviously.

  13. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    June 20-30, 2011 Prices of heavy rare earth products remained soaring. The same happened to dysprosium and its related products due to tight supply. Separation plants held tightly of europium oxide. Refining plants took a positive attitude toward the ma

  14. Market Review

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Rare earth market was inactive affected by sluggish demand for didymium mischmetal and dysprosium metal by NdFeB industry. Most enterprises were waiting to see what was going on with the industry. However, price of didymium oxide rose again and price of heavy rare earths kept strong. Price of Dy oxide and Yt oxide Kept on rising.

  15. Market Review

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ RE Market May 10-20 Learned from Inner Mongolia Rare Earth Association,domestic rare earth market was in good situation driven by high demand. Price of neodymium rose strongly. Dysprosium oxide and terbium oxide still hovered at the higher price level. Price of europia remained stable.

  16. Market Review RE Market April 20-30

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Driven by high demand, China rare earth market was in good situation. Dysprosium oxide and terbium oxide hovered at the higher price level. Price of Pr-Nd oxide kept upward.Price of SmEuGd rose on small extent.

  17. Infrared Transparent Selenide Glasses.

    Science.gov (United States)

    1997-03-14

    crystalline halides, silica and fluoride glasses, and chalcogenide glasses. Crystalline halides undergo plastic deformation and are hygroscopic...mainly for applications operating at wavelengths less than 3 microns. Silicate and fluoride glasses have been developed as optical fiber amplifiers...activity. Preferred rare earths includes praseodymium, neodymium, erbium, cerium , dysprosium, holmium, thulium, terbium, ytterbium or mixtures of

  18. Synthesis and structure of didysprosium complexes with a tetraketone

    Science.gov (United States)

    Yang, Luqin; Yang, Rudong

    1996-06-01

    Two novel didysprosium (Dy 2) complexes of 1,5-bis(1'-phenyl-3'-methyl-5'-pyrazolone-4')-1,5-pentanedione (H 2L), Dy 2L 3·2H 2O and Dy 2L 3·5DMF (DMF = dimethylformamide), have been synthesized. The crystal structure of Dy 2L 3·5DMF was determined by X-ray diffraction. Crystals are triclinic, space group P1¯, with a = 16.99(1), b = 17.970(9), c = 18.28(1) Å, α = 110.36(4), β = 101.47(6), γ = 111.11(5)°, V = 4533(9) Å 3, Mr = 2017.91, Z = 2, D x = 1.48 g cm -3, μ = 17.22 cm -1, F(000) = 2056, R = 0.074 with 3804 reflections used in the refinement. In the complex, each L bonds two dysprosium atoms with its two β-diketone groups. Two DMF solvent molecules bond to each dysprosium ion. The coordination number of the two dysprosium ions is eight. The eight oxygen atoms around the dysprosium ion make up a distorted square antiprism coordination polyhedron. The resonance structures of coordinated β-diketonates are also discussed. Different lanthanide ions may stabilize the specific structure.

  19. Scanning Electron Microscope-Cathodoluminescence Analysis of Rare-Earth Elements in Magnets.

    Science.gov (United States)

    Imashuku, Susumu; Wagatsuma, Kazuaki; Kawai, Jun

    2016-02-01

    Scanning electron microscope-cathodoluminescence (SEM-CL) analysis was performed for neodymium-iron-boron (NdFeB) and samarium-cobalt (Sm-Co) magnets to analyze the rare-earth elements present in the magnets. We examined the advantages of SEM-CL analysis over conventional analytical methods such as SEM-energy-dispersive X-ray (EDX) spectroscopy and SEM-wavelength-dispersive X-ray (WDX) spectroscopy for elemental analysis of rare-earth elements in NdFeB magnets. Luminescence spectra of chloride compounds of elements in the magnets were measured by the SEM-CL method. Chloride compounds were obtained by the dropwise addition of hydrochloric acid on the magnets followed by drying in vacuum. Neodymium, praseodymium, terbium, and dysprosium were separately detected in the NdFeB magnets, and samarium was detected in the Sm-Co magnet by the SEM-CL method. In contrast, it was difficult to distinguish terbium and dysprosium in the NdFeB magnet with a dysprosium concentration of 1.05 wt% by conventional SEM-EDX analysis. Terbium with a concentration of 0.02 wt% in an NdFeB magnet was detected by SEM-CL analysis, but not by conventional SEM-WDX analysis. SEM-CL analysis is advantageous over conventional SEM-EDX and SEM-WDX analyses for detecting trace rare-earth elements in NdFeB magnets, particularly dysprosium and terbium.

  20. Material flow analysis of NdFeB magnets for Denmark: a comprehensive waste flow sampling and analysis approach.

    Science.gov (United States)

    Habib, Komal; Schibye, Peter Klausen; Vestbø, Andreas Peter; Dall, Ole; Wenzel, Henrik

    2014-10-21

    Neodymium-iron-boron (NdFeB) magnets have become highly desirable for modern hi-tech applications. These magnets, in general, contain two key rare earth elements (REEs), i.e., neodymium (Nd) and dysprosium (Dy), which are responsible for the very high strength of these magnets, allowing for considerable size and weight reduction in modern applications. This study aims to explore the current and future potential of a secondary supply of neodymium and dysprosium from recycling of NdFeB magnets. For this purpose, material flow analysis (MFA) has been carried out to perform the detailed mapping of stocks and flows of NdFeB magnets in Denmark. A novel element of this study is the value added to the traditionally practiced MFAs at national and/or global levels by complementing them with a comprehensive sampling and elemental analysis of NdFeB magnets, taken out from a sample of 157 different products representing 18 various product types. The results show that the current amount of neodymium and dysprosium in NdFeB magnets present in the Danish waste stream is only 3 and 0.2 Mg, respectively. However, this number is estimated to increase to 175 Mg of neodymium and 11.4 Mg of dysprosium by 2035. Nevertheless, efficient recovery of these elements from a very diverse electronic waste stream remains a logistic and economic challenge.

  1. Evidence for triaxial deformation near N=86 : Collective bands in Dy-152,Dy-153 and Ho-153

    NARCIS (Netherlands)

    Appelbe, DE; Twin, PJ; Beausang, CW; Cullen, DM; Curien, D; Duchene, G; Erturk, S; Finck, C; Haas, B; Paul, ES; Radford, DC; Rigollet, C; Smith, MB; Stezowski, O; Waddington, JC; Wilson, AN

    2002-01-01

    The N=86,87 isotopes of dysprosium and holmium have been investigated using the Eurogam II gamma-ray spectrometer. A new collective rotational band has been observed in Ho-153 and the previously observed nui(13/2) band in Dy-153 has been extended to much higher spin. Comparing these bands and

  2. Using T2-Exchange from Ln3+DOTA-Based Chelates for Contrast-Enhanced Molecular Imaging of Prostate Cancer with MRI

    Science.gov (United States)

    2016-04-01

    specific ana - tomic features or dynamic processes. The most widely used MRI contrast agents consist of various chelated forms of Gd3þ where the...Vymazal J, Holla M, Frank JA. Dysprosium-DOTA-PAMAM dendrimers as macromolecu- lar T2 contrast agents - preparation and relaxometry. Invest Radiol

  3. Preparation, Structure Characterization and Thermal Decomposition ...

    African Journals Online (AJOL)

    NJD

    The unit cell contains a dinuclear molecule of the title compound. ... The carboxylate groups are bonded to the dysprosium ions in two modes: chelating bidentate ..... 5 R.F. Wang, L.S. Li, L.P. Jin and S.Z. Lu,J. Rare Earths,1998,16, 149–152.

  4. Market Review

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Rare earth market went downward recently.Consumers worried about the continuous price falling in the following one month and were not active in the purchasing.Price of southern ion adsorption clay dropped as well,which consequently resulted in the falling of dysprosium and terbium.

  5. Strained quantum well photovoltaic energy converter

    Science.gov (United States)

    Freundlich, Alexandre (Inventor); Renaud, Philippe (Inventor); Vilela, Mauro Francisco (Inventor); Bensaoula, Abdelhak (Inventor)

    1998-01-01

    An indium phosphide photovoltaic cell is provided where one or more quantum wells are introduced between the conventional p-conductivity and n-conductivity indium phosphide layer. The approach allows the cell to convert the light over a wider range of wavelengths than a conventional single junction cell and in particular convert efficiently transparency losses of the indium phosphide conventional cell. The approach hence may be used to increase the cell current output. A method of fabrication of photovoltaic devices is provided where ternary InAsP and InGaAs alloys are used as well material in the quantum well region and results in an increase of the cell current output.

  6. Photonic crystal cavity-assisted upconversion infrared photodetector.

    Science.gov (United States)

    Gan, Xuetao; Yao, Xinwen; Shiue, Ren-Jye; Hatami, Fariba; Englund, Dirk

    2015-05-18

    We describe an upconversion infrared photodetector assisted by a gallium phosphide photonic crystal nanocavity directly coupled to a silicon photodiode. The strongly cavity-enhanced second harmonic signal radiating from the gallium phosphide membrane can thus be efficiently collected by the silicon photodiode, which promises a high photoresponsivity of the upconversion detector as 0.81 A/W with the coupled power of 1W. The integrated upconversion photodetector also functions as a compact autocorrelator with sub-ps resolution for measuring pulse width and chirp.

  7. Accidental phosphine gas poisoning with fatal myocardial dysfunction in two families.

    Science.gov (United States)

    Akhtar, Saleem; Rehman, Arshalooz; Bano, Surraya; Haque, Anwarul

    2015-05-01

    Aluminum phosphide is commonly used as a rodenticide and insecticide and is one of the most fatal poisons. The active ingredient is Phosphine gas which inhibits cytochrome oxidase and cellular oxygen utilization. The clinical symptoms are due to multiorgan involvement including cardiac toxicity which is the most common cause of mortality. Severity of clinical manifestations depends upon the amount of the gas to which a person is exposed. There is no specific antidote available. High index of suspicion and early aggressive treatment is the key to success. We report 2 cases of aluminum phosphide toxicity in 2 families due to incidental exposure after fumigation.

  8. Direct evidence for the availability of reactive, water soluble phosphorus on the early Earth. H-phosphinic acid from the Nantan meteorite.

    Science.gov (United States)

    Bryant, David E; Kee, Terence P

    2006-06-14

    Anoxic irradiation of a type IIICD iron meteorite known to contain the phosphide mineral schreibersite (Fe,Ni)3P in the presence of ethanol/water affords the reactive oxyacid H-phosphinic acid (H3PO2) as the dominant phosphorus product.

  9. Experimental observation of second-harmonic generation and diffusion inside random media

    NARCIS (Netherlands)

    Faez, Sanli; Johnson, P. M.; Mazurenko, D. A.; Lagendijk, Ad

    2009-01-01

    We have experimentally measured the distribution of the second-harmonic intensity that is generated inside a highly scattering slab of porous gallium phosphide. Two complementary techniques for determining the distribution are used. First, the spatial distribution of second-harmonic light intensity

  10. Experimental determination of the effective refractive index in strongly scattering media

    NARCIS (Netherlands)

    Gómez Rivas, J.; Gomez Rivas, J.; Hau, D.H.; Imhof, A.; Sprik, R.; Bret, B.P.J.; Johnson, P.M.; Hijmans, T.W.; Lagendijk, Aart

    2003-01-01

    Measurements of the angular-resolved-optical transmission through strongly scattering samples of porous gallium phosphide are described. Currently porous GaP is the strongest-scattering material for visible light. From these measurements the effective refractive index and the average reflectivity at

  11. All-optical signal processing at 10 GHz using a photonic crystal molecule

    Energy Technology Data Exchange (ETDEWEB)

    Combrié, Sylvain; Lehoucq, Gaëlle; Junay, Alexandra; De Rossi, Alfredo, E-mail: alfredo.derossi@thalesgroup.com [Thales Research and Technology, 1 Avenue A. Fresnel, 91767 Palaiseau (France); Malaguti, Stefania; Bellanca, Gaetano; Trillo, Stefano [Department of Engineering, Università di Ferrara, v. Saragat 1, 44122 Ferrara (Italy); Ménager, Loic [Thales Systèmes Aeroportés, 2 Av. Gay Lussac, 78851 Elancourt (France); Peter Reithmaier, Johann [Institute of Nanostructure Technologies and Analytics, CINSaT, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel (Germany)

    2013-11-04

    We report on 10 GHz operation of an all-optical gate based on an Indium Phosphide Photonic Crystal Molecule. Wavelength conversion and all-optical mixing of microwave signals are demonstrated using the 2 mW output of a mode locked diode laser. The spectral separation of the optical pump and signal is crucial in suppressing optical cross-talk.

  12. Approved quarantine treatment for Hessian fly (Diptera: Cecidomyiidae) in large-size bales and Hessian fly and cereal leaf beetle (Coleoptera: Chrysomelidae) control by bale compression

    Science.gov (United States)

    An approved quarantine treatment using bale compression (32 kg/sq cm of pressure) and phosphine fumigation (61 g/28.2 cu m) aluminum phosphide for 7 d at 20 degrees C) was determined to control Hessian fly, Mayetiola destructor (Say), in large-size, polypropylene fabric-wrapped bales exported from t...

  13. Phosphorus-based compounds for EUV multilayer optics materials

    NARCIS (Netherlands)

    Medvedev, V.V.; Yakshin, A.E.; Kruijs, van de R.W.E.; Bijkerk, F.

    2015-01-01

    We have evaluated the prospects of phosphorus-based compounds in extreme ultraviolet multilayer optics. Boron phosphide (BP) is suggested to be used as a spacer material in reflective multilayer optics operating just above the L-photoabsorption edge of P (λ ≈9.2 nm). Mo, Ag, Ru, Rh, and Pd were cons

  14. Design procedure for millimeter-wave InP DHBT stacked power amplifiers

    DEFF Research Database (Denmark)

    Squartecchia, Michele; Johansen, Tom Keinicke; Midili, Virginio

    2015-01-01

    The stacked-transistor concept for power amplifiers (PA) has been investigated in this work. Specifically, this architecture has been applied in the design of millimeter-wave monolithic microwave integrated circuits (MMICs) using indium phosphide (InP) double heterojunction bipolar transistors...

  15. Time-resolved pulse propagation in a strongly scattering material

    NARCIS (Netherlands)

    Johnson, Patrick M.; Imhof, Arnout; Bret, B.P.J.; Gomez Rivas, J.; Gomez Rivas, Jaime; Lagendijk, Aart

    2003-01-01

    Light transport in macroporous gallium phosphide, perhaps the strongest nonabsorbing scatterer of visible light, is studied using phase-sensitive femtosecond pulse interferometry. Phase statistics are measured at optical wavelengths in both reflection and transmission and compared with theory. The d

  16. Historical Perspective and Contribution of U.S. Researchers Into the Field of Self-Propagating High-Temperature Synthesis (SHS)/Combustion Synthesis (CS): Personal Reflections

    Science.gov (United States)

    2008-07-01

    Use of zirconium in thermal batteries. ............................................................................3 Figure 2. Combustion front...and (b) TEM images of Al and Ni nanoreactants, (c) reaction chamber, (d) SEM image of nanosize nickel aluminide-alumina composite prepared by...silicides, sulfides, phosphides, hydrides, and oxides of many elements as well as intermetallics, composites, nonstoichiometric compounds, and solid

  17. Ternary Pd-Ni-P hybrid electrocatalysts derived from Pd-Ni core-shell nanoparticles with enhanced formic acid oxidation activity.

    Science.gov (United States)

    Liang, Xin; Liu, Bo; Zhang, Juntao; Lu, Siqi; Zhuang, Zhongbin

    2016-09-25

    Ternary Pd-Ni-P hybrid electrocatalysts were synthesized through low temperature phosphidation of Pd-Ni core-shell nanoparticles. They show enhanced formic acid electro-oxidation activity compared to Pd, Pd-Ni and Pd-P nanoparticles, which is ascribed to the synergistic effect of the Ni and P components with Pd.

  18. Widely available active sites on Ni2P for electrochemical hydrogen evolution - insights from first principles calculations

    DEFF Research Database (Denmark)

    Hansen, Martin Hangaard; Stern, Lucas-Alexandre; Feng, Ligang;

    2015-01-01

    We present insights into the mechanism and the active site for hydrogen evolution on nickel phosphide (Ni2P). Ni2P was recently discovered to be a very active non-precious hydrogen evolution catalyst. Current literature attributes the activity of Ni2P to a particular site on the (0001) facet. In ...

  19. Spatial Extent of Random Laser Modes

    NARCIS (Netherlands)

    Molen, van der Karen L.; Tjerkstra, R. Willem; Mosk, Allard P.; Lagendijk, Ad

    2007-01-01

    We have experimentally studied the distribution of the spatial extent of modes and the crossover from essentially single-mode to distinctly multimode behavior inside a porous gallium phosphide random laser. This system serves as a paragon for random lasers due to its exemplary high index contrast. I

  20. High quantum efficiency GaP avalanche photodiodes.

    Science.gov (United States)

    McIntosh, Dion; Zhou, Qiugui; Chen, Yaojia; Campbell, Joe C

    2011-09-26

    Gallium Phosphide (GaP) reach-through avalanche photodiodes (APDs) are reported. The APDs exhibited dark current less than a pico-ampere at unity gain. A quantum efficiency of 70% was achieved with a recessed window structure; this is almost two times higher than previous work. © 2011 Optical Society of America

  1. InP-based two-dimensional photonic crystals filled with polymers

    NARCIS (Netherlands)

    Van der Heijden, R.; Carlström, C.F.; Snijders, J.A.P.; Van der Heijden, R.W.; Karouta, F.; Nötzel, R.; Salemink, H.W.M.; Kjellander, B.K.C.; Bastiaansen, C.W.M.; Broer, D.J.; Van der Drift, E.

    2006-01-01

    Polymer filling of the air holes of indium-phosphide-based two-dimensional photonic crystals is reported. After infiltration of the holes with a liquid monomer and solidification of the infill in situ by thermal polymerization, complete filling is proven using scanning electron microscopy. Optical t

  2. Discovery of Possible Meteoritic Matter on Shatter Cones and Slickensides — 1. Ries Crater, Southern Germnay

    Science.gov (United States)

    Buchner, E.; Schmieder, M.

    2016-08-01

    In the frame of the “Shatter Cone Coatings Project”, we investigated shatter cones and slickensides from the Ries crater that locally contain high concentrations of Fe, Ni, P, and particles of Fe-Ni-Co metal and metal oxide, and of Fe-Ni phosphide.

  3. Improved fumigation process for stored foodstuffs by using phosphine in sealed chambers.

    Science.gov (United States)

    Formato, Andrea; Naviglio, Daniele; Pucillo, Gian Pio; Nota, Giorgio

    2012-01-11

    In this paper we present an innovative device designed and constructed to improve the fumigation process for stored foodstuffs with the use of phosphine gas in sealed chambers. The device allowed a considerable reduction in phosphine production time (from about 5 to 7 days for traditional systems to 2 days for the equipment considered), maintaining the system below the inflammability threshold, and at the same time achieving the total exhaustion of aluminum (or magnesium) phosphide so as to avoid toxic residues at the end of the process. With the standard device currently available on the market, after the normal 5-7 day fumigating period, the powder residue contains as much as 1-2% (w/w) of phosphide. Thus the residues, according to current legislation, have to be considered toxic and harmful. To overcome this disadvantage, appropriate modifications were made to the cylindrical tray used for the fumigation process: a nebulizer was installed, which has the function of increasing the moisture of the air spreading around the phosphide pellets and allowing a more rapid reaction with phosphide. Moreover, the cylindrical tray was also heated by means of an electrical resistance, and temperature was checked by a thermostat, so as to always obtain the same efficiency, independently of outside temperature, for both hot and cold periods, since reaction speed depends on the system temperature considered. In addition, a control device for air saturation allows condensation processes to be avoided. Using the modified cylindrical tray we performed tests to determine the best values of humidity and temperature for the process concerned, avoiding phosphine concentrations that might result in a fire hazard, and the remixing of phosphide pellets inside the cylindrical tray. Our experimental data allowed us to obtain a mathematical model used to gain an insight into the process in question.

  4. Rague-Like FeP Nanocrystal Assembly on Carbon Cloth: An Exceptionally Efficient and Stable Cathode for Hydrogen Evolution

    KAUST Repository

    Yang, Xiulin

    2015-05-25

    There is a strong demand to replace expensive Pt catalysts with cheap metal sulfides or phosphides for hydrogen generation in water electrolysis. The earth-abundant Fe can be electroplated on carbon cloth (CC) to form high surface area rague-like FeOOH assembly. Subsequent gas phase phosphidation converts the FeOOH to FeP or FeP2 and the morphology of the crystal assembly is controlled by the phosphidation temperature. The FeP prepared at 250 oC presents lower crystallinity and those prepared at higher temperatures 400 oC and 500 oC possess higher crystallinity but lower surface area. The phosphidation at 300 oC produces nanocrystalline FeP and preserves the high-surface area morphology; thus it exhibits the highest HER efficiency in 0.5 M H2SO4; i.e. the required overpotential to reach 10 and 20 mA/cm2 is 34 and 43 mV respectively. These values are lowest among the reported non-precious metal phosphides on CC. The Tafel slope for the FeP prepared at 300 oC is around 29.2 mV/dec comparable to that of Pt/CC, indicating that the hydrogen evolution for our best FeP is limited by Tafel reaction (same as Pt). Importantly, the FeP/CC catalyst exhibits much better stability in a wide range working current density (up to 1 V/cm2), suggesting that it is a promising replacement of Pt for HER.

  5. Material Flow Analysis of NdFeB magnets for Denmark: A comprehensive waste flow sampling and analysis approach

    DEFF Research Database (Denmark)

    Habib, Komal; Schibye, Peter Klausen; Vestbø, Andreas Peter

    2014-01-01

    Neodymium-iron-boron (NdFeB) magnets have become highly desirable for modern hi-tech applications. These magnets, in general, contain two key Rare Earth Elements (REEs) i.e. neodymium (Nd) and dysprosium (Dy), which are responsible for the very high strength of these magnets allowing for consider......Neodymium-iron-boron (NdFeB) magnets have become highly desirable for modern hi-tech applications. These magnets, in general, contain two key Rare Earth Elements (REEs) i.e. neodymium (Nd) and dysprosium (Dy), which are responsible for the very high strength of these magnets allowing...... of stocks and flows of NdFeB magnets in Denmark. A novel element of this study is the value added to the traditionally practiced MFAs at national and/or global level by complementing them with a comprehensive sampling and elemental analysis of NdFeB magnets, taken out from a sample of 157 different products...

  6. Magnetic Properties of the Dy1-xUxCo3 System

    Science.gov (United States)

    Lupşa, Ileana; Petrişor, T.; Balasz-Mureşan, I.

    The magnetic properties of Dy1-xUxCo3 system were investigated in the 4.3-1150 K temperature range and magnetic field up to 120 kOe. The crystalline structure is rhombohedral of PuNi3 type. For x≤0.8, the samples exhibit a ferrimagnetic behavior. The uranium substitution for dysprosium leads to the decreasing of the exchange field and the reducing of the magnetization and the transition temperatures. The Co mean moments (1.9μB/Co for x=0) opposite to the dysprosium ones and the mean effective Co moments (3.75μB/Co for x=0) are gradually decreasing as Dy is replaced by uranium.

  7. Tetraanionic biphenyl lanthanide complexes as single-molecule magnets.

    Science.gov (United States)

    Huang, Wenliang; Le Roy, Jennifer J; Khan, Saeed I; Ungur, Liviu; Murugesu, Muralee; Diaconescu, Paula L

    2015-03-02

    Inverse sandwich biphenyl complexes [(NN(TBS))Ln]2(μ-biphenyl)[K(solvent)]2 [NN(TBS) = 1,1'-fc(NSi(t)BuMe2)2; Ln = Gd, Dy, Er; solvent = Et2O, toluene; 18-crown-6], containing a quadruply reduced biphenyl ligand, were synthesized and their magnetic properties measured. One of the dysprosium biphenyl complexes was found to exhibit antiferromagnetic coupling and single-molecule-magnet behavior with Ueff of 34 K under zero applied field. The solvent coordinated to potassium affected drastically the nature of the magnetic interaction, with the other dysprosium complex showing ferromagnetic coupling. Ab initio calculations were performed to understand the nature of magnetic coupling between the two lanthanide ions bridged by the anionic arene ligand and the origin of single-molecule-magnet behavior.

  8. Spectroscopy of Neutron-Rich $^{168,170}$Dy: Yrast Band Evolution Close to the $N_{p}N_{n}$ Valence Maximum

    CERN Document Server

    Söderström, P A; Regan, P H; Algora, A; de Angelis, G; Ashley, S F; Aydin, S; Bazzacco, D; Casperson, R J; Catford, W N; Cederkäll, J; Chapman, R; Corradi, L; Fahlander, C; Farnea, E; Fioretto, E; Freeman, S J; Gadea, A; Gelletly, W; Gottardo, A; Grodner, E; He, C Y; Jones, G A; Keyes, K; Labiche, M; Liang, X; Liu, Z; Lunardi, S; Muarginean, N; Mason, P; Menegazzo, R; Mengoni, D; Montagnoli, G; Napoli, D; Ollier, J; Pietri, S; Podolyák, Z; Pollarolo, G; Recchia, F; Şahin, E; Scarlassara, F; Silvestri, R; Smith, J F; Spohr, K M; Steer, S J; Stefanini, A M; Szilner, S; Thompson, N J; Tveten, G M; Ur, C A; Valiente-Dobón, J J; Werner, V; Williams, S J; Xu, F R; Zhu, J Y

    2010-01-01

    The yrast sequence of the neutron-rich dysprosium isotope Dy-168 has been studied using multi-nucleon transfer reactions following the collision of a 460-MeV Se-82 beam and a Er-170 target. The reaction products were identified using the PRISMA magnetic spectrometer and the gamma rays detected using the CLARA HPGe-detector array. The 2+ and 4+ members of the previously measured ground state rotational band of Dy-168 was confirmed and the yrast band extended up to 10+. A tentative candidate for the 4+ to 2+ transition in Dy-170 was also identified. The data on this and lighter even-even dysprosium isotopes are interpreted in terms of Total Routhian Surface calculations and the evolution of collectivity approaching the proton-neutron valence product maximum is discussed.

  9. Development of a coprecipitation system for the speciation/preconcentration of chromium in tap waters

    Energy Technology Data Exchange (ETDEWEB)

    Karatepe, Aslihan, E-mail: karatepea@gmail.com [Nevsehir University, Faculty of Science and Arts, Department of Chemistry, 50000 Nevsehir (Turkey); Korkmaz, Esra [Bozok University, Faculty of Science and Arts, Department of Chemistry, Yozgat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey); Elci, Latif [Pamukkale University, Faculty of Science and Arts, Department of Chemistry, 20020 Denizli (Turkey)

    2010-01-15

    A method for the speciation of chromium(III), chromium(VI) and determination of total chromium based on coprecipitation of chromium(III) with dysprosium hydroxide has been investigated and applied to tap water samples. Chromium(III) was quantitatively recovered by the presented method, while the recovery values for chromium(VI) was below 10%. The influences of analytical parameters including amount of dysprosium(III), pH, centrifugation speed and sample volume for the quantitative precipitation were examined. No interferic effects were observed from alkali, earth alkali and some transition metals for the analyte ions. The detection limits (k = 3, N = 15) were 0.65 {mu}g/L for chromium(III) and 0.78 {mu}g/L for chromium(VI). The validation of the presented method was checked by the analysis of certified reference materials.

  10. Development of bulk metallic glasses based on the Dy-Al binary eutectic composition

    Institute of Scientific and Technical Information of China (English)

    LUO Lin; TIAN Rui; XIAO Xueshan

    2008-01-01

    A series of dysprosium-based ternary, quadruple, and quintuple bulk metallic glasses (BMGs) based on Dy-Al binary eutectic compo-sition were obtained with the partial substitution of Co, Gd, and Ni elements, for dysprosium. The results showed that the Dy31Gd25Co20Al24 alloy, which had the best glass forming ability (GFA), could be cast into an amorphous rod with a diameter of 5 mm. The GFA of alloys was evaluated on the basis of the supercooled liquid region width, γ parameter, the formation enthalpy, and the equivalent electronegativity difference of amor-phous alloys. It was found that the eutectic composition was closely correlated with the GFA of the Dy-based BMGs.

  11. Dysprosium carbide iodides Dy{sub 10}(C{sub 2}){sub 2}I{sub 18}, Dy{sub 4}(C{sub 2})I{sub 6} and Dy{sub 12}(C{sub 2}){sub 3}I{sub 17}; Dysprosiumcarbidiodide Dy{sub 10}(C{sub 2}){sub 2}I{sub 18}, Dy{sub 4}(C{sub 2})I{sub 6} und Dy{sub 12}(C{sub 2}){sub 3}I{sub 17}

    Energy Technology Data Exchange (ETDEWEB)

    Mattausch, H.; Hoch, C.; Simon, A. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2007-02-15

    The title compounds are formed by reaction of DyI{sub 3}, Dy metal and C in stoichiometric amounts in closed Ta ampoules, Dy{sub 10}(C{sub 2}){sub 2}I{sub 18} at 930 C for 7 days, Dy{sub 4}(C{sub 2})I{sub 6} at 950 C for 6 days and Dy{sub 12}(C{sub 2}){sub 3}I{sub 17} at 900 C for 11 days as pure samples according to X-ray powder diffraction. Dy{sub 10}(C{sub 2}){sub 2}I{sub 18} crystallizes in space group P2{sub 1}/c with a = 10.470(2), b = 17.152(3), c = 13.983(3) Aa and {beta} = 121.14(3) , Dy{sub 4}(C{sub 2})I{sub 6} in Pnnm with a = 13.622(3), b = 14.335(3) and c = 8.396(2) Aa, and Dy{sub 12}(C{sub 2}){sub 3}I{sub 17} in C2/c with a = 19.149(4), b = 12.069(2), c = 18.595(4) Aa, and {beta} = 90.54(3) . The crystal structure of Dy{sub 10}(C{sub 2}){sub 2}I{sub 18} is composed of Dy double octahedra centered by (C{sub 2}){sup 6-} groups (ethanide) with the iodide ions above the edges and the corners of the Dy{sub 10}(C{sub 2}){sub 2} units. In Dy{sub 4}(C{sub 2})I{sub 6} the Dy atoms form chains of trans-edge sharing octahedra with embedded (C{sub 2}) groups. In the structure of Dy{sub 12}(C{sub 2}){sub 3}I{sub 17} alternately cis-, trans-edge-condensed Dy{sub 6} octahedra centered by (C{sub 2}) groups occur. The iodine atoms surround the chains like in the M{sub 6}X{sub 12} cluster and interconnect neighboring chains. (orig.)

  12. Concepts for using trapped-flux bulk high-temperature superconductor in motors and generators

    Science.gov (United States)

    Hull, John R.; Strasik, Michael

    2010-12-01

    We review previous concepts for using bulk high-temperature superconductors (HTSs) in motors and generators and discuss methods for using trapped-flux (TF) HTSs in motors and generators that have been recently investigated in our laboratory. We examine the expected performance of a brushless motor/generator that uses TF bulk HTSs to provide magnetomotive force, where the stator windings are used to create the TF. A key feature is the use of dysprosium for the stator and rotor cores.

  13. Concepts for using trapped-flux HTS in motors and generators

    Science.gov (United States)

    Hull, John R.; Strasik, Michael

    2013-01-01

    We examine the expected performance of a brushless motor/generator that uses trapped-flux (TF) bulk high-temperature superconductors (HTSs) to provide magnetomotive force, where the stator windings are used to create the TF. A key feature is the use of dysprosium (Dy) for the stator and rotor cores. We also examine methods to energize TF in HTS for generators used in pulsed-power applications.

  14. Concepts for using trapped-flux bulk high-temperature superconductor in motors and generators

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R; Strasik, Michael [Boeing Research and Technology, PO Box 3707, MC 2T-50, Seattle, WA 98124-2207 (United States)

    2010-12-15

    We review previous concepts for using bulk high-temperature superconductors (HTSs) in motors and generators and discuss methods for using trapped-flux (TF) HTSs in motors and generators that have been recently investigated in our laboratory. We examine the expected performance of a brushless motor/generator that uses TF bulk HTSs to provide magnetomotive force, where the stator windings are used to create the TF. A key feature is the use of dysprosium for the stator and rotor cores.

  15. Rare earth optogalvanic spectroscopy: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Destro, Marcelo G.; Neri, Jose W.; Rodrigues, Nicolau A.S.; Silveira, Carlos A.B.; Riva, Rudimar [Instituto de Estudos Avancados (IEAv/EFO), Sao Jose dos Campos, SP (Brazil). Div. de Fotonica]. E-mail: destro@ieav.cta.br; Victor, Alessandro R. [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil)

    2008-07-01

    The IEAv has special interest in the studies of rare earth isotope applications in laser medium and integrated optics as well as aerospace research. We are starting to work with Ytterbium, Erbium, Dysprosium and Neodymium laser selective photoionization research. This paper describes the preliminary results of emission and optogalvanic spectroscopy obtained from a Neodymium hollow cathode lamps. Furthermore these results were used to setup our laser systems to work to leads a Nd isotopes selective laser photoionization. (author)

  16. Rotating Magnetocaloric Effect in an Anisotropic Molecular Dimer.

    Science.gov (United States)

    Lorusso, Giulia; Roubeau, Olivier; Evangelisti, Marco

    2016-03-01

    In contrast to the mainstream research on molecular refrigerants that seeks magnetically isotropic molecules, we show that the magnetic anisotropy of dysprosium acetate tetrahydrate, [{Dy(OAc)3 (H2 O)2}2]⋅4 H2O (1), can be efficiently used for cooling below liquid-helium temperature. This is attained by rotating aligned single-crystal samples in a constant applied magnetic field. The envisioned advantages are fast cooling cycles and potentially compact refrigerators.

  17. Energy dependence of thermoluminescent response of CaSO{sub 4}:Dy, LiF:Mg and micro LiF:Mg,Ti in clinical beams of electrons by using different simulator objects; Dependencia energetica da resposta TL de dosimetros de CaSO{sub 4}:Dy, LiF:Mg e microLiF:Mg,Ti em feixes clinicos de eletrons utilizando diferentes objetos simuladores

    Energy Technology Data Exchange (ETDEWEB)

    Bravim, Amanda; Campos, Leticia Lucente, E-mail: abravin@ipen.b, E-mail: rsakuraba@einstein.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sakuraba, Roberto K.; Cruz, Jose Carlos da, E-mail: rsakuraba@einstein.b, E-mail: josecarlosc@einstein.b [Hospital Israelita Albert Einstein (HIAE), Sao Paulo, SP (Brazil)

    2011-10-26

    Yet not so widely applied in radiotherapy, the calcium sulfate doped with dysprosium (CaSO{sub 4}:Dy) is used in radioprotection and studies has been demonstrated its great potential for the dosimetry in radiotherapy. This work evaluates the energy dependence of the thermoluminescent answer of the CaSO{sub 4}:D, LiF:Mg,Ti (TLD-100) and micro LiF:Mg,Ti in clinical beams of electrons by using water simulators, PMMA and solid water

  18. Surface analysis of model systems: From a metal-graphite interface to an intermetallic catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Kwolek, Emma J. [Iowa State Univ., Ames, IA (United States)

    2016-10-25

    This thesis summarizes research completed on two different model systems. In the first system, we investigate the deposition of the elemental metal dysprosium on highly-oriented pyrolytic graphite (HOPG) and its resulting nucleation and growth. The goal of this research is to better understand the metal-carbon interactions that occur on HOPG and to apply those to an array of other carbon surfaces. This insight may prove beneficial to developing and using new materials for electronic applications, magnetic applications and catalysis.

  19. New Realities: Energy Security in the 2010s and Implications for the U.S. Military

    Science.gov (United States)

    2014-01-01

    of the main renewable energy technologies (RETs)—such as wind power or photovoltaics (PV)—used in electric power generation. Wind turbines , PV... turbines and e-vehicle motors, and neodymium is a light REE used in the same applications as dysprosium as well as in e-vehicle batteries. China supplies...energy sector. For example, supercomputing is a key component to seismic analysis; refineries are increasingly driven by Supervisory Control and Data

  20. Properties of strongly dipolar Bose gases beyond the Born approximation

    CERN Document Server

    Ołdziejewski, Rafał

    2016-01-01

    Strongly dipolar Bose gases can form liquid droplets stabilized by quantum fluctuations. In theoretical description of this phenomenon, low energy scattering amplitude is utilized as an effective potential. We show that for magnetic atoms corrections with respect to Born approximation arise, and derive modified pseudopotential using realistic interaction model. We discuss the resulting changes in collective mode frequencies and droplet stability diagram. Our results are relevant for recent experiments with erbium and dysprosium atoms.

  1. Thermokinetics of Liquid-Liquid Reaction of Dy(NO3)3 with Histidine

    Institute of Scientific and Technical Information of China (English)

    李仲谨; 陈三平; 房艳; 高胜利

    2003-01-01

    The thermokinetics of liquid-liquid reaction of dysprosium nitrate with histidine were studied using a microcalorimeter. On the basis of experimental and calculated results, three thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), the rate constant, three kinetic parameters (the activation energy, the pre-exponential constant and the reaction order) were obtained. On the basis of thermodynamics and kinetics, the formation reaction of the complex was discussed.

  2. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Rare earth market remained weak recently. Dealings of light and heavy rare earth products were sluggish. Demand for didymium and dysprosium related products was soft and purchasers were not interested in replenishing their stocks. The market of NdFeB magnetic materials and phosphors remained inactive. Meanwhile, ceramic, catalyst and polishing powder industries were weak. Affected by global economical recession, export market of rare earth remained weak.

  3. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    November 20-30.2011 Weak demand resulted in the slack rare market. Consumers did not intend to rep earth enish inventories yet and transactions of rare earth products were stagnant. The market of didymium-related products was in the doldrums. Demand for dysprosium-related products was sluggish. Inquiries for europium oxide (99.9%) were few and dealings of the product were difficult.

  4. High Density Ion Implanted Contiguous Disk Bubble Technology.

    Science.gov (United States)

    1985-09-01

    of 0.504pm. A second melt producing films of (Sm1 2Lu 1.7Tm0 . 1( FeGa )5O1 2) was also developed for sub- micron bubbles. Data from films typical of the...Dysprosium film composition was to be (Sm0 .3 Dyl.1 Gd 0 .4Lu0 .7( FeGa ) 50 2) which would have magnetostriction coefficients of -2.8x10 6 and a mismatch of

  5. Single molecule magnet behaviour in a rare trinuclear {Cr(III)Dy} methoxo-bridged complex.

    Science.gov (United States)

    Car, Pierre-Emmanuel; Favre, Annaïck; Caneschi, Andrea; Sessoli, Roberta

    2015-09-28

    The reaction of the chromium(iii) chloride tetrahydrofuran complex with the dipivaloylmethane ligand, the lanthanide alcoholic salt DyCl3·CH3OH and the 1,1,1-tris(hydroxymethyl)-ethane ligand resulted in the formation of a new trinuclear chromium-dysprosium complex. Magnetic investigations revealed that the new 3d-4f complex exhibits single molecule magnet behaviour.

  6. Glass microspheres for medical applications

    Science.gov (United States)

    Conzone, Samuel David

    Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in 100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and a nominal crushing strength of ≈10 MPa. Finally, rhenium glass microspheres, composed of micron-sized, metallic rhenium particles dispersed within a magnesium alumino borate glass matrix were produced by sintering ReO2 powder and glass frit at 1050°C. A 50 mg injection of radioactive rhenium glass

  7. Intoxication of nontarget wildlife with rodenticides in northwestern Kansas.

    Science.gov (United States)

    Ruder, Mark G; Poppenga, Robert H; Bryan, John A; Bain, Matt; Pitman, Jim; Keel, M Kevin

    2011-01-01

    The perception of prairie dogs (Cynomys spp.) both as a nuisance species and a keystone species presents a significant challenge to land, livestock, and wildlife managers. Anticoagulant and nonanticoagulant rodenticides are commonly employed to control prairie dog populations throughout their range. Chlorophacinone, and to a lesser extent zinc phosphide, are widely used in northwestern Kansas for controlling black-tailed prairie dog (Cynomys ludovicianus) populations. Although zinc phosphide poisoning of gallinaceous birds is not uncommon, there are few published accounts of nontarget chlorophacinone poisoning of wildlife. We report three mortality events involving nontarget rodenticide poisoning in several species, including wild turkeys (Meleagris gallopavo), a raccoon (Procyon lotor), and an American badger (Taxidea taxus). This includes the first documentation of chlorophacinone intoxication in wild turkeys and an American badger in the literature. The extent of nontarget poisoning in this area is currently unknown and warrants further investigation.

  8. Schreibersite on the early Earth: Scenarios for prebiotic phosphorylation

    Directory of Open Access Journals (Sweden)

    Matthew A. Pasek

    2017-03-01

    Full Text Available The mineral schreibersite, (Fe,Ni3P, provides a reactive source of phosphorus capable of forming phosphorylated molecules. These molecules may have been an important component of prebiotic chemistry, allowing their build-up and eventual commencement of autopoiesis. Discussed here are potential geochemical routes to providing schreibersite, as a potentially important prebiotic mineral, to the Hadean Earth. Two routes are identified: delivery of phosphides by meteoritic material and the reduction of phosphates to phosphides by high-temperature, low-redox conditions. About 1–10% of all crustal phosphorus is estimated to have been in schreibersite during the Hadean, making the long-term reaction of this mineral with organic-laden water plausible for many years. Ultimately, such conditions would have been conducive to the formation of life as we know it today.

  9. Effects of growth temperature and device structure on GaP solar cells grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Vaisman, M.; Tomasulo, S.; Masuda, T.; Lang, J. R.; Faucher, J.; Lee, M. L. [Department of Electrical Engineering, Yale University, New Haven, Connecticut 06511 (United States)

    2015-02-09

    Gallium phosphide (GaP) is an attractive candidate for wide-bandgap solar cell applications, possessing the largest bandgap of the III-arsenide/phosphides without aluminum. However, GaP cells to date have exhibited poor internal quantum efficiency (IQE), even for photons absorbed by direct transitions, motivating improvements in material quality and device structure. In this work, we investigated GaP solar cells grown by molecular beam epitaxy over a range of substrate temperatures, employing a much thinner emitter than in prior work. Higher growth temperatures yielded the best solar cell characteristics, indicative of increased diffusion lengths. Furthermore, the inclusion of an AlGaP window layer improved both open-circuit voltage and short wavelength IQE.

  10. Nanophotonics for quantum optics using nitrogen-vacancy centers in diamond.

    Science.gov (United States)

    Santori, C; Barclay, P E; Fu, K-M C; Beausoleil, R G; Spillane, S; Fisch, M

    2010-07-09

    Optical microcavities and waveguides coupled to diamond are needed to enable efficient communication between quantum systems such as nitrogen-vacancy centers which are known already to have long electron spin coherence lifetimes. This paper describes recent progress in realizing microcavities with low loss and small mode volume in two hybrid systems: silica microdisks coupled to diamond nanoparticles, and gallium phosphide microdisks coupled to single-crystal diamond. A theoretical proposal for a gallium phosphide nanowire photonic crystal cavity coupled to diamond is also discussed. Comparing the two material systems, silica microdisks are easier to fabricate and test. However, at low temperature, nitrogen-vacancy centers in bulk diamond are spectrally more stable, and we expect that in the long term the bulk diamond approach will be better suited for on-chip integration of a photonic network.

  11. Metal-organic frameworks derived CoxFe1-xP nanocubes for electrochemical hydrogen evolution

    Science.gov (United States)

    Hao, Jinhui; Yang, Wenshu; Zhang, Zhe; Tang, Jilin

    2015-06-01

    Designing and developing active, cost-effective and stable electrocatalysts for hydrogen evolution reaction (HER) are still an ongoing challenge. Herein, we report the synthesis of binary transition metal phosphide (CoxFe1-xP) nanocubes with different Co and Fe ratios through a phosphidation process using metal-organic frameworks (MOFs) as templates. MOF templates contribute well-defined nanocube architectural features after phosphidation, while a suitable phosphidation temperature could allow formation of a crystal structure and maintain the well-defined structure. The incorporation of a binary transition metal results in redistribution of the valence electrons in CoxFe1-xP. The changes imply anionic states of the P and Fe atoms, which act as active sites and thus have stronger electron-donating ability. When CoxFe1-xP nanocubes are employed as electrocatalysts, these characteristic features facilitate the performance of HER. Remarkably, Co0.59Fe0.41P nanocubes prepared at 450 °C afford a current density of 10 mA cm-2 at a low overpotential of 72 mV in acidic conditions and 92 mV in alkaline conditions. Co0.59Fe0.41P nanocubes also exhibit a small Tafel slope of 52 mV decade-1 in acidic conditions and 72 mV decade-1 in alkaline conditions. Moreover, Co0.59Fe0.41P nanocubes show good stability in both acidic and alkaline conditions. Our method produces the highly active HER catalyst based on binary transition metal MOF templates, providing a new avenue for designing excellent electrocatalysts.Designing and developing active, cost-effective and stable electrocatalysts for hydrogen evolution reaction (HER) are still an ongoing challenge. Herein, we report the synthesis of binary transition metal phosphide (CoxFe1-xP) nanocubes with different Co and Fe ratios through a phosphidation process using metal-organic frameworks (MOFs) as templates. MOF templates contribute well-defined nanocube architectural features after phosphidation, while a suitable phosphidation

  12. High-Performance Rh 2 P Electrocatalyst for Efficient Water Splitting

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Haohong; Li, Dongguo; Tang, Yan; He, Yang; Ji, Shufang; Wang, Rongyue; Lv, Haifeng; Lopes, Pietro P.; Paulikas, Arvydas P.; Li, Haoyi; Mao, Scott X.; Wang, Chongmin; Markovic, Nenad M.; Li, Jun; Stamenkovic, Vojislav R.; Li, Yadong

    2017-04-05

    Search for active, stable and cost-efficient electrocatalysts for hydrogen production via water splitting could make substantial impact to the energy technologies that do not rely on fossil fuels. Here we report the synthesis of rhodium phosphide electrocatalyst with low metal loading in the form of nanocubes (NCs) dispersed in high surface area carbon (Rh2P/C) by a facile solvo-thermal approach. The Rh2P/C NCs exhibit remarkable performance for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) compared to Rh/C and Pt/C catalysts. The atomic structure of the rhodium phosphide nanocubes was directly observed by annular dark-field scanning transmission electron microscopy (ADF-STEM), which revealed phosphorous-rich outermost atomic layer. Combined experimental and computational studies suggest that surface phosphorous plays crucial role in determining the robust catalyst properties.

  13. Electrochemical Characterization of InP and GaAs Based Structures for Space Solar Cell Applications.

    Science.gov (United States)

    Faur, Maria; Faur, Mircea; Jenkins, Philip P.; Goradia, Manju; Wilt, David M.

    1994-01-01

    In this paper the emphasis is on accurate majority carrier concentration EC-V profiling of structures based on Indium Phosphide and Gallium Arsenide, using a newly developed electrolyte based on Hydrogen Flouride, Acetic Acid, Phosphoric Acid, 1-phenyl-2-propanamine and Ammonia Diflouride. Some preliminary data on the use of this electrolyte for determining the energy distribution of surface and deep states of these structures, applicable to fabrication process optimization and radiation induced defects studies of solar cells, are also provided.

  14. Superconductivity theory applied to the periodic table of the elements

    Science.gov (United States)

    Elifritz, Thomas Lee

    1995-01-01

    The modern theory of superconductivity, based upon the BCS to Bose-Einstein transition is applied to the periodic table of the elements, in order to isolate the essential features of of high temperature superconductivity and to predict its occurrence with the periodic table. It is predicted that Sodium-Ammonia, Sodium Zinc Phosphide and Bismuth (I) Iodide are promising materials for experimental explorations of high temperature superconductivity.

  15. Electrical and thermal characterization of single and multi-finger InP DHBTs

    DEFF Research Database (Denmark)

    Midili, Virginio; Nodjiadjim, V.; Johansen, Tom Keinicke

    2015-01-01

    This paper presents the characterization of single and multi-finger Indium Phosphide Double Heterojunction Bipolar transistors (InP DHBTs). It is used as the starting point for technology optimization. Safe Operating Area (SOA) and small signal AC parameters are investigated along with thermal...... characteristics. The results are presented comparing different device dimensions and number of fingers. This work gives directions towards further optimization of geometrical parameters and reduction of thermal effects....

  16. Enhancement of the Zero Phonon Line emission from a Single NV-Center in a Nanodiamond via Coupling to a Photonic Crystal Cavity

    CERN Document Server

    Wolters, Janik; Kewes, Güter; Nüsse, Nils; Schoengen, Max; Döscher, Henning; Hannappel, Thomas; öhel, Bernd L; Barth, Michael; Benson, Oliver

    2010-01-01

    Using a nanomanipulation technique a nanodiamond with a single nitrogen vacancy center is placed directly on the surface of a gallium phosphide photonic crystal cavity. A Purcell-enhancement of the fluorescence emission at the zero phonon line (ZPL) by a factor of 12.1 is observed. The ZPL coupling is a first crucial step towards future diamond-based integrated quantum optical devices.

  17. Applied solid state science advances in materials and device research

    CERN Document Server

    Wolfe, Raymond

    2013-01-01

    Applied Solid State Science: Advances in Materials and Device Research, Volume 1 presents articles about junction electroluminescence; metal-insulator-semiconductor (MIS) physics; ion implantation in semiconductors; and electron transport through insulating thin films. The book describes the basic physics of carrier injection; energy transfer and recombination mechanisms; state of the art efficiencies; and future prospects for light emitting diodes. The text then discusses solid state spectroscopy, which is the pair spectra observed in gallium phosphide photoluminescence. The extensive studies

  18. Smokes and Obscurants: A Guidebook of Environmental Assessment. Volume 2. A Sample Environmental Assessment

    Science.gov (United States)

    1987-09-04

    omnivorous. The collared lizard also eats smaller lizards in addition to insects . Seventeen common species of snakes are found at DevU’s Washbasin. They...rattlesnake (C. mitchellii) are both venomous. All of the snakes are predators, eating rodents, small birds, insects , lizards, and other snakes. A list of...corresponding phosphides. The unreacted phosphorus might also react with the alkali hydroxides in the soil to form phosphine and hypophosphites. The amount

  19. MIT Lincoln Laboratory Annual Report 2009

    Science.gov (United States)

    2009-01-01

    wavelengths to nonlinearly up-convert the THz signal to an optical signal, which is then detected using Geiger - mode avalanche photodiode detector...performance computing, imaging, and RF applications. • Lincoln Laboratory’s silicon and indium phosphide Geiger - mode avalanche photodiode (APD...ongoing and emerging work at the Laboratory. The topics of these talks included an overview of the Laboratory, Geiger - mode avalanche photodiode array

  20. Direct Observation of Early-stage Quantum Dot Growth Mechanisms with High-temperature Ab Initio Molecular Dynamics

    OpenAIRE

    2015-01-01

    Colloidal quantum dots (QDs) exhibit highly desirable size- and shape-dependent properties for applications from electronic devices to imaging. Indium phosphide QDs have emerged as a primary candidate to replace the more toxic CdSe QDs, but production of InP QDs with the desired properties lags behind other QD materials due to a poor understanding of how to tune the growth process. Using high-temperature ab initio molecular dynamics (AIMD) simulations, we report the first direct observation o...