Shock-wave compression of lithium niobate from 2.4 to 44 GPa

International Nuclear Information System (INIS)

Stanton, P.L.; Graham, R.A.

1979-01-01

Shock compression of lithium niobate above the Hugoniot elastic limit (about 2.5 GPa) reveals a succession of unusual features. Just above the Hugoniot elastic limit, the shock velocity is observed to be well below the bulk sound speed, indicative of a drastic reduction of shear strength. The shock velocity is observed to increase with particle velocity at an unusually large rate due to the reduction of strength in a very stiff material and an anomalously large pressure derivative of the bulk modulus. This later behavior may be due to the effects of localized shock heating resulting from heterogeneous shear deformation in ferroelectrics like lithium niobate and lithium tantalate in which increases in temperature are shown to have a strong effect on bulk modulus. A shock-induced polymorphic phase transition occurs at 13.9 GPa. Above the transition point the slope of the Hugoniot curve relating shock velocity and particle velocity is unusually low, indicative of a broad mixed phase region of undetermined extent. Limited work is reported on the isomorphous crystal, lithium tantalate, which exhibits features similar to lithium niobate with a Hugoniot elastic limit of 4 GPa and a phase transition in the vicinity of 19 GPa

Shock-induced luminescence from Z-cut lithium niobate

International Nuclear Information System (INIS)

Brannon, P.J.; Morris, R.W.; Asay, J.R.

1985-01-01

Shock-induced luminescence from lithium niobate has been studied in the stress range 1.6--21.0 GPa. Both fast-framing photography and five-channel optical pyrometry were used to observe the luminescence. The framing photography showed that the emission pattern is heterogeneous for stresses just above the dynamic yield point. A further increase of the stress resulted in a pattern which was essentially homogeneous to within the experimental spatial resolution of about 30 μm. Narrowband filters and photomultiplier tubes were used in the optical pyrometry experiments. A broadband spectrum with a peak near 700 nm was observed. A plot of the energy dissipated by the shock versus shock stress correlates very well with a plot of the 700-nm intensity versus shock stress. The mechanism for light emission in lithium niobate appears to be closely related to the dynamic yielding process

Photorefractive effect at 775 nm in doped lithium niobate crystals

Energy Technology Data Exchange (ETDEWEB)

Nava, G.; Minzioni, P.; Cristiani, I.; Degiorgio, V. [Department of Electrical, Computer, and Biomedical Engineering, and CNISM, University of Pavia, 27100 Pavia (Italy); Argiolas, N.; Bazzan, M.; Ciampolillo, M. V.; Pozza, G.; Sada, C. [Physics and Astronomy Departement, University of Padova, 35131 Padova (Italy)

2013-07-15

The photorefractive effect induced by 775-nm laser light on doped lithium niobate crystals is investigated by the direct observation in the far field of the transmitted-beam distortion as a function of time. Measurements performed at various Zr-doping concentrations and different light intensities show that the 775-nm light beam induces a steady-state photorefractive effect comparable to that of 532-nm light, but the observed build-up time of the photovoltaic field is longer by three-orders of magnitude. The 775-nm photorefractivity of lithium niobate crystals doped with 3 mol. % ZrO{sub 2} or with 5.5 mol. % MgO is found to be negligible.

Recharging processes, radiation induced strain and changes of OH{sup -} bands under H{sup +} ion implantation in Ti doped lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Kumar, P. [Crystal Growth Centre, Anna University, Chennai 600025, Tamil Nadu (India); Moorthy Babu, S., E-mail: smoorthybabu@yahoo.co [Crystal Growth Centre, Anna University, Chennai 600025, Tamil Nadu (India); Bhaumik, I.; Ganesamoorthy, S.; Karnal, A.K. [LMDD Division, RRCAT, Indore 452013, Madhya Pradesh (India); Kumar, Praveen; Rodrigues, G.O.; Sulania, I.; Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg 110067, New Delhi (India); Pandey, A.K.; Raman, R. [Solid State Physics Laboratory, Timarpur 110 054, New Delhi (India)

2010-01-15

A systematic analysis of variations in structural and optical characteristics of Z-cut plates of titanium doped congruent lithium niobate single crystals implanted with 120 keV proton beam at various fluences of 10{sup 15}, 10{sup 16} and 10{sup 17} protons/cm{sup 2} is presented. Through, high resolution X-ray diffraction, atomic force microscopy, Fourier transform infrared and UV-visible-NIR analysis of congruent lithium niobate, the correlation of properties before and after implantation are discussed. HRXRD (0 0 6) reflection by Triple Crystal Mode shows that both tensile and compressive strain peak are produced by the high fluence implantation. A distinct tensile peak was observed from implanted region for a fluence of 10{sup 16} protons/cm{sup 2}. AFM micrographs indicate mountain ridges, bumps and protrusions on target surface on implantation. UV-visible-NIR spectra reveal an increase in charge transfer between Ti{sup 3+}/Ti{sup 4+} and ligand oxygen for implantation with 10{sup 15} protons/cm{sup 2}, while spectra for higher fluence implanted samples show complex absorption band in the region from 380-1100 nm. Variations of OH{sup -} stretching vibration mode were observed for cLN Pure, cLNT2% virgin, and implanted samples with FTIR spectra. The concentration of OH{sup -} ion before and after implantation was calculated from integral absorption intensity. The effect of 120 keV proton implantation induced structural, surface and optical studies were correlated.

Micro- and nanostructuration of lithium niobate; Mikro- und Nanostrukturierung von Lithiumniobat

Energy Technology Data Exchange (ETDEWEB)

Hartung, Holger

2010-04-13

In the framework of this thesis the application of the ion-beam-enhanced-etching (IBEE) technique for the fabrication of different optical elements, among these photonic crystals, in lithium niobate, was studied. The development of a mask technology fitted to the requirements of the IBEE technique as well as a simulation of the process were performed. Hereby the limitations of the technique in view on minimal structure sizes and structure quality were analyzed. In chapter 1 first the material lithium niobate with its properties and the structuration procedures studied hitherto in the literature is presented. Chapter 2 presents the functionality of the IBEE process and describes the studies on the application of IBEE in lithium niobate performed in the framework of this thesis. In chapter 3 the experimental conditions of all applied processes of the IBEE procedure, the processes used for the mask fabrication, as well all further applied methods and technologies are summarized. Chapter 4 deals with the mask fabrication. The requirements on the masks and the developments necessary for their fulfilment are studied. In chapter 5 the performed simulation of the irradiation, annealing, and etching process is described. This simulation makes the prediciton of the geometry of the components from the process parameters and vice versa the determination of parameters for the reaching of an optimal element geometry possible. In chapter 6 the application of the technique for the fabrication of photonic-crystal membranes and their optical characterization is described. Chapter 7 shows the fabrication of different waveguide and diffractive elements in lithium niobate by means of IBEE.

Writing single-mode waveguides in lithium niobate by ultra-low intensity solitons

International Nuclear Information System (INIS)

Fazio, E.; Ramadan, W.; Petris, A.; Chauvet, M.; Bosco, A.; Vlad, V.I.; Bertolotti, M.

2005-01-01

Optical waveguides can be conveniently written in photorefractive materials by using spatial solitons. We have generated bright spatial solitons inside lithium niobate which allow single-mode light propagation. Efficient waveguides have been generated with CW light powers as high as few microwatts. According to the soliton formation, waveguides can be formed with different shapes. Due to the slow response time of the lithium niobate, both for soliton formation and relaxation, the soliton waveguide remains memorised for a long time, of the order of months

Optical waveguides in lithium niobate: Recent developments and applications

Energy Technology Data Exchange (ETDEWEB)

Bazzan, Marco, E-mail: marco.bazzan@unipd.it; Sada, Cinzia, E-mail: cinzia.sada@unipd.it [Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, Via Marzolo 8, 35131 Padova (Italy)

2015-12-15

The state of the art of optical waveguide fabrication in lithium niobate is reviewed, with particular emphasis on new technologies and recent applications. The attention is mainly devoted to recently developed fabrication methods, such as femtosecond laser writing, ion implantation, and smart cut waveguides as well as to the realization of waveguides with tailored functionalities, such as photorefractive or domain engineered structures. More exotic systems, such as reconfigurable and photorefractive soliton waveguides, are also considered. Classical techniques, such as Ti in-diffusion and proton exchange, are cited and briefly reviewed as a reference standpoint to highlight the recent developments. In all cases, the application-oriented point of view is preferred, in order to provide the reader with an up-to date panorama of the vast possibilities offered by lithium niobate to integrated photonics.

III-nitride integration on ferroelectric materials of lithium niobate by molecular beam epitaxy

International Nuclear Information System (INIS)

Namkoong, Gon; Lee, Kyoung-Keun; Madison, Shannon M.; Henderson, Walter; Ralph, Stephen E.; Doolittle, W. Alan

2005-01-01

Integration of III-nitride electrical devices on the ferroelectric material lithium niobate (LiNbO 3 ) has been demonstrated. As a ferroelectric material, lithium niobate has a polarization which may provide excellent control of the polarity of III-nitrides. However, while high temperature, 1000 deg. C, thermal treatments produce atomically smooth surfaces, improving adhesion of GaN epitaxial layers on lithium niobate, repolarization of the substrate in local domains occurs. These effects result in multi domains of mixed polarization in LiNbO 3 , producing inversion domains in subsequent GaN epilayers. However, it is found that AlN buffer layers suppress inversion domains of III-nitrides. Therefore, two-dimensional electron gases in AlGaN/GaN heterojunction structures are obtained. Herein, the demonstration of the monolithic integration of high power devices with ferroelectric materials presents possibilities to control LiNbO 3 modulators on compact optoelectronic/electronic chips

Gamma radiation effects on photorefractive and photoelectric properties of lithium niobate crystals

Energy Technology Data Exchange (ETDEWEB)

Vartanyan, Eh.S.; Ovsepyan, R.K.; Pogosyan, A.R.; Timofeev, A.L.

1984-08-01

Investigations into the gamma radiation effect on the photorefractive aned photoelectric properties of lithium niobate crystals have been carried out for the first time. Gamma irradiation has been found to lead to an increase in the photorefractive sensitivity. The effect of optical decoloration has been discovered for the first time along with photorelaxation currents resulting from radiation center decay under the action of light. It has been shown that an increase of photorefractive sensitivity in gamma-irradiated lithium niobate crystals is caused by a new photorefraction mechanism - photorelaxation currents.

Chemical transport of niobium(V) oxide and of lithium niobate with sulphur

International Nuclear Information System (INIS)

Schaefer, H.

1988-01-01

Niobium(V) oxide is transported by means of sulphur (calculated for 10 bar at 1223 K) from 1273 → 1173 K. The same applies for lithium niobate. Similar experiments of lithium oxide lead to turbidity of the quartz ampoule. (author)

Sub-band-gap laser micromachining of lithium niobate

DEFF Research Database (Denmark)

Christensen, F. K.; Müllenborn, Matthias

1995-01-01

method is reported which enables us to do laser processing of lithium niobate using sub-band-gap photons. Using high scan speeds, moderate power densities, and sub-band-gap photon energies results in volume removal rates in excess of 106µm3/s. This enables fast micromachining of small piezoelectric...

Ridge Waveguide Structures in Magnesium-Doped Lithium Niobate, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In this NASA Phase I STTR effort, the feasibility of fabricating isolated ridge waveguides in 5% magnesium-doped lithium niobate (5% MgO:LN) will be established....

Efficient femtosecond mid-infrared pulse generation by dispersivewave radiation in bulk lithium niobate crystal

DEFF Research Database (Denmark)

Zhou, Binbin; Guo, Hairun; Bache, Morten

2014-01-01

We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8–2.92 µm are generated using the single pump wavelengths from 1.25–1.45 µm.......We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8–2.92 µm are generated using the single pump wavelengths from 1.25–1.45 µm....

Material modifications in lithium niobate and lithium tantalate crystals by ion irradiation

International Nuclear Information System (INIS)

Raeth, Niels Lennart

2017-01-01

The artificially produced crystals lithium niobate (LiNbO 3 ) and the closely related lithium tantalate (LiTaO 3 ) are proven starting materials for producing active and passive devices that can guide, amplify, switch and process light. For this purpose, it is often necessary to be able to influence the refractive index of the substrate targeted, which is possible in addition to other methods by irradiation of the materials with fast light ions. In this work, lithium niobate and lithium tantalate crystals are irradiated with alpha particles, 3 He ions, deuterons, and protons at projectile energies of up to 14 MeV / nucleon. Energy and crystal thickness are chosen so that the projectiles penetrate the entire sample and are not implanted. All isotopes responsible for the unwanted nuclear activation of the crystals due to the irradiation are relatively short-lived and overall the activation decreases fast enough to allow the safe handling of the irradiated samples after a storage period of a few days to a few weeks. The refractive index changes produced in lithium niobate and lithium tantalate by irradiation with the different projectiles are determined interferometrically and can also be measured by suitable choice of the sample geometry as a function of the ion penetration depth: In LiNbO 3 the ordinary refractive index decreases, the extraordinary increases equally. In LiTaO 3 , both the ordinary and the extraordinary refractive indices decrease as a result of the irradiation; the ordinary refractive index change is many times stronger than the extraordinary one. There is an enormous long-term stability at room temperature for both crystal systems: Even after eleven (LiNbO 3 ) or three (LiTaO 3 ) years, no decrease in the ion beam-induced refractive index change can be observed. The ion beam-induced refractive index changes are probably the result of atomic displacements such as vacancies, defect clusters or ''latent tracks''. An explanation for

Design of multi-wavelength tunable filter based on Lithium Niobate

Science.gov (United States)

Zhang, Ailing; Yao, Yuan; Zhang, Yue; Song, Hongyun

2018-05-01

A multi-wavelength tunable filter is designed. It consists of multiple waveguides among multiple waveguide gratings. A pair of electrodes were placed on both sides of each waveguide. The tunable filter uses the electro-optic effect of Lithium Niobate to tune the phase caused by each waveguide. Consequently, the wavelength and wavelength spacing of the filter are tuned by changing external voltages added on the electrode pairs. The tunable property of the filter is analyzed by phase matching condition and transfer-matrix method. Numerical results show that not only multiple wavelengths with narrow bandwidth are tuned with nearly equal spacing by synchronously changing the voltages added on all electrode pairs, but also the number of wavelengths is determined by the number of phase shifts caused by electrode pairs. Furthermore, due to the electro-optic effect of Lithium Niobate, the tuning speed of the filter can reach the order of ns.

Structuring of material parameters in lithium niobate crystals with low-mass, high-energy ion radiation

Science.gov (United States)

Peithmann, K.; Eversheim, P.-D.; Goetze, J.; Haaks, M.; Hattermann, H.; Haubrich, S.; Hinterberger, F.; Jentjens, L.; Mader, W.; Raeth, N. L.; Schmid, H.; Zamani-Meymian, M.-R.; Maier, K.

2011-10-01

Ferroelectric lithium niobate crystals offer a great potential for applications in modern optics. To provide powerful optical components, tailoring of key material parameters, especially of the refractive index n and the ferroelectric domain landscape, is required. Irradiation of lithium niobate crystals with accelerated ions causes strong structured modifications in the material. The effects induced by low-mass, high-energy ions (such as 3He with 41 MeV, which are not implanted, but transmit through the entire crystal volume) are reviewed. Irradiation yields large changes of the refractive index Δn, improved domain engineering capability within the material along the ion track, and waveguiding structures. The periodic modification of Δn as well as the formation of periodically poled lithium niobate (PPLN) (supported by radiation damage) is described. Two-step knock-on displacement processes, 3He→Nb and 3He→O causing thermal spikes, are identified as origin for the material modifications.

Optimal design of DC-based polarization beam splitter in lithium niobate on insulator

Science.gov (United States)

Gong, Zisu; Yin, Rui; Ji, Wei; Wang, Junbao; Wu, Chonghao; Li, Xiao; Zhang, Shicheng

2017-08-01

We propose a DC-based polarization beam splitter (PBS) in lithium niobate on insulator (LNOI). Utilizing the high birefringence property of Lithium Niobate (LiNbO3, LN), the device is achieved by simple structure in a short length. With the use of beam propagation method (BPM), the simulation results show that the device has a good performance for the separation of TE and TM polarizations with a high extinction ratio (about 35 dB). The simulated fabrication tolerance for the variation of the waveguide width is about 100 nm and the bandwidth is about 65 nm when the extinction ratio is higher than 10 dB.

Tip-induced domain growth on the non-polar cuts of lithium niobate single-crystals

Science.gov (United States)

Alikin, D. O.; Ievlev, A. V.; Turygin, A. P.; Lobov, A. I.; Kalinin, S. V.; Shur, V. Ya.

2015-05-01

Currently, ferroelectric materials with designed domain structures are considered as a perspective material for new generation of photonic, data storage, and data processing devices. Application of external electric field is the most convenient way of the domain structure formation. Lots of papers are devoted to the investigation of domain kinetics on polar surface of crystals while the forward growth remains one of the most mysterious stages due to lack of experimental methods allowing to study it. Here, we performed tip-induced polarization reversal on X- and Y-non-polar cuts in single-crystal of congruent lithium niobate which allows us to study the forward growth with high spatial resolution. The revealed difference in the shape and length of domains induced on X- and Y-cuts is beyond previously developed theoretical approaches used for the theoretical consideration of the domains growth at non-polar ferroelectric surfaces. To explain experimental results, we used kinetic approach with anisotropy of screening efficiency along different crystallographic directions.

Temperature dependence of the thermoelectric coeffiicients of lithium niobate and lithium tantalate

International Nuclear Information System (INIS)

Khachaturyan, O.A.; Gabrielyan, A.I.; Kolesnik, S.P.

1988-01-01

Thermoelectric Zeebeck,Thomson, Peltier coefficients for LiNbO 3 and LiTaO 3 monocrystals and their dependence on temperature in 300-1400 K range were investigated. It is shown that Zeebeck (α) coefficient changes its sign, depending on temperature change - the higher is α, the higher is material conductivity in the corresponding temperature region. Thomson and Peltier coefficients were calculated analytically for lithium niobate and tantalate

All-optical switching in lithium niobate directional couplers with cascaded nonlinearity

NARCIS (Netherlands)

Schiek, R.; Baek, Y.; Krijnen, Gijsbertus J.M.; Stegeman, G.I.; Baumann, I.; Sohler, W.

1996-01-01

We report on intensity-dependent switching in lithium niobate directional couplers. Large nonlinear phase shifts that are due to cascading detune the coupling between the coupler branches, which makes all-optical switching possible. Depending on the input intensity, the output could be switched

Photoluminescence of Copper-Doped Lithium Niobate Crystals

Science.gov (United States)

Gorelik, V. S.; Pyatyshev, A. Yu.; Sidorov, N. V.

2018-05-01

The photoluminescence (PL) of copper-doped lithium niobate single crystals is studied using different UV-Vis light-emitting diodes and a pulse-periodic laser with a wavelength of 266 nm as excitation radiation sources. With the resonance excitation from a 527-nm light-emitting diode, the intensity of PL increases sharply (by two orders of magnitude). When using a 467-nm light-emitting diode for excitation, the PL spectrum is characterized by the presence of multiphonon lines in the range of 520-620 nm.

Tunable dual-wavelength filter and its group delay dispersion in domain-engineered lithium niobate

Directory of Open Access Journals (Sweden)

Guang-hao Shao

2016-12-01

Full Text Available A tunable dual-wavelength filter is experimentally demonstrated in domain-engineered lithium niobate. Application of an electric field on the y-surfaces of the sample results in the optical axes rotating clockwise and anticlockwise, which makes selective polarization rotation. The quasi phase-matching wavelengths could be adjusted through suitable domain design. A unique dual valley spectrum is obtained in a periodically poled lithium niobate structure with a central defect if the sample is placed between two parallel polarizers. The expected bandwidth could be varied from ∼1 nm to ∼40 nm. Moreover, both the spectral response and group delay dispersion could be engineered.

Monolithic acoustic graphene transistors based on lithium niobate thin film

Science.gov (United States)

Liang, J.; Liu, B.-H.; Zhang, H.-X.; Zhang, H.; Zhang, M.-L.; Zhang, D.-H.; Pang, W.

2018-05-01

This paper introduces an on-chip acoustic graphene transistor based on lithium niobate thin film. The graphene transistor is embedded in a microelectromechanical systems (MEMS) acoustic wave device, and surface acoustic waves generated by the resonator induce a macroscopic current in the graphene due to the acousto-electric (AE) effect. The acoustic resonator and the graphene share the lithium niobate film, and a gate voltage is applied through the back side of the silicon substrate. The AE current induced by the Rayleigh and Sezawa modes was investigated, and the transistor outputs a larger current in the Rayleigh mode because of a larger coupling to velocity ratio. The output current increases linearly with the input radiofrequency power and can be effectively modulated by the gate voltage. The acoustic graphene transistor realized a five-fold enhancement in the output current at an optimum gate voltage, outperforming its counterpart with a DC input. The acoustic graphene transistor demonstrates a paradigm for more-than-Moore technology. By combining the benefits of MEMS and graphene circuits, it opens an avenue for various system-on-chip applications.

Annealed proton exchanged optical waveguides in lithium niobate differences between the X- and Z-cuts

CERN Document Server

Nekvindova, P; Cervena, J; Budnar, M; Razpet, A; Zorko, B; Pelicon, P; 10.1016/S0925-3467(01)00186-0

2002-01-01

Summarizes results and assessments of our systematic fabrication and characterization of proton exchanged (PE) and annealed proton exchanged (APE) waveguides in lithium niobate. This study focused on different behavior of crystallographically diverse X(1120) and Z (0001) substrate cuts during waveguide fabrication, and differences in characteristics of the resulting waveguides. Non-toxic adipic acid was used as a proton source, and the waveguides properties were defined by mode spectroscopy (waveguide characteristics) and neutron depth profiling (NDP, lithium concentration and distribution), infrared vibration spectra and elastic recoil detection analysis (ERDA, concentration and depth distribution of hydrogen). It was discovered that the X-cut structure is more permeable for moving particles (lithium and hydrogen ions), which leads to a higher effectiveness of the PE process within the X-cut. The explanation of this phenomenon is based on fitting X-cut orientation towards cleavage planes of lithium niobate c...

Shape manipulation of ion irradiated Ag nanoparticles embedded in lithium niobate

International Nuclear Information System (INIS)

Wolf, Steffen; Rensberg, Jura; Johannes, Andreas; Ronning, Carsten; Thomae, Rainer; Smit, Frederick; Neveling, Retief; Bharuth-Ram, Krish; Moodley, Mathew; Bierschenk, Thomas; Rodriguez, Matias; Afra, Boshra; Ridgway, Mark; Hasan, Shakeeb Bin; Rockstuhl, Carsten

2016-01-01

Spherical silver nanoparticles were prepared by means of ion beam synthesis in lithium niobate. The embedded nanoparticles were then irradiated with energetic "8"4Kr and "1"9"7Au ions, resulting in different electronic energy losses between 8.1 and 27.5 keV nm"−"1 in the top layer of the samples. Due to the high electronic energy losses of the irradiating ions, molten ion tracks are formed inside the lithium niobate in which the elongated Ag nanoparticles are formed. This process is strongly dependent on the initial particle size and leads to a broad aspect ratio distribution. Extinction spectra of the samples feature the extinction maximum with shoulders on either side. While the maximum is caused by numerous remaining spherical nanoparticles, the shoulders can be attributed to elongated particles. The latter could be verified by COMSOL simulations. The extinction spectra are thus a superposition of the spectra of all individual particles. (paper)

Near-field-optical-microscopy studies of micro-modifications caused by femtosecond laser irradiation in lithium niobate crystals

International Nuclear Information System (INIS)

Lamela, J.; Jaque, D.; Rodenas, A.; Jaque, F.; Torchia, G.A.; Vazquez, J.R.; Mendez, C.; Roso, L.

2008-01-01

Near-field-optical-microscopy has been used to study the micro-modifications caused by femtosecond laser pulses focused at the surface and in the volume of lithium niobate crystals. We have found experimental evidence of the existence, close to femtosecond ablation craters, of periodic modifications in the surface reflectivity. In addition, the potential application of near-field-optical microscopy for the spatial location of permanent modifications caused by femtosecond pulses focused inside lithium niobate crystals has been also demonstrated. (orig.)

Li Storage of Calcium Niobates for Lithium Ion Batteries.

Science.gov (United States)

Yim, Haena; Yu, Seung-Ho; Yoo, So Yeon; Sung, Yung-Eun; Choi, Ji-Won

2015-10-01

New types of niobates negative electrode were studied for using in lithium-ion batteries in order to alternate metallic lithium anodes. The potassium intercalated compound KCa2Nb3O10 and proton intercalated compound HCa2Nb3O10 were studied, and the electrochemical results showed a reversible cyclic voltammetry profile with acceptable discharge capacity. The as-prepared KCa2Nb3O10 negative electrode had a low discharge capacity caused by high overpotential, but the reversible intercalation and deintercalation reaction of lithium ions was activated after exchanging H+ ions for intercalated K+ ions. The initial discharge capacity of HCa2Nb3O10 was 54.2 mAh/g with 92.1% of coulombic efficiency, compared with 10.4 mAh/g with 70.2% of coulombic efficiency for KCa2Nb3O10 at 1 C rate. The improved electrochemical performance of the HCa2Nb3O10 was related to the lower bonding energy between proton cation and perovskite layer, which facilitate Li+ ions intercalating into the cation site, unlike potassium cation and perovskite layer. Also, this negative material can be easily exfoliated to Ca2Nb3O10 layer by using cation exchange process. Then, obtained two-dimensional nanosheets layer, which recently expected to be an advanced electrode material because of its flexibility, chemical stable, and thin film fabricable, can allow Li+ ions to diffuse between the each perovskite layer. Therefore, this new type layered perovskite niobates can be used not only bulk-type lithium ion batteries but also thin film batteries as a negative material.

Design considerations for quasi-phase-matching in doubly resonant lithium niobate hexagonal microresonators

CSIR Research Space (South Africa)

Sono, Tleyane J

2017-08-01

Full Text Available Fabrication capabilities of high optical quality hexagonal superstructures by chemical etching of inverted ferroelectric domains in lithium niobate platform suggests a route for efficient implementation of compact hexagonal microcavities...

Influence of UV light and heat on the ferroelectric properties of lithium niobate crystals

Energy Technology Data Exchange (ETDEWEB)

Steigerwald, Hendrik

2011-08-15

One of the most important non-linear-optical materials is lithium niobate, due to its ease of fabrication, robustness, transparency in the visible-to-infrared and excellent nonlinear properties. In this thesis the issue of tailoring ferroelectric domain structures in lithium niobate crystals is approached from two sides: interaction of defect structures inside the crystal with growing ferroelectric domains is investigated and also actual domain patterning on all crystal faces by different methods is performed. Special emphasis is given to the Mg-doped material. The fundamental understanding and the methods of domain patterning developed in this thesis are then used to obtain tailored domain structures that meet the requirements of their intended application in non-linear optics. (orig.)

UV laser-assisted fabrication of ridge waveguides in lithium niobate crystals

OpenAIRE

Sones, C.L.; Ying, C.Y.J.; Eason, R.W.; Mailis, S.; Ganguly, P.; Soergel, E.

2010-01-01

We present a UV laser-assisted method for the fabrication of ridge waveguides in lithium niobate. The UV laser irradiation step provides the refractive index change required for the vertical light confinement in the waveguide and also defines the ferroelectric domain pattern which produces the ridge structures after chemical etching.

Shape manipulation of ion irradiated Ag nanoparticles embedded in lithium niobate

NARCIS (Netherlands)

Wolf, S.; Rensberg, J.; Johannes, A.; Thomae, R.; Smit, F.; Neveling, R.; Moodley, M.; Bierschenk, T.; Rodriquez, M.; Afra, B.; Hasan, Shakeeb Bin; Rockstuhl, C.; Ridgway, M.; Bharuth-Ram, K.; Ronning, C.

2016-01-01

Spherical silver nanoparticles were prepared by means of ion beam synthesis in lithium niobate. The embedded nanoparticles were then irradiated with energetic 84Kr and 197Au ions, resulting in different electronic energy losses between 8.1 and 27.5 keV nm−1 in the top layer of the samples. Due to

Erbium medium temperature localised doping into lithium niobate and sapphire: A comparative study

Czech Academy of Sciences Publication Activity Database

Nekvindová, P.; Macková, Anna; Peřina, Vratislav; Červená, Jarmila; Čapek, P.; Schrofel, J.; Špirková, J.; Oswald, Jiří

90-91, - (2003), s. 559-564 ISSN 1012-0394 Institutional research plan: CEZ:AV0Z1048901 Keywords : lithium niobate * sapphire * erbium Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.687, year: 2003

Pyroelectric field assisted ion migration induced by ultraviolet laser irradiation and its impact on ferroelectric domain inversion in lithium niobate crystals

International Nuclear Information System (INIS)

Ying, C. Y. J.; Mailis, S.; Daniell, G. J.; Steigerwald, H.; Soergel, E.

2013-01-01

The impact of UV laser irradiation on the distribution of lithium ions in ferroelectric lithium niobate single crystals has been numerically modelled. Strongly absorbed UV radiation at wavelengths of 244–305 nm produces steep temperature gradients which cause lithium ions to migrate and result in a local variation of the lithium concentration. In addition to the diffusion, here the pyroelectric effect is also taken into account which predicts a complex distribution of lithium concentration along the c-axis of the crystal: two separated lithium deficient regions on the surface and in depth. The modelling on the local lithium concentration and the subsequent variation of the coercive field are used to explain experimental results on the domain inversion of such UV treated lithium niobate crystals

Acoustically determined linear piezoelectric response of lithium niobate up to 1100 V

Energy Technology Data Exchange (ETDEWEB)

Patel, N. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87106 (United States); Branch, D. W.; Cular, S. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Schamiloglu, E. [Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87106 (United States)

2014-04-21

We present a method to measure high voltages using the piezoelectric crystal lithium niobate without using voltage dividers. A 36° Y-X cut lithium niobate crystal was coupled to two acoustic transducers, where direct current voltages were applied from 128–1100 V. The time-of-flight through the crystal was determined to be linearly dependent on the applied voltage. A model was developed to predict the time-delay in response to the applied voltage. The results show a sensitivity of 17 fs/V with a measurement error of 1 fs/V was achievable using this method. The sensitivity of this method can be increased by measuring the acoustic wave after multiple passes through the crystal. This method has many advantages over traditional techniques such as: favorable scalability for larger voltages, ease of use, cost effectiveness, and compactness.

Propagation of light in the lithium niobate crystal along directions close to an optical axis

International Nuclear Information System (INIS)

Volkov, V.V.; Egorova, G.A.; Lonskij, Eh.S.; Potapov, E.V.; Rakov, A.V.

1978-01-01

Theoretical and experimental results are given of studying some characteristics of electrooptical modulator from lithium niobate when propagating in it linear-polarized light in directions close to the optical axis, the electric field being applied along the X axis. It has been shown that an increase in an angle of deviation from the optical axis of a light beam passing in the crystal changes the value of the controlling voltage. This is accompanied by the rotation of the polarization plane and the change in the intensity of the light being passed. The methods have been proposed of increasing the modulator aperture, determining the main refraction indices and some electrooptical coefficients fo the lithium niobate crystal

Erbium ion implantation into different crystallographic cuts of lithium niobate

Czech Academy of Sciences Publication Activity Database

Nekvindová, P.; Švecová, B.; Cajzl, J.; Macková, Anna; Malinský, Petr; Oswald, Jiří; Kolitsch, A.; Špirková, J.

2012-01-01

Roč. 34, č. 4 (2012), s. 652-659 ISSN 0925-3467 R&D Projects: GA MŠk(CZ) LC06041; GA ČR GA106/09/0125; GA ČR(CZ) GAP106/10/1477 Institutional research plan: CEZ:AV0Z10480505; CEZ:AV0Z10100521 Keywords : Lithium niobate * Erbium * Ion implantation * Luminescence Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.918, year: 2012

Periodic domain inversion in x-cut single-crystal lithium niobate thin film

Energy Technology Data Exchange (ETDEWEB)

Mackwitz, P., E-mail: peterm@mail.upb.de; Rüsing, M.; Berth, G.; Zrenner, A. [Department Physik, Universität Paderborn, 33095 Paderborn (Germany); Center for Optoelectronics and Photonics Paderborn, 33095 Paderborn (Germany); Widhalm, A.; Müller, K. [Department Physik, Universität Paderborn, 33095 Paderborn (Germany)

2016-04-11

We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film. Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding properties offering high mode confinement and smaller devices compared to in-diffused waveguides in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a stack of LN thin film/SiO{sub 2} layer/Bulk LN, which were patterned by optical lithography. The periodic domain inversion was verified by non-invasive confocal second harmonic microscopy. Our results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures can be interpreted in terms of spatially, overlapping domain filaments which start their growth on the +z side.

Effect of the structure and mechanical properties of the near-surface layer of lithium niobate single crystals on the manufacture of integrated optic circuits

Science.gov (United States)

Sosunov, A. V.; Ponomarev, R. S.; Yur'ev, V. A.; Volyntsev, A. B.

2017-01-01

This paper shows that the near-surface layer of a lithium niobate single layer 15 μm in depth is essentially different from the rest of the volume of the material from the standpoint of composition, structure, and mechanical properties. The pointed out differences are due to the effect of cutting, polishing, and smoothing of the lithium niobate plates, which increase the density of point defects and dislocations. The increasing density of the structural defects leads to uncontrollable changes in the conditions of the formations of waveguides and the drifting of characteristics of integrated optical circuits. The results obtained are very important for the manufacture of lithium niobate based integrated optical circuits.

Interaction of light with impurities in lithium niobate crystals

Energy Technology Data Exchange (ETDEWEB)

Schwesyg, Judith Renate Marie-Luise

2011-06-06

Congruent lithium niobate (LiNbO{sub 3}) and 5-mol% MgO-doped LiNbO{sub 3} (MgO:LN) crystals are widely used as nonlinear-optical crystals in frequency-conversion devices due to their large nonlinear-optic coefficients. These devices usually require high optical pump powers, but absorption of photons by impurities limits their usability due to heat accumulation that leads to thermo-optic refractive index changes. These refractive index changes distort the beam shape and disturb the phase-matching condition. Furthermore pyroelectric fields can build up. In this thesis the residual optical absorption in congruent LiNbO{sub 3} (CLN) and MgO:LN crystals is studied. Absorption spectra of CLN and MgO:LN crystals between 400-2000 nm reveal a residual absorption up to 0.04 cm{sup -1}. This absorption is mainly caused by transition metal impurities. Between 2300-2800 nm unknown hydrogen absorption bands in CLN and MgO:LN are revealed on the order of 0.001 cm{sup -1}. High-temperature annealing is applied to the CLN and MgO:LN crystals, which decreases optical absorption by up to one order of magnitude. As an application, the operation of a 1550-nm pumped singly-resonant CW optical parametric oscillator, resonant around 2600 nm, using a low-loss, periodically-poled, annealed CLN crystal is demonstrated. Another issue that affects CLN is photorefractive damage (PRD), i.e. light-induced refractive index changes. In contrast, MgO:LN crystals do not suffer from PRD even at high optical intensities. However, it is shown in this thesis that PRD can occur within seconds in MgO:LN, using green laser light at light intensity levels as low as 100 mW/cm{sup 2}, if the crystal is heated by several degrees Celsius during or before illumination. Photorefractive damage does not occur in CLN crystals under the same conditions. We show that the pyroelectric effect together with an elevated photoconductivity compared to that of CLN causes this beam distortion and that this effect also

Interaction of light with impurities in lithium niobate crystals

International Nuclear Information System (INIS)

Schwesyg, Judith Renate Marie-Luise

2011-01-01

Congruent lithium niobate (LiNbO 3 ) and 5-mol% MgO-doped LiNbO 3 (MgO:LN) crystals are widely used as nonlinear-optical crystals in frequency-conversion devices due to their large nonlinear-optic coefficients. These devices usually require high optical pump powers, but absorption of photons by impurities limits their usability due to heat accumulation that leads to thermo-optic refractive index changes. These refractive index changes distort the beam shape and disturb the phase-matching condition. Furthermore pyroelectric fields can build up. In this thesis the residual optical absorption in congruent LiNbO 3 (CLN) and MgO:LN crystals is studied. Absorption spectra of CLN and MgO:LN crystals between 400-2000 nm reveal a residual absorption up to 0.04 cm -1 . This absorption is mainly caused by transition metal impurities. Between 2300-2800 nm unknown hydrogen absorption bands in CLN and MgO:LN are revealed on the order of 0.001 cm -1 . High-temperature annealing is applied to the CLN and MgO:LN crystals, which decreases optical absorption by up to one order of magnitude. As an application, the operation of a 1550-nm pumped singly-resonant CW optical parametric oscillator, resonant around 2600 nm, using a low-loss, periodically-poled, annealed CLN crystal is demonstrated. Another issue that affects CLN is photorefractive damage (PRD), i.e. light-induced refractive index changes. In contrast, MgO:LN crystals do not suffer from PRD even at high optical intensities. However, it is shown in this thesis that PRD can occur within seconds in MgO:LN, using green laser light at light intensity levels as low as 100 mW/cm 2 , if the crystal is heated by several degrees Celsius during or before illumination. Photorefractive damage does not occur in CLN crystals under the same conditions. We show that the pyroelectric effect together with an elevated photoconductivity compared to that of CLN causes this beam distortion and that this effect also influences frequency conversion

Surface acoustic waves in acoustic superlattice lithium niobate coated with a waveguide layer

Science.gov (United States)

Yang, G. Y.; Du, J. K.; Huang, B.; Jin, Y. A.; Xu, M. H.

2017-04-01

The effects of the waveguide layer on the band structure of Rayleigh waves are studied in this work based on a one-dimensional acoustic superlattice lithium niobate substrate coated with a waveguide layer. The present phononic structure is formed by the periodic domain-inverted single crystal that is the Z-cut lithium niobate substrate with a waveguide layer on the upper surface. The plane wave expansion method (PWE) is adopted to determine the band gap behavior of the phononic structure and validated by the finite element method (FEM). The FEM is also used to investigate the transmission of Rayleigh waves in the phononic structure with the interdigital transducers by means of the commercial package COMSOL. The results show that, although there is a homogeneous waveguide layer on the surface, the band gap of Rayleigh waves still exist. It is also found that increasing the thickness of the waveguide layer, the band width narrows and the band structure shifts to lower frequency. The present approach can be taken as an efficient tool in designing of phononic structures with waveguide layer.

Surface acoustic waves in acoustic superlattice lithium niobate coated with a waveguide layer

Directory of Open Access Journals (Sweden)

G. Y. Yang

2017-04-01

Full Text Available The effects of the waveguide layer on the band structure of Rayleigh waves are studied in this work based on a one-dimensional acoustic superlattice lithium niobate substrate coated with a waveguide layer. The present phononic structure is formed by the periodic domain-inverted single crystal that is the Z-cut lithium niobate substrate with a waveguide layer on the upper surface. The plane wave expansion method (PWE is adopted to determine the band gap behavior of the phononic structure and validated by the finite element method (FEM. The FEM is also used to investigate the transmission of Rayleigh waves in the phononic structure with the interdigital transducers by means of the commercial package COMSOL. The results show that, although there is a homogeneous waveguide layer on the surface, the band gap of Rayleigh waves still exist. It is also found that increasing the thickness of the waveguide layer, the band width narrows and the band structure shifts to lower frequency. The present approach can be taken as an efficient tool in designing of phononic structures with waveguide layer.

Thermo-electric oxidization of iron in lithium niobate crystals

International Nuclear Information System (INIS)

Falk, Matthias

2007-01-01

Lithium niobate crystals (LiNbO 3 ) are a promising material for nonlinear-optical applications like frequency conversion to generate visible light, e.g., in laser displays, but their achievable output power is greatly limited by the ''optical damage'', i.e., light-induced refractive-index changes caused by excitation of electrons from iron impurities and the subsequent retrapping in unilluminated areas of the crystal. The resulting space-charge fields modify the refractive indices due to the electro-optic effect. By this ''photorefractive effect'' the phase-matching condition, i.e., the avoidance of destructive interference between light generated at different crystal positions due to the dispersion of the fundamental wave and the converted wave, is disturbed critically above a certain light intensity threshold. The influence of annealing treatments conducted in the presence of an externally applied electric field (''thermo-electric oxidization'') on the valence state of iron impurities and thereby on the optical damage is investigated. It is observed that for highly iron-doped LiNbO 3 crystals this treatment leads to a nearly complete oxidization from Fe 2+ to Fe 3+ indicated by the disappearance of the absorption caused by Fe 2+ . During the treatment an absorption front forms that moves through the crystal. The absorption in the visible as well as the electrical conductivity are decreased by up to five orders of magnitude due to this novel treatment. The ratio of the Fe 2+ concentration to the total iron concentration - a measure for the strength of the oxidization - is in the order of 10 -6 for oxidized crystals whereas it is about 10 -1 for untreated samples. Birefringence changes are observed at the absorption front that are explained by the removal of hydrogen and lithium ions from the crystal that compensate for the charges of the also removed electrons from Fe 2+ . A microscopic shock-wave model is developed that explains the observed absorption front by

Growth, defect structure, and THz application of stoichiometric lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Lengyel, K.; Péter, Á.; Kovács, L.; Corradi, G.; Dravecz, G.; Hajdara, I.; Szaller, Zs.; Polgár, K. [Wigner Research Centre for Physics, Hungarian Academy of Sciences, 1121 Budapest, Konkoly-Thege M. út 29-33 (Hungary); Pálfalvi, L.; Unferdorben, M. [Institute of Physics, University of Pécs, 7624 Pécs, Ifjúság útja 6 (Hungary); Hebling, J. [Institute of Physics, University of Pécs, 7624 Pécs, Ifjúság útja 6 (Hungary); MTA-PTE High Field Terahertz Research Group, 7624 Pécs (Hungary)

2015-12-15

Owing to the extraordinary richness of its physical properties, congruent lithium niobate has attracted multidecade-long interest both for fundamental science and applications. The combination of ferro-, pyro-, and piezoelectric properties with large electro-optic, acousto-optic, and photoelastic coefficients as well as the strong photorefractive and photovoltaic effects offers a great potential for applications in modern optics. To provide powerful optical components in high energy laser applications, tailoring of key material parameters, especially stoichiometry, is required. This paper reviews the state of the art of growing large stoichiometric LiNbO{sub 3} (sLN) crystals, in particular, the defect engineering of pure and doped sLN with emphasis on optical damage resistant (ODR) dopants (e.g., Mg, Zn, In, Sc, Hf, Zr, Sn). The discussion is focused on crystals grown by the high temperature top seeded solution growth (HTTSSG) technique using alkali oxide fluxing agents. Based on high-temperature phase equilibria studies of the Li{sub 2}O–Nb{sub 2}O{sub 5}–X{sub 2}O ternary systems (X = Na, K, Rb, Cs), the impact of alkali homologue additives on the stoichiometry of the lithium niobate phase will be analyzed, together with a summary of the ultraviolet, infrared, and far-infrared absorption spectroscopic methods developed to characterize the composition of the crystals. It will be shown that using HTTSSG from K{sub 2}O containing flux, crystals closest to the stoichiometric composition can be grown characterized by a UV-edge position of at about 302 nm and a single narrow hydroxyl band in the IR with a linewidth of less than 3 cm{sup −1} at 300 K. The threshold concentrations for ODR dopants depend on crystal stoichiometry and the valence of the dopants; Raman spectra, hydroxyl vibration spectra, and Z-scan measurements prove to be useful to distinguish crystals below and above the photorefractive threshold. Crystals just above the threshold are

Reduced Dimensionality Lithium Niobate Microsystems

Energy Technology Data Exchange (ETDEWEB)

Eichenfield, Matt [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-01-01

The following report describes work performed under the LDRD program at Sandia National Laboratories October 2014 and September 2016. The work presented demonstrates the ability of Sandia Labs to develop state-of-the-art photonic devices based on thin film lithium niobate (LiNbO₃ ). Section 1 provides an introduction to integrated LiNbO₃ devices and motivation for developing thin film nonlinear optical systems. Section 2 describes the design, fabrication, and photonic performance of thin film optical microdisks fabricated from bulk LiNbO₃ using a bulk implantation method developed at Sandia. Sections 3 and 4 describe the development of similar thin film LiNbO₃ structures fabricated from LiNbO₃ on insulator (LNOI) substrates and our demonstration of optical frequency conversion with state-of-the-art efficiency. Finally, Section 5 describes similar microdisk resonators fabricated from LNOI wafers with a buried metal layer, in which we demonstrate electro-optic modulation.

Bending waveguides made in x-cut lithium niobate crystals for technological applications

International Nuclear Information System (INIS)

Guarepi, V; Perrone, C; Aveni, M; Videla, F; Torchia, GA

2015-01-01

In this paper we analyse the performance of several designs of integrated optical deviators made in x-cut lithium niobate crystals by means of femtosecond laser writing using the double line approach. Straight and bent guiding structures have been designed and implemented using this technique. Well-confined propagation modes at communication wavelengths (1.55 μm) were conducted in these structures with acceptable overall losses (less than 2 dB cm −1 ). Further, a discussion about the optical propagation losses for curved and straight deviators devices is included in this work. At a low aperture angle (less than 0.2°), as expected, low losses were determined for both structures; however, a weak output light was observed for large angles (greater than 0.2°) in the straight optical circuits. In contrast, a smooth variation of the output was measured for the bent structures. The results presented in this paper support the possibility of the technological implementation of integrated optical circuits for optical communications fabricated with ultrashort laser writing in lithium niobate crystals. In addition, some hypotheses of loss mechanisms that are normally not considered are discussed in order to explain the differences between the measured values and predictions obtained by calculating with the usual models. (paper)

Domain wall width of lithium niobate poled during growth

CERN Document Server

Brooks, R; Hole, D E; Callejo, D; Bermudez, V; Diéguez, E

2003-01-01

Good quality crystals of periodically poled lithium niobate can be generated directly during growth. However, the temperature gradients at the zone boundaries define the width of the regions where the polarity is reversed. Hence, the region influenced the domain transition may be a significant fraction of the overall poling period for material poled during growth. Evidence for the scale of this feature is reported both by chemical etching and by the less common method of ion beam luminescence and the 'domain wall' width approximately 1 mu m for these analyses. The influence of the reversal region may differ for alternative techniques but the relevance to device design for second harmonic generation is noted.

Radiation-damage-assisted ferroelectric domain structuring in magnesium-doped lithium niobate

Science.gov (United States)

Jentjens, L.; Peithmann, K.; Maier, K.; Steigerwald, H.; Jungk, T.

2009-06-01

Irradiation of 5% magnesium-doped lithium niobate crystals (LiNbO3:Mg) with high-energy, low-mass 3He ions, which are transmitted through the crystal, changes the domain reversal properties of the material. This enables easier domain engineering compared to non-irradiated material and assists the formation of small-sized periodically poled domains in LiNbO3:Mg. Periodic domain structures exhibiting a width of ≈520 nm are obtained in radiation-damaged sections of the crystals. The ferroelectric poling behavior between irradiated and non-treated material is compared.

Irradiation-induced modification of the material parameters in magnesium-doped lithium niobate

International Nuclear Information System (INIS)

Jentjens, Lena

2010-01-01

In the framework of this thesis the material properties of lithium niobate are directedly influenced by the irradiation with 3 He ions with an energy of 40 MeV. In the first part the irradiation-induced material changes are intensively studied. Long-time stable changes of the refractive index are measured in the range of up to 6.10 -3 , which depend on the radiation dose and exhibit until now no saturation behaviour. Accompanied is this change by an also dose-dependent deformation as well as a brownish change of color of the crystals. Furthermore a by several orders of magnitude increased electrical dark- and photoconductivity, which depends on the ion dose and exhibits until now also no saturation behaviour. An effect independent on the ion dose is the reduction of the coercive field strength by about 10%. Furthermore it was stated the quantity of the effects not only depends on the absolute dose, but also on the irradiation direction in view of the crystallographic c-axis. The second part of this thesis deals with the generation of microscopic structures in lithium niobate. By an ion microbeam respectively a shiftable slit aperture the fabrication of refractive-index gratings is pursued. Grating with periodicity lengths in the range of 12-160 μm could until now be detected and promise in comparison with photorefractive gratings the advance of larger stability.

Integrated optics on Lithium Niobate for sensing applications

Science.gov (United States)

Zaltron, A.; Bettella, G.; Pozza, G.; Zamboni, R.; Ciampolillo, M.; Argiolas, N.; Sada, C.; Kroesen, S.; Esseling, M.; Denz, C.

2015-05-01

In micro-analytical chemistry and biology applications, optofluidic technology holds great promise for creating efficient lab-on-chip systems where higher levels of integration of different stages on the same platform is constantly addressed. Therefore, in this work the possibility of integrating opto-microfluidic functionalities in lithium niobate (LiNbO3) crystals is presented. In particular, a T-junction droplet generator is directly engraved in a LiNbO3 substrate by means of laser ablation process and optical waveguides are realized in the same material by exploiting the Titanium in-diffusion approach. The coupling of these two stages as well as the realization of holographic gratings in the same substrate will allow creating new compact optical sensor prototypes, where the optical properties of the droplets constituents can be monitored.

Twinning structures in near-stoichiometric lithium niobate single crystals

International Nuclear Information System (INIS)

Yao, Shuhua; Chen, Yanfeng

2010-01-01

A near-stoichiometric lithium niobate single crystal has been grown by the Czochralski method in a hanging double crucible with a continuous powder supply system. Twins were found at one of the three characteristic growth ridges of the as-grown crystal. The twin structure was observed and analyzed by transmission synchrotron topography. The image shifts ΔX and ΔY in the transmission synchrotron topograph were calculated for the 3 anti 2 anti 12 and 0 anti 222 reflections based on results from high-resolution X-ray diffractometry. It is confirmed that one of the {01 anti 1 anti 2} m planes is the composition face of the twin and matrix crystals. The formation mechanism of these twins is discussed. (orig.)

Photorefractive lithium niobate crystals for applications in photonics

International Nuclear Information System (INIS)

Hartwig, U.

2006-12-01

Lithium niobate crystals (LiNbO 3 ) generally show a photorefractive response, i.e., light-induced refractive index changes. Crystals are investigated at room temperature and at elevated temperatures. As a result 'classical' photorefractive holographic volume-phase gratings, originating from space charge fields and the electro-optic effect, and 'non-classical' photorefractive volume-phase gratings, which can be traced back to strong absorption gratings, emerge. Single domain and periodically poled crystals (PPLN) are investigated. PPLN is typically used in non-linear optics for frequency conversion. The crystals also show non-linear photorefractive response during holographic recording with isotropically polarized light beams of equal intensity and, in the case of PPLN, by mixing of domain and holographic gratings. The results are important for applications combining the photorefractive and non-linear optical properties of LiNbO 3 . (orig.)

Generation of tunable narrow-band surface-emitted terahertz radiation in periodically poled lithium niobate.

Science.gov (United States)

Weiss, C; Torosyan, G; Avetisyan, Y; Beigang, R

2001-04-15

Generation of tunable narrow-band terahertz (THz) radiation perpendicular to the surface of periodically poled lithium niobate by optical rectification of femtosecond pulses is reported. The generated THz radiation can be tuned by use of different poling periods and different observation angles, limited only by the available bandwidth of the pump pulse. Typical bandwidths were 50-100 GHz, depending on the collection angle and the number of periods involved.

Diffusion of iron in lithium niobate: a secondary ion mass spectrometry study

Energy Technology Data Exchange (ETDEWEB)

Ciampolillo, M.V.; Argiolas, N.; Zaltron, A.; Bazzan, M.; Sada, C. [University of Padova, Physics Department (Italy); CNISM, Padova (Italy)

2011-10-15

Iron-doped X-cut lithium niobate crystals were prepared by means of thermal diffusion from thin film varying in a systematic way the process parameters such as temperature and diffusion duration. Secondary Ion Mass Spectrometry was exploited to characterize the iron in-depth profiles. The evolution of the composition of the Fe thin film in the range between 600 C and 800 C was studied, and the diffusion coefficient at different temperatures in the range between 900 C and 1050 C and the activation energy of the diffusion process were estimated. (orig.)

Fabrication and performance of porous lithium sodium potassium niobate ceramic

Science.gov (United States)

Chen, Caifeng; Zhu, Yuan; Ji, Jun; Cai, Feixiang; Zhang, Youming; Zhang, Ningyi; Wang, Andong

2018-02-01

Porous lithium sodium potassium niobate (LNK) ceramic has excellent piezoelectric properties, chemical stability and great chemical compatibility. It has a good application potential in the field of biological bone substitute. In the paper, porous LNK ceramic was fabricated with egg albumen foaming agent by foaming method. Effects of preparation process of the porous LNK ceramic on density, phase structure, hole size and piezoelectric properties were researched and characterized. The results show that the influence factors of LNK solid content and foaming agent addition are closely relevant to properties of the porous LNK ceramic. When solid content is 65% and foaming agent addition is 30%, the porous LNK ceramic has uniform holes and the best piezoelectric properties.

Distribution of the solute in the lithium niobate crystal grown by the Stepanov method in a periodically changing external electric field

International Nuclear Information System (INIS)

Zhdanov, A.; Nikolayeva, L.; Red'kin, B.

2000-01-01

The Iithium niobate crystals with the periodic domain structure are characterised by the capacity for the light frequency adoption of the laser light. Consequently, they are promising for the development of compact light sources. There are several methods of producing periodic ferroelectric domain structures of the lithium niobate crystals in the growth process. It is evident that the main method of production of the periodic structures in the lithium niobate is the Stepanov method. The development of the mathematical model of the variation of the concentration of the alloying solute with the periodic variation of the conditions of growth of the crystal in the growth of the crystal by the Stepanov methods in the conditions of periodic changes of the drawing rate of the crystal V and the temperature of the thermal junction T have been investigated elsewhere. The formation of the domain structure is also possible in the case of the periodic variation of the electric field, during the supply of the alternating voltage between the shaper and the seed. In this work, we proposed mathematical model discounting the process of formation of the domain structure in the alternating electric field during the growth of the lithium niobate crystal by the Stepanov method. In the mathematical modelling we obtain the numerical solutions of the unidimensional nonstationary problem of the Stepanov type, the diffusion equation for concentration, and the Laplace capillary equation. The proposed mathematical model is at the present and the most complete and accurate description of the variation of the concentration of the solute in the growing crystal. The semi-discrete Galerkin method was used for the equations

Iron site location in Fe-diffused lithium niobate crystals by combined RBS-PIXE-NRA analysis

Energy Technology Data Exchange (ETDEWEB)

Zaltron, A. [University of Padova and CNISM, Via Marzolo 8, 35131 Padova (Italy); Argiolas, N., E-mail: nicola.argiolas@unipd.it [University of Padova and CNISM, Via Marzolo 8, 35131 Padova (Italy); Laboratori Nazionali di Legnaro, Istituto Nazionale Fisica Nucleare, Viale dell' Universita 2, 35020 Legnaro (Padova) (Italy); De Salvador, D.; Bazzan, M. [University of Padova and CNISM, Via Marzolo 8, 35131 Padova (Italy); Laboratori Nazionali di Legnaro, Istituto Nazionale Fisica Nucleare, Viale dell' Universita 2, 35020 Legnaro (Padova) (Italy); Ciampolillo, M.V.; Bacci, L.; Sada, C. [University of Padova and CNISM, Via Marzolo 8, 35131 Padova (Italy)

2012-03-15

Iron diffused x-cut lithium niobate samples have been studied from a structural point of view by ion beam analysis techniques in channeling conditions. The aim of this work is to determine the most probable position of iron atoms after high temperature diffusion treatment in pure oxygen atmosphere and to verify their location after an additional full reducing annealing at low temperature. The results are compared with the bulk doping case that can be considered the final equilibrium state of the diffusion process. By comparing the iron signal with niobium and lithium counterparts in angular scans along proper crystallographic directions, we demonstrate that iron occupies in any case the lithium site or a very close position regardless of the reduction degree, just as in the case of bulk doped samples.

Nanotechnology in lithium niobate for integrated optic frequency conversion in the UV

Science.gov (United States)

Busacca, Alessandro C.; Santini, Claudia; Oliveri, Luigi; Riva-Sanseverino, Stefano; Parisi, Antonino; Cino, Alfonso C.; Assanto, Gaetano

2017-11-01

In the domain of Earth Explorer satellites nanoengineered nonlinear crystals can optimize UV tunable solid-state laser converters. Lightweight sources can be based on Lithium Niobate (LN) domain engineering by electric field poling and guided wave interactions. In this Communication we report the preliminary experimental results and the very first demonstration of UltraViolet second-harmonic generation by first-order quasi-phase-matching in a surface-periodically-poled proton-exchanged LN waveguide. The pump source was a Ti-Sapphire laser with a tunability range of 700- 980 nm and a 40 GHz linewidth. We have measured UV continuous-wave light at 390 nm by means of a lock-in amplifier and of a photodiode with enhanced response in the UV. Measured conversion efficiency was about 1%W-1cm-2. QPM experiments show good agreement with theory and pave the way for a future implementation of the technique in materials less prone to photorefractive damage and wider transparency in the UV, such as Lithium Tantalate.

Ion irradiation effects on lithium niobate etalons for tunable spectral filters

Science.gov (United States)

Garranzo, D.; Ibarmia, S.; Alvarez-Herrero, A.; Olivares, J.; Crespillo, M.; Díaz, M.

2017-11-01

, coupled with the HV field, could trigger a dielectric breakdown in the Lithium Niobate. In this paper we present the electro-optical results obtained when exposing a set of LN samples and a lowquality full size etalon to different radiation conditions. In a first irradiation campaign, performed at the Centre for Micro Analysis of Materials (CMAM-Madrid) facilities, we were mainly focused on the long-term degradation effects with a series of high flux (109 cm-2 s-1) proton tests at an energy of 10 MeV. In order to study the possibility of a single ion breakdown, a second campaign was carried out, at the Texas A&M University (TAMU), exposing Lithium Niobate to high LET ion species (78Kr, 40Ar, 129Xe, 197Au) accelerated to the GeV energy range to penetrate or even pass through the entire Lithium Niobate thickness.

Domain-Reversed Lithium Niobate Single-Crystal Fibers are Potentially for Efficient Terahertz Wave Generation

Directory of Open Access Journals (Sweden)

Yalin Lu

2008-01-01

Full Text Available Nonlinear frequency conversion remains one of the dominant approaches to efficiently generate THz waves. Significant material absorption in the THz range is the main factor impeding the progress towards this direction. In this research, a new multicladding nonlinear fiber design was proposed to solve this problem, and as the major experimental effort, periodic domain structure was introduced into lithium niobate single-crystal fibers by electrical poling. The introduced periodic domain structures were nondestructively revealed using a crossly polarized optical microscope and a confocal scanning optical microscope for quality assurance.

Analysis of Waveguides on Lithium Niobate Thin Films

Directory of Open Access Journals (Sweden)

Yiwen Wang

2018-04-01

Full Text Available Waveguides formed by etching, proton-exchange (PE, and strip-loaded on single-crystal lithium niobate (LN thin film were designed and simulated by a full-vectorial finite difference method. The single-mode condition, optical power distribution, and bending loss of these kinds of waveguides were studied and compared systematically. For the PE waveguide, the optical power distributed in LN layer had negligible change with the increase of PE thickness. For the strip-loaded waveguide, the relationships between optical power distribution in LN layer and waveguide thickness were different for quasi-TE (q-TE and quasi-TM (q-TM modes. The bending loss would decrease with the increase of bending radius. There was a bending loss caused by the electromagnetic field leakage when the neff of q-TM waveguide was smaller than that of nearby TE planar waveguide. LN ridge waveguides possessed a low bending loss even at a relatively small bending radius. This study is helpful for the understanding of waveguide structures as well as for the optimization and the fabrication of high-density integrated optical components.

Magnetophotorefractive effect and interference filters in lithium niobate

International Nuclear Information System (INIS)

Dam-Hansen, C.

1996-03-01

This thesis deals with the fundamental photorefractive and photovoltaic properties of iron-doped lithium niobate crystals. Experimental observations of a strong magnetic field effect on the energy coupling and grating formation in a vectorial interaction scheme are presented. To the author's knowledge these are the first reported results in the field. It is shown that an enhancement of the diffraction efficiency of 60% is possible by applying even a moderate magnetic field of 0.23 T. A new theoretical model of the magnetophotorefractive effect in the vectorial interaction scheme is presented. It describes the space-charge field formation, two-wave mixing and grating formation under the influence of an externally applied magnetic field. Good agreement with the experimental results and the first measurement of nondiagonal components of the magnetophotovoltaic tensor are reported. A theoretical model for the temperature properties of photorefractive interference filters with subangstrom bandwidths are presented and compared favourably with experimental investigations. A novel method for determining the spectral response of these filters from a combined thermal and angular response measurements is described. (au) 9 tabs., 30 ills., 84 refs

Experimental and theoretical investigation of lattice defect structures in a series of Zn, Fe-doped nonstoichiometric lithium niobate

International Nuclear Information System (INIS)

Guo Fengyun; Lue Qiang; Sun Liang; Li Hongtao; Zhen Xihe; Xu Yuheng; Zhao Liancheng

2006-01-01

A series of the double doped lithium niobate (LiNbO 3 , LN) single crystals had been grown by Czochralski method. The Curie temperatures of various concentrations doped or [Li]/[Nb] ratio LN crystals measured by differential thermal analysis (DTA) were discussed to investigate their defect structures with Safaryan et al. new approach about LN lattice defect structure using Curie temperatures calculated. Infrared transmission spectra of various concentrations doped were used to compare the investigation above. The results show that the lithium vacancy model is the more probable to describe the lattice defect structure of the doped LN single crystal

Lightwave Circuits in Lithium Niobate through Hybrid Waveguides with Silicon Photonics.

Science.gov (United States)

Weigel, Peter O; Savanier, Marc; DeRose, Christopher T; Pomerene, Andrew T; Starbuck, Andrew L; Lentine, Anthony L; Stenger, Vincent; Mookherjea, Shayan

2016-03-01

We demonstrate a photonic waveguide technology based on a two-material core, in which light is controllably and repeatedly transferred back and forth between sub-micron thickness crystalline layers of Si and LN bonded to one another, where the former is patterned and the latter is not. In this way, the foundry-based wafer-scale fabrication technology for silicon photonics can be leveraged to form lithium-niobate based integrated optical devices. Using two different guided modes and an adiabatic mode transition between them, we demonstrate a set of building blocks such as waveguides, bends, and couplers which can be used to route light underneath an unpatterned slab of LN, as well as outside the LN-bonded region, thus enabling complex and compact lightwave circuits in LN alongside Si photonics with fabrication ease and low cost.

Aperture scaling effects with monolithic periodically poled lithium niobate optical parametric oscillators and generators.

Science.gov (United States)

Missey, M; Dominic, V; Powers, P; Schepler, K L

2000-02-15

We used elliptical beams to demonstrate aperture scaling effects in nanosecond single-grating and multigrating periodically poled lithium niobate (PPLN) monolithic optical parametric oscillators and generators. Increasing the cavity Fresnel number in single-grating crystals broadened both the beam divergence and the spectral bandwidth. Both effects are explained in terms of the phase-matching geometry. These effects are suppressed when a multigrating PPLN crystal is used because the individual gratings provide small effective subapertures. A flood-pumped multigrating optical parametric generator displayed a low output beam divergence and contained 19 pairs of signal and idler frequencies.

Multiwatt-level continuous-wave midwave infrared generation using difference frequency mixing in periodically poled MgO-doped lithium niobate.

Science.gov (United States)

Guha, Shekhar; Barnes, Jacob O; Gonzalez, Leonel P

2014-09-01

Over 3.5 W of continuous-wave power at 3.4 μm was obtained by single-pass difference frequency mixing of 1.064 and 1.55 μm fiber lasers in a 5 cm long periodically poled lithium niobate crystal. Good agreement was obtained between the observed temperature dependence of the generated power and the prediction from focused Gaussian beam theory.

Tuning characteristics of narrowband THz radiation generated via optical rectification in periodically poled lithium niobate.

Science.gov (United States)

Weiss, C; Torosyan, G; Meyn, J P; Wallenstein, R; Beigang, R; Avetisyan, Y

2001-04-23

The tuning properties of pulsed narrowband THz radiation generated via optical rectification in periodically poled lithium niobate have been investigated. Using a disk-shaped periodically poled crystal tuning was easily accomplished by rotating the crystal around its axis and observing the generated THz radiation in forward direction. In this way no beam deflection during tuning was observed. The total tuning range extended from 180 GHz up to 830 GHz and was limited by the poling period of 127 microm which determines the maximum THz frequency in forward direction.

Cascading second-order nonlinear processes in a lithium niobate-on-insulator microdisk.

Science.gov (United States)

Liu, Shijie; Zheng, Yuanlin; Chen, Xianfeng

2017-09-15

Whispering-gallery-mode (WGM) microcavities are very important in both fundamental science and practical applications, among which on-chip second-order nonlinear microresonators play an important role in integrated photonic functionalities. Here we demonstrate resonant second-harmonic generation (SHG) and cascaded third-harmonic generation (THG) in a lithium niobate-on-insulator (LNOI) microdisk resonator. Efficient SHG in the visible range was obtained with only several mW input powers at telecom wavelengths. THG was also observed through a cascading process, which reveals simultaneous phase matching and strong mode coupling in the resonator. Cascading of second-order nonlinear processes gives rise to an effectively large third-order nonlinearity, which makes on-chip second-order nonlinear microresonators a promising frequency converter for integrated nonlinear photonics.

Lightwave Circuits in Lithium Niobate through Hybrid Waveguides with Silicon Photonics

Science.gov (United States)

Weigel, Peter O.; Savanier, Marc; DeRose, Christopher T.; Pomerene, Andrew T.; Starbuck, Andrew L.; Lentine, Anthony L.; Stenger, Vincent; Mookherjea, Shayan

2016-01-01

We demonstrate a photonic waveguide technology based on a two-material core, in which light is controllably and repeatedly transferred back and forth between sub-micron thickness crystalline layers of Si and LN bonded to one another, where the former is patterned and the latter is not. In this way, the foundry-based wafer-scale fabrication technology for silicon photonics can be leveraged to form lithium-niobate based integrated optical devices. Using two different guided modes and an adiabatic mode transition between them, we demonstrate a set of building blocks such as waveguides, bends, and couplers which can be used to route light underneath an unpatterned slab of LN, as well as outside the LN-bonded region, thus enabling complex and compact lightwave circuits in LN alongside Si photonics with fabrication ease and low cost. PMID:26927022

Evaluation of domain randomness in periodically poled lithium niobate by diffraction noise measurement.

Science.gov (United States)

Dwivedi, Prashant Povel; Choi, Hee Joo; Kim, Byoung Joo; Cha, Myoungsik

2013-12-16

Random duty-cycle errors (RDE) in ferroelectric quasi-phase-matching (QPM) devices not only affect the frequency conversion efficiency, but also generate non-phase-matched parasitic noise that can be detrimental to some applications. We demonstrate an accurate but simple method for measuring the RDE in periodically poled lithium niobate. Due to the equivalence between the undepleted harmonic generation spectrum and the diffraction pattern from the QPM grating, we employed linear diffraction measurement which is much simpler than tunable harmonic generation experiments [J. S. Pelc, et al., Opt. Lett.36, 864-866 (2011)]. As a result, we could relate the RDE for the QPM device to the relative noise intensity between the diffraction orders.

Acoustic wave filter based on periodically poled lithium niobate.

Science.gov (United States)

Courjon, Emilie; Bassignot, Florent; Ulliac, Gwenn; Benchabane, Sarah; Ballandras, Sylvain

2012-09-01

Solutions for the development of compact RF passive transducers as an alternative to standard surface or bulk acoustic wave devices are receiving increasing interest. This article presents results on the development of an acoustic band-pass filter based on periodically poled ferroelectric domains in lithium niobate. The fabrication of periodically poled transducers (PPTs) operating in the range of 20 to 650 MHz has been achieved on 3-in (76.2-mm) 500-μm-thick wafers. This kind of transducer is able to excite elliptical as well as longitudinal modes, yielding phase velocities of about 3800 and 6500 ms(-1), respectively. A new type of acoustic band-pass filter is proposed, based on the use of PPTs instead of the SAWs excited by classical interdigital transducers. The design and the fabrication of such a filter are presented, as well as experimental measurements of its electrical response and transfer function. The feasibility of such a PPT-based filter is thereby demonstrated and the limitations of this method are discussed.

Anisotropic surface acoustic waves in tungsten/lithium niobate phononic crystals

Science.gov (United States)

Sun, Jia-Hong; Yu, Yuan-Hai

2018-02-01

Phononic crystals (PnC) were known for acoustic band gaps for different acoustic waves. PnCs were already applied in surface acoustic wave (SAW) devices as reflective gratings based on the band gaps. In this paper, another important property of PnCs, the anisotropic propagation, was studied. PnCs made of circular tungsten films on a lithium niobate substrate were analyzed by finite element method. Dispersion curves and equal frequency contours of surface acoustic waves in PnCs of various dimensions were calculated to study the anisotropy. The non-circular equal frequency contours and negative refraction of group velocity were observed. Then PnC was applied as an acoustic lens based on the anisotropic propagation. Trajectory of SAW passing PnC lens was calculated and transmission of SAW was optimized by selecting proper layers of lens and applying tapered PnC. The result showed that PnC lens can suppress diffraction of surface waves effectively and improve the performance of SAW devices.

Influence of heat treatment on structure and some physical properties of lithium boro-niobate glass

Science.gov (United States)

Kashif, I.; Sakr, E. M.; Soliman, A. A.; Ratep, A.

2012-08-01

The glass composition (90 mol% Li2B4O7-10 mol% Nb2O5) was prepared by the melt quenching technique. The quenched sample was heat treated at 480°C, 545°C and 630°C for 5 h and heat treated at 780°C with different time. The times were 5, 10, 15, 20, 28, and 36 h. The glass and glass ceramics were studied by differential thermal analysis (DTA), X-ray diffraction (XRD), and dc conductivity as a function of temperature. Lithium niobate (LiNbO3) and lithium diborate (Li2B4O7) were the main phases in glass ceramic addition to traces from LiNb3O8. Crystallite size of the main phases determined from the X-ray diffraction peaks are in the range <100 nm. The fraction of crystalline (LiNbO3) phase increases with increase the heat treatment temperature and time. The relation between physical properties and structure were studied.

Recent Achievements on Photovoltaic Optoelectronic Tweezers Based on Lithium Niobate

Directory of Open Access Journals (Sweden)

Angel García-Cabañes

2018-01-01

Full Text Available This review presents an up-dated summary of the fundamentals and applications of optoelectronic photovoltaic tweezers for trapping and manipulation of nano-objects on the surface of lithium niobate crystals. It extends the contents of previous reviews to cover new topics and developments which have emerged in recent years and are marking the trends for future research. Regarding the theoretical description of photovoltaic tweezers, detailed simulations of the electrophoretic and dielectrophoretic forces acting on different crystal configurations are discussed in relation to the structure of the obtained trapping patterns. As for the experimental work, we will pay attention to the manipulation and patterning of micro-and nanoparticles that has experimented an outstanding progress and relevant applications have been reported. An additional focus is now laid on recent work about micro-droplets, which is a central topic in microfluidics and optofluidics. New developments in biology and biomedicine also constitute a relevant part of the review. Finally, some topics partially related with photovoltaic tweezers and a discussion on future prospects and challenges are included.

Numerical and Experimental Study of Optoelectronic Trapping on Iron-Doped Lithium Niobate Substrate

Directory of Open Access Journals (Sweden)

Michela Gazzetto

2016-09-01

Full Text Available Optoelectronic tweezers (OET are a promising technique for the realization of reconfigurable systems suitable to trap and manipulate microparticles. In particular, dielectrophoretic (DEP forces produced by OET represent a valid alternative to micro-fabricated metal electrodes, as strong and spatially reconfigurable electrical fields can be induced in a photoconductive layer by means of light-driven phenomena. In this paper we report, and compare with the experimental data, the results obtained by analyzing the spatial configurations of the DEP-forces produced by a 532 nm laser beam, with Gaussian intensity distribution, impinging on a Fe-doped Lithium Niobate substrate. Furthermore, we also present a promising preliminary result for water-droplets trapping, which could open the way to the application of this technique to biological samples manipulation.

Irradiation-induced modification of the material parameters in magnesium-doped lithium niobate; Bestrahlungsinduzierte Modifikation der Materialparameter in Magnesiumdotiertem Lithiumniobat

Energy Technology Data Exchange (ETDEWEB)

Jentjens, Lena

2010-07-01

In the framework of this thesis the material properties of lithium niobate are directedly influenced by the irradiation with {sup 3}He ions with an energy of 40 MeV. In the first part the irradiation-induced material changes are intensively studied. Long-time stable changes of the refractive index are measured in the range of up to 6.10{sup -3}, which depend on the radiation dose and exhibit until now no saturation behaviour. Accompanied is this change by an also dose-dependent deformation as well as a brownish change of color of the crystals. Furthermore a by several orders of magnitude increased electrical dark- and photoconductivity, which depends on the ion dose and exhibits until now also no saturation behaviour. An effect independent on the ion dose is the reduction of the coercive field strength by about 10%. Furthermore it was stated the quantity of the effects not only depends on the absolute dose, but also on the irradiation direction in view of the crystallographic c-axis. The second part of this thesis deals with the generation of microscopic structures in lithium niobate. By an ion microbeam respectively a shiftable slit aperture the fabrication of refractive-index gratings is pursued. Grating with periodicity lengths in the range of 12-160 {mu}m could until now be detected and promise in comparison with photorefractive gratings the advance of larger stability.

Generation of ionizing radiation from lithium niobate crystals

Science.gov (United States)

Orlikov, L. N.; Orlikov, N. L.; Arestov, S. I.; Mambetova, K. M.; Shandarov, S. M.

2017-01-01

The work done experimentally explores generation of electron and x-ray radiation in the process of heating and cooling monolithic and iron-doped crystals of lithium niobate. Iron doping to the concentrations in the range of 1023 m3 was carried out by adding ferric oxide into the melt during the process of crystal growth. The research into radiation generation was performed at 1-10 Pa. The speed of heating from -10 to 1070 C was 10-20 degrees a minute. Current pulses appeared at 17, 38, 56, 94, 98, 100, 105, 106, 1070 C with the interval of 1-3 minutes. The obtained electron current increased in direct proportion to the crystal surface area. The maximum current was 3mA at the design voltage 11 kV on the crystal with 14,5x10,5x10 mm3 surface area. The article describes the possibility to control the start of generation by introducing priming pulse. The results achieved are explained by the domain repolarization while heating the crystal and the appearance of electric field local strength. Bias and overcharge currents contribute to the appearance of electric strength, which stimulates breakdown and plasma formation. X-ray radiation appears both at the stage of discharge formation and during electron deceleration on gas and target material.

The compact converter of Bessel beams of zero and second orders on the basis of z-cut lithium niobate

International Nuclear Information System (INIS)

Paranin, V D; Karpeev, S V; Khonina, S N; Tukmakov, K N

2016-01-01

Transformation of zero-order Bessel beams into a second-order vortex beam in the process of propagation in a c-cut of lithium niobate LiNbO 3 crystal has been investigated experimentally. The possibility of controlling beam transformation by means of changing the curve radius of the illuminating beam is shown. The possibility of Bessel beam transforming by compact devices on the basis of thin c-cuts of uniaxial crystals with a diffraction mask formed on their surface is proved. (paper)

Hysteresis-free high-temperature precise bimorph actuators produced by direct bonding of lithium niobate wafers

Energy Technology Data Exchange (ETDEWEB)

Shur, V. Ya.; Baturin, I. S.; Mingaliev, E. A.; Zorikhin, D. V.; Udalov, A. R.; Greshnyakov, E. D. [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 51 Lenin Ave., 620000 Ekaterinburg (Russian Federation)

2015-02-02

The current paper presents a piezoelectric bimorph actuator produced by direct bonding of lithium niobate wafers with the mirrored Y and Z axes. Direct bonding technology allowed to fabricate bidomain plate with precise positioning of ideally flat domain boundary. By optimizing the cutting angle (128° Y-cut), the piezoelectric constant became as large as 27.3 pC/N. Investigation of voltage dependence of bending displacement confirmed that bimorph actuator has excellent linearity and hysteresis-free. Decrease of the applied voltage down to mV range showed the perfect linearity up to the sub-nm deflection amplitude. The frequency and temperature dependences of electromechanical transmission coefficient in wide temperature range (from 300 to 900 K) were investigated.

Heterogeneous integration of lithium niobate and silicon nitride waveguides for wafer-scale photonic integrated circuits on silicon.

Science.gov (United States)

Chang, Lin; Pfeiffer, Martin H P; Volet, Nicolas; Zervas, Michael; Peters, Jon D; Manganelli, Costanza L; Stanton, Eric J; Li, Yifei; Kippenberg, Tobias J; Bowers, John E

2017-02-15

An ideal photonic integrated circuit for nonlinear photonic applications requires high optical nonlinearities and low loss. This work demonstrates a heterogeneous platform by bonding lithium niobate (LN) thin films onto a silicon nitride (Si3N4) waveguide layer on silicon. It not only provides large second- and third-order nonlinear coefficients, but also shows low propagation loss in both the Si3N4 and the LN-Si3N4 waveguides. The tapers enable low-loss-mode transitions between these two waveguides. This platform is essential for various on-chip applications, e.g., modulators, frequency conversions, and quantum communications.

Linear diffraction of light waves on periodically poled domain structures in lithium niobate crystals: collinear, isotropic, and anisotropic geometries

International Nuclear Information System (INIS)

Shandarov, S M; Mandel, A E; Akylbaev, T M; Borodin, M V; Savchenkov, E N; Smirnov, S V; Akhmatkhanov, A R; Shur, V Ya

2017-01-01

The possible variants of experimental observation of light diffraction on periodically poled domain structures (PPDS) in the lithium niobate crystal with 180-degree domain Y-walls are considered. We experimentally investigated isotropic and anisotropic diffraction of coherent light (λ = 655nm) on the PPDS with spatial period Λ = 8.79 μm produced by poling method in a LiNbO 3 : 5% MgO crystal. The central wavelength of irradiation experiencing a collinear diffraction on these PPDS is estimated as λ c = 455 nm. (paper)

Enhancement of Lithium Niobate nanophotonic structures via spin-coating technique for optical waveguides application

Directory of Open Access Journals (Sweden)

Fakhri Makram A.

2017-01-01

Full Text Available This work is dedicated to investigation of temperature effects in Lithium Niobate (LiNbO3 nanostructures. The LiNbO3 nanostructures were deposited on glass substrate by spin-coating technique. LiNbO3 was set down at 3000 rpm for 30 sec and annealed from 100 to 600 °C. The structures were characterized and analyzed by scanning electron microscopy (SEM and ultra-violet visible (UV-vis spectrophotometer. The measured results have showed that by increasing annealing temperatures, the structures start to be more crystallized and be more homogenized until the optimum arrangement was achieved. Once this was accomplished, it's applicable for optical waveguides development. Eventually, it starts to be less crystallization and non-homogeneous. Energy gap was recorded to be at average value of 3.9 eV.

Effect of powder processing conditions on the electromechanical properties of lithium doped potassium sodium niobate

Energy Technology Data Exchange (ETDEWEB)

Mensur-Alkoy, E.; Berksoy-Yavuz, A.

2016-07-01

Lithium doped potassium sodium niobate ceramics with (K0.50−x/2Na0.50−x/2Lix)NbO3 composition where x=0.04 and 0.07 were fabricated by solid state calcination and pressureless sintering methods. However, two different powder processing and calcination routes were used in this study and their effect on the structural and electrical properties were investigated and discussed. The routes were namely loose calcination and compact calcination. A general trend of decreasing grain size was observed in the sintered ceramics prepared from these powders. The most drastic effect was observed on the electromechanical properties of the samples, where the maximum strain of 7% lithium modified sample under an E-field of 50kV/cm was increased from 0.09% to 0.12% by changing processing route. Furthermore, hysteretic behavior of the strain was found to decrease. This tendency was also valid for ferroelectric hysteresis property, with remnant polarization (2Pr) increasing from 23μC/cm2 to 46μC/cm2. The improvements observed in the electrical properties were discussed on the basis of chemical homogeneity and uniform ionic distribution. (Author)

Récuperation d'horloge d'un signal OTDM à 640 Gbit/s transmis sur 50 km par boucle à verrouillage de phase opto-électronique utilisant un dispositif en Niobate de Lithium à inversion de domaines

DEFF Research Database (Denmark)

Gomez, F.; Ware, Agis C.; Oxenløwe, Leif Katsuo

2008-01-01

L'extraction d'horloge d'un signal OTDM à 640 Gbit/s, transmis sur 50 km, à partir d'une boucle à verrouillage de phase utilisant l'effet non-linéaire de mélange à trois ondes dans un composant de niobate de lithium à inversion de domaines a été mise en oeuvre.......L'extraction d'horloge d'un signal OTDM à 640 Gbit/s, transmis sur 50 km, à partir d'une boucle à verrouillage de phase utilisant l'effet non-linéaire de mélange à trois ondes dans un composant de niobate de lithium à inversion de domaines a été mise en oeuvre....

High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

Science.gov (United States)

Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

2017-04-01

Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.

Performance Study of optical Modulator based on electrooptic effect

International Nuclear Information System (INIS)

Palodiya, V; Raghuwanshi, S K

2016-01-01

In this paper, we have studied and derive performance parameter of highly integrated Lithium Niobate optical modulator. This is a chirp free modulator having low switching voltage and large bandwidth. For an external modulator in which travelling-wave electrodes length L imposed the modulating switching voltage, the product of V_π and L is fixed for a given electro optic material Lithium Niobate. We investigate to achieve a low V_π by both magnitude of the electro-optic coefficient for a wide variety of electro-optic materials. A Sellmeier equation for the extraordinary index of congruent lithium niobate is derived. For phase-matching, predictions are accmate for temperature between room temperature 250°C and wavelength ranging from 0.4 to 5µm. The Sellmeier equations predict more accmately refractive indices at long wavelengths. Theoretical result is confirmed by simulated results. We have analysed the various parameters such as switching voltage, device performance index, time constant, transmittance, cut-off frequency, 3-dB bandwidth, power absorption coefficient and transmission bit rate of Lithium Niobate optical Modulator based on electro -optic effect. (paper)

Formation of 2D bright spatial solitons in lithium niobate with photovoltaic response and incoherent background

Science.gov (United States)

Pustozerov, A.; Shandarov, V.

2017-12-01

The influence of incoherent background illumination produced by light-emitting diodes (LED's) of different average wavelengths and laser diode emitting in blue region of visible on diffraction characteristics of narrow coherent light beams of He-Ne laser due to refractive index changes of Fe-doped lithium niobate sample are studied. It has been experimentally demonstrated that nonlinear diffraction of red beams with wavelength 633 nm and diameters on full width of half maximum (FWHM) near to 15 μm may be totally compensated using background light with average wavelengths 450 - 465 nm. To provide the necessary intensity of incoherent background, the combinations of spherical and cylindrical concave lenses with blue LED and laser diode module without focusing its beam have been used.

Investigation of pyroelectric electron emission from monodomain lithium niobate single crystals

International Nuclear Information System (INIS)

Bourim, El Mostafa; Moon, Chang-Wook; Lee, Seung-Woon; Kyeong Yoo, In

2006-01-01

The behaviors of thermally stimulated electron emission from pyroelectric monodomain lithium niobate single crystal (LiNbO 3 ) were investigated by utilizing a Si p-n junction photodiode as electron detector and a receptive electron beam resist (E-beam resist) as electron collector. In high vacuum (10 -6 Torr), the pyroelectric electron emission (PEE) was found to depend on the exposed emitting polar crystal surface (+Z face or -Z face) and was significantly influenced by the emitter-electron receiver gap distances. Thus, the PEE from +Z face was detected during heating and was activated, in small gaps ( 2 mm) the emission was simply mastered by field emission effect. Whereas, The PEE from -Z face was detected during cooling and was solely due to the field ionization effect. Therewith, for small gaps ( 2 mm) PEE was governed by field ionization generating a soft and continuous plasma ambient atmosphere. Significant decrease of electron emission current was observed from +Z face after successive thermal cycles. A fast and fully emission recovery was established after a brief exposure of crystal to a poor air vacuum of 10 -1 Torr

Alloying in an Intercalation Host: Metal Titanium Niobates as Anodes for Rechargeable Alkali-Ion Batteries.

Science.gov (United States)

Das, Suman; Swain, Diptikanta; Araujo, Rafael B; Shi, Songxin; Ahuja, Rajeev; Row, Tayur N Guru; Bhattacharyya, Aninda J

2018-02-02

We discuss here a unique flexible non-carbonaceous layered host, namely, metal titanium niobates (M-Ti-niobate, M: Al 3+ , Pb 2+ , Sb 3+ , Ba 2+ , Mg 2+ ), which can synergistically store both lithium ions and sodium ions via a simultaneous intercalation and alloying mechanisms. M-Ti-niobate is formed by ion exchange of the K + ions, which are specifically located inside galleries between the layers formed by edge and corner sharing TiO 6 and NbO 6 octahedral units in the sol-gel synthesized potassium titanium niobate (KTiNbO 5 ). Drastic volume changes (approximately 300-400 %) typically associated with an alloying mechanism of storage are completely tackled chemically by the unique chemical composition and structure of the M-Ti-niobates. The free space between the adjustable Ti/Nb octahedral layers easily accommodates the volume changes. Due to the presence of an optimum amount of multivalent alloying metal ions (50-75 % of total K + ) in the M-Ti-niobate, an efficient alloying reaction takes place directly with ions and completely eliminates any form of mechanical degradation of the electroactive particles. The M-Ti-niobate can be cycled over a wide voltage range (as low as 0.01 V) and displays remarkably stable Li + and Na + ion cyclability (>2 Li + /Na + per formula unit) for widely varying current densities over few hundreds to thousands of successive cycles. The simultaneous intercalation and alloying storage mechanisms is also studied within the density functional theory (DFT) framework. DFT expectedly shows a very small variation in the volume of Al-titanium niobate following lithium alloying. Moreover, the theoretical investigations also conclusively support the occurrence of the alloying process of Li ions with the Al ions along with the intercalation process during discharge. The M-Ti-niobates studied here demonstrate a paradigm shift in chemical design of electrodes and will pave the way for the development of a multitude of improved electrodes

Gold particle formation via photoenhanced deposition on lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Zaniewski, A.M., E-mail: azaniews@asu.edu; Meeks, V.; Nemanich, R.J.

2017-05-31

Highlights: • Gold chloride is reduced into solid gold nanoparticles at the surface of a polarized semiconductor. • Reduction processes are driven by ultraviolet light. • Gold nanoparticle and silver nanoparticle deposition patterns are compared. - Abstract: In this work, we report on a technique to reduce gold chloride into sub-micron particles and nanoparticles. We use photoelectron transfer from periodically polarized lithium niobate (PPLN) illuminated with above band gap light to drive the surface reactions required for the reduction and particle formation. The particle sizes and distributions on the PPLN surface are sensitive to the solution concentration, with inhibited nucleation and large particles (>150 nm) for both low (2E−8M to 9E−7M) and high (1E−5M to 1E−3M) concentrations of gold chloride. At midrange values of the concentration, nucleation is more frequent, resulting in smaller sized particles (<150 nm). We compare the deposition process to that for silver, which has been previously studied. We find that the reduction of gold chloride into nanoparticles is inhibited compared to silver ion reduction, due to the multi-step reaction required for gold particle formation. This also has consequences for the resulting deposition patterns: while silver deposits into nanowires along boundaries between areas with opposite signed polarizations, such patterning of the deposition is not observed for gold, for a wide range of concentrations studied (2E−8 to 1E−3M).

Photorefractive lithium niobate crystals for applications in photonics; Photorefraktive Lithiumniobatkristalle fuer Anwendungen in der Photonik

Energy Technology Data Exchange (ETDEWEB)

Hartwig, U.

2006-12-15

Lithium niobate crystals (LiNbO{sub 3}) generally show a photorefractive response, i.e., light-induced refractive index changes. Crystals are investigated at room temperature and at elevated temperatures. As a result 'classical' photorefractive holographic volume-phase gratings, originating from space charge fields and the electro-optic effect, and 'non-classical' photorefractive volume-phase gratings, which can be traced back to strong absorption gratings, emerge. Single domain and periodically poled crystals (PPLN) are investigated. PPLN is typically used in non-linear optics for frequency conversion. The crystals also show non-linear photorefractive response during holographic recording with isotropically polarized light beams of equal intensity and, in the case of PPLN, by mixing of domain and holographic gratings. The results are important for applications combining the photorefractive and non-linear optical properties of LiNbO{sub 3}. (orig.)

Dual-wavelength green laser with a 4.5 THz frequency difference based on self-frequency- doubling in Nd3+ -doped aperiodically poled lithium niobate.

Science.gov (United States)

Maestre, H; Torregrosa, A J; Fernández-Pousa, C R; Rico, M L; Capmany, J

2008-05-01

We report a dual-wavelength continuous-wave laser at 542.4 and 546.8 nm based on an Nd(3+)-doped aperiodically poled lithium niobate crystal. Two fundamental infrared (IR) wavelengths at 1084.8 and 1093.6 nm are simultaneously oscillated and self-frequency-doubled to green. The aperiodic domain distribution patterned in the crystal allows for quasi-phase matched self-frequency-doubling of both IR fundamentals while avoiding their sum-frequency mixing.

Using a helium--neon laser to convert infrared radiation to visible emission on lithium niobate crystals

Energy Technology Data Exchange (ETDEWEB)

Aurtyunyan, E.A.; Kostanyan, R.B.; Mkrtchyan, V.S.; Mkrtchyan, M.A.

1975-01-01

The conversion of infrared emission to the visible region was investigated by mixing with helium-neon laser emission in lithium niobate crystals. The infrared source was a Globar, and the laser was the LG-75. Emission of the sum frequencies was filtered out. The spectral composition of the converted radiation was analyzed by the ISP-51 spectrograph with an FEU-79 photomultiplier at the output. The amplified photomultiplier signal was recorded by the ChZ-33 frequency meter. By varying the angle between the optical axis of the crystal and the incident emission, infrared radiation in the 1.75 to 3.3 ..mu..m wavelength band could be converted to visible emission. It is suggested that measurement of the wavelength of converted emission might be used to study the distribution of concentration nonhomogeneities in crystals.

Continuous-wave sodium D2 resonance radiation generated in single-pass sum-frequency generation with periodically poled lithium niobate.

Science.gov (United States)

Yue, J; She, C-Y; Williams, B P; Vance, J D; Acott, P E; Kawahara, T D

2009-04-01

With two cw single-mode Nd:YAG lasers at 1064 and 1319 nm and a periodically poled lithium niobate crystal, 11 mW of 2 kHz/100 ms bandwidth single-mode tunable 589 nm cw radiation has been detected using single-pass sum-frequency generation. The demonstrated conversion efficiency is approximately 3.2%[W(-1) cm(-1)]. This compact solid-state light source has been used in a solid-state-dye laser hybrid sodium fluorescence lidar transmitter to measure temperatures and winds in the upper atmosphere (80-105 km); it is being implemented into the transmitter of a mobile all-solid-state sodium temperature and wind lidar under construction.

Thickness, humidity, and polarization dependent ferroelectric switching and conductivity in Mg doped lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Neumayer, Sabine M.; Rodriguez, Brian J., E-mail: brian.rodriguez@ucd.ie [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Strelcov, Evgheni; Kravchenko, Ivan I.; Kalinin, Sergei V. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Manzo, Michele; Gallo, Katia [Department of Applied Physics, KTH - Royal Institute of Technology, Roslagstullbacken 21, 10691 Stockholm (Sweden); Kholkin, Andrei L. [Department of Physics and CICECO-Aveiro Institute of Materials, 3810-193 Aveiro, Portugal and Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

2015-12-28

Mg doped lithium niobate (Mg:LN) exhibits several advantages over undoped LN such as resistance to photorefraction, lower coercive fields, and p-type conductivity that is particularly pronounced at domain walls and opens up a range of applications, e.g., in domain wall electronics. Engineering of precise domain patterns necessitates well founded knowledge of switching kinetics, which can differ significantly from that of undoped LN. In this work, the role of humidity and sample composition in polarization reversal has been investigated under application of the same voltage waveform. Control over domain sizes has been achieved by varying the sample thickness and initial polarization as well as atmospheric conditions. In addition, local introduction of proton exchanged phases allows for inhibition of domain nucleation or destabilization, which can be utilized to modify domain patterns. Polarization dependent current flow, attributed to charged domain walls and band bending, demonstrates the rectifying ability of Mg:LN in combination with suitable metal electrodes that allow for further tailoring of conductivity.

Thickness, humidity, and polarization dependent ferroelectric switching and conductivity in Mg doped lithium niobate

International Nuclear Information System (INIS)

Neumayer, Sabine M.; Rodriguez, Brian J.; Strelcov, Evgheni; Kravchenko, Ivan I.; Kalinin, Sergei V.; Manzo, Michele; Gallo, Katia; Kholkin, Andrei L.

2015-01-01

Mg doped lithium niobate (Mg:LN) exhibits several advantages over undoped LN such as resistance to photorefraction, lower coercive fields, and p-type conductivity that is particularly pronounced at domain walls and opens up a range of applications, e.g., in domain wall electronics. Engineering of precise domain patterns necessitates well founded knowledge of switching kinetics, which can differ significantly from that of undoped LN. In this work, the role of humidity and sample composition in polarization reversal has been investigated under application of the same voltage waveform. Control over domain sizes has been achieved by varying the sample thickness and initial polarization as well as atmospheric conditions. In addition, local introduction of proton exchanged phases allows for inhibition of domain nucleation or destabilization, which can be utilized to modify domain patterns. Polarization dependent current flow, attributed to charged domain walls and band bending, demonstrates the rectifying ability of Mg:LN in combination with suitable metal electrodes that allow for further tailoring of conductivity

Material modifications in lithium niobate and lithium tantalate crystals by ion irradiation; Materialmodifikationen in Lithiumniobat- und Lithiumtantalat-Kristallen durch Ionenbestrahlung

Energy Technology Data Exchange (ETDEWEB)

Raeth, Niels Lennart

2017-02-17

The artificially produced crystals lithium niobate (LiNbO{sub 3}) and the closely related lithium tantalate (LiTaO{sub 3}) are proven starting materials for producing active and passive devices that can guide, amplify, switch and process light. For this purpose, it is often necessary to be able to influence the refractive index of the substrate targeted, which is possible in addition to other methods by irradiation of the materials with fast light ions. In this work, lithium niobate and lithium tantalate crystals are irradiated with alpha particles, {sup 3}He ions, deuterons, and protons at projectile energies of up to 14 MeV / nucleon. Energy and crystal thickness are chosen so that the projectiles penetrate the entire sample and are not implanted. All isotopes responsible for the unwanted nuclear activation of the crystals due to the irradiation are relatively short-lived and overall the activation decreases fast enough to allow the safe handling of the irradiated samples after a storage period of a few days to a few weeks. The refractive index changes produced in lithium niobate and lithium tantalate by irradiation with the different projectiles are determined interferometrically and can also be measured by suitable choice of the sample geometry as a function of the ion penetration depth: In LiNbO{sub 3} the ordinary refractive index decreases, the extraordinary increases equally. In LiTaO{sub 3}, both the ordinary and the extraordinary refractive indices decrease as a result of the irradiation; the ordinary refractive index change is many times stronger than the extraordinary one. There is an enormous long-term stability at room temperature for both crystal systems: Even after eleven (LiNbO{sub 3}) or three (LiTaO{sub 3}) years, no decrease in the ion beam-induced refractive index change can be observed. The ion beam-induced refractive index changes are probably the result of atomic displacements such as vacancies, defect clusters or ''latent tracks

Complex capacitance in the representation of modulus of the lithium niobate crystals

International Nuclear Information System (INIS)

Alim, Mohammad A.; Batra, A.K.; Bhattacharjee, Sudip; Aggarwal, M.D.

2011-01-01

The lithium niobate (LiNbO 3 or LN) single crystal is grown in-house. The ac small-signal electrical characterization is conducted over a temperature range 35≤T≤150 o C as a function of measurement frequency (10≤f≤10 6 Hz). Meaningful observation is noted only in a narrow temperature range 59≤T≤73 o C. These electrical data when analyzed via complex plane formalisms revealed single semicircular relaxation both in the complex capacitance (C * ) and in the modulus (M * ) planes. The physical meaning of this kind of observation is obtained on identifying the relaxation type, and then incorporating respective equivalent circuit model. The simplistic non-blocking nature of the equivalent circuit model obtained via M * -plane is established as the lumped relaxation is identified in the C * -plane. The feature of the eventual equivalent circuit model allows non-blocking aspect for the LN crystal attributing to the presence of the operative dc conduction process. Identification of this leakage dc conduction via C * -plane is portrayed in the M * -plane where the blocking nature is removed. The interacting interpretation between these two complex planes is successfully presented.

Ridge Waveguide Structures in Magnesium-Doped Lithium Niobate

Science.gov (United States)

Himmer, Phillip; Battle, Philip; Suckow, William; Switzer, Greg

2011-01-01

This work proposes to establish the feasibility of fabricating isolated ridge waveguides in 5% MgO:LN. Ridge waveguides in MgO:LN will significantly improve power handling and conversion efficiency, increase photonic component integration, and be well suited to spacebased applications. The key innovation in this effort is to combine recently available large, high-photorefractive-damage-threshold, z-cut 5% MgO:LN with novel ridge fabrication techniques to achieve high-optical power, low-cost, high-volume manufacturing of frequency conversion structures. The proposed ridge waveguide structure should maintain the characteristics of the periodically poled bulk substrate, allowing for the efficient frequency conversion typical of waveguides and the high optical damage threshold and long lifetimes typical of the 5% doped bulk substrate. The low cost and large area of 5% MgO:LN wafers, and the improved performance of the proposed ridge waveguide structure, will enhance existing measurement capabilities as well as reduce the resources required to achieve high-performance specifications. The purpose of the ridge waveguides in MgO:LN is to provide platform technology that will improve optical power handling and conversion efficiency compared to existing waveguide technology. The proposed ridge waveguide is produced using standard microfabrication techniques. The approach is enabled by recent advances in inductively coupled plasma etchers and chemical mechanical planarization techniques. In conjunction with wafer bonding, this fabrication methodology can be used to create arbitrarily shaped waveguides allowing complex optical circuits to be engineered in nonlinear optical materials such as magnesium doped lithium niobate. Researchers here have identified NLO (nonlinear optical) ridge waveguide structures as having suitable value to be the leading frequency conversion structures. Its value is based on having the low-cost fabrication necessary to satisfy the challenging pricing

Enhanced Cherenkov phase matching terahertz wave generation via a magnesium oxide doped lithium niobate ridged waveguide crystal

Directory of Open Access Journals (Sweden)

K. Takeya

2017-01-01

Full Text Available When combined with a nonlinear waveguide crystal, Cherenkov phase matching allows for highly effective generation of high power and broadband terahertz (THz waves. Using a ridged Lithium Niobate (LiNbO3 waveguide coupled with a specially designed silicon lens, we successfully generated THz waves with intensity of approximately three orders of magnitude stronger than those from conventional photoconductive antenna. The broadband spectrum was from 0.1 THz to 7 THz with a maximum dynamic range of 80 dB. The temporal shape of time domain pulse is a regular single cycle which could be used for high depth resolution time of flight tomography. The generated THz wave can also be easily monitored by compact room-temperature THz camera, enabling us to determine the spatial characteristics of the THz propagation.

X-ray absorption spectroscopy investigation of structurally modified lithium niobate crystals

International Nuclear Information System (INIS)

Vitova, Tonya

2008-02-01

The type and concentration of impurity centers in different valence states are crucial for tuning the photorefractive properties of doped Lithium Niobate (LN) crystals. X-ray Absorption Spectroscopy (XAS) is an appropriate tool for studying the local structure of impurity centers. XAS combined with absorption in UV/VIS/IR and High Resolution X-ray Emission Spectroscopy (HRXES) provide information about the valence state of the dopant ions in as-grown, reduced or oxidized doped LN crystals. Cu (Cu 1+ and Cu 2+ ) and Fe (Fe 2+ and Fe 3+ ) atoms are found in two different valence states, whereas there are indications for a third Mn valency, in addition to Mn 2+ and Mn 3+ in manganese-doped LN crystals. One of the charge compensation mechanisms during reduction of copper- doped LN crystals is outgassing of oxygen atoms. Cu ions in the reduced crystals have at least two different site symmetries: twofold (Cu 1+ ) and sixfold (Cu 2+ ) coordinated by O atoms. Fe and Mn atoms are coordinated by six O atoms. Cu and Fe ions are found to occupy only Li sites, whereas Mn ions are also incorporated into Li and Nb sites. The refractive index change in LN crystals irradiated with 3 He 2+ ions is caused by structurally disordered centers, where Nb atoms are displaced from normal crystallographic sites and Li or/and O vacancies are present. (orig.)

Ferroelectric domain inversion and its stability in lithium niobate thin film on insulator with different thicknesses

Energy Technology Data Exchange (ETDEWEB)

Shao, Guang-hao; Bai, Yu-hang; Cui, Guo-xin; Li, Chen; Qiu, Xiang-biao; Wu, Di; Lu, Yan-qing, E-mail: yqlu@nju.edu.cn [National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Geng, De-qiang [Jinan Jingzheng Electronics Co., Ltd., Jinan 250100 (China)

2016-07-15

Ferroelectric domain inversion and its effect on the stability of lithium niobate thin films on insulator (LNOI) are experimentally characterized. Two sets of specimens with different thicknesses varying from submicron to microns are selected. For micron thick samples (∼28 μm), domain structures are achieved by pulsed electric field poling with electrodes patterned via photolithography. No domain structure deterioration has been observed for a month as inspected using polarizing optical microscopy and etching. As for submicron (540 nm) films, large-area domain inversion is realized by scanning a biased conductive tip in a piezoelectric force microscope. A graphic processing method is taken to evaluate the domain retention. A domain life time of 25.0 h is obtained and possible mechanisms are discussed. Our study gives a direct reference for domain structure-related applications of LNOI, including guiding wave nonlinear frequency conversion, nonlinear wavefront tailoring, electro-optic modulation, and piezoelectric devices.

Annealing behaviour of MeV erbium implanted lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Gortmaker, P.; McCallum, J.C. [Royal Melbourne Inst. of Tech., VIC (Australia)

1993-12-31

Lithium niobate (LiNbO{sub 3}) is a crystalline ceramic commonly used in the fabrication of optoelectronic devices. Recently, rare earth doping of LiNbO{sub 3} has become a topic of particular interest. The electronic configuration of rare earth elements such as Erbium (Er) and Neodymium (Nd) allows them to lase in nearly any host matrix making fabrication of a whole range of new optoelectronic devices possible. At present, the doping technique, for LiNbO{sub 3} are centred upon diffusion technology, but the diffusion profiles for the rare earths are not generally well-matched to the optical modes of the device. The aim of this research is to develop MeV implantation and annealing conditions of rare earth doped LiNbO{sub 3} that would be compatible with optoelectronic device fabrication. To determine the characteristics of the rare earth elements in the LiNbO{sub 3} host material over the depth range of interest in optoelectronic device applications, high energy Rutherford backscattering spectrometry and ion channeling (RBS-C) must be used. Presented here are the Er depth profile and lattice damage results obtained from 5 MeV RBS-C measurements on samples of LiNbO{sub 3} implanted with various doses of MeV Erbium and subsequently thermally annealed at a temperature of 1000 deg C. It was found that there is a peak implant concentration (2 x 10{sup 16} Er/cm{sup 2}) for which erbium no longer goes substitutional in the lattice, and the implantation damage is not fully removed by annealing. 8 refs., 3 figs.

Annealing behaviour of MeV erbium implanted lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Gortmaker, P; McCallum, J C [Royal Melbourne Inst. of Tech., VIC (Australia)

1994-12-31

Lithium niobate (LiNbO{sub 3}) is a crystalline ceramic commonly used in the fabrication of optoelectronic devices. Recently, rare earth doping of LiNbO{sub 3} has become a topic of particular interest. The electronic configuration of rare earth elements such as Erbium (Er) and Neodymium (Nd) allows them to lase in nearly any host matrix making fabrication of a whole range of new optoelectronic devices possible. At present, the doping technique, for LiNbO{sub 3} are centred upon diffusion technology, but the diffusion profiles for the rare earths are not generally well-matched to the optical modes of the device. The aim of this research is to develop MeV implantation and annealing conditions of rare earth doped LiNbO{sub 3} that would be compatible with optoelectronic device fabrication. To determine the characteristics of the rare earth elements in the LiNbO{sub 3} host material over the depth range of interest in optoelectronic device applications, high energy Rutherford backscattering spectrometry and ion channeling (RBS-C) must be used. Presented here are the Er depth profile and lattice damage results obtained from 5 MeV RBS-C measurements on samples of LiNbO{sub 3} implanted with various doses of MeV Erbium and subsequently thermally annealed at a temperature of 1000 deg C. It was found that there is a peak implant concentration (2 x 10{sup 16} Er/cm{sup 2}) for which erbium no longer goes substitutional in the lattice, and the implantation damage is not fully removed by annealing. 8 refs., 3 figs.

Synthesis and thermoluminescent characterization of lithium niobate doped with erbium

International Nuclear Information System (INIS)

Landavazo, M.; Brown, F.; Cubillas, F.; Munoz, I.; Cruz Z, E.

2015-10-01

Full text: Lithium niobate (Nl) is a synthetic dielectric and is mainly used in optical devices. There are reports on the thermoluminescent property of Nl monocrystals doped with rare earths and excited with X and gamma rays. In this study the Nl was synthesized and doped with erbium (Er) at concentrations of 1, 2 and 4 % mol and was characterized by its Tl property. The synthesis was realized by solid state reaction at 1000 degrees C for 22 hours and the formation of Nl:Er was confirmed by X-ray diffraction, scanning electron microscopy and EDS analysis, finding a new phase (ErNbO 4 ). Was studied the dose-response gamma in a range of 1-1000 Gy, the material showed linear behavior of 1-600 Gy. The brightness curves have maxima at 185 and 285 degrees C to 1% in 183 and 301 degrees C for 2%, respectively. While for the concentration of 4% a maximum in 177 degrees C accompanied by a smaller peak at higher temperature of the glow curve was observed. The Tl response of Nl:Er 4% to 450 Gy was increased 271 times compared to pure Nl. The reproducibility of the Tl signal at ten cycles of irradiation-reading, present a standard deviation of 5%. In Nl:Er 1% Tl signal fades in 21.3% after 24 hours, while in 2 and 4% an unusual fading occurs. The Tl characteristics of Nl:Er synthesized material is of interest to gamma radiation dosimetry of high doses. (Author)

Iron doping of lithium niobate by thermal diffusion from thin film: study of the treatment effect

Energy Technology Data Exchange (ETDEWEB)

Ciampolillo, Maria Vittoria; Zaltron, Annamaria; Bazzan, Marco; Argiolas, Nicola; Sada, Cinzia [Universita di Padova (Italy); CNISM, Dipartimento di Fisica ' ' G. Galilei' ' , Padova (Italy); Mignoni, Sabrina; Fontana, Marc [Universite de Metz et Supelec, Laboratoire Materiaux Optiques, Photoniques et Systemes, UMR CNRS 7132, Metz (France)

2011-07-15

Thermal diffusion from thin film is one of the most widespread approaches to prepare iron doped regions in lithium niobate with limited size for photorefractive applications. In this work, we investigate the doping process with the aim of determining the best process conditions giving a doped region with the characteristics required for photorefractive applications. Six samples were prepared by changing the atmosphere employed in the diffusion treatment in order to obtain different combination of diffusion profiles and reduction degrees and also to check the effect of employing a wet atmosphere. The compositional, optical, and structural properties are then extensively characterized by combining Secondary ion Mass Spectrometry, UV, visible and IR spectrophotometry, High Resolution X-Rays Diffraction, and Micro-Raman Spectroscopy. Moreover, the sample topography was checked by Atomic Force Microscopy. An analysis of all our data shows that the best results are obtained performing a double step process, i.e. diffusion in oxidizing atmosphere and subsequent reduction at lower temperature in an hydrogen-containing atmosphere. (orig.)

X-ray absorption spectroscopy investigation of structurally modified lithium niobate crystals

Energy Technology Data Exchange (ETDEWEB)

Vitova, Tonya

2008-02-15

The type and concentration of impurity centers in different valence states are crucial for tuning the photorefractive properties of doped Lithium Niobate (LN) crystals. X-ray Absorption Spectroscopy (XAS) is an appropriate tool for studying the local structure of impurity centers. XAS combined with absorption in UV/VIS/IR and High Resolution X-ray Emission Spectroscopy (HRXES) provide information about the valence state of the dopant ions in as-grown, reduced or oxidized doped LN crystals. Cu (Cu{sup 1+} and Cu{sup 2+}) and Fe (Fe{sup 2+} and Fe{sup 3+}) atoms are found in two different valence states, whereas there are indications for a third Mn valency, in addition to Mn{sup 2+} and Mn{sup 3+} in manganese-doped LN crystals. One of the charge compensation mechanisms during reduction of copper- doped LN crystals is outgassing of oxygen atoms. Cu ions in the reduced crystals have at least two different site symmetries: twofold (Cu{sup 1+}) and sixfold (Cu{sup 2+}) coordinated by O atoms. Fe and Mn atoms are coordinated by six O atoms. Cu and Fe ions are found to occupy only Li sites, whereas Mn ions are also incorporated into Li and Nb sites. The refractive index change in LN crystals irradiated with {sup 3}He{sup 2+} ions is caused by structurally disordered centers, where Nb atoms are displaced from normal crystallographic sites and Li or/and O vacancies are present. (orig.)

Effect of additives for higher removal rate in lithium niobate chemical mechanical planarization

International Nuclear Information System (INIS)

Jeong, Sukhoon; Lee, Hyunseop; Cho, Hanchul; Lee, Sangjik; Kim, Hyoungjae; Kim, Sungryul; Park, Jaehong; Jeong, Haedo

2010-01-01

High roughness and a greater number of defects were created by lithium niobate (LN; LiNbO 3 ) processes such as traditional grinding and mechanical polishing (MP), should be decreased for manufacturing LN device. Therefore, an alternative process for gaining defect-free and smooth surface is needed. Chemical mechanical planarization (CMP) is suitable method in the LN process because it uses a combination approach consisting of chemical and mechanical effects. First of all, we investigated the LN CMP process using commercial slurry by changing various process conditions such as down pressure and relative velocity. However, the LN CMP process time using commercial slurry was long to gain a smooth surface because of lower material removal rate (MRR). So, to improve the material removal rate (MRR), the effects of additives such as oxidizer (hydrogen peroxide; H 2 O 2 ) and complexing agent (citric acid; C 6 H 8 O 7 ) in a potassium hydroxide (KOH) based slurry, were investigated. The manufactured slurry consisting of H 2 O 2 -citric acid in the KOH based slurry shows that the MRR of the H 2 O 2 at 2 wt% and the citric acid at 0.06 M was higher than the MRR for other conditions.

Generation and tunable enhancement of a sum-frequency signal in lithium niobate nanowires

Science.gov (United States)

Sergeyev, Anton; Reig Escalé, Marc; Grange, Rachel

2017-02-01

Recent developments in the fabrication of lithium niobate (LiNbO3) structures down to the nanoscale opens up novel applications of this versatile material in nonlinear optics. Current nonlinear optical studies in sub-micron waveguides are mainly restricted to the generation of second and third harmonics. In this work, we demonstrate the generation and waveguiding of the sum-frequency generation (SFG) signal in a single LiNbO3 nanowire with a cross-section of 517 nm  ×  654 nm. Furthermore, we enhance the guided SFG signal 17.9 times by means of modal phase matching. We also display tuning of the phase-matched wavelength by varying the nanowire cross-section and changing the polarization of the incident laser. The results prove that LiNbO3 nanowires can be successfully used for nonlinear wave-mixing applications and assisting the miniaturization of optical devices. , which features invited work from the best early-career researchers working within the scope of J Phys D. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Rachel Grange was selected by the Editorial Board of J Phys D as an Emerging Leader.

Numerical analysis of continuous charge of lithium niobate in a double-crucible Czochralski system using the accelerated crucible rotation technique

Science.gov (United States)

Kitashima, Tomonori; Liu, Lijun; Kitamura, Kenji; Kakimoto, Koichi

2004-05-01

The transport mechanism of supplied raw material in a double-crucible Czochralski system using the accelerated crucible rotation technique (ACRT) was investigated by three-dimensional and time-dependent numerical simulation. The calculation clarified that use of the ACRT resulted in enhancement of the mixing effect of the supplied raw material. It is, therefore, possible to maintain the composition of the melt in an inner crucible during crystal growth by using the ACRT. The effect of the continuous charge of the raw material on melt temperature was also investigated. Our results showed that the effect of feeding lithium niobate granules on melt temperature was small, since the feeding rate of the granules is small. Therefore, solidification of the melt surface due to the heat of fusion in this system is not likely.

Label-free investigation of the effects of lithium niobate polarization on cell adhesion

Science.gov (United States)

Mandracchia, B.; Gennari, O.; Paturzo, M.; Grilli, S.; Ferraro, P.

2017-06-01

The determination of contact area is pivotal to understand how biomaterials properties influence cell adhesion. In particular, the influence of surface charges is well-known but still controversial, especially when new functional materials and methods are introduced. Here, we use for the first time Holographic Total Internal Reflection Microscopy (HoloTIRM) to study the influence of the spontaneous polarization of ferroelectric lithium niobate (LN) on the adhesion properties of fibroblast cells. The selective illumination of a very thin region directly above the substrate, achieved by Total Internal Reflection, provides high-contrast images of the contact regions. Holographic recording, on the other hand, allows for label-free quantitative phase imaging of the contact areas between cells and LN. Phase signal is more sensitive in the first 100nm and, thus more reliable in order to locate focal contacts. This work shows that cells adhering on negatively polarized LN present a significant increase of the contact area in comparison with cells adhering on the positively polarized LN substrate, as well as an intensification of contact vicinity. This confirms the potential of LN as a platform for investigating the role of charges on cellular processes. The similarity of cell adhesion behavior on negatively polarized LN and glass control also confirms the possibility to use LN as an active substrate without impairing cell behavior.

Interface modulated currents in periodically proton exchanged Mg doped lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Neumayer, Sabine M.; Rodriguez, Brian J., E-mail: brian.rodriguez@ucd.ie, E-mail: gallo@kth.se [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Manzo, Michele; Gallo, Katia, E-mail: brian.rodriguez@ucd.ie, E-mail: gallo@kth.se [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 10691 Stockholm (Sweden); Kholkin, Andrei L. [Department of Physics and CICECO-Aveiro Institute of Materials, 3810-193 Aveiro, Portugal and Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

2016-03-21

Conductivity in Mg doped lithium niobate (Mg:LN) plays a key role in the reduction of photorefraction and is therefore widely exploited in optical devices. However, charge transport through Mg:LN and across interfaces such as electrodes also yields potential electronic applications in devices with switchable conductivity states. Furthermore, the introduction of proton exchanged (PE) phases in Mg:LN enhances ionic conductivity, thus providing tailorability of conduction mechanisms and functionality dependent on sample composition. To facilitate the construction and design of such multifunctional electronic devices based on periodically PE Mg:LN or similar ferroelectric semiconductors, fundamental understanding of charge transport in these materials, as well as the impact of internal and external interfaces, is essential. In order to gain insight into polarization and interface dependent conductivity due to band bending, UV illumination, and chemical reactivity, wedge shaped samples consisting of polar oriented Mg:LN and PE phases were investigated using conductive atomic force microscopy. In Mg:LN, three conductivity states (on/off/transient) were observed under UV illumination, controllable by the polarity of the sample and the externally applied electric field. Measurements of currents originating from electrochemical reactions at the metal electrode–PE phase interfaces demonstrate a memresistive and rectifying capability of the PE phase. Furthermore, internal interfaces such as domain walls and Mg:LN–PE phase boundaries were found to play a major role in the accumulation of charge carriers due to polarization gradients, which can lead to increased currents. The insight gained from these findings yield the potential for multifunctional applications such as switchable UV sensitive micro- and nanoelectronic devices and bistable memristors.

III-Nitrides growth and AlGaN/GaN heterostructures on ferroelectric materials

International Nuclear Information System (INIS)

Lee, Kyoung-Keun; Namkoong, Gon; Madison, Shannon M.; Ralph, Stephen E.; Doolittle, W. Alan; Losurdo, Maria; Bruno, Giovanni; Cho, Hyung Koun

2007-01-01

The growth of III-nitrides on the ferroelectric materials lithium niobate (LN) and lithium tantalate (LT) via molecular beam epitaxy (MBE) using rf plasma source has been investigated. We have found that gallium nitride (GaN) epitaxial layers have a crystalline relationship with lithium niobate (tantalate) as follows: (0 0 0 1) GaN || (0 0 0 1) LN (LT) with [10-10] GaN || [11-20] LN (LT). The surface stability of LN and LT substrates has been monitored by in situ spectroscopic ellipsometry in the vacuum chamber. Three different temperature zones have been discerned; surface degas and loss of OH group (100-350 deg. C); surface segregation/accumulation of Li and O-species (400-700 deg. C); surface evaporation of O-species and Li desorption (over 750 deg. C). However, LT shows only surface degassing in the range of 100-800 deg. C. Therefore, congruent LN substrates were chemically unstable at the growth temperature of 550-650 deg. C, and therefore developed an additional phase of Li-deficient lithium niobate (LiNb 3 O 8 ) along with lithium niobate (LiNbO 3 ), confirmed by X-ray diffraction. On the other hand, LT showed better chemical stability at these temperatures, with no additional phase development. The structural quality of GaN epitaxial layers has shown slight improvement on LT substrates over LN substrates, according to X-ray diffraction. Herein, we demonstrate AlGaN/GaN heterostructure devices on ferroelectric materials that will allow future development of multifunctional electrical and optical applications

III-Nitrides growth and AlGaN/GaN heterostructures on ferroelectric materials

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyoung-Keun [Georgia Institute of Technology, School of Electrical and Computer Engineering, 777 Atlantic Dr., Atlanta, GA 30332 (United States); Namkoong, Gon [Old Dominion University, Department of Electrical and Computer Engineering, Norfolk, VA 23529 (United States); Madison, Shannon M. [Georgia Institute of Technology, School of Electrical and Computer Engineering, 777 Atlantic Dr., Atlanta, GA 30332 (United States); Ralph, Stephen E. [Georgia Institute of Technology, School of Electrical and Computer Engineering, 777 Atlantic Dr., Atlanta, GA 30332 (United States); Doolittle, W. Alan [Georgia Institute of Technology, School of Electrical and Computer Engineering, 777 Atlantic Dr., Atlanta, GA 30332 (United States)]. E-mail: alan.doolittle@ece.gatech.edu; Losurdo, Maria [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, Department of Chemistry, University of Bari, via Orabona, 4 70126 Bari (Italy); Bruno, Giovanni [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, Department of Chemistry, University of Bari, via Orabona, 4 70126 Bari (Italy); Cho, Hyung Koun [Department of Materials Science and Engineering, Sung Kyun Kwan University, Suwon 440-746 (Korea, Republic of)

2007-06-15

The growth of III-nitrides on the ferroelectric materials lithium niobate (LN) and lithium tantalate (LT) via molecular beam epitaxy (MBE) using rf plasma source has been investigated. We have found that gallium nitride (GaN) epitaxial layers have a crystalline relationship with lithium niobate (tantalate) as follows: (0 0 0 1) GaN || (0 0 0 1) LN (LT) with [10-10] GaN || [11-20] LN (LT). The surface stability of LN and LT substrates has been monitored by in situ spectroscopic ellipsometry in the vacuum chamber. Three different temperature zones have been discerned; surface degas and loss of OH group (100-350 deg. C); surface segregation/accumulation of Li and O-species (400-700 deg. C); surface evaporation of O-species and Li desorption (over 750 deg. C). However, LT shows only surface degassing in the range of 100-800 deg. C. Therefore, congruent LN substrates were chemically unstable at the growth temperature of 550-650 deg. C, and therefore developed an additional phase of Li-deficient lithium niobate (LiNb{sub 3}O{sub 8}) along with lithium niobate (LiNbO{sub 3}), confirmed by X-ray diffraction. On the other hand, LT showed better chemical stability at these temperatures, with no additional phase development. The structural quality of GaN epitaxial layers has shown slight improvement on LT substrates over LN substrates, according to X-ray diffraction. Herein, we demonstrate AlGaN/GaN heterostructure devices on ferroelectric materials that will allow future development of multifunctional electrical and optical applications.

Imaging the ultrafast Kerr effect, free carrier generation, relaxation and ablation dynamics of Lithium Niobate irradiated with femtosecond laser pulses

Energy Technology Data Exchange (ETDEWEB)

Garcia-Lechuga, Mario, E-mail: mario@io.cfmac.csic.es; Siegel, Jan, E-mail: j.siegel@io.cfmac.csic.es; Hernandez-Rueda, Javier; Solis, Javier [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, 28006 Madrid (Spain)

2014-09-21

The interaction of high-power single 130 femtosecond (fs) laser pulses with the surface of Lithium Niobate is experimentally investigated in this work. The use of fs-resolution time-resolved microscopy allows us to separately observe the instantaneous optical Kerr effect induced by the pulse and the generation of a free electron plasma. The maximum electron density is reached 550 fs after the peak of the Kerr effect, confirming the presence of a delayed carrier generation mechanism. We have also observed the appearance of transient Newton rings during the ablation process, related to optical interference of the probe beam reflected at the front and back surface of the ablating layer. Finally, we have analyzed the dynamics of the photorefractive effect on a much longer time scale by measuring the evolution of the transmittance of the irradiated area for different fluences below the ablation threshold.

Imaging the ultrafast Kerr effect, free carrier generation, relaxation and ablation dynamics of Lithium Niobate irradiated with femtosecond laser pulses

International Nuclear Information System (INIS)

Garcia-Lechuga, Mario; Siegel, Jan; Hernandez-Rueda, Javier; Solis, Javier

2014-01-01

The interaction of high-power single 130 femtosecond (fs) laser pulses with the surface of Lithium Niobate is experimentally investigated in this work. The use of fs-resolution time-resolved microscopy allows us to separately observe the instantaneous optical Kerr effect induced by the pulse and the generation of a free electron plasma. The maximum electron density is reached 550 fs after the peak of the Kerr effect, confirming the presence of a delayed carrier generation mechanism. We have also observed the appearance of transient Newton rings during the ablation process, related to optical interference of the probe beam reflected at the front and back surface of the ablating layer. Finally, we have analyzed the dynamics of the photorefractive effect on a much longer time scale by measuring the evolution of the transmittance of the irradiated area for different fluences below the ablation threshold.

Inscription of type I and depressed cladding waveguides in lithium niobate using a femtosecond laser.

Science.gov (United States)

Bhardwaj, S; Mittholiya, K; Bhatnagar, A; Bernard, R; Dharmadhikari, J A; Mathur, D; Dharmadhikari, A K

2017-07-10

We describe two types of waveguides (type I and depressed cladding) inscribed in lithium niobate using a variable repetition rate (200 kHz-25 MHz), 270 fs duration fiber laser. The type I modification-based waveguides have propagation losses in the range from 1.2 to 10 dB/cm at 1550 nm, depending on experimental parameters. These waveguides are not permanent; they deteriorate over time. Such deterioration of waveguides can be slowed down from 30 days to 100 days by pre-annealing the samples and by writing at a 720 kHz laser repetition rate. The propagation losses measured at 1550 nm show significant improvement for pre-annealed samples. The depressed cladding-inscribed waveguides are permanent, but the propagation loss depends on the number of damage tracks. A track separation of ∼1  μm between adjacent damage tracks yields the lowest propagation loss of 0.5 dB/cm at 1550 nm for a 40 μm diameter waveguide. We observe multimode guidance for sizes in the range of 20-80 μm in these waveguide structures at 1550 nm. Their crystalline nature is found to remain intact, as inferred from second-harmonic generation within the waveguide region.

Domain wall kinetics of lithium niobate single crystals near the hexagonal corner

Energy Technology Data Exchange (ETDEWEB)

Choi, Ju Won [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Ko, Do-Kyeong [Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, GIST, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Yu, Nan Ei, E-mail: neyu@gist.ac.kr, E-mail: jhro@pnu.edu [Advanced Photonics Research Institute, GIST, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Kitamura, Kenji [National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Ro, Jung Hoon, E-mail: neyu@gist.ac.kr, E-mail: jhro@pnu.edu [Department of Biomedical Engineering, School of Medicine, Pusan National University, Busan 602-739 (Korea, Republic of)

2015-03-09

A mesospheric approach based on a simple microscopic 2D Ising model in a hexagonal lattice plane is proposed to explain macroscopic “asymmetric in-out domain wall motion” observation in the (0001) plane of MgO-doped stoichiometric lithium niobate. Under application of an electric field that was higher than the conventional coercive field (E{sub c}) to the ferroelectric crystal, a natural hexagonal domain was obtained with walls that were parallel to the Y-axis of the crystal. When a fraction of the coercive field of around 0.1E{sub c} is applied in the reverse direction, this hexagonal domain is shrunk (moved inward) from the corner site into a shape with a corner angle of around 150° and 15° wall slopes to the Y-axis. A flipped electric field of 0.15E{sub c} is then applied to recover the natural hexagonal shape, and the 150° corner shape changes into a flat wall with 30° slope (moved outward). The differences in corner domain shapes between inward and outward domain motion were analyzed theoretically in terms of corner and wall site energies, which are described using the domain corner angle and wall slope with respect to the crystal Y-axis, respectively. In the inward domain wall motion case, the energy levels of the evolving 150° domain corner and 15° slope walls are most competitive, and could co-exist. In the outward case, the energy levels of corners with angles >180° are highly stable when compared with the possible domain walls; only a flat wall with 30° slope to the Y-axis is possible during outward motion.

Depinning of the ferroelectric domain wall in congruent LiNbO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Lee, Donghwa, E-mail: donghwa96@jnu.ac.kr [School of Materials Science and Engineering, Chonnam National University, Gwangju 61186 (Korea, Republic of); Gopalan, Venkatraman [Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Phillpot, Simon R. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2016-08-22

The high coercive field, E{sub c}, of congruent LiNbO{sub 3} can be reduced by doping with Mg or Zn atoms, or by increasing the temperature above a threshold value. The physical origin for this reduction is not currently understood. Here, density functional theory calculations illustrate the atomic origin of the change in the switching field of the congruent LiNbO{sub 3}. They show that the high E{sub c} in the congruent LiNbO{sub 3} is a result of niobium antisite atoms on the lithium sublattice, pinning the motion of the domain walls. Thus, the healing of antisites by diffusion can significantly reduce the coercive field. In addition, this work demonstrates that the migration of these niobium antisites can be enhanced by doping or by changing the temperature. Thus, the depinning process of the congruent LiNbO{sub 3} is understood by the migration of the niobium antisite defect across the domain wall.

Photonic guiding structures in lithium niobate crystals produced by energetic ion beams

Science.gov (United States)

Chen, Feng

2009-10-01

A range of ion beam techniques have been used to fabricate a variety of photonic guiding structures in the well-known lithium niobate (LiNbO3 or LN) crystals that are of great importance in integrated photonics/optics. This paper reviews the up-to-date research progress of ion-beam-processed LiNbO3 photonic structures and reports on their fabrication, characterization, and applications. Ion beams are being used with this material in a wide range of techniques, as exemplified by the following examples. Ion beam milling/etching can remove the selected surface regions of LiNbO3 crystals via the sputtering effects. Ion implantation and swift ion irradiation can form optical waveguide structures by modifying the surface refractive indices of the LiNbO3 wafers. Crystal ion slicing has been used to obtain bulk-quality LiNbO3 single-crystalline thin films or membranes by exfoliating the implanted layer from the original substrate. Focused ion beams can either generate small structures of micron or submicron dimensions, to realize photonic bandgap crystals in LiNbO3, or directly write surface waveguides or other guiding devices in the crystal. Ion beam-enhanced etching has been extensively applied for micro- or nanostructuring of LiNbO3 surfaces. Methods developed to fabricate a range of photonic guiding structures in LiNbO3 are introduced. Modifications of LiNbO3 through the use of various energetic ion beams, including changes in refractive index and properties related to the photonic guiding structures as well as to the materials (i.e., electro-optic, nonlinear optic, luminescent, and photorefractive features), are overviewed in detail. The application of these LiNbO3 photonic guiding structures in both micro- and nanophotonics are briefly summarized.

Ion-beam enhanced etching for the 3D structuration of lithium niobate

International Nuclear Information System (INIS)

Gischkat, Thomas

2010-01-01

The present thesis deals with the usage of the ion-beam enhanced etching (IBEE) for the 3D structuration of lithium niobate (LiNbO 3 ).Hereby the approach of the enhancement of the wet-chemical etching rate due to the irradiation with energetic ions is pursued. This method is very success promising for the realization of micro- and nanostructures with perpendicular structural walls as well as small roughnesses. The aim of this thesis consisted therein to form the foundations for the realization of three-dimensional micro- and nanostructures (for instance: Layer systems and photonic crystals) in LiNbO 3 with high optical quality and to demonstrate on selected examples. Conditions for the success of the IBEE structuration technique is first of all the understanding of the defect formation under ion irradiation as well as the radiation-induced structure changes in the crystal and the change of the chemical resistance connected with this. For this the defect formation was studied in dependence on th ion mass, the ion energy, and the irradiation temperature. Thermally induced influences and effects on the radiation damage, as they can occur in intermediate steps in the complex processing, must be known and were studied by means of subsequent temperature treatment. The results from the defect studies were subsequently applied for the fabrication of micro- and nanostructures in LiNbO 3 . Shown is the realization of lateral structure with nearly perpendicular structure walls as well as the realization of thin membranes and slits. The subsequent combination of lateral structuration with the fabrication of thin membranes and slits allowed the three-dimensional structuration of LiNbO 3 . This is exemplarily shown for a microresonator and for a 2D photonic crystal with below lying air slit. [de

Interface and thickness dependent domain switching and stability in Mg doped lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Neumayer, Sabine M.; Rodriguez, Brian J., E-mail: gallo@kth.se, E-mail: brian.rodriguez@ucd.ie [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Ivanov, Ilia N. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Manzo, Michele; Gallo, Katia, E-mail: gallo@kth.se, E-mail: brian.rodriguez@ucd.ie [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 10691 Stockholm (Sweden); Kholkin, Andrei L. [Department of Physics and CICECO-Aveiro Institute of Materials, 3810-193 Aveiro (Portugal); Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

2015-12-14

Controlling ferroelectric switching in Mg doped lithium niobate (Mg:LN) is of fundamental importance for optical device and domain wall electronics applications that require precise domain patterns. Stable ferroelectric switching has been previously observed in undoped LN layers above proton exchanged (PE) phases that exhibit reduced polarization, whereas PE layers have been found to inhibit lateral domain growth. Here, Mg doping, which is known to significantly alter ferroelectric switching properties including coercive field and switching currents, is shown to inhibit domain nucleation and stability in Mg:LN above buried PE phases that allow for precise ferroelectric patterning via domain growth control. Furthermore, piezoresponse force microscopy (PFM) and switching spectroscopy PFM reveal that the voltage at which polarization switches from the “up” to the “down” state increases with increasing thickness in pure Mg:LN, whereas the voltage required for stable back switching to the original “up” state does not exhibit this thickness dependence. This behavior is consistent with the presence of an internal frozen defect field. The inhibition of domain nucleation above PE interfaces, observed in this study, is a phenomenon that occurs in Mg:LN but not in undoped samples and is mainly ascribed to a remaining frozen polarization in the PE phase that opposes polarization reversal. This reduced frozen depolarization field in the PE phase also influences the depolarization field of the Mg:LN layer above due to the presence of uncompensated polarization charge at the PE-Mg:LN boundary. These alterations in internal electric fields within the sample cause long-range lattice distortions in Mg:LN via electromechanical coupling, which were corroborated with complimentary Raman measurements.

Noise Analysis of Second-Harmonic Generation in Undoped and MgO-Doped Periodically Poled Lithium Niobate

Directory of Open Access Journals (Sweden)

Yong Wang

2008-01-01

Full Text Available Noise characteristics of second-harmonic generation (SHG in periodically poled lithium niobate (PPLN using the quasiphase matching (QPM technique are analyzed experimentally. In the experiment, a0.78 μm second-harmonic (SH wave was generated when a 1.56 μm fundamental wave passed through a PPLN crystal (bulk or waveguide. The time-domain and frequency-domain noise characteristics of the fundamental and SH waves were analyzed. By using the pump-probe method, the noise characteristics of SHG were further analyzed when a visible light (532 nm and an infrared light (1090 nm copropagated with the fundamental light, respectively. The noise characterizations were also investigated at different temperatures. It is found that for the bulk and waveguide PPLN crystals, the SH wave has a higher relative noise level than the corresponding fundamental wave. For the same fundamental wave, the SH wave has lower noise in a bulk crystal than in a waveguide, and in MgO-doped PPLN than in undoped PPLN. The 532 nm irradiation can lead to higher noise in PPLN than the 1090 nm irradiation. In addition, increasing temperature of device can alleviate the problem of noise in conjunction with the photorefractive effect incurred by the irradiation light. This is more significant in undoped PPLN than in MgO-doped one.

Systematic hardness studies on lithium niobate crystals

Indian Academy of Sciences (India)

Unknown

crystals with different growth origins, and a Fe-doped sample. The problem of load ... The true hardness of LiNbO3 is found to be 630 ± 30 kg/mm2. .... Experimental. Pure lithium ... the index of d strikes at this simple and meaningful defini-.

Sub-nanosecond periodically poled lithium niobate optical parametric generator and amplifier pumped by an actively Q-switched diode-pumped Nd:YAG microlaser

Science.gov (United States)

Liu, L.; Wang, H. Y.; Ning, Y.; Shen, C.; Si, L.; Yang, Y.; Bao, Q. L.; Ren, G.

2017-05-01

A sub-nanosecond seeded optical parametric generator (OPG) based on magnesium oxide-doped periodically poled lithium niobate (MgO:PPLN) crystal is presented. Pumped by an actively Q-switched diode-pumped 1 kHz, 1064 nm, Nd:YAG microlaser and seeded with a low power distributed feedback (DFB) diode continuous-wave (CW) laser, the OPG generated an output energy of 41.4 µJ and 681 ps pulse duration for the signal at 1652.4 nm, achieving a quantum conversion efficiency of 61.2% and a slope efficiency of 41.8%. Signal tuning was achieved from 1651.0 to 1652.4 nm by tuning the seed-laser current. The FWHM of the signal spectrum was approximately from 35 nm to 0.5 nm by injection seed laser. The SHG doubled the frequency of OPG signal to produce a output energy of 12 µJ with the energy conversion efficiency of 29.0% and tunanble wavelength near 826 nm.

Primordial lithium abundance from interstellar lithium lines towards SN 1987A

International Nuclear Information System (INIS)

Sahu, K.C.; Pottasch, S.R.; Sahu, M.

1989-01-01

The primoridal lithium abundance is known to be one of the best probes to test the standard as well as the non-standard Big Bang nucleosynthesis theories, and to measure the nucleon abundance in the early universe in the standard Big Bang (SSB) model. We have obtained high-resolution ((λ)/(δλ)congruent 100,000), high signal-to-noise (S/N approx-gt 1,500) spectra of SN 1987A around the Li:I λ6708 A region, using the ESO 1.4m CAT and the Coude Echelle Spectrograph. The non-detection of any lithium feature in our sepctra places an upper limit on the lithium abundance

Nonlinear excitations and charge transport in lithium niobate crystals investigated using femtosecond-light gratings; Nichtlineare Anregungen und Ladungstransport in Lithiumniobatkristallen untersucht mit Femtosekunden-Lichtgittern

Energy Technology Data Exchange (ETDEWEB)

Maxein, Karl Dominik

2009-12-15

Lithium niobate (LiNbO{sub 3}) is a widely employed material in nonlinear optics and photonics. Its usage is hampered by the photorefractive effect, which can destroy beam profiles and phase matching conditions. Existing methods to suppress photorefraction fail for the interesting regime of very high intensities and short pulses. Therefore, the photorefractive effect is investigated using femtosecond laser pulses: By utilizing so-called 2K holography, the occupation of energetically shallow traps is observed to occur in less than 100 fs after a two-photon excitation. Writing of photorefractive gratings into oxidized iron-doped LiNbO{sub 3} is much faster with pulses than with cw light. This is explained by the sensitization of the crystal due to charge trapping in photorefractive centers after nonlinear excitations. Finally, light-induced scattering of pulse light is suppressed compared to the scattering of cw light due to the small coherence length of pulses. (orig.)

More efficient second harmonic generation of whispering gallery modes by selective out-coupling

OpenAIRE

Trainor, Luke S.; Sedlmeir, Florian; Peuntinger, Christian; Schwefel, Harald G. L.

2017-01-01

We demonstrate second harmonic generation (SHG) in an $x$-cut congruent lithium niobate (LN) whispering gallery mode resonator. We first show theoretically that independent control of the coupling of the pump and signal modes is optimal for high conversion rates. A scheme based on our earlier work in Ref. [1] is then implemented experimentally to verify this. Thereby we are able to improve on the efficiency of SHG by more than an order of magnitude by selectively out-coupling using a LN prism...

Optical properties of nanocrystalline potassium lithium niobate in the glass system (100-x) TeO2-x(1.5K2O-Li2O-2.5Nb2O5).

Science.gov (United States)

Ahamad, M Niyaz; Varma, K B R

2009-08-01

Optically clear glasses of various compositions in the system (100-x) TeO2-x(1.5K2O-Li2O-2.5Nb2O5) (2 glasses comprising potassium lithium niobate (K3Li2Nb5O15) microcrystallites on the surface and nanocrystallites within the glass were obtained by controlled heat-treatment of the as-quenched glasses just above the glass transition temperature (T(g)). The optical transmission spectra of these glasses and glass-crystal composites of various compositions were recorded in the 200-2500 nm wavelength range. Various optical parameters such as optical band gap, Urbach energy, refractive index were determined. Second order optical non-linearity was established in the heat-treated samples by employing the Maker-Fringe method.

Optical properties of calcium barium niobate

Energy Technology Data Exchange (ETDEWEB)

Heine, Urs; Betzler, Klaus [Department of Physics, University of Osnabrueck (Germany); Burianek, Manfred; Muehlberg, Manfred [Institute of Crystallography, University of Cologne (Germany)

2010-07-01

We report on optical measurements on the novel tungsten bronze type calcium barium niobate. [001]-oriented transparent and colorless single crystals were grown by the Czochralski method with dimensions of 12 mm in diameter and about 80 mm in length. With its relatively high Curie temperature of about 538 K for the congruently melting composition of 28.1 mole% calcium and its high nonlinear coefficients, CBN is a promising material for future applications. Recent experiments revealed, that the application of an external electric field of several kV/cm to CBN at room temperature leads to an increasing opacity of the sample. This might be a drawback considering the future usability of CBN in optical systems. We present investigations on the transmittance behaviour of CBN under external electric fields, demonstrating the erasement of the clouding without affecting the polarization. Experiments have been performed at temperatures ranging from room temperature to approximately 480 K. When heating up the sample, its colorless appearance changes to a light yellow, which can be attributed to a shift of the band edge to longer wavelengths with increasing temperature. To further investigate the transmittance properties of CBN, measurements of the band edge under various temperatures up to the ferroelectric phase transition have been performed.

Piezoelectric and ferroelectric properties of lead-free niobium-rich potassium lithium tantalate niobate single crystals

Energy Technology Data Exchange (ETDEWEB)

Li, Jun, E-mail: lijuna@hit.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Li, Yang [Department of chemistry, Harbin Institute of Technology, Harbin 150001 (China); Zhou, Zhongxiang [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Guo, Ruyan; Bhalla, Amar S. [Multifunctional Electronic Materials and Device Research Lab, Department of Electrical and Computer Engineering, The University of Texas at San Antonio, San Antonio 78249 (United States)

2014-01-01

Graphical abstract: - Highlights: • Lead-free K{sub 0.95}Li{sub 0.05}Ta{sub 1−x}Nb{sub x}O{sub 3} single crystals were grown using the top-seeded melt growth method. • The piezoelectric and ferroelectric properties of as-grown crystals were systematically investigated. • The piezoelectric properties are very attractive, e.g. for x = 0.60 composition, k{sub t} ≈ 70%, k{sub 31} ≈ 70%, k{sub 33} ≈ 77%, d{sub 31} ≈ 230 pC/N, d{sub 33} ≈ 600 pC/N. • The coercive fields of P–E hysteresis loops are quite small, about or less than 1 kV/mm. - Abstract: Lead-free potassium lithium tantalate niobate single crystals with the composition of K{sub 0.95}Li{sub 0.05}Ta{sub 1−x}Nb{sub x}O{sub 3} (abbreviated as KLTN, x = 0.51, 0.60, 0.69, 0.78) were grown using the top-seeded melt growth method. Their piezoelectric and ferroelectric properties in as-grown crystals have been systematically investigated. The phase transitions and Curie temperatures were determined from dielectric and pyroelectric measurements. Piezoelectric coefficients and electromechanical coupling factors in thickness mode, length-extensional mode and longitudinal mode were obtained. The piezoelectric properties are very attractive, e.g. for x = 0.60 composition, k{sub t} ≈ 70%, k{sub 31} ≈ 70%, k{sub 33} ≈ 77%, d{sub 31} ≈ 230 pC/N, d{sub 33} ≈ 600 pC/N are comparable to the lead-based PZT composition. The polarization versus electric field hysteresis loops show saturated shapes. In short, lead-free niobium-rich KLTN system possesses comparable properties to those in important lead-based piezoelectric material nowadays.

Luminescence life time and time-resolved spectroscopy of Cr3+ ions in strontium barium niobate

International Nuclear Information System (INIS)

Han, T.P.J.; Jaque, F.; Jaque, D.; Garcia-Sole, J.; Ivleva, L.

2006-01-01

This paper reports on the photo-luminescence spectroscopic results of congruent strontium-barium-niobate (SBN) crystals doped with Cr 2 O, at cryogenic temperature (20 K). The experimental results reveal the need of re-assignment of the Cr 3+ ions defect centres in this material. For first time, a broad emission band in the near infrared region centred at ca. 950 nm is reported. This emission band has micro-seconds decaytime constant and a band-width full-width at half-maximum (FWHM) larger than 1700 cm -1 and has been ascribed to the vibronically assisted 4 T 2 →4 A 2 transition. A much narrower emission band centred at ca. 764 nm with milli-seconds decaytime constant and a FWHM band-width of ca. 170 cm -1 is correlated to the 2 E →4 A 2 radiative transition (R-line)

Catalytic oxidation of soot over alkaline niobates

International Nuclear Information System (INIS)

Pecchi, G.; Cabrera, B.; Buljan, A.; Delgado, E.J.; Gordon, A.L.; Jimenez, R.

2013-01-01

Highlights: ► No previous reported studies about alkaline niobates as catalysts for soot oxidation. ► NaNbO 3 and KNbO 3 perovskite-type oxides show lower activation energy than other lanthanoid perovskite-type oxides. ► The alkaline niobate does not show deactivation by metal loss. - Abstract: The lack of studies in the current literature about the assessment of alkaline niobates as catalysts for soot oxidation has motivated this research. In this study, the synthesis, characterization and assessment of alkaline metal niobates as catalysts for soot combustion are reported. The solids MNbO 3 (M = Li, Na, K, Rb) are synthesized by a citrate method, calcined at 450 °C, 550 °C, 650 °C, 750 °C, and characterized by AAS, N 2 adsorption, XRD, O 2 -TPD, FTIR and SEM. All the alkaline niobates show catalytic activity for soot combustion, and the activity depends basically on the nature of the alkaline metal and the calcination temperature. The highest catalytic activity, expressed as the temperature at which combustion of carbon black occurs at the maximum rate, is shown by KNbO 3 calcined at 650 °C. At this calcination temperature, the catalytic activity follows an order dependent on the atomic number, namely: KNbO 3 > NaNbO 3 > LiNbO 3 . The RbNbO 3 solid do not follow this trend presumably due to the perovskite structure was not reached. The highest catalytic activity shown by of KNbO 3 , despite the lower apparent activation energy of NaNbO 3 , stress the importance of the metal nature and suggests the hypothesis that K + ions are the active sites for soot combustion. It must be pointed out that alkaline niobate subjected to consecutive soot combustion cycles does not show deactivation by metal loss, due to the stabilization of the alkaline metal inside the perovskite structure.

Optimized Wavelength-Tuned Nonlinear Frequency Conversion Using a Liquid Crystal Clad Waveguide

Science.gov (United States)

Stephen, Mark A. (Inventor)

2018-01-01

An optimized wavelength-tuned nonlinear frequency conversion process using a liquid crystal clad waveguide. The process includes implanting ions on a top surface of a lithium niobate crystal to form an ion implanted lithium niobate layer. The process also includes utilizing a tunable refractive index of a liquid crystal to rapidly change an effective index of the lithium niobate crystal.

The use of one-dimensional Niobate to improve MgH{sub 2} hydrogen sorption

Energy Technology Data Exchange (ETDEWEB)

Brum, M.C., E-mail: mbrum@metalmat.ufrj.br; Conceição, M.O.T. da; Jardim, P.M.; Santos, D.S. dos

2014-12-05

Highlights: • The 1-D Niobate W and Niobate C catalysts were synthesized. • The composites MgH{sub 2} + 5 wt.% catalysts were obtained by 20 min of mechanical milling. • The synthesized wired-like material 1-D Niobate W showed to be a promising catalyst. • A desorption capacity of 6.0 wt.%. of H{sub 2} was attained in 10 min with MgH{sub 2} + 5 wt.% 1-D Niobate W. - Abstract: A study was performed on the hydrogen absorption/desorption properties of MgH{sub 2} with the addition of Niobates synthesized by hydrothermal treatment of Nb{sub 2}O{sub 5} in 10 M NaOH. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) were used to evaluate their synthesis and show the morphological and crystallographic differences between Nb{sub 2}O{sub 5} used as a precursor and the Niobates produced, the one-dimensional wired type, 1-D Niobate W and the cuboid one, Niobate C. The ball milling of MgH{sub 2} with the Niobates was performed within only 20 min and afterwards the Differential Scanning Calorimetry (DSC) examination of MgH{sub 2} + 1-D Niobate W and MgH{sub 2} + Niobate C showed the shifting of the peaks for both composites in comparison to pure MgH{sub 2}. The influence of the two different types of Niobates and also the Nb{sub 2}O{sub 5} on the hydrogen absorption/desorption capacity was evaluated at 350 °C. The higher absorption and desorption values were attained by the MgH{sub 2} + 5 wt.% 1-D Niobate W composite, reaching, in 10 min, approximately 5.0 wt.% and 6.0 wt.%, respectively. The possible mechanism involved in such property improvement upon adding niobium based catalysts with different morphology and structure was discussed.

High-temperature thermal conductivity of uranium chromite and uranium niobate

International Nuclear Information System (INIS)

Fedoseev, D.V.; Varshavskaya, I.G.; Lavrent'ev, A.V.; Oziraner, S.N.; Kuznetsova, D.G.

1979-01-01

The technique of determining thermal conductivity coefficient of uranium niobate and uranium chromite on heating with laser radiation is described. Determined is the coefficient of free-convective heat transfer (with provision for a conduction component) by means of a standard specimen. The thermal conductivity coefficients of uranium chromite and niobate were measured in the 1300-1700 K temperature range. The results are presented in a diagram form. It has been calculated, that the thermal conductivity coefficient for uranium niobate specimens is greater in comparison with uranium chromite specimens. The thermal conductivity coefficients of the materials mentioned depend on temperature very slightly. Thermal conductivity of the materials considerably depends on their porosity. The specimens under investigation were fabricated by the pressing method and had the following porosity: uranium chromite - 30 %, uranium niobate - 10 %. Calculation results show, that thermal conductivity of dense uranium chromite is higher than thermal conductivity of dense uranium niobate. The experimental error equals approximately 20 %, that is mainly due to the error of measuring the temperature equal to +-25 deg, with a micropyrometer

Thermal plasma fabricated lithium niobate-tantalate films on sapphire substrate

International Nuclear Information System (INIS)

Kulinich, S.A.; Yoshida, T.; Yamamoto, H.; Terashima, K.

2003-01-01

We report the deposition of LiNb 1-x Ta x O 3 (0≤x≤1) films on (001) sapphire substrates in soft vacuum using a radio frequency thermal plasma. The growth rate, crystallinity, c-axis orientation, and surface roughness were examined as functions of substrate temperature, precursor feed rate, and substrate surface condition. The film Nb/Ta ratio was well controlled by using an appropriate uniform mixture of lithium-niobium and lithium-tantalum alkoxide solutions. The epitaxy and crystallinity of the films were much improved when the film growth rate was raised from 20 to 180-380 nm/min, where the films with the (006) rocking curve full width at half maximum values as low as 0.12 deg. -0.2 deg. could be produced. The film roughness could be reduced by using a liquid precursor with higher metal concentrations, achieving the root-mean-square value on the order of 5 nm. The refractive indices of the films are in good correspondence with their composition and crystallinity

Characterization and control of the electro-optic phase dispersion in lithium niobate modulators for wide spectral band interferometry applications in the mid-infrared.

Science.gov (United States)

Heidmann, S; Ulliac, G; Courjal, N; Martin, G

2017-05-10

Mid-infrared wideband modulation (3.2-3.7 μm) is achieved in an electro-optic Y-junction using lithium niobate waveguides in TE polarized light. Comparison between external (scanning mirror) and internal (electro-optical) modulation allows studying the chromatic polynomial dependence of the relative phase. Internal modulation consists on a V AC ramp up to 370 V at 0.25 Hz, applied over 14 mm long electrodes with 14 μm separation. The overall V π L π obtained is 17.5 V·cm, meaning that using a 300 V generator we can actively scan and track the whole L-band (3.4-4.1 μm) wideband fringes. We observe a dramatic reduction of the coherence length under electro-optic modulation, which is attributed to a strong nonlinear dependence of the electro-optic effect on the wavelength upon application of such high voltages. We study the effect of applying a V DC offset, from -50  V to 200 V (50 V step). We characterize this dispersion and propose an improved dispersion model that is used to show active dispersion compensation in wideband fringe modulation in the mid-infrared. This can be useful for long baseline interferometry or pulse compression applications when light propagates along fibers, in order to compensate for chromatic effects that induce differential dispersion or pulse spreading, respectively.

Molecular Beam Epitaxy Growth of High Crystalline Quality LiNbO3

Science.gov (United States)

Tellekamp, M. Brooks; Shank, Joshua C.; Goorsky, Mark S.; Doolittle, W. Alan

2016-12-01

Lithium niobate is a multi-functional material with wide reaching applications in acoustics, optics, and electronics. Commercial applications for lithium niobate require high crystalline quality currently limited to bulk and ion sliced material. Thin film lithium niobate is an attractive option for a variety of integrated devices, but the research effort has been stagnant due to poor material quality. Both lattice matched and mismatched lithium niobate are grown by molecular beam epitaxy and studied to understand the role of substrate and temperature on nucleation conditions and material quality. Growth on sapphire produces partially coalesced columnar grains with atomically flat plateaus and no twin planes. A symmetric rocking curve shows a narrow linewidth with a full width at half-maximum (FWHM) of 8.6 arcsec (0.0024°), which is comparable to the 5.8 arcsec rocking curve FWHM of the substrate, while the film asymmetric rocking curve is 510 arcsec FWHM. These values indicate that the individual grains are relatively free of long-range disorder detectable by x-ray diffraction with minimal measurable tilt and twist and represents the highest structural quality epitaxial material grown on lattice mismatched sapphire without twin planes. Lithium niobate is also grown on lithium tantalate producing high quality coalesced material without twin planes and with a symmetric rocking curve of 193 arcsec, which is nearly equal to the substrate rocking curve of 194 arcsec. The surface morphology of lithium niobate on lithium tantalate is shown to be atomically flat by atomic force microscopy.

Comparative study of 0° X-cut and Y + 36°-cut lithium niobate high-voltage sensing

Science.gov (United States)

Patel, N.; Branch, D. W.; Schamiloglu, E.; Cular, S.

2015-08-01

A comparison study between Y + 36° and 0° X-cut lithium niobate (LiNbO3) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y + 36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to both crystals, the voltage-induced shift scaled linearly with voltage. For the Y + 36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz-100 kHz. Using the same conditions as the Y + 36° cut, the 0° X-cut crystal sensed a shift of 10-273 ps for DC voltages and 189-813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250-2 ns and the Y + 36°-cut crystal sensed a time shift of 0.115-1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. When the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment.

Giant piezoelectricity in potassium-sodium niobate lead-free ceramics.

Science.gov (United States)

Wang, Xiaopeng; Wu, Jiagang; Xiao, Dingquan; Zhu, Jianguo; Cheng, Xiaojing; Zheng, Ting; Zhang, Binyu; Lou, Xiaojie; Wang, Xiangjian

2014-02-19

Environment protection and human health concern is the driving force to eliminate the lead from commercial piezoelectric materials. In 2004, Saito et al. [ Saito et al., Nature , 2004 , 432 , 84 . ] developed an alkali niobate-based perovskite solid solution with a peak piezoelectric constant d33 of 416 pC/N when prepared in the textured polycrystalline form, intriguing the enthusiasm of developing high-performance lead-free piezoceramics. Although much attention has been paid on the alkali niobate-based system in the past ten years, no significant breakthrough in its d33 has yet been attained. Here, we report an alkali niobate-based lead-free piezoceramic with the largest d33 of ∼490 pC/N ever reported so far using conventional solid-state method. In addition, this material system also exhibits excellent integrated performance with d33∼390-490 pC/N and TC∼217-304 °C by optimizing the compositions. This giant d33 of the alkali niobate-based lead-free piezoceramics is ascribed to not only the construction of a new rhombohedral-tetragonal phase boundary but also enhanced dielectric and ferroelectric properties. Our finding may pave the way for "lead-free at last".

Synthesis and thermoluminescent characterization of lithium niobate doped with erbium; Sintesis y caracterizacion termoluminiscente de niobato de litio impurificado con erbio

Energy Technology Data Exchange (ETDEWEB)

Landavazo, M.; Brown, F.; Cubillas, F. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Blvd. Luis Encinas y Rosales s/n, 83000 Hermosillo, Sonora (Mexico); Munoz, I. [Universidad de Sonora, Departamento de Ciencias Quimico Biologicas, 83000 Hermosillo, Sonora (Mexico); Cruz Z, E., E-mail: imunoz@polimeros.uson.mx [UNAM, Instituto de Ciencias Nucleares, Apdo. Postal 70-543, 04510 Mexico D. F. (Mexico)

2015-10-15

Full text: Lithium niobate (Nl) is a synthetic dielectric and is mainly used in optical devices. There are reports on the thermoluminescent property of Nl monocrystals doped with rare earths and excited with X and gamma rays. In this study the Nl was synthesized and doped with erbium (Er) at concentrations of 1, 2 and 4 % mol and was characterized by its Tl property. The synthesis was realized by solid state reaction at 1000 degrees C for 22 hours and the formation of Nl:Er was confirmed by X-ray diffraction, scanning electron microscopy and EDS analysis, finding a new phase (ErNbO{sub 4}). Was studied the dose-response gamma in a range of 1-1000 Gy, the material showed linear behavior of 1-600 Gy. The brightness curves have maxima at 185 and 285 degrees C to 1% in 183 and 301 degrees C for 2%, respectively. While for the concentration of 4% a maximum in 177 degrees C accompanied by a smaller peak at higher temperature of the glow curve was observed. The Tl response of Nl:Er 4% to 450 Gy was increased 271 times compared to pure Nl. The reproducibility of the Tl signal at ten cycles of irradiation-reading, present a standard deviation of 5%. In Nl:Er 1% Tl signal fades in 21.3% after 24 hours, while in 2 and 4% an unusual fading occurs. The Tl characteristics of Nl:Er synthesized material is of interest to gamma radiation dosimetry of high doses. (Author)

Macroscopic polarization and thermoluminescence of barium niobate - sodium niobate

International Nuclear Information System (INIS)

Gorban', I.S.; Gumenyuk, A.F.; Omel'yanenko, V.A.

1989-01-01

Thermoluminescence (TL) of initial and thermally treated purposely undoped crystals of barium niobate - sodium has been studied within 85-400 K. The TL intensity is found to depend on the temperature to which the sample has been heated. A conclusion is drawn that nonstationarity of the TL properties is due to slowly occuring processes of compensation of pyrocharge, which depend on the temperatural prehistory of the sample. A mechanism of the traps transformation in a strong pyrofield of high-impedance crystals is discussed

Rare-Earth Tantalates and Niobates Single Crystals: Promising Scintillators and Laser Materials

Directory of Open Access Journals (Sweden)

Renqin Dou

2018-01-01

Full Text Available Rare-earth tantalates, with high density and monoclinic structure, and niobates with monoclinic structure have been paid great attention as potential optical materials. In the last decade, we focused on the crystal growth technology of rare-earth tantalates and niobates and studied their luminescence and physical properties. A series of rare-earth tantalates and niobates crystals have been grown by the Czochralski method successfully. In this work, we summarize the research results on the crystal growth, scintillation, and laser properties of them, including the absorption and emission spectra, spectral parameters, energy levels structure, and so on. Most of the tantalates and niobates exhibit excellent luminescent properties, rich physical properties, and good chemical stability, indicating that they are potential outstanding scintillators and laser materials.

The effects of dopants on the electrical resistivity in lead magnesium niobate multilayer ceramic capacitors

International Nuclear Information System (INIS)

Chang, D.D.; Ling, H.C.

1989-01-01

Electrical resistivity studies were performed on multilayer ceramic capacitors (MLC) based on lead magnesium niobate and containing dopants of lead titanate, lead zinc niobate, and lead cobalt niobate. The results showed that lead titanate and/or lead zinc niobate had no effect on the electrical resistivity while lead cobalt niobate decreased the resistivity. In samples without lead cobalt niobate, we observed a conduction mechanism with an activation energy of --1 eV, which is commonly observed in barium titanate based dielectrics. This is attributed to ionic conduction via the motion of oxygen vacancies. The increase in conductivity (or decrease in resistivity) resulting from the addition of lead cobalt niobate was rationalized as due to electronic conduction through charge hopping among the cations. This conduction mechanism was characterized by an activation energy of --0.5 eV. Since the activation energy associated with the long-term failure was previously determined by a matrix of temperature and voltage accelerated life tests to be -- 1 eV, they conclude that conduction through charge hopping is not affecting the long-term reliability of these devices

New, dense, and fast scintillators based on rare-earth tantalo-niobates

International Nuclear Information System (INIS)

Voloshyna, O.V.; Boiaryntseva, I.A.; Baumer, V.N.; Ivanov, A.I.; Korjik, M.V.; Sidletskiy, O.Ts.

2014-01-01

Samples of undoped yttrium and gadolinium tantalo-niobates with common formulae RE(Nb x Ta 1−x )O 4 , where RE=Y or Gd and x=0–1, have been obtained by solid-state reaction. Systematic study of structural, luminescent, and scintillation properties of these compounds was carried out. Lattice parameters and space groups of the mixed compounds were identified. UV- and X-ray luminescence spectra, as well as relative light outputs and scintillation decay times are measured. Gadolinium tantalo-niobate with the formulae GdNb 0.2 Ta 0.8 O 4 showed the light output around 13 times larger than PbWO 4 and fast decay with time constant 12 ns without additional slow component. Gadolinium tantalo-niobates may be considered as promising materials for high energy physics due to extremely high density, substantial light output, and fast decay. -- Highlights: •Structural, optical and scintillation properties of the rare earth tantalo-niobates were studied. •Light output shows about gradual increase with Nb content in GdTa x Nb 1−x O 4 . •Light output increases by 2–7 times relatively to yttrium tantalate and niobate in YTa x Nb 1−x O 4 . •GdTa 0.8 Nb 0.2 O 4 demonstrates the most promising scintillation parameters

Comparative study of 0° X-cut and Y + 36°-cut lithium niobate high-voltage sensing

International Nuclear Information System (INIS)

Patel, N.; Branch, D. W.; Cular, S.; Schamiloglu, E.

2015-01-01

A comparison study between Y + 36° and 0° X-cut lithium niobate (LiNbO 3 ) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y + 36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to both crystals, the voltage-induced shift scaled linearly with voltage. For the Y + 36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz–100 kHz. Using the same conditions as the Y + 36° cut, the 0° X-cut crystal sensed a shift of 10–273 ps for DC voltages and 189–813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250–2 ns and the Y + 36°-cut crystal sensed a time shift of 0.115–1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. When the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment

Nb 3d and O 1s core levels and chemical bonding in niobates

International Nuclear Information System (INIS)

Atuchin, V.V.; Kalabin, I.E.; Kesler, V.G.; Pervukhina, N.V.

2005-01-01

A set of available experimental data on binding energies of Nb 3d 5/2 and O 1s core levels in niobates has been observed with using energy difference (O 1s-Nb 3d 5/2 ) as a robust parameter for compound characterization. An empirical relationship between (O 1s-Nb 3d 5/2 ) values measured with XPS for Nb 5+ -niobates and mean chemical bond length L(Nb-O) has been discussed. A range of (O 1s-Nb 3d 5/2 ) values possible in Nb 5+ -niobates has been defined. An energy gap ∼1.4-1.8 eV is found between (O 1s-Nb 3d 5/2 ) values reasonable for Nb 5+ and Nb 4+ states in niobates

Nb 3d and O 1s core levels and chemical bonding in niobates

Energy Technology Data Exchange (ETDEWEB)

Atuchin, V.V. [Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090 (Russian Federation)]. E-mail: atuchin@thermo.isp.nsc.ru; Kalabin, I.E. [Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090 (Russian Federation); Kesler, V.G. [Technical Center, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090 (Russian Federation); Pervukhina, N.V. [Laboratory of Crystal Chemistry, Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation)

2005-02-01

A set of available experimental data on binding energies of Nb 3d{sub 5/2} and O 1s core levels in niobates has been observed with using energy difference (O 1s-Nb 3d{sub 5/2}) as a robust parameter for compound characterization. An empirical relationship between (O 1s-Nb 3d{sub 5/2}) values measured with XPS for Nb{sup 5+}-niobates and mean chemical bond length L(Nb-O) has been discussed. A range of (O 1s-Nb 3d{sub 5/2}) values possible in Nb{sup 5+}-niobates has been defined. An energy gap {approx}1.4-1.8 eV is found between (O 1s-Nb 3d{sub 5/2}) values reasonable for Nb{sup 5+} and Nb{sup 4+} states in niobates.

Shape of isolated domains in lithium tantalate single crystals at elevated temperatures

International Nuclear Information System (INIS)

Shur, V. Ya.; Akhmatkhanov, A. R.; Baturin, I. S.; Chezganov, D. S.; Lobov, A. I.; Smirnov, M. M.

2013-01-01

The shape of isolated domains has been investigated in congruent lithium tantalate (CLT) single crystals at elevated temperatures and analyzed in terms of kinetic approach. The obtained temperature dependence of the growing domain shape in CLT including circular shape at temperatures above 190 °C has been attributed to increase of relative input of isotropic ionic conductivity. The observed nonstop wall motion and independent domain growth after merging in CLT as opposed to stoichiometric lithium tantalate have been attributed to difference in wall orientation. The computer simulation has confirmed applicability of the kinetic approach to the domain shape explanation

Temperature and composition dependence of birefringence of lithium-tantalate crystals determined by holographic scattering

International Nuclear Information System (INIS)

Bastwoeste, K.; Schwalenberg, S.; Baeumer, Ch.; Kraetzig, E.

2003-01-01

Iron-doped lithium-tantalate samples with different compositions ranging from the congruently melting to the stoichiometric one are analyzed by anisotropic holographic scattering. The temperature dependence of the birefringence yields information on the composition of the crystals. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Temperature and composition dependence of birefringence of lithium-tantalate crystals determined by holographic scattering

Energy Technology Data Exchange (ETDEWEB)

Bastwoeste, K.; Schwalenberg, S.; Baeumer, Ch.; Kraetzig, E. [Fachbereich Physik, Universitaet Osnabrueck, D-49069 Osnabrueck (Germany)

2003-09-01

Iron-doped lithium-tantalate samples with different compositions ranging from the congruently melting to the stoichiometric one are analyzed by anisotropic holographic scattering. The temperature dependence of the birefringence yields information on the composition of the crystals. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Lithium tantalate single crystal for pyroelectricity-based laser energy-meter: growth, application and phase transition study

International Nuclear Information System (INIS)

Bhaumik, Indranil; Ganesamoorthy, S.; Bhatt, R.; Karnal, A.K.; Gupta, P.K.

2009-01-01

Single crystals of lithium tantalate have been grown. Dielectric-spectroscopy study reveals phase transition in congruent lithium tantalate (CLT) single crystal is diffusive and frequency dependent in contrast to that in near stoichiometric lithium tantalate where it is sharper. The ac conductivity measurements show that the conductivity is lower for 0.5Mg-SLT as compared to 1.0Mg-SLT. This is explained in terms of a Li-vacancy model. Calculation of activation energy from the lnσ vs. 1000/T plot reveals that hopping of Li + ions becomes difficult for 0.5 Mg-SLT. The pyroelectric response of CLT for pulsed Nd:YAG laser output has been tested. (author)

Laser-induced forward transfer (LIFT) of congruent voxels

Energy Technology Data Exchange (ETDEWEB)

Piqué, Alberto, E-mail: pique@nrl.navy.mil [Materials Science and Technology Division, Code 6364, Naval Research Laboratory, Washington, DC 20375 (United States); Kim, Heungsoo; Auyeung, Raymond C.Y.; Beniam, Iyoel [Materials Science and Technology Division, Code 6364, Naval Research Laboratory, Washington, DC 20375 (United States); Breckenfeld, Eric [National Research Council Fellow at the Naval Research Laboratory, Washington, DC 20375 (United States)

2016-06-30

Highlights: • Laser-induced forward transfer (LIFT) is demonstrated with high viscosity Ag nanopaste. • Under the right conditions (viscosity and fluence) the transfer of congruent voxels was achieved. • For viscosities under 100 Pa s, congruent voxel transfer of silver nano-suspensions is only possible under a very narrow range of conditions. • For viscosities over 100 Pa s, congruent voxel transfer of silver nano-pastes works over a wider range of fluences, donor substrate thickness, gap distances and voxel areas. • The laser transfer of congruent voxels can be used for printing electronic patterns in particular interconnects. - Abstract: Laser-induced forward transfer (LIFT) of functional materials offers unique advantages and capabilities for the rapid prototyping of electronic, optical and sensor elements. The use of LIFT for printing high viscosity metallic nano-inks and nano-pastes can be optimized for the transfer of voxels congruent with the shape of the laser pulse, forming thin film-like structures non-lithographically. These processes are capable of printing patterns with excellent lateral resolution and thickness uniformity typically found in 3-dimensional stacked assemblies, MEMS-like structures and free-standing interconnects. However, in order to achieve congruent voxel transfer with LIFT, the particle size and viscosity of the ink or paste suspensions must be adjusted to minimize variations due to wetting and drying effects. When LIFT is carried out with high-viscosity nano-suspensions, the printed voxel size and shape become controllable parameters, allowing the printing of thin-film like structures whose shape is determined by the spatial distribution of the laser pulse. The result is a new level of parallelization beyond current serial direct-write processes whereby the geometry of each printed voxel can be optimized according to the pattern design. This work shows how LIFT of congruent voxels can be applied to the fabrication of 2D

Laser-induced forward transfer (LIFT) of congruent voxels

International Nuclear Information System (INIS)

Piqué, Alberto; Kim, Heungsoo; Auyeung, Raymond C.Y.; Beniam, Iyoel; Breckenfeld, Eric

2016-01-01

Highlights: • Laser-induced forward transfer (LIFT) is demonstrated with high viscosity Ag nanopaste. • Under the right conditions (viscosity and fluence) the transfer of congruent voxels was achieved. • For viscosities under 100 Pa s, congruent voxel transfer of silver nano-suspensions is only possible under a very narrow range of conditions. • For viscosities over 100 Pa s, congruent voxel transfer of silver nano-pastes works over a wider range of fluences, donor substrate thickness, gap distances and voxel areas. • The laser transfer of congruent voxels can be used for printing electronic patterns in particular interconnects. - Abstract: Laser-induced forward transfer (LIFT) of functional materials offers unique advantages and capabilities for the rapid prototyping of electronic, optical and sensor elements. The use of LIFT for printing high viscosity metallic nano-inks and nano-pastes can be optimized for the transfer of voxels congruent with the shape of the laser pulse, forming thin film-like structures non-lithographically. These processes are capable of printing patterns with excellent lateral resolution and thickness uniformity typically found in 3-dimensional stacked assemblies, MEMS-like structures and free-standing interconnects. However, in order to achieve congruent voxel transfer with LIFT, the particle size and viscosity of the ink or paste suspensions must be adjusted to minimize variations due to wetting and drying effects. When LIFT is carried out with high-viscosity nano-suspensions, the printed voxel size and shape become controllable parameters, allowing the printing of thin-film like structures whose shape is determined by the spatial distribution of the laser pulse. The result is a new level of parallelization beyond current serial direct-write processes whereby the geometry of each printed voxel can be optimized according to the pattern design. This work shows how LIFT of congruent voxels can be applied to the fabrication of 2D

Textured and tungsten-bronze-niobate-doped (K,Na,Li)(Nb,Ta)O3 piezoceramic materials

International Nuclear Information System (INIS)

Soller, Thomas; Bathelt, Robert; Benkert, Katrin; Bodinger, Hermann; Schuh, Carsten; Schlenkrich, Falko

2010-01-01

In this study, the effects of an alkaline-earth niobate doping in tungsten-bronze (TB) stoichiometry on the piezoelectric properties and the phase transition temperatures of lead-free (K,Na,Li)(Nb,Ta)O 3 ceramics were investigated. In particular, the TB compounds barium niobate (BN), barium sodium niobate (BNN) and strontium calcium sodium niobate (SCNN) were investigated. The TB-modified ceramics show promising piezoelectric properties with large-signal piezo coefficients, d 33 * lose to 400 pm/V, planar coupling coefficients, k p , up to 0.45 and Curie temperatures of approximately 310 .deg. C. In addition, the effect of texturing on the undoped (K,Na,Li)(Nb,Ta)O 3 base composition via templated grain growth (TGG) with microcrystalline NaNbO 3 templates was examined. Lotgering factors up to 81% and strain enhancements by a factor 1.5 with large-signal values of d 33 * up to 550 pm/V could be achieved in the textured samples.

Cortical oscillations related to processing congruent and incongruent grapheme-phoneme pairs.

Science.gov (United States)

Herdman, Anthony T; Fujioka, Takako; Chau, Wilkin; Ross, Bernhard; Pantev, Christo; Picton, Terence W

2006-05-15

In this study, we investigated changes in cortical oscillations following congruent and incongruent grapheme-phoneme stimuli. Hiragana graphemes and phonemes were simultaneously presented as congruent or incongruent audiovisual stimuli to native Japanese-speaking participants. The discriminative reaction time was 57 ms shorter for congruent than incongruent stimuli. Analysis of MEG responses using synthetic aperture magnetometry (SAM) revealed that congruent stimuli evoked larger 2-10 Hz activity in the left auditory cortex within the first 250 ms after stimulus onset, and smaller 2-16 Hz activity in bilateral visual cortices between 250 and 500 ms. These results indicate that congruent visual input can modify cortical activity in the left auditory cortex.

Cortical oscillations modulated by congruent and incongruent audiovisual stimuli.

Science.gov (United States)

Herdman, A T; Fujioka, T; Chau, W; Ross, B; Pantev, C; Picton, T W

2004-11-30

Congruent or incongruent grapheme-phoneme stimuli are easily perceived as one or two linguistic objects. The main objective of this study was to investigate the changes in cortical oscillations that reflect the processing of congruent and incongruent audiovisual stimuli. Graphemes were Japanese Hiragana characters for four different vowels (/a/, /o/, /u/, and /i/). They were presented simultaneously with their corresponding phonemes (congruent) or non-corresponding phonemes (incongruent) to native-speaking Japanese participants. Participants' reaction times to the congruent audiovisual stimuli were significantly faster by 57 ms as compared to reaction times to incongruent stimuli. We recorded the brain responses for each condition using a whole-head magnetoencephalograph (MEG). A novel approach to analysing MEG data, called synthetic aperture magnetometry (SAM), was used to identify event-related changes in cortical oscillations involved in audiovisual processing. The SAM contrast between congruent and incongruent responses revealed greater event-related desynchonization (8-16 Hz) bilaterally in the occipital lobes and greater event-related synchronization (4-8 Hz) in the left transverse temporal gyrus. Results from this study further support the concept of interactions between the auditory and visual sensory cortices in multi-sensory processing of audiovisual objects.

Properties of complex tungstates, niobates, translated with fluorite-like structure

International Nuclear Information System (INIS)

Vetkina, S.N.; Zolin, V.F.; Sirotinkin, V.P.; Smirnov, S.A.

1989-01-01

Spectra of ternary tungstates, niobates and tantalates (MeLa 2 WO 7 , La 3 TO 7 ; Me=Ba, Sr; T=Ta, Nb) related to the layered fluorite group are analyzed. The laser pumping and time resolved luminescence are used for selecting spectra of unequivalent centers. The symmetry of the first center is near to the distorted cubic one. The vibrational spectra of europium in Eu 3 NbO 7 and SrLa 2 WO 7 are due to the chain-like structure of niobates and to the net-like structure of tantalates. The stimulated emission of Nd 3+ in powders of BaLa 2 WO 7 and La 3 NbO 7 is observed at wavelengths of 1.07 and 1.063 μm, respectively

The Congruent Number Problem

Indian Academy of Sciences (India)

One could endlessly churn out congruent numbers following the method in Box 1 without being certain when a given number n (or n x m 2, for some integer m) will ap- pear on the list. Continuing in this way ·would exhaust one's computing resources, not to mention one's patience! Also, this procedure is of no avail if n is not ...

Macroscopic polarization and thermoluminescence of barium niobate - sodium niobate. Makroskopicheskaya polyarizatsiya i termolyuminestsentsiya niobata bariya - natriya

Energy Technology Data Exchange (ETDEWEB)

Gorban' , I S; Gumenyuk, A F; Omel' yanenko, V A [Kievskij Gosudarstvennyj Univ., Kiev (Ukrainian SSR)

1989-11-01

Thermoluminescence (TL) of initial and thermally treated purposely undoped crystals of barium niobate - sodium has been studied within 85-400 K. The TL intensity is found to depend on the temperature to which the sample has been heated. A conclusion is drawn that nonstationarity of the TL properties is due to slowly occuring processes of compensation of pyrocharge, which depend on the temperatural prehistory of the sample. A mechanism of the traps transformation in a strong pyrofield of high-impedance crystals is discussed.

Enhanced electrochemical properties of vanadium-doped titanium niobate as a new anode material for lithium-ion batteries

International Nuclear Information System (INIS)

Wen, Xiaoyan; Ma, Chenxiang; Du, Chenqiang; Liu, Jie; Zhang, Xinhe; Qu, Deyang; Tang, Zhiyuan

2015-01-01

The Vanadium-doped TiNb 2 O 7 (TNO) samples have been investigated as novel anode active materials for application in lithium-ion batteries. The samples are characterized by X-ray diffraction patterns (XRD), raman spectrum, scanning electron microscopy (SEM), transmission electron microscopy (TEM), galvanostatic charge-discharge tests, and cyclic voltammetry (CV) tests. The XRD results indicate that V-doping expands the lattice parameters of TiNb 2 O 7 samples and facilitates the enhanced lithium ion diffusion. SEM and TEM results show that lattice expansion caused by V-doping doesn’t significantly change the particle size distribution of TiNb 2 O 7 samples. The electrochemical measurements indicate that the TiNb 1.98 V 0.02 O 7 anode material displays a highly reversible capacity and excellent cycling stability. The initial discharge capacities of TiNb 1.98 V 0.02 O 7 are 298.48 mAh g −1 and 171.99 mAh g −1 at 0.3C and 10C, respectively, indicating that the TiNb 1.98 V 0.02 O 7 material can be utilized as a promising anode material for lithium-ion batteries.

Thin films of ErNbO.sub.4./sub. and YbNbO.sub.4./sub. prepared by sol–gel

Czech Academy of Sciences Publication Activity Database

Jakeš, V.; Rubešová, K.; Hlásek, T.; Polák, V.; Oswald, Jiří; Nádherný, L.

2016-01-01

Roč. 78, č. 3 (2016), s. 600-605 ISSN 0928-0707 Institutional support: RVO:68378271 Keywords : rare earth niobate * lithium niobate * doping * metal alkoxide * spin coating Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.575, year: 2016

Highly Symmetric and Congruently Tiled Meshes for Shells and Domes

Science.gov (United States)

Rasheed, Muhibur; Bajaj, Chandrajit

2016-01-01

We describe the generation of all possible shell and dome shapes that can be uniquely meshed (tiled) using a single type of mesh face (tile), and following a single meshing (tiling) rule that governs the mesh (tile) arrangement with maximal vertex, edge and face symmetries. Such tiling arrangements or congruently tiled meshed shapes, are frequently found in chemical forms (fullerenes or Bucky balls, crystals, quasi-crystals, virus nano shells or capsids), and synthetic shapes (cages, sports domes, modern architectural facades). Congruently tiled meshes are both aesthetic and complete, as they support maximal mesh symmetries with minimal complexity and possess simple generation rules. Here, we generate congruent tilings and meshed shape layouts that satisfy these optimality conditions. Further, the congruent meshes are uniquely mappable to an almost regular 3D polyhedron (or its dual polyhedron) and which exhibits face-transitive (and edge-transitive) congruency with at most two types of vertices (each type transitive to the other). The family of all such congruently meshed polyhedra create a new class of meshed shapes, beyond the well-studied regular, semi-regular and quasi-regular classes, and their duals (platonic, Catalan and Johnson). While our new mesh class is infinite, we prove that there exists a unique mesh parametrization, where each member of the class can be represented by two integer lattice variables, and moreover efficiently constructable. PMID:27563368

Beam Switching of an Nd:YAG Laser Using Domain-Engineered Prisms in Magnesium-Oxide-Doped Congruent Lithium Niobate

Science.gov (United States)

2010-08-01

explicitly: (2.45) The equalities shown in (2.45) are known as the “ Manley -Rowe relations” for the nonlinear process. These equalities...this discussion, O ve ra ll Tr an sl at io n 36 but it can be seen from Snell’s Law that these structures are equivalent as beam deflectors...an EOBS channel. Figure 3.15 shows that for nearly all values of , the most optimal beam diameter for which to design is 160  . O ve ra ll Tr an

Field induced modification of defect complexes in magnesium-doped lithium niobate

Energy Technology Data Exchange (ETDEWEB)

Meyer, Nadège; Granzow, Torsten [Department of Materials Research and Technology, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422 Belvaux (Luxembourg); Nataf, Guillaume F., E-mail: nataf@lippmann.lu [Department of Materials Research and Technology, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422 Belvaux (Luxembourg); CEA, DSM/IRAMIS/SPEC, F-91191 Gif-sur-Yvette Cedex (France)

2014-12-28

Dielectric constant, thermally stimulated depolarization currents (TSDC), and conductivity of undoped and 5% Mg-doped LiNbO{sub 3} single crystals between −100 °C and 200 °C have been investigated. A Debye-like dielectric relaxation with an activation energy of 135 meV is observed in the Mg-doped material, but not in undoped crystals. On heating this relaxation disappears near 140 °C and does not reappear after cooling. Anomalies observed in TSDC around this temperature are attributed to the motion of lithium vacancies, in agreement with conductivity measurements. It is proposed that in thermal equilibrium the electrons from the Mg{sub Li}{sup •} donors are trapped in (4Mg{sub Li}{sup •}+4V{sub Li}{sup ′}) defect complexes. High-temperature poling breaks these defect complexes. The transition of the liberated electrons between the Mg{sub Li}{sup •} donor centers and the Nb{sub Nb} forming the conduction band gives rise to the observed dielectric relaxation.

Context-dependent control of attention capture: Evidence from proportion congruent effects.

Science.gov (United States)

Crump, Matthew J C; Milliken, Bruce; Leboe-McGowan, Jason; Leboe-McGowan, Launa; Gao, Xiaoqing

2018-06-01

There are several independent demonstrations that attentional phenomena can be controlled in a context-dependent manner by cues associated with differing attentional control demands. The present set of experiments provide converging evidence that attention-capture phenomena can be modulated in a context-dependent fashion. We determined whether methods from the proportion congruent literature (listwide and item- and context-specific proportion congruent designs) that are known to modulate distractor interference effects in Stroop and flanker tasks are capable of modulating attention capture by salient feature singletons. Across experiments we found evidence that attention capture can be modulated by listwide, item-specific, and context-specific manipulations of proportion congruent. We discuss challenges associated with interpreting results from proportion congruent studies but propose that our findings converge with existing work that has demonstrated context-dependent control of attention capture. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Congruent leadership: values in action.

Science.gov (United States)

Stanley, David

2008-07-01

To discuss the significance of an appropriate leadership theory in order to develop an understanding of clinical leadership. Leadership theories developed from management and related paradigms, particularly transformational leadership, may be ineffective in supporting nurses to gain insights into clinical leadership or to develop and implement clinical leadership skills. Instead, congruent leadership theory, based on a match between the clinical leaders' actions and their values and beliefs about care and nursing, may offer a more firm theoretical foundation on which clinical nurses can build an understanding of and capacity to implement clinical leadership or become clinical leaders. Evaluation The information used is drawn from the contemporary literature and a study conducted by the author. Leadership can be better understood when an appropriate theoretical foundation is employed. With regard to clinical leadership, congruent leadership is proposed as the most appropriate theory. It is important to recognize that leadership theories based on a management paradigm may not be appropriate for all clinical applications. Education should be aimed specifically at clinical leaders, recognizing that clinical leaders are followed not for their vision or creativity (even if they demonstrate these), but because they translate their values and beliefs about care into action.

Stability of congruent Darwin ellipsoids

International Nuclear Information System (INIS)

Tassoul, M.

1975-01-01

The problem of synchronous oscillations of congruent Darwin ellipsoids is reconsidered. Contrary to results obtained by Chandrasekhar, it is shown that along a Darwin sequence the configurations remain stable with respect to ellipsoidal disturbances until they become too closely spaced. The precise limit which separates stable from unstable systems is found. Apart from some minor differences the Darwin sequence is the exact analog of the Roche sequence

Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers.

Science.gov (United States)

Mu, Wanjun; Li, Xingliang; Liu, Guoping; Yu, Qianhong; Xie, Xiang; Wei, Hongyuan; Jian, Yuan

2016-01-14

Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag2O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I(-) anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag2O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag(+) concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag2O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I(-) anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I(-) anions from basic wastewater.

Precipitation of HNbO{sub 3} at the Ti:LiNbO{sub 3} surface

Energy Technology Data Exchange (ETDEWEB)

Kalabin, Ivan E.; Grigorieva, Tatiana I.; Pokrovsky, Lev D.; Atuchin, Victor V

2004-03-30

The conditions of HNbO{sub 3} precipitation on the lithium niobate single-crystal and titanium diffused lithium niobate, LiNbO{sub 3} (LN) were studied. It has been shown, that the maximum of HNbO{sub 3} precipitation corresponds to the highest humidity of atmosphere at the annealing temperatures of 800-850 deg. C for 5-10 h. Moreover, the application of humid atmosphere during the annealing of LN at 600-850 deg. C does not ensure in full measure the lack of LiNb{sub 3}O{sub 8} precipitation.

Design of high-temperature piezoelectric acceleration sensor based lithium niobate%基于铌酸锂的高温压电加速度传感器设计

Institute of Scientific and Technical Information of China (English)

顾宝龙; 赵振平; 陈浩远; 闫旭; 陈佳璧; 郭子昂

2017-01-01

设计一种耐高温、高稳定性、高可靠性的加速度传感器,针对航空发动机高温恶劣的振动测试环境,传感器选用高居里温度的铌酸锂晶体作为压电元件,整体采用剪切式结构,利用特征系数最大的压电晶体切型,确定特征系数最大的压电晶体切向,以获得铌酸锂晶体较强的压电效应.研制双层铠装高温低噪声电缆,采用高温合金及矿物绝缘等耐高温材料,可在高温环境下长期使用,有效解决传感器小信号高温传输可靠性问题.优化设计传感器结构、封装工艺和测量系统,传感器频响、动态协议性能大为改善.通过对传感器的频率和温度响应、电容损耗等试验表明该传感器在550℃高温环境下能够保持高的可靠性和稳定性,提升航空发动机振动测试的技术能力.%This paper aims to develop and design a high-temperature resistant acceleration sensor with excellent stability and reliability. Considering the harsh and high-temperature environment of aero-engine vibration test, the sensor employs lithum niobate crystal with high Curie temperature as the piezoelectric element and adopts a shear-type configuration. The cutting pattern and direction of piezoelectric crystal that allow for the maximum characteristic coefficient are utilized and identified to obtain a strong piezoelectric effect for the lithium niobate crystal. Besides, a double-layer armoured high-temperature and low-noise cable is also developed using high-temperature alloy, mineral-insulated and other heat-resisting materials, which can be used in high-temperature environment for a long time, addressing effectively the reliability problem of small signals transmitted by sensor at high temperatures. Sensor structure, packaging technology and measuring system are also optimized and designed, which improves the frequency response and dynamic protocol performance of the sensor significantly. The testing on frequency and temperature

Crystallization of Reduced Strontium and Barium Niobate Perovskites from Borate Fluxes.

NARCIS (Netherlands)

Hessen, B.; Sunshine, S.A.; Siegrist, T.; Jimenez, R.

1991-01-01

Single crystals of three AxNbO3 (A = Sr, Ba) reduced niobate cubic perovskites have been obtained by recrystallization of reduced ternary ceramic precursors from borate fluxes under high-vacuum. Product formation could be influenced by variation of the alkaline-earth metal oxide content of the flux,

Laser-induced forward transfer (LIFT) of congruent voxels

Science.gov (United States)

Piqué, Alberto; Kim, Heungsoo; Auyeung, Raymond C. Y.; Beniam, Iyoel; Breckenfeld, Eric

2016-06-01

Laser-induced forward transfer (LIFT) of functional materials offers unique advantages and capabilities for the rapid prototyping of electronic, optical and sensor elements. The use of LIFT for printing high viscosity metallic nano-inks and nano-pastes can be optimized for the transfer of voxels congruent with the shape of the laser pulse, forming thin film-like structures non-lithographically. These processes are capable of printing patterns with excellent lateral resolution and thickness uniformity typically found in 3-dimensional stacked assemblies, MEMS-like structures and free-standing interconnects. However, in order to achieve congruent voxel transfer with LIFT, the particle size and viscosity of the ink or paste suspensions must be adjusted to minimize variations due to wetting and drying effects. When LIFT is carried out with high-viscosity nano-suspensions, the printed voxel size and shape become controllable parameters, allowing the printing of thin-film like structures whose shape is determined by the spatial distribution of the laser pulse. The result is a new level of parallelization beyond current serial direct-write processes whereby the geometry of each printed voxel can be optimized according to the pattern design. This work shows how LIFT of congruent voxels can be applied to the fabrication of 2D and 3D microstructures by adjusting the viscosity of the nano-suspension and laser transfer parameters.

PHYSICAL AND ELECTRICAL PROPERTIES ENHANCEMENT OF RARE-EARTH DOPED-POTASSIUM SODIUM NIOBATE (KNN: A REVIEW

Directory of Open Access Journals (Sweden)

Akmal Mat Harttat Maziati

2015-06-01

Full Text Available Alkaline niobate mainly potassium sodium niobate, (KxNa1-x NbO3 (abreviated as KNN has long attracted attention as piezoelectric materials as its high Curie temperature (Tc and piezoelectric properties. The volatility of alkaline element (K, Na is, however detrimental to the stoichiometry of KNN, contributing to the failure to achieve high-density structure and lead to the formation of intrinsic defects. By partially doping of several rare-earth elements, the inherent defects could be improved significantly. Therefore, considerable attempts have been made to develop doped-KNN based ceramic materials with high electrical properties. In this paper, these research activities are reviewed, including dopants type and doping role in KNN perovskite structure.

Congruent Transformation | Henry | Journal of the Nigerian ...

African Journals Online (AJOL)

... inside a triangle ABC and P, Q, R are feet of the perpendicular from 0 upon the respective sides BC, CA, AB, then OA + OB + OC > 2(OP+OQ+OP) Keywords: Congruent Transformation, Isometry, Invariant Points, Reflection Journal of the Nigerian Association of Mathematical Physics, Volume 20 (March, 2012), pp 23 – 26 ...

Congruent, Divergent and Incoherent Corporate Level Strategies

OpenAIRE

Bowman, Cliff; Ward, Keith; Kakabadse, Andrew P.

2002-01-01

This paper draws together four related strands of theory to address the processes of corporate value creation. Specifically, contributions from resource-based theory, dynamic capabilities, corporate strategy and Mintzberg’s structure theory have been combined to derive four congruent resource-creating strategies: financial control, scale, leverage, and creativity. Mintzberg’s configurations approach is used to explore the organisational structures and processes associated wi...

Mood-Congruent Memory and Natural Mood: New Evidence.

Science.gov (United States)

Mayer, John D.; And Others

1995-01-01

Presents new evidence that everyday mood does bring about a hypothesized effect on memory, termed mood-congruent memory (MCM). Results of three studies provided evidence for MCM among normal individuals (n=614). Findings support prior studies and bolster notions that mood and memory constantly covary in everyday experience. (RJM)

Grasp Preparation Improves Change Detection for Congruent Objects

Science.gov (United States)

Symes, Ed; Tucker, Mike; Ellis, Rob; Vainio, Lari; Ottoboni, Giovanni

2008-01-01

A series of experiments provided converging support for the hypothesis that action preparation biases selective attention to action-congruent object features. When visual transients are masked in so-called "change-blindness scenes," viewers are blind to substantial changes between 2 otherwise identical pictures that flick back and forth. The…

Congruent and Incongruent Cues in Highly Familiar Audiovisual Action Sequences: An ERP Study

Directory of Open Access Journals (Sweden)

SM Wuerger

2012-07-01

Full Text Available In a previous fMRI study we found significant differences in BOLD responses for congruent and incongruent semantic audio-visual action sequences (whole-body actions and speech actions in bilateral pSTS, left SMA, left IFG, and IPL (Meyer, Greenlee, & Wuerger, JOCN, 2011. Here, we present results from a 128-channel ERP study that examined the time-course of these interactions using a one-back task. ERPs in response to congruent and incongruent audio-visual actions were compared to identify regions and latencies of differences. Responses to congruent and incongruent stimuli differed between 240–280 ms, 340–420 ms, and 460–660 ms after stimulus onset. A dipole analysis revealed that the difference around 250 ms can be partly explained by a modulation of sources in the vicinity of the superior temporal area, while the responses after 400 ms are consistent with sources in inferior frontal areas. Our results are in line with a model that postulates early recognition of congruent audiovisual actions in the pSTS, perhaps as a sensory memory buffer, and a later role of the IFG, perhaps in a generative capacity, in reconciling incongruent signals.

Slimming starters. Intake of a diet-congruent food reduces meal intake in active dieters.

Science.gov (United States)

Buckland, Nicola J; Finlayson, Graham; Hetherington, Marion M

2013-12-01

Dietary restraint is known to break down in the face of tempting foods. Previous research suggests exposure to cues associated with slimming such as images or odours act as prompts to restrict intake of a tempting snack in dieters. The effects of consuming diet-congruent foods on subsequent intake of a meal have not yet been investigated. Thus, using a repeated measures design 26 female participants (dieters or non-dieters) consumed a diet-congruent (100 kcal salad), hedonic (100 kcal garlic bread) or neutral (0 kcal water) preload. A lexical decision task measured the salience of diet and hedonic thoughts and participants were then offered pizza as a main meal. Appetite sensations were measured throughout the study. Compared to the hedonic and neutral preload, a diet-congruent preload reduced dieters' entire meal intake by 21%. In contrast, non-dieters consumed 9% more in the hedonic preload condition compared to the neutral preload, yet showed no differences between the diet-congruent and other conditions. Salad lowered participants desire to eat and increased fullness compared to garlic bread and water preloads. Dieters were also less hungry after the salad compared to the garlic bread and water preloads. Consuming a diet-congruent first course may prompt lower intake at a meal, in part due to facilitating resolve to refrain from overeating a tempting second course. Copyright © 2013. Published by Elsevier Ltd.

Phase Behavior of Diblock Copolymer–Homopolymer Ternary Blends: Congruent First-Order Lamellar–Disorder Transition

Energy Technology Data Exchange (ETDEWEB)

Hickey, Robert J.; Gillard, Timothy M.; Irwin, Matthew T.; Morse, David C.; Lodge, Timothy P.; Bates, Frank S. (UMM)

2016-10-13

We have established the existence of a line of congruent first-order lamellar-to-disorder (LAM–DIS) transitions when appropriate amounts of poly(cyclohexylethylene) (C) and poly(ethylene) (E) homopolymers are mixed with a corresponding compositionally symmetric CE diblock copolymer. The line of congruent transitions, or the congruent isopleth, terminates at the bicontinuous microemulsion (BμE) channel, and its trajectory appears to be influenced by the critical composition of the C/E binary homopolymer blend. Blends satisfying congruency undergo a direct LAM–DIS transition without passing through a two-phase region. We present complementary optical transmission, small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and dynamic mechanical spectroscopy (DMS) results that establish the phase behavior at constant copolymer volume fraction and varying C/E homopolymer volume ratios. Adjacent to the congruent composition at constant copolymer volume fraction, the lamellar and disordered phases are separated by two-phase coexistence windows, which converge, along with the line of congruent transitions, at an overall composition in the phase prism coincident with the BμE channel. Hexagonal and cubic (double gyroid) phases occur at higher diblock copolymer concentrations for asymmetric amounts of C and E homopolymers. These results establish a quantitative method for identifying the detailed phase behavior of ternary diblock copolymer–homopolymer blends, especially in the vicinity of the BμE.

Visualization of ferroelectric domain structures in lithium niobate by means of confocal nonlinear microscopy; Visualisierung ferroelektrischer Domaenenstrukturen in Lithiumniobat mittels konfokaler nichtlinearer Mikroskopie

Energy Technology Data Exchange (ETDEWEB)

Berth, Gerhard

2010-07-01

In the field of integrated optics nonlinear-optical effects play a central role. A typical example for the commercial use of such phenomena is the frequency conversion. A deciding parameter is here the phase matching, which determines the quantity of the constructive interaction range of contributing optical fields. In view of a high efficiency of such processes the dispersion of a crystal must be balanced for the contributing frequencies. In nonlinear components on the base of optical waveguides the principle of the ''quasi-phase matching'' is applied, which uses the microdomain inversion. Phase jumps occuring at the domain boundaries compensate in the mean the different phase velocities. The application range of such periodical structures depends essentially on sharpness, homogeneity, depth extent, and period of the domain structure. The nonlinear confocal laser scanning microscopy makes a mapping of this transferred ferroelectric domain structure possible. Primary aim of this thesis is the characterization and mapping of the transferred ferroelectric domain structure in lithium niobate. A modularly kept confocal microscope makes here a nonlinear analysis in reflection and transmission geometry possible. In both geometries systematic studies as function of important process parameters were performed. It was shown that because of the larger nonlinear coherence length in the transmission modus the SHG ensues above all in forward direction. By depth-resolved studies at Z-cut PPLN structured between the surface region and the volume crystal a flippling of the SHG contrast could be observed. In samples with circular pole structure additionally in the crystal a transition to a hexagonal structure took place. In the Ti:PPLN strip waveguide a strong and specific increasement of the nonlinear signal of the domain walls was discovered. Here also the usual SHG surface contrast between dhe domains and the boundaries is inverted. Also differently processed

Are lithium niobate (LiNbO{sub 3}) and lithium tantalate (LiTaO{sub 3}) ferroelectrics bioactive?

Energy Technology Data Exchange (ETDEWEB)

Vilarinho, Paula Maria, E-mail: paula.vilarinho@ua.pt; Barroca, Nathalie; Zlotnik, Sebastian; Félix, Pedro; Fernandes, Maria Helena

2014-06-01

The use of functional materials, such as ferroelectrics, as platforms for tissue growth in situ or ex situ, is new and holds great promise. But the usage of materials in any bioapplication requires information on biocompatibility and desirably on bioactive behavior when bone tissue engineering is envisaged. Both requirements are currently unknown for many ferroelectrics. Herein the bioactivity of LiNbO{sub 3} and LiTaO{sub 3} is reported. The formation of apatite-like structures on the surface of LiNbO{sub 3} and LiTaO{sub 3} powders after immersion in simulated body fluid (SBF) for different soaking periods indicates their bioactive potential. The mechanism of apatite formation is suggested. In addition, the significant release of lithium ions from the ferroelectric powders in the very first minutes of soaking in SBF is examined and ways to overcome this likely hurdle addressed. - Highlights: • LiNbO{sub 3} and LiTaO{sub 3} are bioactive ferroelectrics. • Cauliflower apatite type structures indicative of in-vitro bioactivity of LiNbO{sub 3} and LiTaO{sub 3.} • Negative surface charges anchor Ca{sup 2+} to which PO{sub 4}{sup 3−} attracts forming apatite structure nuclei. • Use of ferroelectrics as platforms for tissue growth in situ or ex situ is new and holds great promise.

Dissociating proportion congruent and conflict adaptation effects in a Simon-Stroop procedure.

Science.gov (United States)

Torres-Quesada, Maryem; Funes, Maria Jesús; Lupiáñez, Juan

2013-02-01

Proportion congruent and conflict adaptation are two well known effects associated with cognitive control. A critical open question is whether they reflect the same or separate cognitive control mechanisms. In this experiment, in a training phase we introduced a proportion congruency manipulation for one conflict type (i.e. Simon), whereas in pre-training and post-training phases two conflict types (e.g. Simon and Spatial Stroop) were displayed with the same incongruent-to-congruent ratio. The results supported the sustained nature of the proportion congruent effect, as it transferred from the training to the post-training phase. Furthermore, this transfer generalized to both conflict types. By contrast, the conflict adaptation effect was specific to conflict type, as it was only observed when the same conflict type (either Simon or Stroop) was presented on two consecutive trials (no effect was observed on conflict type alternation trials). Results are interpreted as supporting the reactive and proactive control mechanisms distinction. Copyright © 2013 Elsevier B.V. All rights reserved.

XPS study of Li/Nb ratio in LiNbO{sub 3} crystals. Effect of polarity and mechanical processing on LiNbO{sub 3} surface chemical composition

Energy Technology Data Exchange (ETDEWEB)

Skryleva, E.A., E-mail: easkryleva@gmail.com; Kubasov, I.V., E-mail: kubasov.ilya@gmail.com; Kiryukhantsev-Korneev, Ph.V., E-mail: kiruhancev-korneev@yandex.ru; Senatulin, B.R., E-mail: borisrs@yandex.ru; Zhukov, R.N., E-mail: rom_zhuk@mail.ru; Zakutailov, K.V., E-mail: zakkonst@gmail.com; Malinkovich, M.D., E-mail: malinkovich@yandex.ru; Parkhomenko, Yu.N., E-mail: parkh@rambler.ru

2016-12-15

Highlights: • XPS Li/Nb ratio measurement uncertainty in LNbO3 specimens was obtained. • The effect of polarization on surface chemistry was observed only on cleaves. • Li/Nb ratio on positive cleave surface is higher than on negative one. • The positive cleave surface adsorbs fluorine more efficiently than negative one. • Mechanical processing of crystals reduces surface Li/Nb. - Abstract: Different sections of congruent lithium niobate (CLN) crystals have been studied using X-ray photoelectron spectroscopy (XPS). We have developed a method for measuring the lithium-to-niobium atomic ratio Li/Nb from the ratio of the Li1s and Nb4s spectral integral intensities with an overall error of within 8 %. Polarity and mechanical processing affect the Li/Nb ratio on CLN crystal surfaces. The Li/Nb ratio is within the tolerance (0.946 ± 0.074) on the negative cleave surface Z, and there is excess lithium (Li/Nb = 1.25 ± 0.10) on the positive surface. The positive surfaces of the 128° Y cut plates after long exposure to air exhibit LiOH formation indications (obvious lithium excess, higher Li1s spectral binding energy and a wide additional peak in the O1s spectrum produced by nonstructural oxygen). XPS and glow discharge optical electron spectroscopy showed that mechanical processing of differently oriented crystals (X, Z and 128° Y) and different polarities dramatically reduces the Li/Nb ratio. In situ fluorine adsorption experiments revealed the following regularities: fluorine adsorption only occurred on crystal cleaves and was not observed for mechanically processed specimens. Positive cleave surfaces have substantially higher fluorine adsorption capacity compared to negative ones.

Differences in the neural signature of remembering schema-congruent and schema-incongruent events.

Science.gov (United States)

Brod, Garvin; Lindenberger, Ulman; Werkle-Bergner, Markus; Shing, Yee Lee

2015-08-15

New experiences are remembered in relation to one's existing world knowledge or schema. Recent research suggests that the medial prefrontal cortex (mPFC) supports the retrieval of schema-congruent information. However, the neural mechanisms supporting memory for information violating a schema have remained elusive, presumably because incongruity is inherently ambiguous in tasks that rely on world knowledge. We present a novel paradigm that experimentally induces hierarchically structured knowledge to directly contrast neural correlates that contribute to the successful retrieval of schema-congruent versus schema-incongruent information. We hypothesize that remembering incongruent events engages source memory networks including the lateral PFC. In a sample of young adults, we observed enhanced activity in the dorsolateral PFC (DLPFC), in the posterior parietal cortex, and in the striatum when successfully retrieving incongruent events, along with enhanced connectivity between DLPFC and striatum. In addition, we found enhanced mPFC activity for successfully retrieved events that are congruent with the induced schema, presumably reflecting a role of the mPFC in biasing retrieval towards schema-congruent episodes. We conclude that medial and lateral PFC contributions to memory retrieval differ by schema congruency, and highlight the utility of the new experimental paradigm for addressing developmental research questions. Copyright © 2015 Elsevier Inc. All rights reserved.

Gaze-independent ERP-BCIs: augmenting performance through location-congruent bimodal stimuli

Science.gov (United States)

Thurlings, Marieke E.; Brouwer, Anne-Marie; Van Erp, Jan B. F.; Werkhoven, Peter

2014-01-01

Gaze-independent event-related potential (ERP) based brain-computer interfaces (BCIs) yield relatively low BCI performance and traditionally employ unimodal stimuli. Bimodal ERP-BCIs may increase BCI performance due to multisensory integration or summation in the brain. An additional advantage of bimodal BCIs may be that the user can choose which modality or modalities to attend to. We studied bimodal, visual-tactile, gaze-independent BCIs and investigated whether or not ERP components’ tAUCs and subsequent classification accuracies are increased for (1) bimodal vs. unimodal stimuli; (2) location-congruent vs. location-incongruent bimodal stimuli; and (3) attending to both modalities vs. to either one modality. We observed an enhanced bimodal (compared to unimodal) P300 tAUC, which appeared to be positively affected by location-congruency (p = 0.056) and resulted in higher classification accuracies. Attending either to one or to both modalities of the bimodal location-congruent stimuli resulted in differences between ERP components, but not in classification performance. We conclude that location-congruent bimodal stimuli improve ERP-BCIs, and offer the user the possibility to switch the attended modality without losing performance. PMID:25249947

Effects of Laser Operating Parameters on Piezoelectric Substrates Micromachining with Picosecond Laser

Directory of Open Access Journals (Sweden)

Lamia EL Fissi

2014-12-01

Full Text Available Ten picoseconds (200 kHz ultrafast laser micro-structuring of piezoelectric substrates including AT-cut quartz, Lithium Niobate and Lithium Tantalate have been studied for the purpose of piezoelectric devices application ranging from surface acoustic wave devices, e.g., bandpass filters, to photonic devices such as optical waveguides and holograms. The study examines the impact of changing several laser parameters on the resulting microstructural shapes and morphology. The micromachining rate has been observed to be strongly dependent on the operating parameters, such as the pulse fluence, the scan speed and the scan number. The results specifically indicate that ablation at low fluence and low speed scan tends to form a U-shaped cross-section, while a V-shaped profile can be obtained by using a high fluence and a high scan speed. The evolution of surface morphology revealed that laser pulses overlap in a range around 93% for both Lithium Niobate (LiNbO3 and Lithium Tantalate (LiTaO3 and 98% for AT-cut quartz can help to achieve optimal residual surface roughness.

Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes

Directory of Open Access Journals (Sweden)

Shinichiro Kawada

2015-11-01

Full Text Available Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain (Smax/Emax of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where Smax denotes the maximum strain and Emax denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed.

Steering Charge Kinetics of Tin Niobate Photocatalysts: Key Roles of Phase Structure and Electronic Structure.

Science.gov (United States)

Huang, Shushu; Wang, Chunyan; Sun, Hao; Wang, Xiaojing; Su, Yiguo

2018-05-23

Tin niobate photocatalysts with the phase structures of froodite (SnNb 2 O 6 ) and pyrochlore (Sn 2 Nb 2 O 7 ) were obtained by a facile solvothermal method in order to explore the impact of phase structure and electronic structure on the charge kinetics and photocatalytic performance. By employing tin niobate as a model compound, the effects of phase structure over electronic structure, photocatalytic activity toward methyl orange solution and hydrogen evolution were systematically investigated. It is found that the variation of phase structure from SnNb 2 O 6 to Sn 2 Nb 2 O 7 accompanied with modulation of particle size and band edge potentials that has great consequences on photocatalytic performance. In combination with the electrochemical impedance spectroscopy (EIS), transient photocurrent responses, transient absorption spectroscopy (TAS), and the analysis of the charge-carrier dynamics suggested that variation of electronic structure has great impacts on the charge separation and transfer rate of tin niobate photocatalysts and the subsequent photocatalytic performance. Moreover, the results of the X-ray photoelectron spectroscopy (XPS) indicated that the existent of Sn 4+ species in Sn 2 Nb 2 O 7 could result in a decrease in photocatalytic activity. Photocatalytic test demonstrated that the SnNb 2 O 6 (froodite) catalyst possesses a higher photocatalytic activity toward MO degradation and H 2 evolution compared with the sample of Sn 2 Nb 2 O 7 (pyrochlore). On the basis of spin resonance measurement and trapping experiment, it is expected that photogenerated holes, O 2 -• , and OH • active species dominate the photodegradation of methyl orange.

Mood-congruent false memories persist over time

OpenAIRE

Knott, L.; Thorley, C.

2014-01-01

In this study we examined the role of mood-congruency and retention interval on the false recognition of emotion laden items using the Deese/Roediger-McDermott (DRM) paradigm. Previous research has shown a mood-congruent false memory enhancement during immediate recognition tasks. The present study examined the persistence of this effect following a one-week delay. Participants were placed in a negative or neutral mood, presented with negative-emotion and neutral-emotion DRM word lists, and a...

Spectral evolution of Eu{sup 3+} doped Y{sub 3}NbO{sub 7} niobate induced by temperature

Energy Technology Data Exchange (ETDEWEB)

Kim, K-Y.; Durand, A. [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Heintz, J-M.; Veillere, A. [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Bordeaux INP, ICMCB, UPR 9048, F-33600 Pessac (France); Jubera, V., E-mail: veronique.jubera@u-bordeaux.fr [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France)

2016-03-15

A Eu{sup 3+} doped Y{sub 3}NbO{sub 7} niobate powder was synthetized using a polymerizable complex route. It gave rise to nanometric particles that crystallized in the fluorine structure, corresponding to the Y{sub 3}NbO{sub 7} phase. The thermal evolution of this powder was followed up to 1600 °C, using X-ray diffraction and optical characterizations. The fluorine structure was maintained in the whole temperature range. However, spectral evolution of the samples calcined above 900 °C showed a more complex situation. Emission spectra of powders heat treated at different temperatures showed an evolution of the emission lines that can be attributed first to a better crystallization of the niobate phase and second to its partial decomposition in favor of the formation of YNbO{sub 4} and Y{sub 2}O{sub 3}. Although the Y{sub 3}NbO{sub 7} phase appeared stable up to 1650 °C, from X-ray diffraction analysis, spectral analysis showed that the local environment of the doping element is modified from 1100 °C. - Graphical abstract: Spectral evolution of Eu{sup 3+} doped Y{sub 3}NbO{sub 7} niobate induced by temperature.

Flexible Piezoelectric Touch Sensor by Alignment of Lead-Free Alkaline Niobate Microcubes in PDMS

NARCIS (Netherlands)

Deutz, D.B.; Mascarenhas, N.T.; Schelen, J.B.J.; de Leeuw, D.M.; van der Zwaag, S.; Groen, W.A.

2017-01-01

A highly sensitive, lead-free, and flexible piezoelectric touch sensor is reported based on composite films of alkaline niobate K_0.485Na_0.485Li_0.03NbO₃ (KNLN) powders aligned in a polydimethylsiloxane (PDMS) matrix. KNLN powder is fabricated by

Robust surface registration using N-points approximate congruent sets

Directory of Open Access Journals (Sweden)

Yao Jian

2011-01-01

Full Text Available Abstract Scans acquired by 3D sensors are typically represented in a local coordinate system. When multiple scans, taken from different locations, represent the same scene these must be registered to a common reference frame. We propose a fast and robust registration approach to automatically align two scans by finding two sets of N-points, that are approximately congruent under rigid transformation and leading to a good estimate of the transformation between their corresponding point clouds. Given two scans, our algorithm randomly searches for the best sets of congruent groups of points using a RANSAC-based approach. To successfully and reliably align two scans when there is only a small overlap, we improve the basic RANSAC random selection step by employing a weight function that approximates the probability of each pair of points in one scan to match one pair in the other. The search time to find pairs of congruent sets of N-points is greatly reduced by employing a fast search codebook based on both binary and multi-dimensional lookup tables. Moreover, we introduce a novel indicator of the overlapping region quality which is used to verify the estimated rigid transformation and to improve the alignment robustness. Our framework is general enough to incorporate and efficiently combine different point descriptors derived from geometric and texture-based feature points or scene geometrical characteristics. We also present a method to improve the matching effectiveness of texture feature descriptors by extracting them from an atlas of rectified images recovered from the scan reflectance image. Our algorithm is robust with respect to different sampling densities and also resilient to noise and outliers. We demonstrate its robustness and efficiency on several challenging scan datasets with varying degree of noise, outliers, extent of overlap, acquired from indoor and outdoor scenarios.

Lithium

Science.gov (United States)

Bradley, Dwight C.; Stillings, Lisa L.; Jaskula, Brian W.; Munk, LeeAnn; McCauley, Andrew D.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Lithium, the lightest of all metals, is used in air treatment, batteries, ceramics, glass, metallurgy, pharmaceuticals, and polymers. Rechargeable lithium-ion batteries are particularly important in efforts to reduce global warming because they make it possible to power cars and trucks from renewable sources of energy (for example, hydroelectric, solar, or wind) instead of by burning fossil fuels. Today, lithium is extracted from brines that are pumped from beneath arid sedimentary basins and extracted from granitic pegmatite ores. The leading producer of lithium from brine is Chile, and the leading producer of lithium from pegmatites is Australia. Other potential sources of lithium include clays, geothermal brines, oilfield brines, and zeolites. Worldwide resources of lithium are estimated to be more than 39 million metric tons, which is enough to meet projected demand to the year 2100. The United States is not a major producer at present but has significant lithium resources.

Device for congruent X-ray images of teeth

International Nuclear Information System (INIS)

Wegner, H.; Zeumer, H.

1987-01-01

This invention has to do with a device for congruent X-ray images of teeth by means of the long-tube parallel technique and the long-tube semi-angle technique. The aim is to have no disturbing lever forces in order to avoid mechanical tensions between patient and X-ray tube assembly and to achieve a true projection of teeth and jaw-bone part also under unfavourable anatomical conditions

Congruent evaporation temperature of GaAs(001) controlled by As flux

International Nuclear Information System (INIS)

Zhou, Z. Y.; Zheng, C. X.; Tang, W. X.; Jesson, D. E.; Tersoff, J.

2010-01-01

The congruent evaporation temperature T c is a fundamental surface characteristic of GaAs and similar compounds. Above T c the rate of As evaporation exceeds that of Ga during Langmuir (free) evaporation into a vacuum. However, during molecular beam epitaxy (MBE) there is generally an external As flux F incident on the surface. Here we show that this flux directly controls T c . We introduce a sensitive approach to measure T c based on Ga droplet stability, and determine the dependence of T c on F. This dependence is explained by a simple model for evaporation in the presence of external flux. The capability of manipulating T c via changing F offers a means of controlling congruent evaporation with relevance to MBE, surface preparation methods, and droplet epitaxy.

Mood-congruent memory in depression - the influence of personal relevance and emotional context.

Science.gov (United States)

Wittekind, Charlotte E; Terfehr, Kirsten; Otte, Christian; Jelinek, Lena; Hinkelmann, Kim; Moritz, Steffen

2014-03-30

The investigation of veridical mood-congruent memory (MCM) in major depressive disorder (MDD) has been subject of many studies, whereas mood-congruent false memory has received comparatively little attention. The present study examined the influence of valence, personal relevance and the valence of the context of the learning material on true and false MCM in 20 inpatients with MDD and 20 healthy controls. Sixty positive, negative, neutral or personally relevant nouns were either combined with a positive, negative or neutral adjective. Word pairs were presented to participants in a learning trial. In a recognition task, participants had to identify the previously studied word pairs. A MCM effect could not be found for hits. However, in exploratory analyses, word pairs containing personally relevant nouns were more rated towards old by the patient relative to the control group. Furthermore, depressed patients tended to rate items more towards old than controls when the words were presented in a negative new context. Results are in line with previous findings in depression research emphasizing the role of mood-congruent false memories for mood disorders. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Atomic scale imaging of structural changes in solid electrolyte lanthanum lithium niobate upon annealing

International Nuclear Information System (INIS)

Hu, Xiaobing; Fisher, Craig A.J.; Kobayashi, Shunsuke; Ikuhara, Yumi H.; Fujiwara, Yasuyuki; Hoshikawa, Keigo; Moriwake, Hiroki; Kohama, Keiichi; Iba, Hideki; Ikuhara, Yuichi

2017-01-01

La (1-x)/3 Li x NbO 3 (LLNbO) is a promising electrolyte material for solid-state lithium-ion batteries because it is stable in contact with Li metal and contains a high concentration of intrinsic Li-ion vacancies. One strategy for improving its ionic conductivity and making it more competitive with other solid-state Li-ion electrolytes is to disorder the Li-ion vacancies by appropriate post-synthesis heat treatment, e.g., annealing. In this study, we examine the effects of annealing on single crystals of LLNbO with Li contents x = 0.07 and 0.13 based on simultaneous atomic resolution high angle annular dark field and annular bright field imaging methods using state-of-the-art aberration corrected scanning transmission electron microscopes. It is found that La modulation within A1 layers of the cation-deficient layered perovskite structure becomes more diffuse after annealing. In addition, some La atoms move to A-site positions and O4 window positions in the nominally vacant A2 layer, while O atom columns in this layer become rumpled in the [001] p direction, indicating that the NbO 6 octahedra are more heavily distorted after annealing. The observed crystal structure differences between as-prepared and annealed single crystals explain the drop in Li-ion conductivities of LLNbO single crystals after heat treatment.

Lithium Intoxication

Directory of Open Access Journals (Sweden)

Sermin Kesebir

2011-09-01

Full Text Available Lithium has been commonly used for the treatment of several mood disorders particularly bipolar disorder in the last 60 years. Increased intake and decreased excretion of lithium are the main causes for the development of lithium intoxication. The influence of lithium intoxication on body is evaluated as two different groups; reversible or irreversible. Irreversible damage is usually related with the length of time passed as intoxicated. Acute lithium intoxication could occur when an overdose of lithium is received mistakenly or for the purpose of suicide. Patients may sometimes take an overdose of lithium for self-medication resulting in acute intoxication during chronic, while others could develop chronic lithium intoxication during a steady dose treatment due to a problem in excretion of drug. In such situations, it is crucial to be aware of risk factors, to recognize early clinical symptoms and to conduct a proper medical monitoring. In order to justify or exclude the diagnosis, quantitative evaluation of lithium in blood and toxicologic screening is necessary. Following the monitoring schedules strictly and urgent intervention in case of intoxication would definitely reduce mortality and sequela related with lithium intoxication. In this article, the etiology, frequency, definition, clinical features and treatment approaches to the lithium intoxication have been briefly reviewed.

Ion-beam enhanced etching for the 3D structuration of lithium niobate; Ionenstrahlverstaerktes Aetzen fuer die 3D-Strukturierung von Lithiumniobat

Energy Technology Data Exchange (ETDEWEB)

Gischkat, Thomas

2010-01-12

The present thesis deals with the usage of the ion-beam enhanced etching (IBEE) for the 3D structuration of lithium niobate (LiNbO{sub 3}).Hereby the approach of the enhancement of the wet-chemical etching rate due to the irradiation with energetic ions is pursued. This method is very success promising for the realization of micro- and nanostructures with perpendicular structural walls as well as small roughnesses. The aim of this thesis consisted therein to form the foundations for the realization of three-dimensional micro- and nanostructures (for instance: Layer systems and photonic crystals) in LiNbO{sub 3} with high optical quality and to demonstrate on selected examples. Conditions for the success of the IBEE structuration technique is first of all the understanding of the defect formation under ion irradiation as well as the radiation-induced structure changes in the crystal and the change of the chemical resistance connected with this. For this the defect formation was studied in dependence on th ion mass, the ion energy, and the irradiation temperature. Thermally induced influences and effects on the radiation damage, as they can occur in intermediate steps in the complex processing, must be known and were studied by means of subsequent temperature treatment. The results from the defect studies were subsequently applied for the fabrication of micro- and nanostructures in LiNbO{sub 3}. Shown is the realization of lateral structure with nearly perpendicular structure walls as well as the realization of thin membranes and slits. The subsequent combination of lateral structuration with the fabrication of thin membranes and slits allowed the three-dimensional structuration of LiNbO{sub 3}. This is exemplarily shown for a microresonator and for a 2D photonic crystal with below lying air slit. [German] Die vorliegende Arbeit beschaeftigt sich mit der Ausnutzung des ionenstrahlverstaerkten Aetzens (IBEE: Ion Beam Enhanced Etching) fuer die 3D-Strukturierung von

Multiple-octave spanning high-energy mid-IR supercontinuum generation in bulk quadratic nonlinear crystals

DEFF Research Database (Denmark)

Zhou, Binbin; Bache, Morten

2016-01-01

Bright and broadband coherent mid-IR radiation is important for exciting and probing molecular vibrations. Using cascaded nonlinearities in conventional quadratic nonlinear crystals like lithium niobate, self-defocusing near-IR solitons have been demonstrated that led to very broadband...

Short-term duloxetine administration affects neural correlates of mood-congruent memory

NARCIS (Netherlands)

Tendolkar, Indira; van Wingen, Guido; Urner, Maren; Verkes, Robbert Jan; Fernández, Guillén

2011-01-01

It is unknown how antidepressants reverse mood-congruent memory bias, a cognitive core factor causing and maintaining depression. Using a double-blind, placebo-controlled, cross-over design, we investigated the effect of a short-term treatment (14 days) with the dual reuptake inhibitor duloxetine on

Pulsed Traveling-wave Quadrature Squeezing Using Quasi-phase Matched Lithium Niobate Crystals

Science.gov (United States)

Chen, Chao-Hsiang

Interests in generating higher quantum noise squeezing in order to develop methods to enhance optical measurement below the shot-noise limit in various applications has grown in recent years. The noise suppression from squeezing can improve the SNR in coherent optical systems when the returning signal power is weak, such as optical coherence tomography, LADAR, confocal microscopy and low-light coherent imaging. Unlike the generation of squeezing with a continuous wave, which is currently developed mainly for gravitational wave detection in LIGO project, the study of pulsed-traveling waves is focused on industrial, medical and other commercial interests. This dissertation presents the experimental results of pulsed traveling wave squeezing. The intention of the study is to explore the possibility of using quasi-phase matched crystals to generate the highest possible degree of quadrature squeezing. In order to achieve this goal, efforts to test the various effects from spatial Gaussian modes and relative beam waist placement for the second-harmonic pump were carried out in order to further the understanding of limiting factors to pulsed traveling wave squeezing. 20mm and 30mm-long periodically poled lithium noibate (PPLN) crystals were used in the experiment to generate a squeezed vacuum state. A maximum of 4.2+/-0.2dB quadrature squeezing has been observed, and the measured anti-squeezing exceeds 20dB.The phase sensitive amplification (PSA) gain and de-gain performance were also measured to compare the results of measured squeezing. The PPLN crystals can produce high conversion efficiency of second-harmonic generation (SHG) without a cavity. When a long PPLN crystal is used in a squeezer, the beam propagation in the nonlinear medium does not follow the characteristics in thin crystals. Instead, it is operated under the long-crystal criteria, which the crystal length is multiple times longer than the Rayleigh range of the injected beam i n the crystals. Quasi

Porosity Dependence of Piezoelectric Properties for Porous Potassium Niobate System Ceramics

Energy Technology Data Exchange (ETDEWEB)

Wada, S; Mase, Y; Shimizu, S; Maeda, K; Fujii, I; Nakashima, K; Pulpan, P; Miyajima, N, E-mail: swada@yamanashi.ac.jp [Interdisciplinary Graduate School of Medical and Engineering, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi 400-8510 (Japan)

2011-10-29

Porous potassium niobate (KNbO{sub 3}, KN) system ceramics were prepared by a conventional sintering method using carbon black (CB) nanoparticles. First, KN nanoparticles with a size of 100 nm was mixed with CB nanoparticles and binder using ball milling with ethanol. The mixture was dried, and pressed into pellets using uniaxial pressing. After binder burnout, these ceramics was sintered in air. Their piezoelectric properties were measured and discussed a relationship between porosity and piezoelectric properties. As the results, with increasing porosity, piezoelectric g33 constant increased significantly, which suggested that porous ceramics were effective for stress sensor application.

Porosity Dependence of Piezoelectric Properties for Porous Potassium Niobate System Ceramics

International Nuclear Information System (INIS)

Wada, S; Mase, Y; Shimizu, S; Maeda, K; Fujii, I; Nakashima, K; Pulpan, P; Miyajima, N

2011-01-01

Porous potassium niobate (KNbO 3 , KN) system ceramics were prepared by a conventional sintering method using carbon black (CB) nanoparticles. First, KN nanoparticles with a size of 100 nm was mixed with CB nanoparticles and binder using ball milling with ethanol. The mixture was dried, and pressed into pellets using uniaxial pressing. After binder burnout, these ceramics was sintered in air. Their piezoelectric properties were measured and discussed a relationship between porosity and piezoelectric properties. As the results, with increasing porosity, piezoelectric g33 constant increased significantly, which suggested that porous ceramics were effective for stress sensor application.

Influence of Fe{sup 3+} substitution on the dielectric and ferroelectric characteristics of Lead Indium Niobate

Energy Technology Data Exchange (ETDEWEB)

Divya, A.S.; Kumar, V., E-mail: vkumar10@yahoo.com

2015-07-15

Highlights: • Prepared phase-pure Fe{sup 3+}-substituted Lead Indium Niobate, Pb[(In{sub 0.50−x}Fe{sub x})Nb{sub 0.50}]O{sub 3} by sol–gel method. • Spontaneous Relaxor (R) → Ferroelectric (FE) transition observed for the composition with x = 0.20. • Local structural rearrangement responsible for R → FE transition has been confirmed by Raman spectroscopy. - Abstract: Lead Indium Niobate, Pb(In{sub 0.50}Nb{sub 0.50})O{sub 3} (PIN) is a complex perovskite that exhibits Relaxor (R) characteristics. In this study, we report the synthesis of phase-pure compositions in the system Pb[(In{sub 0.50−x}Fe{sub x})Nb{sub 0.50}]O{sub 3} by sol–gel method and discuss the influence of isovalent substitution of Indium by Iron on the dielectric and ferroelectric characteristics. Spontaneous transition to the Ferroelectric (FE) phase has been observed for the composition having x = 0.20. Local structural rearrangements responsible for R → FE transition have also been studied by Raman spectroscopy and are discussed in detail.

Discrete emotion-congruent false memories in the DRM paradigm.

Science.gov (United States)

Bland, Cassandra E; Howe, Mark L; Knott, Lauren

2016-08-01

Research has shown that false-memory production is enhanced for material that is emotionally congruent with the mood of the participant at the time of encoding. So far this research has only been conducted to examine the influence of generic negative affective mood states and generic negative stimuli on false-memory production. In addition, much of the research is limited as it focuses on valence and arousal dimensions, and fails to take into account the more comprehensive nature of emotions. The current study demonstrates that this effect goes beyond general negative or positive moods and acts at a more discrete emotional level. Participants underwent a standard emotion-induction procedure before listening to negative emotional or neutral associative word lists. The emotions induced, negative word lists, and associated nonpresented critical lures, were related to either fear or anger, 2 negative valence emotions that are also both high in arousal. Results showed that when valence and arousal are controlled for, false memories are more likely to be produced for discrete emotionally congruent compared with incongruent materials. These results support spreading activation theories of false remembering and add to our understanding of the adaptive nature of false-memory production. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Process for recovery of lithium from spent lithium batteries

Energy Technology Data Exchange (ETDEWEB)

Kunugita, Eiichi; Jonghwa, Kim; Komasawa, Isao [Osaka Univ., Faculty of Engineering Science, Osaka, (Japan)

1989-07-10

An experimental study of the recovery and purification of lithium from spent lithium batteries was carried out, taking advantage of the characterisitics of lithium ion and its carbonate. More than 75% of the lithium contained in the whole battery or its anode component can be leached with sulfuric acid where the pH of the final pregnant liquor is 7.7 or higher, the other metals being left in the residue is their hydroxides. The extracted liquor is evaporated/concentrated, added with saturated sodium carbonate solution at around 100{sup 0}C to precipitate lithium as a carbonate. The coprecipitated sodium carbonate is washed/removed with a hotwater to give 99% pure lithium carbonate. Separation of lithium and sodium in the barren liquor is conducted with LIX 51, a chelating/extracting agent, and TOPO, a neutral organic phosphate, which have a synergic effect, to selectively extract lithium; the organic phase is reverse-extracted with a dilute hydrochloric acid to obtain lithium of 99% purity. 9 refs., 4 figs., 5 tabs.

X-ray and neutron diffuse scattering in LiNbO3 from 38 to 1200 K

International Nuclear Information System (INIS)

Zotov, N.; Mayer, H.M.; Guethoff, F.; Hohlwein, D.

1995-01-01

A semi-quantitative description of X-ray and neutron diffuse scattering from congruent lithium niobate, LiNbO 3 , is given. The diffuse scattering is concentrated in three sets of diffuse planes perpendicular to the pseudo-cubic symmetry-related [221], [241] and [ anti 4 anti 21] directions and can be attributed to one-dimensional displacive and chemical disorder along these directions. The variation of the X-ray and neutron diffuse intensities with the scattering vector, as well as the comparison between X-ray and neutron data, indicate that more than one type of atom is involved. Temperature variations are followed from 38 to 1200 K. Different disorder models are discussed. The increase of the integrated intensities of the diffuse lines along the [0 1k 2l] * and [0 anti 1k 4l] * directions (i.e. sections of the diffuse planes) up to 800 K followed by a slight decrease at higher temperatures may be interpreted either by static disorder related to temperature-dependent variation of disorder/defect clusters or by dynamic disorder. Inelastic neutron scattering experiments do not show any anomaly of the transversal acoustic (TA) modes. (orig.)

Properties of complex tungstates, niobates, translated with fluorite-like structure. Svojstva slozhnykh vol'framatov, niobatov, tantalatov s flyuoritopodobnoj strukturoj

Energy Technology Data Exchange (ETDEWEB)

Vetkina, S N; Zolin, V F; Sirotinkin, V P; Smirnov, S A

1989-04-01

Spectra of ternary tungstates, niobates and tantalates (MeLa{sub 2}WO{sub 7}, La{sub 3}TO{sub 7}; Me=Ba, Sr; T=Ta, Nb) related to the layered fluorite group are analyzed. The laser pumping and time resolved luminescence are used for selecting spectra of unequivalent centers. The symmetry of the first center is near to the distorted cubic one. The vibrational spectra of europium in Eu{sub 3}NbO{sub 7} and SrLa{sub 2}WO{sub 7} are due to the chain-like structure of niobates and to the net-like structure of tantalates. The stimulated emission of Nd{sup 3+} in powders of BaLa{sub 2}WO{sub 7} and La{sub 3}NbO{sub 7} is observed at wavelengths of 1.07 and 1.063 {mu}m, respectively.

In support of a distinction between voluntary and stimulus-driven control: A review of the literature on proportion congruent effects

Directory of Open Access Journals (Sweden)

Julie M. Bugg

2012-09-01

Full Text Available Cognitive control is by now a large umbrella term referring collectively to multiple processes that plan and coordinate actions to meet task goals. A common feature of paradigms that engage cognitive control is the task requirement to select relevant information despite a habitual tendency (or bias to select goal-irrelevant information. At least since the 70s, researchers have employed proportion congruent manipulations to experimentally establish selection biases and evaluate the mechanisms used to control attention. Proportion congruent manipulations vary the frequency with which irrelevant information conflicts (i.e., is incongruent with relevant information. The purpose of this review is to summarize the growing body of literature on proportion congruent effects across selective attention paradigms, beginning first with Stroop, and then describing parallel effects in flanker and task-switching paradigms. The review chronologically tracks the expansion of the proportion congruent manipulation from its initial implementation at the list-wide level, to more recent implementations at the item-specific and context-specific levels. An important theoretical aim is demonstrating that proportion congruent effects at different levels (e.g., list-wide vs. item or context-specific support a distinction between voluntary forms of cognitive control, which operate based on anticipatory information, and relatively automatic or reflexive forms of cognitive control, which are rapidly triggered by the processing of particular stimuli or stimulus features. A further aim is to highlight those proportion congruent manipulations that allow researchers to dissociate stimulus-driven control from other stimulus-driven processes (e.g., S-R responding; episodic retrieval. We conclude by discussing the utility of proportion congruent manipulations for exploring the distinction between voluntary control and stimulus-driven control in other relevant paradigms.

Reproducibility and discriminability of brain patterns of semantic categories enhanced by congruent audiovisual stimuli.

Directory of Open Access Journals (Sweden)

Yuanqing Li

Full Text Available One of the central questions in cognitive neuroscience is the precise neural representation, or brain pattern, associated with a semantic category. In this study, we explored the influence of audiovisual stimuli on the brain patterns of concepts or semantic categories through a functional magnetic resonance imaging (fMRI experiment. We used a pattern search method to extract brain patterns corresponding to two semantic categories: "old people" and "young people." These brain patterns were elicited by semantically congruent audiovisual, semantically incongruent audiovisual, unimodal visual, and unimodal auditory stimuli belonging to the two semantic categories. We calculated the reproducibility index, which measures the similarity of the patterns within the same category. We also decoded the semantic categories from these brain patterns. The decoding accuracy reflects the discriminability of the brain patterns between two categories. The results showed that both the reproducibility index of brain patterns and the decoding accuracy were significantly higher for semantically congruent audiovisual stimuli than for unimodal visual and unimodal auditory stimuli, while the semantically incongruent stimuli did not elicit brain patterns with significantly higher reproducibility index or decoding accuracy. Thus, the semantically congruent audiovisual stimuli enhanced the within-class reproducibility of brain patterns and the between-class discriminability of brain patterns, and facilitate neural representations of semantic categories or concepts. Furthermore, we analyzed the brain activity in superior temporal sulcus and middle temporal gyrus (STS/MTG. The strength of the fMRI signal and the reproducibility index were enhanced by the semantically congruent audiovisual stimuli. Our results support the use of the reproducibility index as a potential tool to supplement the fMRI signal amplitude for evaluating multimodal integration.

Engineered Quasi-Phase Matching for Nonlinear Quantum Optics in Waveguides

Science.gov (United States)

Van Camp, Mackenzie A.

Entanglement is the hallmark of quantum mechanics. Quantum entanglement--putting two or more identical particles into a non-factorable state--has been leveraged for applications ranging from quantum computation and encryption to high-precision metrology. Entanglement is a practical engineering resource and a tool for sidestepping certain limitations of classical measurement and communication. Engineered nonlinear optical waveguides are an enabling technology for generating entangled photon pairs and manipulating the state of single photons. This dissertation reports on: i) frequency conversion of single photons from the mid-infrared to 843nm as a tool for incorporating quantum memories in quantum networks, ii) the design, fabrication, and test of a prototype broadband source of polarization and frequency entangled photons; and iii) a roadmap for further investigations of this source, including applications in quantum interferometry and high-precision optical metrology. The devices presented herein are quasi-phase-matched lithium niobate waveguides. Lithium niobate is a second-order nonlinear optical material and can mediate optical energy conversion to different wavelengths. This nonlinear effect is the basis of both quantum frequency conversion and entangled photon generation, and is enhanced by i) confining light in waveguides to increase conversion efficiency, and ii) quasi-phase matching, a technique for engineering the second-order nonlinear response by locally altering the direction of a material's polarization vector. Waveguides are formed by diffusing titanium into a lithium niobate wafer. Quasi-phase matching is achieved by electric field poling, with multiple stages of process development and optimization to fabricate the delicate structures necessary for broadband entangled photon generation. The results presented herein update and optimize past fabrication techniques, demonstrate novel optical devices, and propose future avenues for device development

The Stroop Effect: Why Proportion Congruent Has Nothing to Do with Congruency and Everything to Do with Contingency

Science.gov (United States)

Schmidt, James R.; Besner, Derek

2008-01-01

The item-specific proportion congruent (ISPC) effect refers to the observation that the Stroop effect is larger for words that are presented mostly in congruent colors (e.g., "BLUE" presented 75% of the time in blue) and smaller for words that are presented mostly in a given incongruent color (e.g., "YELLOW" presented 75% of…

A mathematical model for transducer working at high temperature

International Nuclear Information System (INIS)

Fabre, J.P.

1974-01-01

A mathematical model is proposed for a lithium niobate piezoelectric transducer working at high temperature in liquid sodium. The model proposed suitably described the operation of the high temperature transducer presented; it allows the optimization of the efficiency and band-pass [fr

Discrete microfluidics based on aluminum nitride surface acoustic wave devices

OpenAIRE

Zhou, J.; Pang, H.F.; Garcia-Gancedo, L.; Iborra, E.; Clement, M.; De Miguel-Ramos, M.; Jin, H.; Luo, J.K.; Smith, S.; Dong, S.R.; Wang, D.M.; Fu, Y.Q.

2015-01-01

To date, most surface acoustic wave (SAW) devices have been made from bulk piezoelectric materials, such as quartz, lithium niobate or lithium tantalite. These bulk materials are brittle, less easily integrated with electronics for control and signal processing, and difficult to realize multiple wave modes or apply complex electrode designs. Using thin film SAWs makes it convenient to integrate microelectronics and multiple sensing or microfluidics techniques into a lab-on-a-chip with low cos...

Metastable Magnesium fluorescence spectroscopy using a frequency-stabilized 517 nm laser

DEFF Research Database (Denmark)

He, Ming; Jensen, Brian B; Therkildsen, Kasper T

2009-01-01

We present a laser operating at 517 nm for our Magnesium laser-cooling and atomic clock project. A two-stage Yb-doped fiber amplifier (YDFA) system generates more than 1.5 W of 1034 nm light when seeded with a 15 mW diode laser. Using a periodically poled lithium niobate (PPLN) waveguide, we obta...... obtained more than 40 mW of 517 nm output power by single pass frequency doubling. In addition, fluorescence spectroscopy of metastable magnesium atoms could be used to stabilize the 517 nm laser to an absolute frequency within 1 MHz.......We present a laser operating at 517 nm for our Magnesium laser-cooling and atomic clock project. A two-stage Yb-doped fiber amplifier (YDFA) system generates more than 1.5 W of 1034 nm light when seeded with a 15 mW diode laser. Using a periodically poled lithium niobate (PPLN) waveguide, we...

Lithium isotope effect accompanying electrochemical intercalation of lithium into graphite

CERN Document Server

Yanase, S; Oi, T

2003-01-01

Lithium has been electrochemically intercalated from a 1:2 (v/v) mixed solution of ethylene carbonate (EC) and methylethyl carbonate (MEC) containing 1 M LiClO sub 4 into graphite, and the lithium isotope fractionation accompanying the intercalation was observed. The lighter isotope was preferentially fractionated into graphite. The single-stage lithium isotope separation factor ranged from 1.007 to 1.025 at 25 C and depended little on the mole ratio of lithium to carbon of the lithium-graphite intercalation compounds (Li-GIC) formed. The separation factor increased with the relative content of lithium. This dependence seems consistent with the existence of an equilibrium isotope effect between the solvated lithium ion in the EC/MEC electrolyte solution and the lithium in graphite, and with the formation of a solid electrolyte interfaces on graphite at the early stage of intercalation. (orig.)

Transcultural nursing: providing culturally congruent care to the Hausa of Northwest Africa.

Science.gov (United States)

Chmielarczyk, V

1991-01-01

Research around the world is now beginning to validate the theory of Cultural Care as an important means to provide culturally congruent care to clients, families, and groups of diverse cultures. Knowledge of Leininger's Theory of Cultural Care Diversity and Universality can provide meaningful care to clients who have different traditional and current beliefs and values. The Leininger Sunrise Model can serve as a valuable guide to discover care meanings and practices related to the theory, and to provide practical and meaningful culture specific care decisions and actions by nurses. The three major modes of action, namely, cultural care maintenance or preservation, accommodation or negotiation, and repatterning or restructuring, are important differential means to provide culturally congruent care to clients within their own cultural setting. This article considers the application of such care for the Hausa of Northwest Africa.(ABSTRACT TRUNCATED AT 250 WORDS)

Multi-layered, chemically bonded lithium-ion and lithium/air batteries

Science.gov (United States)

Narula, Chaitanya Kumar; Nanda, Jagjit; Bischoff, Brian L; Bhave, Ramesh R

2014-05-13

Disclosed are multilayer, porous, thin-layered lithium-ion batteries that include an inorganic separator as a thin layer that is chemically bonded to surfaces of positive and negative electrode layers. Thus, in such disclosed lithium-ion batteries, the electrodes and separator are made to form non-discrete (i.e., integral) thin layers. Also disclosed are methods of fabricating integrally connected, thin, multilayer lithium batteries including lithium-ion and lithium/air batteries.

Lithium Poisoning

DEFF Research Database (Denmark)

Baird-Gunning, Jonathan; Lea-Henry, Tom; Hoegberg, Lotte C G

2017-01-01

Lithium is a commonly prescribed treatment for bipolar affective disorder. However, treatment is complicated by lithium's narrow therapeutic index and the influence of kidney function, both of which increase the risk of toxicity. Therefore, careful attention to dosing, monitoring, and titration...... is required. The cause of lithium poisoning influences treatment and 3 patterns are described: acute, acute-on-chronic, and chronic. Chronic poisoning is the most common etiology, is usually unintentional, and results from lithium intake exceeding elimination. This is most commonly due to impaired kidney...... function caused by volume depletion from lithium-induced nephrogenic diabetes insipidus or intercurrent illnesses and is also drug-induced. Lithium poisoning can affect multiple organs; however, the primary site of toxicity is the central nervous system and clinical manifestations vary from asymptomatic...

Optical Cherenkov radiation by cascaded nonlinear interaction: an efficient source of few-cycle energetic near- to mid-IR pulses

DEFF Research Database (Denmark)

Bache, Morten; Bang, Ole; Zhou, Binbin

2011-01-01

When ultrafast noncritical cascaded second-harmonic generation of energetic femtosecond pulses occur in a bulk lithium niobate crystal optical Cherenkov waves are formed in the near- to mid-IR. Numerical simulations show that the few-cycle solitons radiate Cherenkov (dispersive) waves in the λ = 2...

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Method of implementing frequency-encoded NOT, OR and NOR logic operations using lithium niobate waveguide and reflecting semiconductor optical amplifiers · Sisir Kumar Garai Sourangshu Mukhopadhyay · More Details Abstract Fulltext PDF. Optics has already proved its strong potentiality for the conduction of parallel ...

Method of implementing frequency-encoded NOT, OR and NOR

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 73; Issue 5. Method of implementing frequency-encoded NOT, OR and NOR logic operations using lithium niobate waveguide and reflecting semiconductor optical amplifiers. Sisir Kumar Garai Sourangshu Mukhopadhyay. Volume 73 Issue 5 November 2009 pp 901- ...

Discrete emotion-congruent false memories in the DRM paradigm

OpenAIRE

Bland, C.; Howe, M. L.; Knott, L.

2016-01-01

Research has shown that false memory production is enhanced for material that is emotionally congruent with the mood of the participant at the time of encoding. So far this research has only examined the influence of generic negative affective mood states and generic negative stimuli on false memory production. In addition, much of the research is limited as it focuses on valence and arousal dimensions, and fails to take into account the more comprehensive nature of emotions. The current stud...

Pyroelectric Ceramics as Temperature Sensors for Energy System Applications

Science.gov (United States)

Silva, Jorge Luis

Temperature is continuously monitored in energy systems to ensure safe operation temperatures, increase efficiency and avoid high emissions. Most of energy systems operate at high temperature and harsh environments to achieve higher efficiencies, therefore temperature sensing devices that can operate under these conditions are highly desired. The interest has increased in temperature sensors capable to operate and in harsh environments and temperature sensors capable to transmit thermal information wirelessly. One of the solutions for developing harsh environment sensors is to use ceramic materials, especially functional ceramics such as pyroelectrics. Pyroelectric ceramics could be used to develop active sensors for both temperature and pressure due to their capabilities in coupling energy among mechanical, thermal, and electrical domains. In this study, two different pyroelectric materials were used to develop two different temperature sensors systems. First, a high temperature sensor was developed using a lithium niobate (LiNbO3) pyroelectric ceramic. With its Curie temperature of 1210 °C, lithium niobate is capable to maintain its pyroelectric properties at high temperature making it ideal for temperature sensing at high temperature applications. Lithium niobate has been studied previously in the attempt to use its pyroelectric current as the sensing mechanism to measure temperatures up to 500 °C. Pyroelectric coefficient of lithium niobate is a function of temperature as reported in a previous study, therefore a dynamic technique is utilized to measure the pyroelectric coefficient of the lithium niobate used in this study. The pyroelectric coefficient was successfully measured up to 500 °C with coefficients ranging from -8.5 x 10 -5 C/m2 °C at room temperature to -23.70 x 10 -5 C/m2 °C at 500 °C. The lithium niobate sensor was then tested at higher temperatures: 220 °C, 280 °C, 410 °C and 500 °C with 4.31 %, 2.1 %, 0.4 % and 0.6 % deviation

Resolved E-symmetry zone-centre phonons in LiTaO.sub.3./sub. and LiNbO.sub.3./sub..

Czech Academy of Sciences Publication Activity Database

Margueron, S.; Bartasyte, A.; Glazier, A. M.; Simon, Elizabeth; Hlinka, Jiří; Gregora, Ivan; Gleize, J.

2012-01-01

Roč. 111, č. 10 (2012), "104105-1"-"104105-6" ISSN 0021-8979. [International Symposium on Integrated Functionalities (ISIF) /22./. San Juan, Puerto Rico , 13.06.2010-16.06.2010] R&D Projects: GA AV ČR KAN301370701; GA ČR GAP204/10/0616 Institutional research plan: CEZ:AV0Z10100520 Keywords : phonons * infrared and Raman spectroscopy * lithium niobate * lithium tantalate * ferroelectric Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.210, year: 2012

Effect of Ion Irradiation in Cadmium Niobate Pyrochlores

International Nuclear Information System (INIS)

Jiang, Weilin; Weber, William J.; Thevuthasan, Suntharampillai; Boatner, Lynn A.

2003-01-01

Irradiation experiments have been performed for cadmium niobate pyrochlore (CdNb2O) single crystals at both 150 and 300 K using 1.0 MeV Au ions over fluences ranging from 0.01 to 0.10 ions/nm. In-situ 3.0 MeV He Rutherford backscattering spectrometry along the -axial channeling direction (RBS/C) has been applied to study the damage states ranging from small defect concentrations to a fully amorphous state. Results show that the crystal can be readily amorphized under the irradiation conditions. Room-temperature recovery of the defects produced at 150 K has been observed, while the defects produced at 300 K are thermally stable at room temperature. Results also indicate that the RBS/C analysis used in this study induced negligible damage in the near-surface regime. In addition, irradiation at and below room temperature using He and C3 ions leads to surface exfoliation at the corresponding damage peaks

Approach to lithium burn-up effect in lithium ceramics

International Nuclear Information System (INIS)

Rasneur, B.

1994-01-01

The lithium burn-up in Li 2 ZrO 3 is simulated by removing lithium under Li 2 O form and trapping it in high specific surface area powder while heating during 15 days or 1 month at moderate temperature so that lithium mobility be large enough without causing any sintering neither of the specimens nor of the powder. In a first treatment at 775 deg C during 1 month. 30% of the lithium content could be removed inducing a lithium concentration gradient in the specimen and the formation of a lithium-free monoclinic ZrO 2 skin. Improvements led to similar results at 650 deg C and 600 deg C, the latter temperatures are closer to the operating temperature of the ceramic breeder blanket of a fusion reactor. (author) 4 refs.; 4 figs.; 1 tab

Frequency control of a 1163 nm singly resonant OPO based on MgO:PPLN

NARCIS (Netherlands)

Gross, P.; Lindsay, I.D.; Lee, Christopher James; Nittmann, M.; Bauer, T.; Bartschke, J.; Warring, U.; Fischer, A.; Kellenbauer, A.; Boller, Klaus J.

2010-01-01

We report the realization of a singly resonant optical parametric oscillator (SRO) that is designed to provide narrow-bandwidth, continuously tunable radiation at a wavelength of 1163 nm for optical cooling of osmium ions. The SRO is based on periodically poled, magnesium-oxide-doped lithium niobate

Rapidly tunable continuous-wave optical parametric oscillator pumped by a fiber laser

NARCIS (Netherlands)

Klein, M.E.; Gross, P.; Boller, Klaus J.; Auerbach, M.; Wessels, P.; Fallnich, C.

2003-01-01

We report on rapid, all-electronically controlled wavelength tuning of a continuous-wave (cw) optical parametric oscillator (OPO) pumped by an ytterbium fiber laser. The OPO is singly resonant for the signal wave and consists of a 40-mm-long periodically poled lithium niobate crystal in a

Programming scale-free optics in disordered ferroelectrics.

Science.gov (United States)

Parravicini, Jacopo; Conti, Claudio; Agranat, Aharon J; DelRe, Eugenio

2012-06-15

Using the history dependence of a dipolar glass hosted in a compositionally disordered lithium-enriched potassium tantalate niobate (KTN:Li) crystal, we demonstrate scale-free optical propagation at tunable temperatures. The operating equilibration temperature is determined by previous crystal spiralling in the temperature/cooling-rate phase space.

Programming scale-free optics in disordered ferroelectrics

OpenAIRE

Parravicini, Jacopo; Conti, Claudio; Agranat, Aharon J.; DelRe, Eugenio

2012-01-01

Using the history-dependence of a dipolar glass hosted in a compositionally-disordered lithium-enriched potassium-tantalate-niobate (KTN:Li) crystal, we demonstrate scale-free optical propagation at tunable temperatures. The operating equilibration temperature is determined by previous crystal spiralling in the temperature/cooling-rate phase-space.

Characteristics of fundamental acoustic wave modes in thin piezoelectric plates.

Science.gov (United States)

Joshi, S G; Zaitsev, B D; Kuznetsova, I E; Teplykh, A A; Pasachhe, A

2006-12-22

The characteristics of the three lowest order plate waves (A(0), S(0), and SH(0)) propagating in piezoelectric plates whose thickness h is much less than the acoustic wavelength lambda are theoretically analyzed. It is found that these waves can provide much higher values of electromechanical coupling coefficient K(2) and lower values of temperature coefficient of delay (TCD) than is possible with surface acoustic waves (SAWs). For example, in 30Y-X lithium niobate, the SH(0) mode has K(2)=0.46 and TCD=55 ppm/degrees C. The corresponding values for SAW in the widely used, strong coupling material of 128Y-X lithium niobate are K(2)=0.053 and TCD=75 ppm/degrees C. Another important advantage of plate waves is that, unlike the case of SAWs, they can operate satisfactorily in contact with a liquid medium, thus making possible their use in liquid phase sensors.

Thermal stability of Dion-Jacobson mixed-metal-niobate double-layered perovskites

International Nuclear Information System (INIS)

Hermann, Andrew T.; Wiley, John B.

2009-01-01

The thermal stability and decomposition pathways of six Dion-Jacobson-related double-layered perovskites, ALaNb 2 O 7 (A = H, Li, Na, Ag) and (ACl)LaNb 2 O 7 (A = Fe, Cu), are investigated. These compounds are made by low temperature ( 2 O 7 . All the compounds are low temperature phases with some of them exhibiting decomposition exotherms consistent with metastability. Decomposition temperatures and reactions pathways vary with the identity of A with most decompositions resulting in the formation of a niobate (containing A) and LaNbO 4 . Results from differential scanning calorimetry and high temperature X-ray powder diffraction studies are presented and structural parameters pertinent to compound stability discussed

Stabilized Lithium-Metal Surface in a Polysulfide-Rich Environment of Lithium-Sulfur Batteries.

Science.gov (United States)

Zu, Chenxi; Manthiram, Arumugam

2014-08-07

Lithium-metal anode degradation is one of the major challenges of lithium-sulfur (Li-S) batteries, hindering their practical utility as next-generation rechargeable battery chemistry. The polysulfide migration and shuttling associated with Li-S batteries can induce heterogeneities of the lithium-metal surface because it causes passivation by bulk insulating Li2S particles/electrolyte decomposition products on a lithium-metal surface. This promotes lithium dendrite formation and leads to poor lithium cycling efficiency with complicated lithium surface chemistry. Here, we show copper acetate as a surface stabilizer for lithium metal in a polysulfide-rich environment of Li-S batteries. The lithium surface is protected from parasitic reactions with the organic electrolyte and the migrating polysulfides by an in situ chemical formation of a passivation film consisting of mainly Li2S/Li2S2/CuS/Cu2S and electrolyte decomposition products. This passivation film also suppresses lithium dendrite formation by controlling the lithium deposition sites, leading to a stabilized lithium surface characterized by a dendrite-free morphology and improved surface chemistry.

Lithium alloys and metal oxides as high-capacity anode materials for lithium-ion batteries

International Nuclear Information System (INIS)

Liang, Chu; Gao, Mingxia; Pan, Hongge; Liu, Yongfeng; Yan, Mi

2013-01-01

Highlights: •Progress in lithium alloys and metal oxides as anode materials for lithium-ion batteries is reviewed. •Electrochemical characteristics and lithium storage mechanisms of lithium alloys and metal oxides are summarized. •Strategies for improving electrochemical lithium storage properties of lithium alloys and metal oxides are discussed. •Challenges in developing lithium alloys and metal oxides as commercial anodes for lithium-ion batteries are pointed out. -- Abstract: Lithium alloys and metal oxides have been widely recognized as the next-generation anode materials for lithium-ion batteries with high energy density and high power density. A variety of lithium alloys and metal oxides have been explored as alternatives to the commercial carbonaceous anodes. The electrochemical characteristics of silicon, tin, tin oxide, iron oxides, cobalt oxides, copper oxides, and so on are systematically summarized. In this review, it is not the scope to retrace the overall studies, but rather to highlight the electrochemical performances, the lithium storage mechanism and the strategies in improving the electrochemical properties of lithium alloys and metal oxides. The challenges and new directions in developing lithium alloys and metal oxides as commercial anodes for the next-generation lithium-ion batteries are also discussed

Lithium use in batteries

Science.gov (United States)

Goonan, Thomas G.

2012-01-01

Lithium has a number of uses but one of the most valuable is as a component of high energy-density rechargeable lithium-ion batteries. Because of concerns over carbon dioxide footprint and increasing hydrocarbon fuel cost (reduced supply), lithium may become even more important in large batteries for powering all-electric and hybrid vehicles. It would take 1.4 to 3.0 kilograms of lithium equivalent (7.5 to 16.0 kilograms of lithium carbonate) to support a 40-mile trip in an electric vehicle before requiring recharge. This could create a large demand for lithium. Estimates of future lithium demand vary, based on numerous variables. Some of those variables include the potential for recycling, widespread public acceptance of electric vehicles, or the possibility of incentives for converting to lithium-ion-powered engines. Increased electric usage could cause electricity prices to increase. Because of reduced demand, hydrocarbon fuel prices would likely decrease, making hydrocarbon fuel more desirable. In 2009, 13 percent of worldwide lithium reserves, expressed in terms of contained lithium, were reported to be within hard rock mineral deposits, and 87 percent, within brine deposits. Most of the lithium recovered from brine came from Chile, with smaller amounts from China, Argentina, and the United States. Chile also has lithium mineral reserves, as does Australia. Another source of lithium is from recycled batteries. When lithium-ion batteries begin to power vehicles, it is expected that battery recycling rates will increase because vehicle battery recycling systems can be used to produce new lithium-ion batteries.

Growth and decomposition of Lithium and Lithium hydride on Nickel

DEFF Research Database (Denmark)

Engbæk, Jakob; Nielsen, Gunver; Nielsen, Jane Hvolbæk

2006-01-01

In this paper we have investigated the deposition, structure and decomposition of lithium and lithium-hydride films on a nickel substrate. Using surface sensitive techniques it was possible to quantify the deposited Li amount, and to optimize the deposition procedure for synthesizing lithium......-hydride films. By only making thin films of LiH it is possible to study the stability of these hydride layers and compare it directly with the stability of pure Li without having any transport phenomena or adsorbed oxygen to obscure the results. The desorption of metallic lithium takes place at a lower...... temperature than the decomposition of the lithium-hydride, confirming the high stability and sintering problems of lithium-hydride making the storage potential a challenge. (c) 2006 Elsevier B.V. All rights reserved....

Ultrashort pulse chirp measurement via transverse second-harmonic generation in strontium barium niobate crystal

Energy Technology Data Exchange (ETDEWEB)

Trull, J.; Wang, B.; Parra, A.; Vilaseca, R.; Cojocaru, C. [Departament de Física i Enginyeria Nuclear, Universitat Politècnica Catalunya, Terrassa 08222 (Spain); Sola, I. [Grupo de Investigación en Óptica Extrema (GIOE), Departamento de Física Aplicada, Universidad de Salamanca, Plaza de la Merced s/n, 37008 Salamanca (Spain); Krolikowski, W. [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Science Program, Texas A and M University at Qatar, Doha (Qatar); Sheng, Y. [Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

2015-06-01

Pulse compression in dispersive strontium barium niobate crystal with a random size and distribution of the anti-parallel orientated nonlinear domains is observed via transverse second harmonic generation. The dependence of the transverse width of the second harmonic trace along the propagation direction allows for the determination of the initial chirp and duration of pulses in the femtosecond regime. This technique permits a real-time analysis of the pulse evolution and facilitates fast in-situ correction of pulse chirp acquired in the propagation through an optical system.

Ultrashort pulse chirp measurement via transverse second-harmonic generation in strontium barium niobate crystal

International Nuclear Information System (INIS)

Trull, J.; Wang, B.; Parra, A.; Vilaseca, R.; Cojocaru, C.; Sola, I.; Krolikowski, W.; Sheng, Y.

2015-01-01

Pulse compression in dispersive strontium barium niobate crystal with a random size and distribution of the anti-parallel orientated nonlinear domains is observed via transverse second harmonic generation. The dependence of the transverse width of the second harmonic trace along the propagation direction allows for the determination of the initial chirp and duration of pulses in the femtosecond regime. This technique permits a real-time analysis of the pulse evolution and facilitates fast in-situ correction of pulse chirp acquired in the propagation through an optical system

High-voltage safety fuses for the transition-radiation tracking detector in the ATLAS experiment

NARCIS (Netherlands)

Voronov, SA; Voronov, YA; Onishchenko, EM; Simakov, AB; Sosnovtsev, VV; Suchkov, SI; Sugrobova, TA

2004-01-01

A safety fuse has been designed for the electrical protection of gas-filled detectors in the ATLAS experiment at CERN (Geneva, Switzerland). The fuse is a polished lithium niobate plate with a titanium strip of 91-kOmega resistance deposited by the photolithographic technique. The forced blow-out

Generating Efficient Femtosecond Mid-infrared Pulse by Single Near-infrared Pump Wavelength in Bulk Nonlinear Crystal Without Phase-matching

DEFF Research Database (Denmark)

Zhou, Binbin; Guo, Hairun; Bache, Morten

2014-01-01

We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8-2.92 μm are generated using the single pump wavelengths from 1.25-1.45 μm. © 2014 Optical Society of America...

Electrolytic method for the production of lithium using a lithium-amalgam electrode

Science.gov (United States)

Cooper, John F.; Krikorian, Oscar H.; Homsy, Robert V.

1979-01-01

A method for recovering lithium from its molten amalgam by electrolysis of the amalgam in an electrolytic cell containing as a molten electrolyte a fused-salt consisting essentially of a mixture of two or more alkali metal halides, preferably alkali metal halides selected from lithium iodide, lithium chloride, potassium iodide and potassium chloride. A particularly suitable molten electrolyte is a fused-salt consisting essentially of a mixture of at least three components obtained by modifying an eutectic mixture of LiI-KI by the addition of a minor amount of one or more alkali metal halides. The lithium-amalgam fused-salt cell may be used in an electrolytic system for recovering lithium from an aqueous solution of a lithium compound, wherein electrolysis of the aqueous solution in an aqueous cell in the presence of a mercury cathode produces a lithium amalgam. The present method is particularly useful for the regeneration of lithium from the aqueous reaction products of a lithium-water-air battery.

[Negative bias on self-referent processing in depression: focused on mood congruent effects].

Science.gov (United States)

Tagami, Kyoko

2002-12-01

The purpose of this study was to investigate negative bias on self-referent processing in depression, focused on the mood congruent effects in a natural depressed state and an experimentally induced transient depressed mood state. In Experiment 1, autobiographical memories and self-relevant ratings of personality trait words were examined in a natural depressed state or non-depressed state, which were measured by Beck Depression Inventory. Results revealed the mood congruent effects on both tasks. In Experiment 2, the same tasks as Experiment 1 were conducted in a transient depressed mood state or non-depressed mood state, which were induced through listening music. Unlike Experiment 1, there were no effects in both tasks, and a positive bias was observed in both mood states. It was suggested that transient mood state did not bias self-referent processing in depression, and Beck's schema hypothesis was supported.

Structure and band gap determination of irradiation-induced amorphous nano-channels in LiNbO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Sachan, R., E-mail: sachanr@ornl.gov; Pakarinen, O. H.; Chisholm, M. F. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Liu, P. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan 250100 (China); Patel, M. K. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Zhang, Y. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Wang, X. L. [School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan 250100 (China); Weber, W. J. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2015-04-07

The irradiation of lithium niobate with swift heavy ions results in the creation of amorphous nano-sized channels along the incident ion path. These nano-channels are on the order of a hundred microns in length and could be useful for photonic applications. However, there are two major challenges in these nano-channels characterization: (i) it is difficult to investigate the structural characteristics of these nano-channels due to their very long length and (ii) the analytical electron microscopic analysis of individual ion track is complicated due to electron beam sensitive nature of lithium niobate. Here, we report the first high resolution microscopic characterization of these amorphous nano-channels, widely known as ion-tracks, by direct imaging them at different depths in the material, and subsequently correlating the key characteristics with electronic energy loss of ions. Energetic Kr ions ({sup 84}Kr{sup 22} with 1.98 GeV energy) are used to irradiate single crystal lithium niobate with a fluence of 2 × 10{sup 10} ions/cm{sup 2}, which results in the formation of individual ion tracks with a penetration depth of ∼180 μm. Along the ion path, electron energy loss of the ions, which is responsible for creating the ion tracks, increases with depth under these conditions in LiNbO{sub 3}, resulting in increases in track diameter of a factor of ∼2 with depth. This diameter increase with electronic energy loss is consistent with predictions of the inelastic thermal spike model. We also show a new method to measure the band gap in individual ion track by using electron energy-loss spectroscopy.

ENABLING USE OF STANDARD COSTING IN LEAN ORGANIZATIONS AS DETERMINANT OF GOAL CONGRUENT BEHAVIOR

DEFF Research Database (Denmark)

Kristensen, Thomas Borup; Israelsen, Poul

2014-01-01

Using the enabling formalization framework in two longitudinal case studies combined with a survey in the companies, we find that a standard costing model can be perceived as a form of enabling formalization in Lean organizations. Hence, standard costing cannot be characterized as coercive...... formalization per se. This contradicts conventional wisdom. Repair is a feature of enabling formalization through the use of standard costing. Applying a structural equation model, we present evidence that this repair feature has a direct effect on behavior that is congruent with Lean objectives. Internal...... and global transparency together with flexibility are three other features of enabling formalization through use of standard costing, but these have an indirect effect on Lean-goal-congruent behavior through the repair feature. Thus, these three features are antecedents of the repair feature, and we also...

Lithium batteries; Les accumulateurs au lithium

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

This workshop on lithium batteries is divided into 4 sections dealing with: the design and safety aspects, the cycling, the lithium intercalation and its modeling, and the electrolytes. These 4 sections represent 19 papers and are completed by a poster session which corresponds to 17 additional papers. (J.S.)

Lithium batteries; Les accumulateurs au lithium

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

This workshop on lithium batteries is divided into 4 sections dealing with: the design and safety aspects, the cycling, the lithium intercalation and its modeling, and the electrolytes. These 4 sections represent 19 papers and are completed by a poster session which corresponds to 17 additional papers. (J.S.)

High performance discharges in the Lithium Tokamak eXperiment with liquid lithium walls

Energy Technology Data Exchange (ETDEWEB)

Schmitt, J. C.; Bell, R. E.; Boyle, D. P.; Esposti, B.; Kaita, R.; Kozub, T.; LeBlanc, B. P.; Lucia, M.; Maingi, R.; Majeski, R.; Merino, E.; Punjabi-Vinoth, S.; Tchilingurian, G. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Capece, A.; Koel, B.; Roszell, J. [Princeton University, Princeton, New Jersey 08544 (United States); Biewer, T. M.; Gray, T. K. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Kubota, S. [University of California at Los Angeles, Los Angeles, California 90095 (United States); Beiersdorfer, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2015-05-15

The first-ever successful operation of a tokamak with a large area (40% of the total plasma surface area) liquid lithium wall has been achieved in the Lithium Tokamak eXperiment (LTX). These results were obtained with a new, electron beam-based lithium evaporation system, which can deposit a lithium coating on the limiting wall of LTX in a five-minute period. Preliminary analyses of diamagnetic and other data for discharges operated with a liquid lithium wall indicate that confinement times increased by 10× compared to discharges with helium-dispersed solid lithium coatings. Ohmic energy confinement times with fresh lithium walls, solid and liquid, exceed several relevant empirical scaling expressions. Spectroscopic analysis of the discharges indicates that oxygen levels in the discharges limited on liquid lithium walls were significantly reduced compared to discharges limited on solid lithium walls. Tokamak operations with a full liquid lithium wall (85% of the total plasma surface area) have recently started.

High performance discharges in the Lithium Tokamak eXperiment with liquid lithium walls

International Nuclear Information System (INIS)

Schmitt, J. C.; Bell, R. E.; Boyle, D. P.; Esposti, B.; Kaita, R.; Kozub, T.; LeBlanc, B. P.; Lucia, M.; Maingi, R.; Majeski, R.; Merino, E.; Punjabi-Vinoth, S.; Tchilingurian, G.; Capece, A.; Koel, B.; Roszell, J.; Biewer, T. M.; Gray, T. K.; Kubota, S.; Beiersdorfer, P.

2015-01-01

The first-ever successful operation of a tokamak with a large area (40% of the total plasma surface area) liquid lithium wall has been achieved in the Lithium Tokamak eXperiment (LTX). These results were obtained with a new, electron beam-based lithium evaporation system, which can deposit a lithium coating on the limiting wall of LTX in a five-minute period. Preliminary analyses of diamagnetic and other data for discharges operated with a liquid lithium wall indicate that confinement times increased by 10× compared to discharges with helium-dispersed solid lithium coatings. Ohmic energy confinement times with fresh lithium walls, solid and liquid, exceed several relevant empirical scaling expressions. Spectroscopic analysis of the discharges indicates that oxygen levels in the discharges limited on liquid lithium walls were significantly reduced compared to discharges limited on solid lithium walls. Tokamak operations with a full liquid lithium wall (85% of the total plasma surface area) have recently started

Effects of congruent and incongruent visual cues on speech perception and brain activity in cochlear implant users.

Science.gov (United States)

Song, Jae-Jin; Lee, Hyo-Jeong; Kang, Hyejin; Lee, Dong Soo; Chang, Sun O; Oh, Seung Ha

2015-03-01

While deafness-induced plasticity has been investigated in the visual and auditory domains, not much is known about language processing in audiovisual multimodal environments for patients with restored hearing via cochlear implant (CI) devices. Here, we examined the effect of agreeing or conflicting visual inputs on auditory processing in deaf patients equipped with degraded artificial hearing. Ten post-lingually deafened CI users with good performance, along with matched control subjects, underwent H 2 (15) O-positron emission tomography scans while carrying out a behavioral task requiring the extraction of speech information from unimodal auditory stimuli, bimodal audiovisual congruent stimuli, and incongruent stimuli. Regardless of congruency, the control subjects demonstrated activation of the auditory and visual sensory cortices, as well as the superior temporal sulcus, the classical multisensory integration area, indicating a bottom-up multisensory processing strategy. Compared to CI users, the control subjects exhibited activation of the right ventral premotor-supramarginal pathway. In contrast, CI users activated primarily the visual cortices more in the congruent audiovisual condition than in the null condition. In addition, compared to controls, CI users displayed an activation focus in the right amygdala for congruent audiovisual stimuli. The most notable difference between the two groups was an activation focus in the left inferior frontal gyrus in CI users confronted with incongruent audiovisual stimuli, suggesting top-down cognitive modulation for audiovisual conflict. Correlation analysis revealed that good speech performance was positively correlated with right amygdala activity for the congruent condition, but negatively correlated with bilateral visual cortices regardless of congruency. Taken together these results suggest that for multimodal inputs, cochlear implant users are more vision-reliant when processing congruent stimuli and are disturbed

Preparation and photocatalytic property of potassium niobate K6Nb10.8O30

International Nuclear Information System (INIS)

Zhang Gaoke; Zou Xi; Gong Jie; He Fangsheng; Zhang Hao; Zhang Qiang; Liu Ying; Yang Xia; Hu Bo

2006-01-01

The TB-type potassium niobate K 6 Nb 10.8 O 30 was synthesized by a simple solid-state reaction method. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to characterize the structure of the photocatalyst. The photocatalyst K 6 Nb 10.8 O 30 shows high photocatalytic activity to photodegrade acid red G under UV irradiation. The influences of catalyst dosage, initial concentration of acid red G on the photocatalytic reaction were investigated. The kinetics of photocatalytic degradation of acid red G follows the first order kinetics

Solid-state lithium battery

Science.gov (United States)

Ihlefeld, Jon; Clem, Paul G; Edney, Cynthia; Ingersoll, David; Nagasubramanian, Ganesan; Fenton, Kyle Ross

2014-11-04

The present invention is directed to a higher power, thin film lithium-ion electrolyte on a metallic substrate, enabling mass-produced solid-state lithium batteries. High-temperature thermodynamic equilibrium processing enables co-firing of oxides and base metals, providing a means to integrate the crystalline, lithium-stable, fast lithium-ion conductor lanthanum lithium tantalate (La.sub.1/3-xLi.sub.3xTaO.sub.3) directly with a thin metal foil current collector appropriate for a lithium-free solid-state battery.

The testing report of the development for the lithium grains and lithium rod automatic machine

International Nuclear Information System (INIS)

Qian Zongkui; Kong Xianghong; Huang Yong

2008-06-01

With the development of lithium industry, the lithium grains and lithium rod, as additive or catalyzer, having a big comparatively acreage and a strong activated feature, have a broad application. The lithium grains and lithium rod belong to the kind of final machining materials. The principle of the lithium grains and lithium rod that how to take shape through the procedures of extrusion, cutting, anti-conglutination, threshing and so on are analysed, A sort of lithium grains and lithium rod automatic machine is developed. (authors)

Mood-congruent false memories persist over time.

Science.gov (United States)

Knott, Lauren M; Thorley, Craig

2014-01-01

In this study, we examined the role of mood-congruency and retention interval on the false recognition of emotion laden items using the Deese/Roediger-McDermott (DRM) paradigm. Previous research has shown a mood-congruent false memory enhancement during immediate recognition tasks. The present study examined the persistence of this effect following a one-week delay. Participants were placed in a negative or neutral mood, presented with negative-emotion and neutral-emotion DRM word lists, and administered with both immediate and delayed recognition tests. Results showed that a negative mood state increased remember judgments for negative-emotion critical lures, in comparison to neutral-emotion critical lures, on both immediate and delayed testing. These findings are discussed in relation to theories of spreading activation and emotion-enhanced memory, with consideration of the applied forensic implications of such findings.

Giving cognition a helping hand: the effect of congruent gestures on object name retrieval.

Science.gov (United States)

Pine, Karen J; Reeves, Lindsey; Howlett, Neil; Fletcher, Ben C

2013-02-01

The gestures that accompany speech are more than just arbitrary hand movements or communicative devices. They are simulated actions that can both prime and facilitate speech and cognition. This study measured participants' reaction times for naming degraded images of objects when simultaneously adopting a gesture that was either congruent with the target object, incongruent with it, and when not making any hand gesture. A within-subjects design was used, with participants (N= 122) naming 10 objects under each condition. Participants named the objects significantly faster when adopting a congruent gesture than when not gesturing at all. Adopting an incongruent gesture resulted in significantly slower naming times. The findings are discussed in the context of the intrapersonal cognitive and facilitatory effects of gestures and underline the relatedness between language, action, and cognition. © 2012 The British Psychological Society.

Electrooptic and piezoelectric measurements in photorefractive barium titanate and strontium barium niobate

International Nuclear Information System (INIS)

Ducharme, S.; Feinberg, J.; Neurgaonkar, R.R.

1987-01-01

The authors measured the low-frequency (''unclamped'') electrooptic and piezoelectric coefficients in undoped BaTiO/sub 3/ and Sr/sub x/Ba/sub 1-x/Nb/sub 2/O/sub 6/ (chi - 0.61) crystals using interferometric techniques. The contribution of the piezoelectric effect to the Pockels measurement is discussed. For an applied ac electric field in the range 0.1-200 V/cm, the electrooptic and piezoelectric effects are linear in the magnitude of of the applied field and independent of its frequency in the range of 10 Hz-100 kHz. The unclamped electrooptic coefficients of poled BaTiO/sub 3/ single crystals are r/sub 13/ = 19.5 +- 1 pm/V and r/sub 33/ = 97 +- 7 pm/V, and for strontium barium niobate are r/sub 13/ = 47 +- 5 pm/V and r/sub 33/ = 235 +- 21 pm/V, all measured at a wavelength of 514.5 nm and at T = 23 0 C. For the barium titanate samples the measured Pockels coefficient r/sub c/ identical to r/sub 33/ - (n/sub 1//n/sub 3/)/sup 3/r/sub 13/ = 79 +- 6 pm/V in good agreement with the value r/sub c/ = 76 +- 7 pm/V computed from the above values of r/sub 13/ and r/sub 33/, where n/sub 1/ and n/sub 3/ are the ordinary and extraordinary indexes of refraction, respectively. The measured piezoelectric coefficient is d/sub 23/ = +28.7 +- 2 pm/V for barium titanate, and is d/sub 23/ = +24.6 +- 2 pm/V for strontium barium niobate. They also measured the photoreflective coupling of two optical beams in the crystals, and they show that the dependence of the coupling strength on beam polarization is in fair agreement with the measured values of the Pockels coefficients

Wetting properties of liquid lithium on lithium compounds

Energy Technology Data Exchange (ETDEWEB)

Krat, S.A., E-mail: stepan.krat@gmail.com [Center for Plasma Material Interactions, Department of Nuclear, Plasma, and Radiological Engineering, University Illinois at Urbana-Champaign, Urbana (United States); National Research Nuclear University MEPhI, Moscow (Russian Federation); Popkov, A.S. [Center for Plasma Material Interactions, Department of Nuclear, Plasma, and Radiological Engineering, University Illinois at Urbana-Champaign, Urbana (United States); National Research Nuclear University MEPhI, Moscow (Russian Federation); Gasparyan, Yu. M.; Pisarev, A.A. [National Research Nuclear University MEPhI, Moscow (Russian Federation); Fiflis, Peter; Szott, Matthew; Christenson, Michael; Kalathiparambil, Kishor; Ruzic, David N. [Center for Plasma Material Interactions, Department of Nuclear, Plasma, and Radiological Engineering, University Illinois at Urbana-Champaign, Urbana (United States)

2017-04-15

Highlights: • Contact angles of liquid lithium and Li{sub 3}N, Li{sub 2}O, Li{sub 2}CO{sub 3} were measured. • Liquid lithium wets lithium compounds at relatively low temperatures: Li{sub 3}N at 257 °C, Li{sub 2}O at 259 °C, Li{sub 2}CO{sub 3} at 323 °C. • Li wets Li{sub 2}O and Li{sub 3}N better than previously measured fusion-relevant materials (W, Mo, Ta, TZM, stainless steel). • Li wets Li{sub 2}CO{sub 3} better than most previously measured fusion-relevant materials (W, Mo, Ta). - Abstract: Liquid metal plasma facing components (LMPFC) have shown a potential to supplant solid plasma facing components materials in the high heat flux regions of magnetic confinement fusion reactors due to the reduction or elimination of concerns over melting, wall damage, and erosion. To design a workable LMPFC, one must understand how liquid metal interacts with solid underlying structures. Wetting is an important factor in such interaction, several designs of LMPFC require liquid metal to wet the underlying solid structures. The wetting of lithium compounds (lithium nitride, oxide, and carbonate) by 200 °C liquid lithium at various surface temperature from 230 to 330 °C was studied by means of contact angle measurements. Wetting temperatures, defined as the temperature above which the contact angle is less than 90°, were measured. The wetting temperature was 257 °C for nitride, 259 °C for oxide, and 323 °C for carbonate. Surface tensions of solid lithium compounds were calculated from the contact angle measurements.

Lithium uptake and the corrosion of zirconium alloys in aqueous lithium hydroxide solutions

International Nuclear Information System (INIS)

Ramasubramanian, N.

1991-01-01

This paper reports on corrosion films on zirconium alloys that were analyzed for lithium by Atomic Absorption Spectroscopy (AAS), Secondary Ion Mass Spectrometry (SIMS), and Infrared Reflection Absorption Spectroscopy (IRAS). The oxides grown in reactor in dilute lithium hydroxide solution, specimens cut from Zircaloy, and Zr-2.5Nb alloy pressure tubes removed from CANDU (Canada Deuterium Uranium, Registered Trademark) reactors showed low concentrations of lithium (4 to 50 ppm). The lithium was not leachable in a warm dilute acid. 6 Li undergoes transmutation by the 6 Li(n,t) 4 He reaction. However, SIMS profiles for d 7 Li were identical through the bulk oxide and the isotopic ratio was close to the natural abundance value. The lithium in the oxide, existing as adsorbed lithium on the surface, has been in dynamic equilibrium with lithium in the coolant, and, in spite of many Effective Full Power Years (EFPY) of operation, lithium added to the CANDU coolant at ∼2.5 ppm is not concentrating in the oxides. On the other hand, corrosion films grown in the laboratory in concentrated lithium hydroxide solutions were very porous and contained hundreds of ppm of lithium in the oxide

Method for fabricating carbon/lithium-ion electrode for rechargeable lithium cell

Science.gov (United States)

Huang, Chen-Kuo (Inventor); Surampudi, Subbarao (Inventor); Attia, Alan I. (Inventor); Halpert, Gerald (Inventor)

1995-01-01

The method includes steps for forming a carbon electrode composed of graphitic carbon particles adhered by an ethylene propylene diene monomer binder. An effective binder composition is disclosed for achieving a carbon electrode capable of subsequent intercalation by lithium ions. The method also includes steps for reacting the carbon electrode with lithium ions to incorporate lithium ions into graphitic carbon particles of the electrode. An electrical current is repeatedly applied to the carbon electrode to initially cause a surface reaction between the lithium ions and to the carbon and subsequently cause intercalation of the lithium ions into crystalline layers of the graphitic carbon particles. With repeated application of the electrical current, intercalation is achieved to near a theoretical maximum. Two differing multi-stage intercalation processes are disclosed. In the first, a fixed current is reapplied. In the second, a high current is initially applied, followed by a single subsequent lower current stage. Resulting carbon/lithium-ion electrodes are well suited for use as an anode in a reversible, ambient temperature, lithium cell.

All-optical broadcast and multicast technologies based on PPLN waveguide

DEFF Research Database (Denmark)

Ye, Lingyun; Wang, Ju; Hu, Hao

2013-01-01

All-optical 1×4 broadcast and 1×3 multicast experiments of a 40-Gb/s return-to-zero on-off keying (RZ-OOK) signal based on a periodically poled lithium niobate (PPLN) waveguide are demonstrated in this letter. Clear opened eye diagrams and error-free performance are achieved for the broadcast...

The influence of oxidant and fuel on the powders characteristics of ...

Indian Academy of Sciences (India)

62

Lithium niobate (LiNbO3) is widely recognized as a promising material for replacing lead-based ... molten salt method, peroxide route, and combustion synthesis [9–20]. Among ... Depending on the amount of heat generated during the ... quickly transferred to a furnace pre-heated at 600 °C where the combustion reaction.

Tightly congruent bursts of lineage and phenotypic diversification identified in a continental ant radiation

NARCIS (Netherlands)

Price, Shauna L; Etienne, Rampal S; Powell, Scott

Adaptive diversification is thought to be shaped by ecological opportunity. A prediction of this ecological process of diversification is that it should result in congruent bursts of lineage and phenotypic diversification, but few studies have found this expected association. Here, we study the

Het motiveren van cliënten in directieve therapie met congruente en judoachtige technieken

NARCIS (Netherlands)

Lange, A.

2009-01-01

This article discusses techniques and attitudes which enable directive therapists to motivate their clients. The author distinguishes congruent techniques, where the therapist has no hidden agenda, from judo-like behaviour with a hidden agenda. The judo-attitude and techniques are necessary if there

Enriched lithium collection from lithium plasma flow

International Nuclear Information System (INIS)

Karchevsky, A.I.; Laz'ko, V.S.; Muromkin, Y.A.; Pashkovsky, V.G.; Ustinov, A.L.; Dolgolenko, D.A.

1994-01-01

In order to understand the physical processes concerned with the selective heating by ion cyclotron resonance and with the subsequent collection of heated particles, experiments were carried out with the extraction of lithium samples, enriched with 6 Li isotopes. Probe and integral extractors allow to collect enriched Li at the end of the selective heating region. Surface density distribution on the collector and local isotopic content of lithium are measured, as a function of the screen height and the retarding potential. Dependence of the collected amount of lithium and of its isotopic content on the value of the magnetic field is also measured. 4 figs., 2 tabs., 5 refs

Electron-stimulated desorption of lithium ions from lithium halide thin films

International Nuclear Information System (INIS)

Markowski, Leszek

2007-01-01

Electron-stimulated desorption of positive lithium ions from thin layers of lithium halides deposited onto Si(1 1 1) are investigated by the time-of-flight technique. The determined values of isotope effect of the lithium ( 6 Li + / 7 Li + ) are 1.60 ± 0.04, 1.466 ± 0.007, 1.282 ± 0.004, 1.36 ± 0.01 and 1.33 ± 0.01 for LiH, LiF, LiCl, LiBr and LiI, respectively. The observed most probable kinetic energies of 7 Li + are 1.0, 1.9, 1.1, 0.9 and 0.9 eV for LiH, LiF, LiCl, LiBr and LiI, respectively, and seem to be independent of the halide component mass. The values of lithium ion emission yield, lithium kinetic energy and lithium isotope effect suggest that the lattice relaxation is only important in the lithium ion desorption process from the LiH system. In view of possible mechanisms and processes involved into lithium ion desorption the obtained results indicate that for LiH, LiCl, LiBr and LiI the ions desorb in a rather classical way. However, for LiF, ion desorption has a more quantum character and the modified wave packet squeezing model has to be taken into account

Processing and characterization of lead-free ceramics on the base of sodium-potassium niobate

Science.gov (United States)

Politova, E. D.; Golubko, N. V.; Kaleva, G. M.; Mosunov, A. V.; Sadovskaya, N. V.; Stefanovich, S. Yu.; Kiselev, D. A.; Kislyuk, A. M.; Panda, P. K.

Lead-free sodium-potassium niobate-based piezoelectric materials are most intensively studied in order to replace the widely used Pb-based ones. In this work, the effects of modification of compositions by donor and acceptor dopants in the A- and B-sites of perovskite lattice on structure, dielectric, ferroelectric, and piezoelectric properties of ceramics from Morphotropic Phase Boundary in the (1-x)(K0.5Na0.5)NbO3-xBaTiO3 system and in compositions with x=0.05 and 0.06 additionally doped by Ni3+ cations have been studied.

Processing and characterization of lead-free ceramics on the base of sodium–potassium niobate

Directory of Open Access Journals (Sweden)

E. D. Politova

2018-02-01

Full Text Available Lead-free sodium–potassium niobate-based piezoelectric materials are most intensively studied in order to replace the widely used Pb-based ones. In this work, the effects of modification of compositions by donor and acceptor dopants in the A- and B-sites of perovskite lattice on structure, dielectric, ferroelectric, and piezoelectric properties of ceramics from Morphotropic Phase Boundary in the (1−x(K0.5Na0.5NbO3–xBaTiO3 system and in compositions with x=0.05 and 0.06 additionally doped by Ni3+ cations have been studied.

Lithium treatment of manio-depressive disorder. Two examples of treatment regimes with varying serum lithium concentration curves

International Nuclear Information System (INIS)

Veimer Jensen, H.

1998-07-01

The importance of serum lithium profile in lithium maintenance treatment of manic-depressive disorder was studied by comparing pro-phylactic efficacy, side-effects and brain lithium level in patients on daily or alternate-day lithium dosing schedules. The aim of the study was to determine firstly, whether it is only necessary for the serum lithium concentration to periodically reach a certain level in order to ensure good prophylactic efficacy, and secondly, whether periodical lowering of the serum lithium level diminishes lithium-related side-effects. This was examined by extending the interval between lithium doses from 1 to 2 days, while maintaining the 12-h serum lithium concentration unchanged so as to achieve an unchanged serum lithium profile during the first 24-h period after lithium intake. The 12-h brain lithium concentration measured by 7 Li-magnetic resonance spectroscopy seemed to be independent of lithium dosing schedule, but correlated significantly with the 12-h serum lithium concentration, suggesting that at identical 12-h serum lithium concentrations, the 12-h brain lithium concentration is similar with both treatment regimens. (EG)

The Lithium Battery: assessing the neurocognitive profile of lithium in bipolar disorder.

Science.gov (United States)

Malhi, Gin S; McAulay, Claire; Gershon, Samuel; Gessler, Danielle; Fritz, Kristina; Das, Pritha; Outhred, Tim

2016-03-01

The aim of the present study was to characterize the neurocognitive effects of lithium in bipolar disorder to inform clinical and research approaches for further investigation. Key words pertaining to neurocognition in bipolar disorder and lithium treatment were used to search recognized databases to identify relevant literature. The authors also retrieved gray literature (e.g., book chapters) known to them and examined pertinent articles from bibliographies. A limited number of studies have examined the effects of lithium on neurocognition in bipolar disorder and, although in some domains a consistent picture emerges, in many domains the findings are mixed. Lithium administration appears to reshape key components of neurocognition - in particular, psychomotor speed, verbal memory, and verbal fluency. Notably, it has a sophisticated neurocognitive profile, such that while lithium impairs neurocognition across some domains, it seemingly preserves others - possibly those vulnerable to the effects of bipolar disorder. Furthermore, its effects are likely to be direct and indirect (via mood, for example) and cumulative with duration of treatment. Disentangling the components of neurocognition modulated by lithium in the context of a fluctuating and complex illness such as bipolar disorder is a significant challenge but one that therefore demands a stratified and systematic approach, such as that provided by the Lithium Battery. In order to delineate the effects of lithium therapy on neurocognition in bipolar disorder within both research and clinical practice, a greater understanding and measurement of the relatively stable neurocognitive components is needed to examine those that indeed change with lithium treatment. In order to achieve this, we propose a Lithium Battery-Clinical and a Lithium Battery-Research that can be applied to these respective settings. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A stable organic-inorganic hybrid layer protected lithium metal anode for long-cycle lithium-oxygen batteries

Science.gov (United States)

Zhu, Jinhui; Yang, Jun; Zhou, Jingjing; Zhang, Tao; Li, Lei; Wang, Jiulin; Nuli, Yanna

2017-10-01

A stable organic-inorganic hybrid layer (OIHL) is direct fabricated on lithium metal surface by the interfacial reaction of lithium metal foil with 1-chlorodecane and oxygen/carbon dioxide mixed gas. This favorable OIHL is approximately 30 μm thick and consists of lithium alkyl carbonate and lithium chloride. The lithium-oxygen batteries with OIHL protected lithium metal anode exhibit longer cycle life (340 cycles) than those with bare lithium metal anode (50 cycles). This desirable performance can be ascribed to the robust OIHL which prevents the growth of lithium dendrites and the corrosion of lithium metal.

LiNbO3 surfaces from a microscopic perspective

Science.gov (United States)

Sanna, Simone; Gero Schmidt, Wolf

2017-10-01

A large number of oxides has been investigated in the last twenty years as possible new materials for various applications ranging from opto-electronics to heterogeneous catalysis. In this context, ferroelectric oxides are particularly promising. The electric polarization plays a crucial role at many oxide surfaces, and it largely determines their physical and chemical properties. Ferroelectrics offer in addition the possibility to control/switch the electric polarization and hence the surface chemistry, allowing for the realization of domain-engineered nanoscale devices such as molecular detectors or highly efficient catalysts. Lithium niobate (LiNbO3) is a ferroelectric with a high spontaneous polarization, whose surfaces have a huge and largely unexplored potential. Owing to recent advances in experimental techniques and sample preparation, peculiar and exclusive properties of LiNbO3 surfaces could be demonstrated. For example, water films freeze at different temperatures on differently polarized surfaces, and the chemical etching properties of surfaces with opposite polarization are strongly different. More important, the ferroelectric domain orientation affects temperature dependent surface stabilization mechanisms and molecular adsorption phenomena. Various ab initio theoretical investigations have been performed in order to understand the outcome of these experiments and the origin of the exotic behavior of the lithium niobate surfaces. Thanks to these studies, many aspects of their surface physics and chemistry could be clarified. Yet other puzzling features are still not understood. This review gives a résumé on the present knowledge of lithium niobate surfaces, with a particular view on their microscopic properties, explored in recent years by means of ab initio calculations. Relevant aspects and properties of the surfaces that need further investigation are briefly discussed. The review is concluded with an outlook of challenges and potential payoff

Upconversion detector for range-resolved DIAL measurement of atmospheric CH₄

DEFF Research Database (Denmark)

Meng, Lichun; Fix, Andreas; Wirth, Martin

2018-01-01

backscatter signal at 1646 nm in a 25-mm long periodically poled lithium niobate crystal. The upconverted signal at 646 nm is detected by a photomultiplier tube (PMT). The UCD with a noise equivalent power around 127 fW/Hz1/2 outperforms a conventional InGaAs based avalanche photodetector when both are used...

Up to 30 mW of broadly tunable CW green-to-orange light, based on sum-frequency mixing of Cr4+:forsterite and Nd:YVO4 lasers

DEFF Research Database (Denmark)

Mortensen, Jesper Liltorp; McWilliam, Allan; G. Leburn, Christopher

2006-01-01

Efficient generation of continuous-wave (CW) tunable light in the yellow region is reported. The method is based on sum-frequency mixing of a tunable Cr4+:forsterite laser with a Nd:YVO4 laser. A periodically poled lithium niobate crystal was placed intra-cavity in a Nd:YVO4 laser, and the Cr4...

Performances of a lithium-carbon ``lithium ion``battery for electric powered vehicle; Performances d`un accumulateur au lithium-carbone ``Lithium Ion`` pour vehicule electrique

Energy Technology Data Exchange (ETDEWEB)

Broussely, M.; Planchat, J.P.; Rigobert, G.; Virey, D.; Sarre, G. [SAFT, Advanced and Industrial Battery Group, 86 - Poitiers (France)

1996-12-31

The lithium battery, also called `lithium-carbon` or `lithium ion`, is today the most promising candidate that can reach the expected minimum traction performances of electric powered vehicles. Thanks to a more than 20 years experience on lithium generators and to a specific research program on lithium batteries, the SAFT company has developed a 100 Ah electrochemical system, and full-scale prototypes have been manufactured for this application. These prototypes use the Li{sub x}NiO{sub 2} lithiated graphite electrochemical pair and were tested in terms of their electrical performances. Energy characteristics of 125 Wh/kg and 265 Wh/dm{sup 3} could be obtained. The possibility of supplying a power greater than 200 W/kg, even at low temperature (-10 deg. C) has been demonstrated with these elements. A full battery set of about 20 kWh was built and its evaluation is in progress. It comprises the electronic control systems for the optimum power management during charge and output. (J.S.) 9 refs.

Performances of a lithium-carbon ``lithium ion``battery for electric powered vehicle; Performances d`un accumulateur au lithium-carbone ``Lithium Ion`` pour vehicule electrique

Energy Technology Data Exchange (ETDEWEB)

Broussely, M; Planchat, J P; Rigobert, G; Virey, D; Sarre, G [SAFT, Advanced and Industrial Battery Group, 86 - Poitiers (France)

1997-12-31

The lithium battery, also called `lithium-carbon` or `lithium ion`, is today the most promising candidate that can reach the expected minimum traction performances of electric powered vehicles. Thanks to a more than 20 years experience on lithium generators and to a specific research program on lithium batteries, the SAFT company has developed a 100 Ah electrochemical system, and full-scale prototypes have been manufactured for this application. These prototypes use the Li{sub x}NiO{sub 2} lithiated graphite electrochemical pair and were tested in terms of their electrical performances. Energy characteristics of 125 Wh/kg and 265 Wh/dm{sup 3} could be obtained. The possibility of supplying a power greater than 200 W/kg, even at low temperature (-10 deg. C) has been demonstrated with these elements. A full battery set of about 20 kWh was built and its evaluation is in progress. It comprises the electronic control systems for the optimum power management during charge and output. (J.S.) 9 refs.

Lithium ion behavior in lithium oxide by neutron scattering studies

International Nuclear Information System (INIS)

Ishii, Yoshinobu; Morii, Yukio; Katano, Susumu; Watanabe, Hitoshi; Funahashi, Satoru; Ohno, Hideo; Nicklow, R.M.

1992-01-01

Lithium ion behavior in lithium oxide, Li 2 O, was studied in the temperature range from 293 K to 1120 K by the High-Resolution Powder Diffractometer (HRPD) installed in the JRR-3M. The diffraction patterns were analyzed with the RIETAN program. At room temperature, the thermal parameters related to the mean square of the amplitude of vibration of the lithium and the oxygen ions were 6 x 10 -21 m 2 and 4 x 10 -21 m 2 , respectively. AT 1120 K the thermal parameter of the lithium ion was 34 x 10 -21 m 2 . On the other hand, the parameter of the oxygen ion was 16 x 10 -21 m 2 . Inelastic neutron scattering studies for the lithium oxide single crystal were also carried out on the triple-axis neutron spectrometers installed at the JRR-2 and the HFIR. Although the value of a phonon energy of a transverse acoustic mode (Σ 3 ) at zone boundary was 30.6 meV at room temperature, this value was decreased to 25.1 meV at 700 K. This large softening was caused by anharmonicity of the crystal potential of lithium oxide. (author)

Nonlinear optical properties of TeO2-P2 O5- ZnO-LiNbO3 glass doped with Er3+ ions

Science.gov (United States)

Miedzinski, R.; Fuks-Janczarek, I.; El Sayed Said, Y.

2016-10-01

A series of lithium niobate LiNbO3 (LN) single crystals doped with Er3+ were grown under the same conditions by melt-quenching method. The distribution coefficients of rare-earth (RE) elements in the "crystal-melt" system of LN were determined at the beginning of the crystal growth. Their dependence on the dopant concentration in melt for 0.4 and 0.8 wt % was investigated. The procedure is applied to RE-doped lithium niobate (LiNbO3), a material of great interest for optoelectronic applications. We have obtained the real χR(3) and imaginary parts χI(3) of the third-order, nonlinear optical susceptibility to the nonlinear refractive index n2 and the nonlinear absorption coefficient β that are valid for absorbing systems. We show that nonlinear refractive or absorptive effects are the consequence of the interplay between the real and imaginary parts of the third-order susceptibilities of the materials. The method for measuring non-linear absorption coefficients and nonlinear refractive index based on well-known Z-scan is presented.

Examination results on reaction of lithium

International Nuclear Information System (INIS)

Asada, Takashi

2000-12-01

Before the material corrosion tests in lithium, the reactions of lithium with air and ammonia that will be used for lithium cleaning were examined, and the results were as follows. 1. When lithium put into air, surface of lithium changes to black first but soon to white, and the white layer becomes gradually thick. The first black of lithium surface is nitride (Li 3 N) and it changes to white lithium hydroxide (LiOH) by reaction with water in air, and it grows. The growth rate of the lithium hydroxide is about 1/10 in the desiccator (humidity of about 10%) compare with in air. 2. When lithium put into nitrogen, surface of lithium changes to black, and soon changes to brown and cracks at surface. At the same time with this cracking, weight of lithium piece increases and nitridation progresses respectively rapidly. This nitridation completed during 1-2 days on lithium rod of 10 mm in diameter, and increase in weight stopped. 3. Lithium melts in liquid ammonia and its melting rate is about 2-3 hour to lithium of 1 g. The liquid ammonia after lithium melting showed dark brown. (author)

Hydrogen Outgassing from Lithium Hydride

Energy Technology Data Exchange (ETDEWEB)

Dinh, L N; Schildbach, M A; Smith, R A; Balazs1, B; McLean II, W

2006-04-20

Lithium hydride is a nuclear material with a great affinity for moisture. As a result of exposure to water vapor during machining, transportation, storage and assembly, a corrosion layer (oxide and/or hydroxide) always forms on the surface of lithium hydride resulting in the release of hydrogen gas. Thermodynamically, lithium hydride, lithium oxide and lithium hydroxide are all stable. However, lithium hydroxides formed near the lithium hydride substrate (interface hydroxide) and near the sample/vacuum interface (surface hydroxide) are much less thermally stable than their bulk counterpart. In a dry environment, the interface/surface hydroxides slowly degenerate over many years/decades at room temperature into lithium oxide, releasing water vapor and ultimately hydrogen gas through reaction of the water vapor with the lithium hydride substrate. This outgassing can potentially cause metal hydriding and/or compatibility issues elsewhere in the device. In this chapter, the morphology and the chemistry of the corrosion layer grown on lithium hydride (and in some cases, its isotopic cousin, lithium deuteride) as a result of exposure to moisture are investigated. The hydrogen outgassing processes associated with the formation and subsequent degeneration of this corrosion layer are described. Experimental techniques to measure the hydrogen outgassing kinetics from lithium hydride and methods employing the measured kinetics to predict hydrogen outgassing as a function of time and temperature are presented. Finally, practical procedures to mitigate the problem of hydrogen outgassing from lithium hydride are discussed.

Explosion of lithium-thionyl-chloride battery due to presence of lithium nitride

DEFF Research Database (Denmark)

Hennesø, E.; Hedlund, Frank Huess

2015-01-01

An explosion of a lithium–thionyl-chloride (Li–SOCl2) battery during production (assembly) leads to serious worker injury. The accident cell batch had been in a dry-air intermediate storage room for months before being readied with thionyl chloride electrolyte. Metallic lithium can react...... with atmospheric nitrogen to produce lithium nitride. Nodules of lithium nitride were found to be present on the lithium foil in other cells of the accident batch. The investigation attributed the explosion to the formation of porous lithium nitride during intermediate storage and a violent exothermal...... decomposition with the SOCl2–LiAlCl4 electrolyte triggered by welding. The literature is silent on hazards of explosion of Li–SOCl2 cells associated with the presence of lithium nitride. The silence is intriguing. Possible causes may be that such explosions are very rare, that explosions go unpublished...

Lithium neurotoxicity.

Science.gov (United States)

Suraya, Y; Yoong, K Y

2001-09-01

Inspite of the advent of newer antimanic drugs, lithium carbonate remains widely used in the treatment and prevention of manic-depressive illness. However care has to be exercised due to its low therapeutic index. The central nervous system and renal system are predominantly affected in acute lithium intoxication and is potentially lethal. The more common side effect involves the central nervous system. It occurs early and is preventable. We describe three cases of lithium toxicity admitted to Johor Bahru Hospital, with emphasis on its neurological preponderance.

Manufacturing of Protected Lithium Electrodes for Advanced Lithium-Air, Lithium-Water & Lithium-Sulfur Batteries

Energy Technology Data Exchange (ETDEWEB)

Visco, Steven J

2015-11-30

The global demand for rechargeable batteries is large and growing rapidly. Assuming the adoption of electric vehicles continues to increase, the need for smaller, lighter, and less expensive batteries will become even more pressing. In this vein, PolyPlus Battery Company has developed ultra-light high performance batteries based on its proprietary protected lithium electrode (PLE) technology. The Company’s Lithium-Air and Lithium-Seawater batteries have already demonstrated world record performance (verified by third party testing), and we are developing advanced lithium-sulfur batteries which have the potential deliver high performance at low cost. In this program PolyPlus Battery Company teamed with Corning Incorporated to transition the PLE technology from bench top fabrication using manual tooling to a pre- commercial semi-automated pilot line. At the inception of this program PolyPlus worked with a Tier 1 battery manufacturing engineering firm to design and build the first-of-its-kind pilot line for PLE production. The pilot line was shipped and installed in Berkeley, California several months after the start of the program. PolyPlus spent the next two years working with and optimizing the pilot line and now produces all of its PLEs on this line. The optimization process successfully increased the yield, throughput, and quality of PLEs produced on the pilot line. The Corning team focused on fabrication and scale-up of the ceramic membranes that are key to the PLE technology. PolyPlus next demonstrated that it could take Corning membranes through the pilot line process to produce state-of-the-art protected lithium electrodes. In the latter part of the program the Corning team developed alternative membranes targeted for the large rechargeable battery market. PolyPlus is now in discussions with several potential customers for its advanced PLE-enabled batteries, and is building relationships and infrastructure for the transition into manufacturing. It is likely

Explosion of lithium-thionyl-chloride battery due to presence of lithium nitride

OpenAIRE

Hennesø, E.; Hedlund, Frank Huess

2015-01-01

An explosion of a lithium–thionyl-chloride (Li–SOCl2) battery during production (assembly) leads to serious worker injury. The accident cell batch had been in a dry-air intermediate storage room for months before being readied with thionyl chloride electrolyte. Metallic lithium can react with atmospheric nitrogen to produce lithium nitride. Nodules of lithium nitride were found to be present on the lithium foil in other cells of the accident batch. The investigation attributed the explosion t...

Lithium niobate. Defects, photorefraction and ferroelectric switching

Energy Technology Data Exchange (ETDEWEB)

Volk, Tatyana [Russian Academy of Sciences, Inst. for Crystallography, Moscow (Russian Federation); Woehlecke, Manfred [Osnabrueck Univ. (Germany). Fachbereich Physik

2008-07-01

The book presents the current state of studies of point defects, both intrinsic and extrinsic (impurities, radiation centers, etc.), in LiNbO{sub 3}. The contribution of intrinsic defects to photoinduced charge transport, i.e. to the photorefraction, is explained. The photorefractive and optical properties of LiNbO{sub 3} crystals with different stoichiometry and of those doped with so-called ''optical-damage resistant'' impurities controlling the intrinsic defect structure are described in detail. Applications included are to the problem of non-erasable recording of photorefractive holograms in LiNbO{sub 3} and the current situation of studies in the ferroelectric switching and domain structure of LiNbO{sub 3}, as well as the creation of periodically-poled structures for the optical frequency conversion. (orig.)

Piezo-optic surfaces of lithium niobate crystals

International Nuclear Information System (INIS)

Mytsyk, B. G.; Dem'yanyshyn, N. M.

2006-01-01

A method of construction of the spatial distribution of the piezo-optic effect in crystals is proposed. A particular case of this method is the known technique of construction of indicator surfaces of the piezo-optic effect. The essence of the proposed method consists in determining the difference in the radius vectors of the optical indicatrix perturbed by stress and the free optical indicatrix. It is shown that this difference in the radius vectors is mathematically identical to the law of transformation of the piezo-optic tensor during the rotation of the coordinate system

Experimental results of two stage harmonic generation with picosecond pulses on the Stanford Mark III FEL

International Nuclear Information System (INIS)

Hooper, B.A.; Utah Univ., Salt Lake City; Stanford Univ., CA; Benson, S.V.; Madey, M.J.; Cutolo, A.; Naples Univ.

1988-01-01

We report experimental results on upper harmonic conversion using a lithium niobate and a beta barium borate crystal to quadruple the FEL light up into the visible and near infrared. The effects of finite linewidth, birefringent walk-off, and group velocity walk-off on conversion efficiency will be discussed with reference to the experimental results. (orig.)

CW frequency doubling of 1029 nm radiation using single pass bulk and waveguide PPLN crystals

Czech Academy of Sciences Publication Activity Database

Chiodo, N.; Du Burck, F.; Hrabina, Jan; Candela, Y.; Wallerand, J. P.; Acef, O.

2013-01-01

Roč. 311, 15 January (2013), s. 239-244 ISSN 0030-4018 R&D Projects: GA ČR GPP102/11/P820 Institutional support: RVO:68081731 Keywords : IR laser * second harmonic generation * waveguide and bulk crystals * periodically poled lithium niobate * 1029 nm wavelength Subject RIV: BH - Optics , Masers, Lasers Impact factor: 1.542, year: 2013

Light-induced space-charge fields for the structuration of dielectric materials; Lichtinduzierte Raumladungsfelder zur Strukturierung dielektrischer Materialien

Energy Technology Data Exchange (ETDEWEB)

Eggert, H A

2006-11-15

Light-induced space-charge fields in lithium-niobate crystals are used for patterning of dielectric materials. This includes tailored ferroelectric domains in the bulk of the crystal, different sorts of micro and nanoparticles on a crystal surface, as well as poling of electrooptic chromophores. A stochastical model is introduced, which can describe the spatial inhomogeneous domain inversion. (orig.)

Light-induced space-charge fields for the structuration of dielectric materials

International Nuclear Information System (INIS)

Eggert, H.A.

2006-11-01

Light-induced space-charge fields in lithium-niobate crystals are used for patterning of dielectric materials. This includes tailored ferroelectric domains in the bulk of the crystal, different sorts of micro and nanoparticles on a crystal surface, as well as poling of electrooptic chromophores. A stochastical model is introduced, which can describe the spatial inhomogeneous domain inversion. (orig.)

Lithium in drinking water and suicide mortality: The interplay with lithium prescriptions

NARCIS (Netherlands)

Helbich, M; Leitner, M; Kapusta, N

Background Little is known about the effects of lithium intake through drinking water on suicide. This intake originates either from natural rock and soil elution and/or accumulation of lithium-based pharmaceuticals in ground water. Aims To examine the interplay between natural lithium in drinking

Studies on electrochemical lithium insertion in isostructural titanium niobate and tantalate phases with shear ReO3 structure

International Nuclear Information System (INIS)

Saritha, D.; Varadaraju, U.V.

2013-01-01

Graphical abstract: - Highlights: • Electrochemical lithium insertion into ReO 3 type phases TiNb 2 O 7 , TiTa 2 O 7 is feasible. • TiNb 2 O 7 exhibits good cycling behavior and high reversible capacity of 212 mAh g −1 . • TiTa 2 O 7 exhibits reversible capacity of 100 mAh g −1 . - Abstract: TiNb 2 O 7 and TiTa 2 O 7 phases are synthesized by solid-state reaction method and are investigated for electrochemical Li insertion/extraction. The electrochemical insertion of Li in these phases is characterized by both solid solution and two-phase regimes. The structure is stable toward Li insertion/extraction. The first cycle discharge capacity values are 307 mAh g −1 and 215 mAh g −1 in the voltage range of 3.0–1.0 V for TiNb 2 O 7 and TiTa 2 O 7 phases, respectively. The discharge capacities of TiNb 2 O 7 and TiTa 2 O 7 are 212 mAh g −1 and 100 mAh g −1 , respectively, after 20 cycles

Heteroaromatic-based electrolytes for lithium and lithium-ion batteries

Science.gov (United States)

Cheng, Gang; Abraham, Daniel P.

2017-04-18

The present invention provides an electrolyte for lithium and/or lithium-ion batteries comprising a lithium salt in a liquid carrier comprising heteroaromatic compound including a five-membered or six-membered heteroaromatic ring moiety selected from the group consisting of a furan, a pyrazine, a triazine, a pyrrole, and a thiophene, the heteroaromatic ring moiety bearing least one carboxylic ester or carboxylic anhydride substituent bound to at least one carbon atom of the heteroaromatic ring. Preferred heteroaromatic ring moieties include pyridine compounds, pyrazine compounds, pyrrole compounds, furan compounds, and thiophene compounds.

Lithium Batteries

Science.gov (United States)

National Laboratory, Materials Science and Technology Division Lithium Batteries Resources with Additional thin-film lithium batteries for a variety of technological applications. These batteries have high essentially any size and shape. Recently, Teledyne licensed this technology from ORNL to make batteries for

Towards a sensory congruent beer bottle: Consumer associations between beer brands, flavours, and bottle designs

NARCIS (Netherlands)

Fenko, Anna; Heiltjes, Sanne; van den Berg-Weitzel, Lianne; Lloyd, Peter; Bohemia, Erik

2016-01-01

Sensory packaging design congruent with product and brand characteristics may be used as an innovative tool to communicate product and brand values to consumers and to enhance taste experience. This study investigated whether consumers associate sensory properties of beer bottles with certain brand

Lithium: for harnessing renewable energy

Science.gov (United States)

Bradley, Dwight; Jaskula, Brian W.

2014-01-01

Lithium, which has the chemical symbol Li and an atomic number of 3, is the first metal in the periodic table. Lithium has many uses, the most prominent being in batteries for cell phones, laptops, and electric and hybrid vehicles. Worldwide sources of lithium are broken down by ore-deposit type as follows: closed-basin brines, 58%; pegmatites and related granites, 26%; lithium-enriched clays, 7%; oilfield brines, 3%; geothermal brines, 3%; and lithium-enriched zeolites, 3% (2013 statistics). There are over 39 million tons of lithium resources worldwide. Of this resource, the USGS estimates there to be approximately 13 million tons of current economically recoverable lithium reserves. To help predict where future lithium supplies might be located, USGS scientists study how and where identified resources are concentrated in the Earth’s crust, and they use that knowledge to assess the likelihood that undiscovered resources also exist.

Solid Lithium Ion Conductors (SLIC) for Lithium Solid State Batteries

Data.gov (United States)

National Aeronautics and Space Administration — To identify the most lithium-ion conducting solid electrolytes for lithium solid state batteries from the emerging types of solid electrolytes, based on a...

Measuring nanocurie quantities of tritium bred in metallic lithium and lithium oxide samples

International Nuclear Information System (INIS)

Bertone, P.C.

1985-01-01

The LBM program requires that nanocurie quantities of tritium, bred in both lithium oxide pellets and lithium samples, be measured with an uncertainty not exceeding + or - 6%. Two methods of accurately measuring nanocurie quantities of tritium bred in LBM lithium oxide pellets and one method of accurately measuring nanocurie quantities of tritium bred in lithium samples are described. Potential errors associated with these tritium measurement techniques are also discussed

Phase decomposition in niobate glasses and the electrooptical effect in materials based on them

Energy Technology Data Exchange (ETDEWEB)

Alekseeva, I.P.; Karapetyan, G.O.; Korolov, Y.G.; Maksimov, L.V.

1986-10-01

This paper studies the effect of the composition and heat treatment on the dielectric, electrooptical, and structural-physical proprties of niobium-containing glasses. The appearance and intensification of fluctuations of the niobium concentration accompanying an increase in the niobium content in the samples is characteristic for glasses in the system Na/sub 2/O-K/sub 2/O-Nb/sub 2/O/sub 5/-SiO/sub 2/. The presence of insignificant quantities of NaNbO/sub 3/ microcrystals in niobate glasses gives rise to a significant growth of the dielectric constant (by a factor of 508) and the appearance of a quadratic electrooptical effect.

Growth of potassium niobate micro-hexagonal tablets with monoclinic phase and its excellent piezoelectric property

Science.gov (United States)

Chen, Zhong; Huang, Jingyun; Wang, Ye; Yang, Yefeng; Wu, Yongjun; Ye, Zhizhen

2012-09-01

Potassium niobate micro-hexagonal tablets were synthesized through hydrothermal reaction with KOH, H2O and Nb2O5 as source materials by using a polycrystalline Al2O3 as substrate. X-ray diffraction, Raman spectra and selected area electron diffraction analysis results indicated that the tablets exhibit monoclinic phase structure and are highly crystallized. Meanwhile, piezoelectric property of the micro-hexagonal tablets was investigated. The as-synthesized tablets exhibit excellent piezoactivities in the experiments, and an effective piezoelectric coefficient of around 80 pm/V was obtained. The tablets have huge potential applications in micro/nano-integrated piezoelectric and optical devices.

Recovery of Lithium from Geothermal Brine with Lithium-Aluminum Layered Double Hydroxide Chloride Sorbents.

Science.gov (United States)

Paranthaman, Mariappan Parans; Li, Ling; Luo, Jiaqi; Hoke, Thomas; Ucar, Huseyin; Moyer, Bruce A; Harrison, Stephen

2017-11-21

We report a three-stage bench-scale column extraction process to selectively extract lithium chloride from geothermal brine. The goal of this research is to develop materials and processing technologies to improve the economics of lithium extraction and production from naturally occurring geothermal and other brines for energy storage applications. A novel sorbent, lithium aluminum layered double hydroxide chloride (LDH), is synthesized and characterized with X-ray powder diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis. Each cycle of the column extraction process consists of three steps: (1) loading the sorbent with lithium chloride from brine; (2) intermediate washing to remove unwanted ions; (3) final washing for unloading the lithium chloride ions. Our experimental analysis of eluate vs feed concentrations of Li and competing ions demonstrates that our optimized sorbents can achieve a recovery efficiency of ∼91% and possess excellent Li apparent selectivity of 47.8 compared to Na ions and 212 compared to K ions, respectively in the brine. The present work demonstrates that LDH is an effective sorbent for selective extraction of lithium from brines, thus offering the possibility of effective application of lithium salts in lithium-ion batteries leading to a fundamental shift in the lithium supply chain.

Lanthanum Nitrate As Electrolyte Additive To Stabilize the Surface Morphology of Lithium Anode for Lithium-Sulfur Battery.

Science.gov (United States)

Liu, Sheng; Li, Guo-Ran; Gao, Xue-Ping

2016-03-01

Lithium-sulfur (Li-S) battery is regarded as one of the most promising candidates beyond conventional lithium ion batteries. However, the instability of the metallic lithium anode during lithium electrochemical dissolution/deposition is still a major barrier for the practical application of Li-S battery. In this work, lanthanum nitrate, as electrolyte additive, is introduced into Li-S battery to stabilize the surface of lithium anode. By introducing lanthanum nitrate into electrolyte, a composite passivation film of lanthanum/lithium sulfides can be formed on metallic lithium anode, which is beneficial to decrease the reducibility of metallic lithium and slow down the electrochemical dissolution/deposition reaction on lithium anode for stabilizing the surface morphology of metallic Li anode in lithium-sulfur battery. Meanwhile, the cycle stability of the fabricated Li-S cell is improved by introducing lanthanum nitrate into electrolyte. Apparently, lanthanum nitrate is an effective additive for the protection of lithium anode and the cycling stability of Li-S battery.

Electronic and Optical Properties of Sodium Niobate: A Density Functional Theory Study

Directory of Open Access Journals (Sweden)

Daniel Fritsch

2018-01-01

Full Text Available In recent years, much effort has been devoted to replace the most commonly used piezoelectric ceramic lead zirconate titanate Pb[ZrxTi1−x]O3 (PZT with a suitable lead-free alternative for memory or piezoelectric applications. One possible alternative to PZT is sodium niobate as it exhibits electrical and mechanical properties that make it an interesting material for technological applications. The high-temperature simple cubic perovskite structure undergoes a series of structural phase transitions with decreasing temperature. However, particularly the phases at room temperature and below are not yet fully characterised and understood. Here, we perform density functional theory calculations for the possible phases at room temperature and below and report on the structural, electronic, and optical properties of the different phases in comparison to experimental findings.

Ferroelectric lead magnesium niobate-lead titanate single crystals for ultrasonic hydrophone applications

International Nuclear Information System (INIS)

Lau, S.T.; Lam, K.H.; Chan, H.L.W.; Choy, C.L.; Luo, H.S.; Yin, Q.R.; Yin, Z.W.

2004-01-01

Ferroelectric lead magnesium niobate-lead titanate (PMN-PT) single crystals with a composition around the rhombohedral-tetragonal morphotropic phase boundary (65 mol% of PMN) were used to fabricate single-element needle-type hydrophones for measuring the spatial and temporal characteristics of medical ultrasonic transducers. PMN-PT single crystal was grown by a modified Bridgman method. Discs (0.5 mm thick) with normal along the direction were cut and then poled by a dc field in the thickness direction. The single crystal has a high relative permittivity (ε r ∼4000) making it appropriate for small area hydrophone applications. Single-element needle-type hydrophones with this material as the sensing element have been fabricated and characterized. The hydrophones have flat frequency response and good receiving sensitivity over certain frequency range in the megahertz region

Recovery of lithium from seawater

International Nuclear Information System (INIS)

Ooi, Kenta; Miyai, Yoshitaka; Katoh, Shunsaku; Abe, Mitsuo.

1989-01-01

Lithium has been used for air conditioners, aluminum refining, ceramics, organic metal compounds, batteries and many other uses. Besides, attention is paid as the aluminum-lithium alloys as aircraft materials, and the raw materials for large capacity batteries and nuclear fusion reactors for the future. The amount of lithium resources has been estimated as 14 million tons, and is relatively abundant, but when the future increase of demand is considered, it is not necessarily sufficient. Japan lacks lithium resources, and the stable ensuring of the resources has become an important problem. Seawater contains lithium by 170 μg/l, and its total amount reaches 230 billion tons. The process of recovering lithium from seawater, geothermal water and natural gas brine has been actively researched since 10 years ago centering around Japan. At present, the search for the adsorbent that effectively collects lithium is the main subject. Also the recovery by coprecipitation has been investigated basically. The inorganic adsorbent for lithium is classified into aluminum type, compound antimonic acid type, layered compound type, ion sieve oxide type and others. Their lithium adsorption performance and adsorption mechanism are different remarkably, therefore, these of each group are described. (K.I.) 70 refs

Raman spectra of lithium compounds

Science.gov (United States)

Gorelik, V. S.; Bi, Dongxue; Voinov, Y. P.; Vodchits, A. I.; Gorshunov, B. P.; Yurasov, N. I.; Yurasova, I. I.

2017-11-01

The paper is devoted to the results of investigating the spontaneous Raman scattering spectra in the lithium compounds crystals in a wide spectral range by the fibre-optic spectroscopy method. We also present the stimulated Raman scattering spectra in the lithium hydroxide and lithium deuteride crystals obtained with the use of powerful laser source. The symmetry properties of the lithium hydroxide, lithium hydroxide monohydrate and lithium deuteride crystals optical modes were analyzed by means of the irreducible representations of the point symmetry groups. We have established the selection rules in the Raman and infrared absorption spectra of LiOH, LiOH·H2O and LiD crystals.

Behavioral and Event-Related-Potential Correlates of Processing Congruent and Incongruent Self-Relevant Information

Science.gov (United States)

Clark, Sheri L.

2013-01-01

People want to be viewed by others as they view themselves. Being confronted with self-relevant information that is either congruent or incongruent with one's self-view has been shown to differentially affect subsequent behavior, memory for the information, and evaluation of the source of the information. However, no research has examined…

Safe and recyclable lithium-ion capacitors using sacrificial organic lithium salt

Science.gov (United States)

Jeżowski, P.; Crosnier, O.; Deunf, E.; Poizot, P.; Béguin, F.; Brousse, T.

2018-02-01

Lithium-ion capacitors (LICs) shrewdly combine a lithium-ion battery negative electrode capable of reversibly intercalating lithium cations, namely graphite, together with an electrical double-layer positive electrode, namely activated carbon. However, the beauty of this concept is marred by the lack of a lithium-cation source in the device, thus requiring a specific preliminary charging step. The strategies devised thus far in an attempt to rectify this issue all present drawbacks. Our research uncovers a unique approach based on the use of a lithiated organic material, namely 3,4-dihydroxybenzonitrile dilithium salt. This compound can irreversibly provide lithium cations to the graphite electrode during an initial operando charging step without any negative effects with respect to further operation of the LIC. This method not only restores the low CO2 footprint of LICs, but also possesses far-reaching potential with respect to designing a wide range of greener hybrid devices based on other chemistries, comprising entirely recyclable components.

Lithium Azide as an Electrolyte Additive for All-Solid-State Lithium-Sulfur Batteries.

Science.gov (United States)

Eshetu, Gebrekidan Gebresilassie; Judez, Xabier; Li, Chunmei; Bondarchuk, Oleksandr; Rodriguez-Martinez, Lide M; Zhang, Heng; Armand, Michel

2017-11-27

Of the various beyond-lithium-ion battery technologies, lithium-sulfur (Li-S) batteries have an appealing theoretical energy density and are being intensely investigated as next-generation rechargeable lithium-metal batteries. However, the stability of the lithium-metal (Li°) anode is among the most urgent challenges that need to be addressed to ensure the long-term stability of Li-S batteries. Herein, we report lithium azide (LiN 3 ) as a novel electrolyte additive for all-solid-state Li-S batteries (ASSLSBs). It results in the formation of a thin, compact and highly conductive passivation layer on the Li° anode, thereby avoiding dendrite formation, and polysulfide shuttling. It greatly enhances the cycling performance, Coulombic and energy efficiencies of ASSLSBs, outperforming the state-of-the-art additive lithium nitrate (LiNO 3 ). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Direct observation of lithium polysulfides in lithium-sulfur batteries using operando X-ray diffraction

Science.gov (United States)

Conder, Joanna; Bouchet, Renaud; Trabesinger, Sigita; Marino, Cyril; Gubler, Lorenz; Villevieille, Claire

2017-06-01

In the on going quest towards lithium-battery chemistries beyond the lithium-ion technology, the lithium-sulfur system is emerging as one of the most promising candidates. The major outstanding challenge on the route to commercialization is controlling the so-called polysulfide shuttle, which is responsible for the poor cycling efficiency of the current generation of lithium-sulfur batteries. However, the mechanistic understanding of the reactions underlying the polysulfide shuttle is still incomplete. Here we report the direct observation of lithium polysulfides in a lithium-sulfur cell during operation by means of operando X-ray diffraction. We identify signatures of polysulfides adsorbed on the surface of a glass-fibre separator and monitor their evolution during cycling. Furthermore, we demonstrate that the adsorption of the polysulfides onto SiO2 can be harnessed for buffering the polysulfide redox shuttle. The use of fumed silica as an electrolyte additive therefore significantly improves the specific charge and Coulombic efficiency of lithium-sulfur batteries.

When is identity congruent with the self? A self-determination theory perspective

OpenAIRE

Soenens, Bart; Vansteenkiste, Maarten

2011-01-01

Within the identity literature, self and identity are often used as interchangeable terms. By contrast, in Self-Determination Theory (SDT; Ryan & Deci, 2003) both terms have a differentiated meaning and it is maintained that identities may vary in the extent to which they are congruent with the basic growth tendencies of the self that are fueled by the basic psychological needs for autonomy, competence, and relatedness. Specifically, the level of congruence between identities and the self is ...

[Mood-congruent effect in self-relevant information processing: a study using an autobiographical memory recall task].

Science.gov (United States)

Itoh, M

2000-10-01

The pattern of the mood-congruent effect in an autobiographical memory recall task was investigated. Each subject was randomly assigned to one of three experimental conditions: positive mood, negative mood (induced with music), and control groups (no specific mood). Subjects were then presented with a word at a time from a list of trait words, which were pleasant or unpleasant. They decided whether they could recall any of their autobiographical memories related to the word, and responded with "yes" or "no" buttons as rapidly and accurately as possible. After the task, they were given five minutes for an incidental free recall test. Results indicated that the mood-congruent effect was found regardless of whether there was an autobiographical memory related to the word or not in both positive and negative mood states. The effect of moods on self-relevant information processing was discussed.

Verifying the prevalence, properties, and congruent hydraulics of at-many-stations hydraulic geometry (AMHG) for rivers in the continental United States

Science.gov (United States)

Barber, Caitline A.; Gleason, Colin J.

2018-01-01

Hydraulic geometry (HG) has long enabled daily discharge estimates, flood risk monitoring, and water resource and habitat assessments, among other applications. At-many-stations HG (AMHG) is a newly discovered form of HG with an evolving understanding. AMHG holds that there are temporally and spatially invariant ('congruent') depth, width, velocity, and discharge values that are shared by all stations of a river. Furthermore, these river-wide congruent hydraulics have been shown to link at-a-station HG (AHG) in space, contrary to previous expectation of AHG as spatially unpredictable. To date, AMHG has only been thoroughly examined on six rivers, and its congruent hydraulics are not well understood. To address the limited understanding of AMHG, we calculated AMHG for 191 rivers in the United States using USGS field-measured data from over 1900 gauging stations. These rivers represent nearly all geologic and climatic settings found in the continental U.S. and allow for a robust assessment of AMHG across scales. Over 60% of rivers were found to have AMHG with strong explanatory power to predict AHG across space (defined as r2 > 0.6, 118/191 rivers). We also found that derived congruent hydraulics bear little relation to their observed time-varying counterparts, and the strength of AMHG did not correlate with any available observed or congruent hydraulic parameters. We also found that AMHG is expressed at all fluvial scales in this study. Some statistically significant spatial clusters of rivers with strong and weak AMHG were identified, but further research is needed to identify why these clusters exist. Thus, this first widespread empirical investigation of AMHG leads us to conclude that AMHG is indeed a widely prevalent natural fluvial phenomenon, and we have identified linkages between known fluvial parameters and AMHG. Our work should give confidence to future researchers seeking to perform the necessary detailed hydraulic analysis of AMHG.

Lithium-induced downbeat nystagmus.

Science.gov (United States)

Schein, Flora; Manoli, Pierre; Cathébras, Pascal

2017-09-01

We report the case of a 76-year old lady under lithium carbonate for a bipolar disorder who presented with a suspected optic neuritis. A typical lithium-induced downbeat nystagmus was observed. Discontinuation of lithium therapy resulted in frank improvement in visual acuity and disappearance of the nystagmus.

Startup of Experimental Lithium System

International Nuclear Information System (INIS)

McCauley, D.L.

1980-06-01

The Experimental Lithium System (ELS) is designed for full-scale testing of targets and other lithium system components for the Fusion Materials Irradiation Test (FMIT) Facility. The system also serves as a test bed for development of lithium purification and characterization equipment, provides experience in operation of large lithium systems, and helps guide FMIT design

Lithium purity and characterization

International Nuclear Information System (INIS)

Meadows, G.E.; Keough, R.F.

1981-02-01

The accurate measurement of impurities in lithium is basic to the study of lithium compatibility with fusion reactor materials. In the last year the Hanford Engineering Development Laboratory (HEDL) has had the opportunity to develop sampling and analytical techniques and to apply them in support of the Experimental Lithium System (ELS) as a part of the Fusion Materials Irradiation Test Project. In this paper we present the analytical results from the fill, start-up and operation of the ELS. In addition, the analysis and purification of navy surplus ingot lithium which is being considered for use in a larger system will be discussed. Finally, the analytical techniques used in our laboratory will be summarized and the results of a recent round robin lithium analysis will be presented

Lithium and Renal Impairment

DEFF Research Database (Denmark)

Nielsen, René Ernst; Kessing, Lars Vedel; Nolen, Willem A

2018-01-01

INTRODUCTION: Lithium is established as an effective treatment of mania, of depression in bipolar and unipolar disorder, and in maintenance treatment of these disorders. However, due to the necessity of monitoring and concerns about irreversible adverse effects, in particular renal impairment......, after long-term use, lithium might be underutilized. METHODS: This study reviewed 6 large observational studies addressing the risk of impaired renal function associated with lithium treatment and methodological issues impacting interpretation of results. RESULTS: An increased risk of renal impairment...... associated with lithium treatment is suggested. This increased risk may, at least partly, be a result of surveillance bias. Additionally, the earliest studies pointed toward an increased risk of end-stage renal disease associated with lithium treatment, whereas the later and methodologically most sound...

Dissolution behavior of lithium compounds in ethanol

Directory of Open Access Journals (Sweden)

Tomohiro Furukawa

2016-12-01

Full Text Available In order to exchange the components which received irradiation damage during the operation at the International Fusion Materials Irradiation Facility, the adhered lithium, which is partially converted to lithium compounds such as lithium oxide and lithium hydroxide, should be removed from the components. In this study, the dissolution experiments of lithium compounds (lithium nitride, lithium hydroxide, and lithium oxide were performed in a candidate solvent, allowing the clarification of time and temperature dependence. Based on the results, a cleaning procedure for adhered lithium on the inner surface of the components was proposed.

Lithium availability and future production outlooks

International Nuclear Information System (INIS)

Vikström, Hanna; Davidsson, Simon; Höök, Mikael

2013-01-01

Highlights: • Review of reserves, resources and key properties of 112 lithium deposits. • Discussions of widely diverging results from recent lithium supply estimates. • Forecasting future lithium production by resource-constrained models. • Exploring implications for future deployment of electric cars. - Abstract: Lithium is a highly interesting metal, in part due to the increasing interest in lithium-ion batteries. Several recent studies have used different methods to estimate whether the lithium production can meet an increasing demand, especially from the transport sector, where lithium-ion batteries are the most likely technology for electric cars. The reserve and resource estimates of lithium vary greatly between different studies and the question whether the annual production rates of lithium can meet a growing demand is seldom adequately explained. This study presents a review and compilation of recent estimates of quantities of lithium available for exploitation and discusses the uncertainty and differences between these estimates. Also, mathematical curve fitting models are used to estimate possible future annual production rates. This estimation of possible production rates are compared to a potential increased demand of lithium if the International Energy Agency’s Blue Map Scenarios are fulfilled regarding electrification of the car fleet. We find that the availability of lithium could in fact be a problem for fulfilling this scenario if lithium-ion batteries are to be used. This indicates that other battery technologies might have to be implemented for enabling an electrification of road transports

Modified sol–gel preparation of LiNbO.sub.3./sub. target for PLD

Czech Academy of Sciences Publication Activity Database

Jakeš, V.; Rubešová, V.; Erben, J.; Nekvindová, P.; Jelínek, Miroslav

2013-01-01

Roč. 35, č. 12 (2013), s. 2540-2543 ISSN 0925-3467 R&D Projects: GA ČR(CZ) GAP106/10/1477 Institutional support: RVO:68378271 Keywords : lithium niobate * PLD * sol–gel * Pechini polyesterification * transmittance Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.075, year: 2013 http://dx.doi.org/10.1016/j.optmat.2013.07.019

PbBr3 Perovskite Crystals

KAUST Repository

Wei, Tzu-Chiao; Mokkapati, Sudha; Li, Ting-You; Lin, Chun-Ho; Lin, Gong-Ru; Jagadish, Chennupati; He, Jr-Hau

2018-01-01

, such as lithium niobate (LiNbO3), LiTaO3, KTiOPO4, and KH2PO4. Such a strong two-photon absorption effect in CH3NH3PbBr3 can be used to modulate the spectral and spatial profiles of laser pulses, as well as to reduce noise, and can be used to strongly control

Features of APE waveguides in different Er : LiNbO3 and (Er+Yb): LiNbO3 cuts: electrooptical coefficient r(33)

Czech Academy of Sciences Publication Activity Database

Nekvindová, P.; Červená, Jarmila; Čapek, J.; Macková, Anna; Peřina, Vratislav; Schröfel, J.; Špirková, J.

2003-01-01

Roč. 24, č. 3 (2003), s. 527-535 ISSN 0925-3467 R&D Projects: GA ČR GA102/99/D017; GA AV ČR KSK1010104 Institutional research plan: CEZ:AV0Z1048901 Keywords : lithium niobate * optical waveguides * annealed proton exchange Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.623, year: 2003

Integrated optical circuit engineering V; Proceedings of the Meeting, San Diego, CA, Aug. 17-20, 1987

Science.gov (United States)

Mentzer, Mark A.

Recent advances in the theoretical and practical design and applications of optoelectronic devices and optical circuits are examined in reviews and reports. Topics discussed include system and market considerations, guided-wave phenomena, waveguide devices, processing technology, lithium niobate devices, and coupling problems. Consideration is given to testing and measurement, integrated optics for fiber-optic systems, optical interconnect technology, and optical computing.

Grain Boundary Engineering of Lithium-Ion-Conducting Lithium Lanthanum Titanate for Lithium-Air Batteries

Science.gov (United States)

2016-01-01

Titanate for Lithium-Air Batteries by Victoria L Blair, Claire V Weiss Brennan, and Joseph M Marsico Approved for public...Air Batteries by Victoria L Blair and Claire V Weiss Brennan Weapons and Materials Research Directorate, ARL Joseph M Marsico Rochester...Titanate for Lithium-Air Batteries 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Victoria L Blair, Claire V

Application of neutron radiography to visualize the distribution of lithium in lithium batteries

International Nuclear Information System (INIS)

Kamata, Masahiro; Esaka, Takao; Fujine, Sigenori; Yoneda, Kenji; Kanda, Keiji.

1995-01-01

The authors have tried to visualize the motion of lithium ions in lithium ion conductors such as Li 1.33 Ti 1.67 O 4 at high temperatures using neutron radiography (NR) technique and confirmed that NR is very effective to the 6 Li containing systems. This means NR may be used as a non-destructive investigating method to study the electrode reactions and the mass transfer in lithium batteries. Here in this work, it was tried to visualize the distribution of lithium in commercial lithium batteries before and after discharge using NR technique. Obtained NR images will be presented with brief explanation on NR method. Further explanations on the principle of NR and on the NR facilities were presented elsewhere. (J.P.N.)

Highly Stable Lithium Metal Batteries Enabled by Regulating the Solvation of Lithium Ions in Nonaqueous Electrolytes.

Science.gov (United States)

Zhang, Xue-Qiang; Chen, Xiang; Cheng, Xin-Bing; Li, Bo-Quan; Shen, Xin; Yan, Chong; Huang, Jia-Qi; Zhang, Qiang

2018-05-04

Safe and rechargeable lithium metal batteries have been difficult to achieve because of the formation of lithium dendrites. Herein an emerging electrolyte based on a simple solvation strategy is proposed for highly stable lithium metal anodes in both coin and pouch cells. Fluoroethylene carbonate (FEC) and lithium nitrate (LiNO 3 ) were concurrently introduced into an electrolyte, thus altering the solvation sheath of lithium ions, and forming a uniform solid electrolyte interphase (SEI), with an abundance of LiF and LiN x O y on a working lithium metal anode with dendrite-free lithium deposition. Ultrahigh Coulombic efficiency (99.96 %) and long lifespans (1000 cycles) were achieved when the FEC/LiNO 3 electrolyte was applied in working batteries. The solvation chemistry of electrolyte was further explored by molecular dynamics simulations and first-principles calculations. This work provides insight into understanding the critical role of the solvation of lithium ions in forming the SEI and delivering an effective route to optimize electrolytes for safe lithium metal batteries. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A note on age differences in mood-congruent vs. mood-incongruent emotion processing in faces.

Science.gov (United States)

Voelkle, Manuel C; Ebner, Natalie C; Lindenberger, Ulman; Riediger, Michaela

2014-01-01

(1) Does experienced mood affect emotion perception in faces and is this perception mood-congruent or mood-incongruent?(2) Are there age-group differences in the interplay between experienced mood and emotion perception? (3) Does emotion perception in faces change as a function of the temporal sequence of study sessions and stimuli presentation, and (4) does emotion perception in faces serve a mood-regulatory function? One hundred fifty-four adults of three different age groups (younger: 20-31 years; middle-aged: 44-55 years; older adults: 70-81 years) were asked to provide multidimensional emotion ratings of a total of 1026 face pictures of younger, middle-aged, and older men and women, each displaying six different prototypical (primary) emotional expressions. By analyzing the likelihood of ascribing an additional emotional expression to a face whose primary emotion had been correctly recognized, the multidimensional rating approach permits the study of emotion perception while controlling for emotion recognition. Following up on previous research on mood responses to recurring unpleasant situations using the same dataset (Voelkle et al., 2013), crossed random effects analyses supported a mood-congruent relationship between experienced mood and perceived emotions in faces. In particular older adults were more likely to perceive happiness in faces when being in a positive mood and less likely to do so when being in a negative mood. This did not apply to younger adults. Temporal sequence of study sessions and stimuli presentation had a strong effect on the likelihood of ascribing an additional emotional expression. In contrast to previous findings, however, there was neither evidence for a change from mood-congruent to mood-incongruent responses over time nor evidence for a mood-regulatory effect.

Balancing surface adsorption and diffusion of lithium-polysulfides on nonconductive oxides for lithium?sulfur battery design

OpenAIRE

Tao, Xinyong; Wang, Jianguo; Liu, Chong; Wang, Haotian; Yao, Hongbin; Zheng, Guangyuan; Seh, Zhi Wei; Cai, Qiuxia; Li, Weiyang; Zhou, Guangmin; Zu, Chenxi; Cui, Yi

2016-01-01

Lithium?sulfur batteries have attracted attention due to their six-fold specific energy compared with conventional lithium-ion batteries. Dissolution of lithium polysulfides, volume expansion of sulfur and uncontrollable deposition of lithium sulfide are three of the main challenges for this technology. State-of-the-art sulfur cathodes based on metal-oxide nanostructures can suppress the shuttle-effect and enable controlled lithium sulfide deposition. However, a clear mechanistic understandin...

Cathode material for lithium batteries

Science.gov (United States)

Park, Sang-Ho; Amine, Khalil

2013-07-23

A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.

X-ray analysis of phase coexistence and electric poling processing in alkaline niobate-based compositions

International Nuclear Information System (INIS)

Fu Jian; Zuo Ruzhong; Liu Yi

2010-01-01

The characteristic and origin of two-phase coexistence and the content of each phase in typical alkaline niobate-based lead-free compositions were investigated through the refinement of X-ray diffraction peaks and the measurement of dielectric constant versus temperature curves. The diffuse nature of polymorphic phase transition has resulted in the coexistence of two ferroelectric phases within a wide composition and temperature range. As a result, the optimum piezoelectric properties appear in the composition rich in tetragonal phases and there is a remarkable poling temperature effect. Discussions on the difference between morphotropic phase boundary and polymorphic phase boundary were made in combination with the variation of electrical properties.

Predictors of excellent response to lithium

DEFF Research Database (Denmark)

Kessing, Lars Vedel; Hellmund, Gunnar; Andersen, Per Kragh

2011-01-01

The aim of this study was to identify sociodemographic and clinical predictors of excellent response, that is, 'cure' of future affective episodes, to lithium in monotherapy. We used nationwide registers to identify all patients with a diagnosis of bipolar disorder in psychiatric hospital settings...... who were prescribed lithium from 1995 to 2006 in Denmark (N=3762). Excellent lithium responders were defined as patients who after a stabilization lithium start-up period of 6 months, continued lithium in monotherapy without getting hospitalized. The rate of excellent response to lithium...... with somatic comorbidity had increased rates of non-response to lithium compared with patients without somatic comorbidity (HR=1.23, 95% CI: 1.00-1.52).It is concluded that the prevalence of excellent response to lithium monotherapy is low and such patients are characterized by few earlier psychiatric...

Metabolic Side Effects of Lithium

Directory of Open Access Journals (Sweden)

M. Cagdas Eker

2010-04-01

Full Text Available Lithium is an alkaline ion being used since 19th century. After its widespread use in psychiatric disorders, observed side effects caused skepticism about its therapeutic efficacy. Despite several disadvantages, lithium is one of the indispensible drugs used in affective disorders, especially in bipolar disorder. It became a necessity for physicians to recognize its side effects since lithium is still accepted as a gold standard in the treatment of bipolar disorder. Adverse effects of chronic administration of lithium on several organ systems are widely known. In this article metabolic effects of lithium on thyroid and parathyroid glands, body mass index and kidneys will be discussed along with their mechanisms, clinical findings, possible risk factors and treatment. One of the most common side effect of lithium is hypothyroidism. It has the same clinical and biochemical properties as primary hypothyroidism and observed as subclinical hypothyroidism in the first place. Hypothyroidism, even its subclinical form, may be associated with non-response or inadequate response and is indicated as a risk factor for development of rapid cycling bipolar disorder. Therefore, hypothyroidism should be screened no matter how severe it is and should be treated with thyroid hormone in the presence of clinical hypothyroidism. Weight gain due to lithium administration disturbs the compliance to treatment and negatively affects the course of the illness. Increased risk for diabetes, hypertension, ischemic heart disease and stroke because of weight gain constitute other centers of problem. Indeed, it is of importance to determine the risk factors before treatment, to follow up the weight, to re-organize nutritional habits and to schedule exercises. Another frequent problematic side effect of lithium treatment is renal dysfunction which clinically present as nephrogenic diabetes insipidus with the common symptoms of polyuria and polydipsia. Nephrogenic diabetes

Anxiety promotes memory for mood-congruent faces but does not alter loss aversion.

Science.gov (United States)

Charpentier, Caroline J; Hindocha, Chandni; Roiser, Jonathan P; Robinson, Oliver J

2016-04-21

Pathological anxiety is associated with disrupted cognitive processing, including working memory and decision-making. In healthy individuals, experimentally-induced state anxiety or high trait anxiety often results in the deployment of adaptive harm-avoidant behaviours. However, how these processes affect cognition is largely unknown. To investigate this question, we implemented a translational within-subjects anxiety induction, threat of shock, in healthy participants reporting a wide range of trait anxiety scores. Participants completed a gambling task, embedded within an emotional working memory task, with some blocks under unpredictable threat and others safe from shock. Relative to the safe condition, threat of shock improved recall of threat-congruent (fearful) face location, especially in highly trait anxious participants. This suggests that threat boosts working memory for mood-congruent stimuli in vulnerable individuals, mirroring memory biases in clinical anxiety. By contrast, Bayesian analysis indicated that gambling decisions were better explained by models that did not include threat or treat anxiety, suggesting that: (i) higher-level executive functions are robust to these anxiety manipulations; and (ii) decreased risk-taking may be specific to pathological anxiety. These findings provide insight into the complex interactions between trait anxiety, acute state anxiety and cognition, and may help understand the cognitive mechanisms underlying adaptive anxiety.

Synthesis and characterization of bismuth zinc niobate pyrochlore nanopowders

Directory of Open Access Journals (Sweden)

Sonia Maria Zanetti

2007-09-01

Full Text Available Bismuth zinc niobate pyrochlores Bi1.5ZnNb1.5O7 (alpha-BZN, and Bi2(Zn1/3Nb2/32O 7 (beta-BZN have been synthesized by chemical method based on the polymeric precursors. The pyrochlore phase was investigated by differential scanning calorimetry, infrared spectroscopy, and X ray diffraction. Powder and sintered pellets morphology was examined by scanning electron microscopy. The study of alpha-BZN phase formation reveals that, at 500 °C, the pyrochlore phase was already present while a single-phased nanopowder was obtained after calcination at 700 °C. The crystallization mechanism of the beta-BZN is quite different, occurring through the crystallization of alpha-BZN and BiNbO4 intermediary phases. Both compositions yielded soft agglomerated powders. alpha-BZN pellets, sintered at 800 °C for 2 hours, presented a relative density of 97.3% while those of beta-BZN, sintered at 900 °C for 2 hours, reached only 91.8%. Dielectric constant and dielectric loss, measured at 1 MHz, were 150 and 4 x/10-4 for a-BZN, and 97 and 8 x 10-4 for beta-BZN.

Lithium-aluminum-iron electrode composition

Science.gov (United States)

Kaun, Thomas D.

1979-01-01

A negative electrode composition is presented for use in a secondary electrochemical cell. The cell also includes an electrolyte with lithium ions such as a molten salt of alkali metal halides or alkaline earth metal halides that can be used in high-temperature cells. The cell's positive electrode contains a a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent in an alloy of aluminum-iron. Various binary and ternary intermetallic phases of lithium, aluminum and iron are formed. The lithium within the intermetallic phase of Al.sub.5 Fe.sub.2 exhibits increased activity over that of lithium within a lithium-aluminum alloy to provide an increased cell potential of up to about 0.25 volt.

Superior lithium adsorption and required magnetic separation behavior of iron-doped lithium ion-sieves

Energy Technology Data Exchange (ETDEWEB)

Wang, Shulei; Zheng, Shili; Wang, Zheming; Cui, Wenwen; Zhang, Hailin; Yang, Liangrong; Zhang, Yi; Li, Ping

2018-01-01

The recent research on adsorption-based lithium recovery from lithium-containing solutions has been centred on adsorption capacity and separation of lithium ion-sieves powder from solutions. Herein, an effective iron-doped lithium titanium oxide (Fe-doped Li2TiO3) was synthesized by Fe-doping via solid state reactions followed by acid treatment to form iron-doped lithium ion-sieves (Fe/Ti-x(H)). The resulting solid powder displays both superior adsorption capacity of lithium and high separation efficiency of the adsorbent from the solutions. SEM imaging and BET surface area measurement results showed that at Fe doping levels x0.15, Fe-doping led to grain shrinkage as compared to Li2TiO3 and at the same time the BET surface area increased. The Fe/Ti-0.15(H) exhibited saturated magnetization values of 13.76 emu g-1, allowing effective separation of the material from solid suspensions through the use of a magnet. Consecutive magnetic separation results suggested that the Fe/Ti-0.15(H) powders could be applied at large-scale and continuously removed from LiOH solutions with separation efficiency of 96% or better. Lithium adsorption studies indicated that the equilibrium adsorption capacity of Fe/Ti-0.15(H) in LiOH 2 solutions (1.8 g L-1 Li, pH 12) reached 53.3 mg g-1 within 24 h, which was higher than that of pristine Li2TiO3 (50.5 mg g-1) without Fe doping. Competitive adsorption and regeneration results indicated that the Fe/Ti-0.15(H) possessed a high selectivity for Li with facile regeneration. Therefore, it could be expected that the iron-doped lithium ion-sieves have practical applicability potential for large scale lithium extraction and recovery from lithium-bearing solutions.

Lithium position and occupancy fluctuations in a cathode during charge/discharge cycling of lithium-ion battery

International Nuclear Information System (INIS)

Sharma, N.; Yu, D.; Zhu, Y.; Wu, Y.; Peterson, V. K.

2012-01-01

Lithium-ion batteries are undergoing rapid development to meet the energy demands of the transportation and renewable energy-generation sectors. The capacity of a lithium-ion battery is dependent on the amount of lithium that can be reversibly incorporated into the cathode. Neutron diffraction provides greater sensitivity towards lithium relative to other diffraction techniques. In conjunction with the penetration depth afforded by neutron diffraction, the information concerning lithium gained in a neutron diffraction study allows commercial lithium-ion batteries to be explored with respect to the lithium content in the whole cathode. Furthermore, neutron diffraction instruments featuring area detectors that allow relatively fast acquisitions enable perturbations of lithium location and occupancy in the cathode during charge/discharge cycling to be determined in real time. Here, we present the time, current, and temperature dependent lithium transfer occurring within a cathode functioning under conventional charge-discharge cycling. The lithium location and content, oxygen positional parameter, and lattice parameter of the Li 1+y Mn 2 0 4 cathode are measured and linked to the battery's charge/discharge characteristics (performance). We determine that the lithium-transfer mechanism involves two crystallographic sites, and that the mechanism differs between discharge and charge, explaining the relative ease of discharging (compared with charging) this material. Furthermore, we find that the rate of change of the lattice is faster on charging than discharging, and is dependent on the lithium insertion/ extraction processes (e.g. dependent on how the site occupancies evolve). Using in situ neutron diffraction data the atomic-scale understanding of cathode functionality is revealed, representing detailed information that can be used to direct improvements in battery performance at both the practical and fundamental level.

Maximum Recommended Dosage of Lithium for Pregnant Women Based on a PBPK Model for Lithium Absorption

Directory of Open Access Journals (Sweden)

Scott Horton

2012-01-01

Full Text Available Treatment of bipolar disorder with lithium therapy during pregnancy is a medical challenge. Bipolar disorder is more prevalent in women and its onset is often concurrent with peak reproductive age. Treatment typically involves administration of the element lithium, which has been classified as a class D drug (legal to use during pregnancy, but may cause birth defects and is one of only thirty known teratogenic drugs. There is no clear recommendation in the literature on the maximum acceptable dosage regimen for pregnant, bipolar women. We recommend a maximum dosage regimen based on a physiologically based pharmacokinetic (PBPK model. The model simulates the concentration of lithium in the organs and tissues of a pregnant woman and her fetus. First, we modeled time-dependent lithium concentration profiles resulting from lithium therapy known to have caused birth defects. Next, we identified maximum and average fetal lithium concentrations during treatment. Then, we developed a lithium therapy regimen to maximize the concentration of lithium in the mother’s brain, while maintaining the fetal concentration low enough to reduce the risk of birth defects. This maximum dosage regimen suggested by the model was 400 mg lithium three times per day.

Reversible Lithium Neurotoxicity: Review of the Literature

Science.gov (United States)

Netto, Ivan

2012-01-01

Objective: Lithium neurotoxicity may be reversible or irreversible. Reversible lithium neurotoxicity has been defined as cases of lithium neurotoxicity in which patients recovered without any permanent neurologic sequelae, even after 2 months of an episode of lithium toxicity. Cases of reversible lithium neurotoxicity differ in clinical presentation from those of irreversible lithium neurotoxicity and have important implications in clinical practice. This review aims to study the clinical presentation of cases of reversible lithium neurotoxicity. Data Sources: A comprehensive electronic search was conducted in the following databases: MEDLINE (PubMed), 1950 to November 2010; PsycINFO, 1967 to November 2010; and SCOPUS (EMBASE), 1950 to November 2010. MEDLINE and PsycINFO were searched by using the OvidSP interface. Study Selection: A combination of the following search terms was used: lithium AND adverse effects AND central nervous system OR neurologic manifestation. Publications cited include articles concerned with reversible lithium neurotoxicity. Data Extraction: The age, sex, clinical features, diagnostic categories, lithium doses, serum lithium levels, precipitating factors, and preventive measures of 52 cases of reversible lithium neurotoxicity were extracted. Data Synthesis: Among the 52 cases of reversible lithium neurotoxicity, patients ranged in age from 10 to 80 years and a greater number were female (P = .008). Most patients had affective disorders, schizoaffective disorders, and/or depression (P lithium levels were less than or equal to 1.5 mEq/L (P lithium, underlying brain pathology, abnormal tissue levels, specific diagnostic categories, and elderly populations were some of the precipitating factors reported for reversible lithium neurotoxicity. The preventive measures were also described. Conclusions: Reversible lithium neurotoxicity presents with a certain clinical profile and precipitating factors for which there are appropriate

Reversible lithium neurotoxicity: review of the literatur.

Science.gov (United States)

Netto, Ivan; Phutane, Vivek H

2012-01-01

Lithium neurotoxicity may be reversible or irreversible. Reversible lithium neurotoxicity has been defined as cases of lithium neurotoxicity in which patients recovered without any permanent neurologic sequelae, even after 2 months of an episode of lithium toxicity. Cases of reversible lithium neurotoxicity differ in clinical presentation from those of irreversible lithium neurotoxicity and have important implications in clinical practice. This review aims to study the clinical presentation of cases of reversible lithium neurotoxicity. A comprehensive electronic search was conducted in the following databases: MEDLINE (PubMed), 1950 to November 2010; PsycINFO, 1967 to November 2010; and SCOPUS (EMBASE), 1950 to November 2010. MEDLINE and PsycINFO were searched by using the OvidSP interface. A combination of the following search terms was used: lithium AND adverse effects AND central nervous system OR neurologic manifestation. Publications cited include articles concerned with reversible lithium neurotoxicity. The age, sex, clinical features, diagnostic categories, lithium doses, serum lithium levels, precipitating factors, and preventive measures of 52 cases of reversible lithium neurotoxicity were extracted. Among the 52 cases of reversible lithium neurotoxicity, patients ranged in age from 10 to 80 years and a greater number were female (P = .008). Most patients had affective disorders, schizoaffective disorders, and/or depression (P lithium levels were less than or equal to 1.5 mEq/L (P lithium, underlying brain pathology, abnormal tissue levels, specific diagnostic categories, and elderly populations were some of the precipitating factors reported for reversible lithium neurotoxicity. The preventive measures were also described. Reversible lithium neurotoxicity presents with a certain clinical profile and precipitating factors for which there are appropriate preventive measures. This recognition will help in early diagnosis and prompt treatment of

Problem of the lithium peroxide thermal stability

International Nuclear Information System (INIS)

Nefedov, R A; Ferapontov, Yu A; Kozlova, N P

2016-01-01

The behavior of lithium peroxide and lithium peroxide monohydrate samples under heating in atmospheric air was studied by the method of thermogravimetric analysis (TGA) and differential thermal analysis (DTA). It was found that in the temperature range of 32°C to 82°C the interaction of lithium peroxides and steam with the formation of lithium peroxide monohydrate occurs, which was confirmed chemically and by X-ray Single-qualitative analysis. It was experimentally found that lithium peroxide starts to decompose into the lithium oxide and oxygen in the temperature range of 340 ÷ 348°C. It was established that the resulting thermal decomposition of lithium oxide, lithium peroxide at the temperature of 422°C melts with lithium carbonate eutecticly. The manifestation of polymorphism was not marked(seen or noticed) under the heating of studied samples of lithium peroxide and lithium peroxide monohydrate in the temperature range of 25°C ÷ 34°C. (paper)

Epitaxial growth of Er, Ti doped LiNbO3 films prepared by sol-gel method

International Nuclear Information System (INIS)

Takahashi, Makoto; Yoshiga, Tsuyoshi; Kajitani, Naofumi; Takeda, Yuki; Sato, Shoji; Wakita, Koichi; Ohnishi, Naoyuki; Hotta, Kazutoshi; Kurachi, Masato

2006-01-01

Erbium (Er 3+ ) doped lithium niobate (LiNbO 3 ) thick films were deposited on z-cut congruent LiNbO 3 (LN) substrate by the sol-gel method from the 0.20 mol/dm 3 precursor solution containing various Er 3+ concentration and 0.10 mol/dm 3 poly(vinyl alcohol) (PVA), and their crystal characteristics were evaluated. The Er 3+ concentration in the LN film was controlled by the Er 3+ concentration in the starting solution. The orientation relationships between Er doped LN films and substrates were determined by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy, and (006) oriented Er doped LN epitaxial layers with parallel epitaxial relationships could be grown on the z-cut LN wafer. Moreover, it was made clear from the electron beam diffraction measurements that the film came to be polycrystalline, when the Er concentration was over 3 mol%. The refractive index of Er-doped LN films decreased with increasing Er concentration. 1.5 mol% Ti: 1.0 mol% Er LN films, which acted as a waveguide, were prepared by our so-gel method. It showed the 1530 nm emission by 980 nm excitation, which was considered to be due to the Er 3+ corresponding to the 4 I 13/2 → 4 I 15/2 transition. (author)

Probing the interatomic potential of solids with strong-field nonlinear phononics

Science.gov (United States)

von Hoegen, A.; Mankowsky, R.; Fechner, M.; Först, M.; Cavalleri, A.

2018-03-01

Nonlinear optical techniques at visible frequencies have long been applied to condensed matter spectroscopy. However, because many important excitations of solids are found at low energies, much can be gained from the extension of nonlinear optics to mid-infrared and terahertz frequencies. For example, the nonlinear excitation of lattice vibrations has enabled the dynamic control of material functions. So far it has only been possible to exploit second-order phonon nonlinearities at terahertz field strengths near one million volts per centimetre. Here we achieve an order-of-magnitude increase in field strength and explore higher-order phonon nonlinearities. We excite up to five harmonics of the A1 (transverse optical) phonon mode in the ferroelectric material lithium niobate. By using ultrashort mid-infrared laser pulses to drive the atoms far from their equilibrium positions, and measuring the large-amplitude atomic trajectories, we can sample the interatomic potential of lithium niobate, providing a benchmark for ab initio calculations for the material. Tomography of the energy surface by high-order nonlinear phononics could benefit many aspects of materials research, including the study of classical and quantum phase transitions.

APPARATUS FOR THE PRODUCTION OF LITHIUM METAL

Science.gov (United States)

Baker, P.S.; Duncan, F.R.; Greene, H.B.

1961-08-22

Methods and apparatus for the production of high-purity lithium from lithium halides are described. The apparatus is provided for continuously contacting a molten lithium halide with molten barium, thereby forming lithium metal and a barium halide, establishing separate layers of these reaction products and unreacted barium and lithium halide, and continuously withdrawing lithium and barium halide from the reaction zone. (AEC)

Experimental lithium system. Final report

International Nuclear Information System (INIS)

Kolowith, R.; Berg, J.D.; Miller, W.C.

1985-04-01

A full-scale mockup of the Fusion Materials Irradiation Test (FMIT) Facility lithium system was built at the Hanford Engineering Development Laboratory (HEDL). This isothermal mockup, called the Experimental Lithium System (ELS), was prototypic of FMIT, excluding the accelerator and dump heat exchanger. This 3.8 m 3 lithium test loop achieved over 16,000 hours of safe and reliable operation. An extensive test program demonstrated satisfactory performance of the system components, including the HEDL-supplied electromagnetic lithium pump, the lithium jet target, the purification and characterization hardware, as well as the auxiliary argon and vacuum systems. Experience with the test loop provided important information on system operation, performance, and reliability. This report presents a complete overview of the entire Experimental Lithium System test program and also includes a summary of such areas as instrumentation, coolant chemistry, vapor/aerosol transport, and corrosion

Lithium clearance in chronic nephropathy

DEFF Research Database (Denmark)

Kamper, A L; Holstein-Rathlou, N H; Leyssac, P P

1989-01-01

1. Lithium clearance measurements were made in 72 patients with chronic nephropathy of different aetiology and moderate to severely reduced renal function. 2. Lithium clearance was strictly correlated with glomerular filtration rate, and there was no suggestion of distal tubular reabsorption...... of lithium or influence of osmotic diuresis. 3. Fractional reabsorption of lithium was reduced in most patients with glomerular filtration rates below 25 ml/min. 4. Calculated fractional distal reabsorption of sodium was reduced in most patients with glomerular filtration rates below 50 ml/min. 5. Lithium...... that lithium clearance may be a measure of the delivery of sodium and water from the renal proximal tubule. With this assumption it was found that adjustment of the sodium excretion in chronic nephropathy initially takes place in the distal parts of the nephron (loop of Henle, distal tubule and collecting duct...

Interactions of liquid lithium with various atmospheres, concretes, and insulating materials; and filtration of lithium aerosols

International Nuclear Information System (INIS)

Jeppson, D.W.

1979-06-01

This report describes the facilities and experiments and presents test results of a program being conducted at the hanford Engineering Development Laboratory (HEDL) in support of the fusion reactor development effort. This experimental program is designed to characterize the interaction of liquid lithium with various atmospheres, concretes, and insulating materials. Lithium-atmosphere reaction tests were conducted in normal humidity air, pure nitrogen, and carbon dioxide. These tests are described and their results, such as maximum temperatures, aerosol generated, and reaction rates measured, are reported. Initial lithium temperatures for these tests ranged between 224 0 C and 843 0 C. A lithium-concrete reaction test, using 10 kg of lithium at 327 0 C, and lithium-insulating materials reaction tests, using a few grams of lithium at 350 0 C and 600 0 C, are also described and results are presented. In addition, a lithium-aerosol filter loading test was conducted to determine the mass loading capacity of a commercial high efficiency particulate air (HEPA) filter. The aerosol was characterized, and the loading-capacity-versus-pressure-buildup across the filter is reported

Electrolytes for lithium and lithium-ion batteries

CERN Document Server

Jow, T Richard; Borodin, Oleg; Ue, Makoto

2014-01-01

Electrolytes for Lithium and Lithium-ion Batteries provides a comprehensive overview of the scientific understanding and technological development of electrolyte materials in the last?several years. This book covers key electrolytes such as LiPF6 salt in mixed-carbonate solvents with additives for the state-of-the-art Li-ion batteries as well as new electrolyte materials developed recently that lay the foundation for future advances.?This book also reviews the characterization of electrolyte materials for their transport properties, structures, phase relationships, stabilities, and impurities.

A note on age differences in mood-congruent versus mood-incongruent emotion processing in faces

Directory of Open Access Journals (Sweden)

Manuel C. Voelkle

2014-06-01

Full Text Available This article addresses four interrelated research questions: (1 Does experienced mood affect emotion perception in faces and is this perception mood-congruent or mood-incongruent? (2 Are there age-group differences in the interplay between experienced mood and emotion perception? (3 Does emotion perception in faces change as a function of the temporal sequence of study sessions and stimuli presentation, and (4 does emotion perception in faces serve a mood-regulatory function? One hundred fifty-four adults of three different age groups (younger: 20–31 years; middle-aged: 44–55 years; older adults: 70–81 years were asked to provide multidimensional emotion ratings of a total of 1,026 face pictures of younger, middle-aged, and older men and women, each displaying six different prototypical (primary emotional expressions. By analyzing the likelihood of ascribing an additional emotional expression to a face whose primary emotion had been correctly recognized, the multidimensional rating approach permits the study of emotion perception while controlling for emotion recognition. Following up on previous research on mood responses to recurring unpleasant situations using the same dataset (Voelkle, Ebner, Lindenberger, & Riediger, 2013, crossed random effects analyses supported a mood-congruent relationship between experienced mood and perceived emotions in faces. In particular older adults were more likely to perceive happiness in faces when being in a positive mood and less likely to do so when being in a negative mood. This did not apply to younger adults. Temporal sequence of study sessions and stimuli presentation had a strong effect on the likelihood of ascribing an additional emotional expression. In contrast to previous findings, however, there was neither evidence for a change from mood-congruent to mood-incongruent responses over time nor evidence for a mood-regulatory effect.

Mood-congruent free recall bias in anxious individuals is not a consequence of response bias.

Science.gov (United States)

Russo, Riccardo; Whittuck, Dora; Roberson, Debi; Dutton, Kevin; Georgiou, George; Fox, Elaine

2006-05-01

The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.

Features of non-congruent phase transition in modified Coulomb model of the binary ionic mixture

International Nuclear Information System (INIS)

Stroev, N E; Iosilevskiy, I L

2016-01-01

Non-congruent gas-liquid phase transition (NCPT) have been studied previously in modified Coulomb model of a binary ionic mixture C(+6) + O(+8) on a uniformly compressible ideal electronic background /BIM(∼)/. The features of NCPT in improved version of the BIM(∼) model for the same mixture on background of non-ideal electronic Fermi-gas and comparison it with the previous calculations are the subject of present study. Analytical fits for Coulomb corrections to equation of state of electronic and ionic subsystems were used in present calculations within the Gibbs-Guggenheim conditions of non-congruent phase equilibrium. Parameters of critical point-line were calculated on the entire range of proportions of mixed ions 0 < X < 1. Strong “distillation” effect was found for NCPT in the present BIM(∼) model. Just similar distillation was obtained in the variant of NCPT in dense nuslear matter. The absence of azeotropic compositions was revealed in studied variants of BIM(∼) in contrast to an explicit existence of the azeotropic compositions for the NCPT in chemically reacting plasmas and in astrophysical applications. (paper)

Features of non-congruent phase transition in modified Coulomb model of the binary ionic mixture

Science.gov (United States)

Stroev, N. E.; Iosilevskiy, I. L.

2016-11-01

Non-congruent gas-liquid phase transition (NCPT) have been studied previously in modified Coulomb model of a binary ionic mixture C(+6) + O(+8) on a uniformly compressible ideal electronic background /BIM(∼)/. The features of NCPT in improved version of the BIM(∼) model for the same mixture on background of non-ideal electronic Fermi-gas and comparison it with the previous calculations are the subject of present study. Analytical fits for Coulomb corrections to equation of state of electronic and ionic subsystems were used in present calculations within the Gibbs-Guggenheim conditions of non-congruent phase equilibrium. Parameters of critical point-line were calculated on the entire range of proportions of mixed ions 0 distillation” effect was found for NCPT in the present BIM(∼) model. Just similar distillation was obtained in the variant of NCPT in dense nuslear matter. The absence of azeotropic compositions was revealed in studied variants of BIM(∼) in contrast to an explicit existence of the azeotropic compositions for the NCPT in chemically reacting plasmas and in astrophysical applications.

Positive electrode for a lithium battery

Science.gov (United States)

Park, Sang-Ho; Amine, Khalil

2015-04-07

A method for producing a lithium alkali transition metal oxide for use as a positive electrode material for lithium secondary batteries by a precipitation method. The positive electrode material is a lithium alkali transition metal composite oxide and is prepared by mixing a solid state mixed with alkali and transition metal carbonate and a lithium source. The mixture is thermally treated to obtain a small amount of alkali metal residual in the lithium transition metal composite oxide cathode material.

Method of producing spherical lithium aluminate particles

International Nuclear Information System (INIS)

Yang, L.; Medico, R.R.; Baugh, W.A.

1983-01-01

Spherical particles of lithium aluminate are formed by initially producing aluminium hydroxide spheroids, and immersing the spheroids in a lithium ion-containing solution to infuse lithium ions into the spheroids. The lithium-infused spheroids are rinsed to remove excess lithium ion from the surface, and the rinsed spheroids are soaked for a period of time in a liquid medium, dried and sintered to form lithium aluminate spherical particles. (author)

Radiation defects in some oxide compounds

International Nuclear Information System (INIS)

Kaczmarek, S.M.

1999-01-01

Yttrium aluminium garnets, yttrium aluminium perovskite, strontium and barium lanthanum and gadolinium gallates, lithium niobate and tantalate as-grown crystals and doped by diffusion with rare-earth (Nd, Dy, Er, Tm, Ho, Pr, Ce, Eu) and ions of the first transition series (Mn, Cr, Cu, Fe) were investigated optically and using electron spin resonance method before and after gamma, electron and proton irradiation. (author)

Experimental study of gaseous lithium deuterides and lithium oxides. Implications for the use of lithium and Li2O as breeding materials in fusion reactor blankets

International Nuclear Information System (INIS)

Ihle, H.R.; Wu, C.H.; Kudo, H.

1980-01-01

In addition to LiH, which has been studied extensively by optical spectroscopy, the existence of a number of other stable lithium hydrides has been predicted theoretically. By analysis of the saturated vapour over dilute solutions of the hydrogen isotopes in lithium, using Knudsen effusion mass spectrometry, all lithium hydrides predicted to be stable were found. Solutions of deuterium in lithium were used predominantly because of practical advantages for mass spectrometric measurements. The heats of dissociation of LiD, Li 2 D, LiD 2 and Li 2 D 2 , and the binding energies of their singly charged positive ions were determined, and the constants of the gas/liquid equilibria were calculated. The existence of these lithium deuterides in the gas phase over solutions of deuterium in lithium leads to enrichment of deuterium in the gas above 1240 K. The enrichment factor, which increases exponentially with temperature and is independent of concentration for low concentrations of deuterium in the liquid, was determined by Rayleigh distillation experiments. It was found that it is thermodynamically possible to separate deuterium from lithium by distillation. One of the alternatives to the use of lithium in (D,T)-fusion reactors as tritium-breeding blanket material is to employ solid lithium oxide. This has a high melting point, a high lithium density and still favourable tritium-breeding properties. Because of its rather high volatility, an experimental study of the vaporization of Li 2 O was undertaken by mass spectrometry. It vaporizes to give lithium and oxygen, and LiO, Li 2 O, Li 3 O and Li 2 O 2 . The molecule Li 3 O was found as a new species. Heats of dissociation, binding energies of the various ions and the constants of the gas/solid equilibria were determined. The effect of using different materials for the Knudsen cells and the relative thermal stabilities of lithium-aluminium oxides were also studied. (author)

Experimental lithium system experience

International Nuclear Information System (INIS)

Atwood, J.M.; Berg, J.D.; Kolowith, R.; Miller, W.C.

1984-01-01

The Experimental Lithium System is a test loop built to support design and operation of the Fusion Materials Irradiation Test Facility. ELS has achieved over 15,000 hours of safe and reliable operation. An extensive test program has demonstrated satisfactory performance of the system components, including an electromagnetic pump, lithium jet target, and vacuum system. Data on materials corrosion and behavior of lithium impurities are also presented. (author)

Influence of electrical boundary conditions on profiles of acoustic field and electric potential of shear-horizontal acoustic waves in potassium niobate plates.

Science.gov (United States)

Kuznetsova, I E; Nedospasov, I A; Kolesov, V V; Qian, Z; Wang, B; Zhu, F

2018-05-01

The profiles of an acoustic field and electric potential of the forward and backward shear-horizontal (SH) acoustic waves of a higher order propagating in X-Y potassium niobate plate have been theoretically investigated. It has been shown that by changing electrical boundary conditions on a surface of piezoelectric plates, it is possible to change the distributions of an acoustic field and electric potential of the forward and backward acoustic waves. The dependencies of the distribution of a mechanical displacement and electrical potential over the plate thickness for electrically open and electrically shorted plates have been plotted. The influence of a layer with arbitrary conductivity placed on a one or on the both plate surfaces on the profiles under study, phase and group velocities of the forward and backward acoustic waves in X-Y potassium niobate has been also investigated. The obtained results can be useful for development of the method for control of a particle or electrical charge movement inside the piezoelectric plates, as well a sensor for definition of the thin film conductivity. Copyright © 2018 Elsevier B.V. All rights reserved.

Twelve-hour brain lithium concentration in lithium maintenance treatment of manic-depressive disorder: daily versus alternate-day dosing schedule

DEFF Research Database (Denmark)

Jensen, H.V.; Plenge, P; Stensgaard, A

1996-01-01

The 12-h brain lithium concentration was measured by lithium-7 magnetic resonance spectroscopy in ten manic-depressive patients receiving daily or alternate-day lithium carbonate treatment. The median dose of lithium carbonate was 800 mg in the daily treatment group and 1200 mg in the alternate......-day group. Median 12-h serum lithium concentration in the two groups was 0.86 mmol l-1 and 0.55 mmol l-1, respectively, while the corresponding concentration in brain was 0.67 mmol l-1 and 0.52 mmol l-1, respectively. The 12-h brain lithium concentration was independent of lithium dosing schedule (multiple...... linear regression), but correlated significantly with the 12-h serum lithium concentration (P = 0.003; B = 0.53, 95% c.l. 0.24-0.82; beta = 0.83). Thus at identical 12-h serum lithium concentrations the 12-h brain lithium concentration is similar with both treatment regimes. As the risk of manic...

Conical light scattering in strontium barium niobate crystals related to an intrinsic composition inhomogeneity

International Nuclear Information System (INIS)

Bastwoeste, K; Sander, U; Imlau, M

2007-01-01

Conical light scattering is uncovered in poly- and mono-domain, nominally pure and Eu-doped strontium barium niobate (SBN) crystals over a wide temperature regime. The appearance of two scattering cones, a scattering line and a corona is observed and can be explained comprehensively within the Ewald sphere concept. Photorefraction, scattering from domain boundaries or from growth striations can be excluded from explaining the origin of the scattering. It is shown that the temperature-persistent scattering process is related to a growth-induced seeding rod, i.e. a composition inhomogeneity primarily localized at the centre of the SBN sample. The rod is directed parallel to the c axis and yields a refractive-index inhomogeneity with spatial frequencies on the micro-scale

Do Sex, Sex-Role Orientation, and Exposure to Gender-Congruent Therapy Models Influence Receptivity to Psychotherapy?

Science.gov (United States)

Park, Heather L.; Hatchett, Gregory T.

2006-01-01

This study had two objectives. The first objective was to evaluate how well sex and sex-role orientation predicted receptivity to psychotherapy. The second objective was to evaluate whether exposure to gender-congruent therapy videos influenced participants' receptivity to psychotherapy. Participants were randomly assigned to three conditions: (1)…

Lithium vapor trapping at a high-temperature lithium PFC divertor target

Science.gov (United States)

Jaworski, Michael; Abrams, T.; Goldston, R. J.; Kaita, R.; Stotler, D. P.; de Temmerman, G.; Scholten, J.; van den Berg, M. A.; van der Meiden, H. J.

2014-10-01

Liquid lithium has been proposed as a novel plasma-facing material for NSTX-U and next-step fusion devices but questions remain on the ultimate temperature limits of such a PFC during plasma bombardment. Lithium targets were exposed to high-flux plasma bombardment in the Magnum-PSI experimental device resulting in a temperature ramp from room-temperature to above 1200°C. A stable lithium vapor cloud was found to form directly in front of the target and persist to temperature above 1000°C. Consideration of mass and momentum balance in the pre-sheath region of an attached plasma indicates an increase in the magnitude of the pre-sheath potential drop with the inclusion of ionization sources as well as the inclusion of momentum loss terms. The low energy of lithium emission from a surface measured in previous experiments (Contract DE-AC02-09CH11466.

Synthesis of Lithium Fluoride from Spent Lithium Ion Batteries

Directory of Open Access Journals (Sweden)

Daniela S. Suarez

2017-05-01

Full Text Available Lithium (Li is considered a strategic element whose use has significantly expanded. Its current high demand is due to its use in lithium ion batteries for portable electronic devices, whose manufacture and market are extensively growing every day. These days there is a great concern about the final disposal of these batteries. Therefore, the possibility of developing new methodologies to recycle their components is of great importance, both commercially and environmentally. This paper presents results regarding important operational variables for the dissolution of the lithium and cobalt mixed-oxide (LiCoO2 cathodes from spent lithium ion batteries (LIBs with hydrofluoric acid. The recovery and synthesis of Co and Li compounds were also investigated. The dissolution parameters studied were: temperature, reaction time, solid-liquid ratio, stirring speed, and concentration of HF. The investigated recovery parameters included: pH, temperature, and time with and without stirring. The final precipitation of lithium fluoride was also examined. The results indicate that an increase in the HF concentration, temperature, and reaction time favors the leaching reaction of the LiCoO2. Dissolutions were close to 60%, at 75 °C and 120 min with a HF concentration of 25% (v/v. The recovery of Co and Li were 98% and 80%, respectively, with purities higher than 94%. Co and Li compounds, such as Co3O4 and LiF, were synthesized. Furthermore, it was possible to almost completely eliminate the F− ions as CaF2.

Secondary lithium solid polymer electrolyte cells

International Nuclear Information System (INIS)

Fix, K.A.; Sammells, A.F.

1988-01-01

A strategy for developing morphologically invariant lithium/solid polymer electrolyte interface is being investigated via the use of lithium intercalated electrodes. Emphasis is being placed upon the rutile material Li/sub x/WO/sub 2/ 0.1 < x < 1.0. An absence of shape change at this interface is expected to result in both long cycle life electrochemical cells and the simultaneous maintenance of small interelectrode spacing so that low IR losses can be maintained. During fabrication of cells investigated here both electrochemical and chemical lithium intercalation of WO/sub 2/ was pursued. In the case of larger WO/sub 2/ electrodes initially prepared for fully discharged state cells, electrochemical intercalation during cell charge was found to require significant time, and the reproducible achievement of complete uniform intercalation across the negative electrode became an issue. Emphasis was consequently placed upon cells fabricated using Li/sub x/WO/sub 2/ electrodes initially chemically intercalated by lithium prior to cell assembly. Previous work has demonstrated direct lithium intercalation of metal dichalcogenides using n-BuLi. Lithium activity in n-BuLi is, however, insufficient to achieve lithium intercalation of WO/sub 2//sup 4/. However, recent work has shown that WO/sub 2/ can be directly lithium intercalated upon immersion in lithium naphthalide. Li/sub x/WO/sub 2/ electrodes prepared in this work were intercalated using lithium naphthalide (0.8M) in 2MeTHF. Lithium intercalation was found to readily occur at room temperature, being initially rapid and slowing as bulk intercalation within the electrode proceeded. For electrodes intercalated in this manner, a relationship was identified between the degree of lithium intercalation and initial open-circuit potential in liquid non-aqueous electrolyte

Lithium Oxysilicate Compounds Final Report.

Energy Technology Data Exchange (ETDEWEB)

Apblett, Christopher A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Coyle, Jaclyn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

In this study, the structure and composition of lithium silicate thin films deposited by RF magnetron co-sputtering is investigated. Five compositions ranging from Li2Si2O5 to Li8SiO6 were confirmed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and structure analysis on the evolution of non-bridging oxygens in the thin films was conducted with fourier transform infrared (FTIR) spectroscopy. It was found that non-bridging oxygens (NBOs) increased as the silicate network breaks apart with increasing lithium content which agrees with previous studies on lithium silicates. Thin film impurities were examined with x-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectroscopy (TOFSIMS) and traced back to target synthesis. This study utilizes a unique synthesis technique for lithium silicate thin films and can be referred to in future studies on the ionic conductivity of lithium silicates formed on the surface of silicon anodes in lithium ion batteries.

Extracorporeal Treatment for Lithium Poisoning

DEFF Research Database (Denmark)

Decker, Brian S; Goldfarb, David S; Dargan, Paul I

2015-01-01

The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical and toxico......The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical...... extraction of patient-level data. The workgroup concluded that lithium is dialyzable (Level of evidence=A) and made the following recommendations: Extracorporeal treatment is recommended in severe lithium poisoning (1D). Extracorporeal treatment is recommended if kidney function is impaired and the [Li...... treatment (1D), but continuous RRT is an acceptable alternative (1D). The workgroup supported the use of extracorporeal treatment in severe lithium poisoning. Clinical decisions on when to use extracorporeal treatment should take into account the [Li(+)], kidney function, pattern of lithium toxicity...

Lithium-Based High Energy Density Flow Batteries

Science.gov (United States)

Bugga, Ratnakumar V. (Inventor); West, William C. (Inventor); Kindler, Andrew (Inventor); Smart, Marshall C. (Inventor)

2014-01-01

Systems and methods in accordance with embodiments of the invention implement a lithium-based high energy density flow battery. In one embodiment, a lithium-based high energy density flow battery includes a first anodic conductive solution that includes a lithium polyaromatic hydrocarbon complex dissolved in a solvent, a second cathodic conductive solution that includes a cathodic complex dissolved in a solvent, a solid lithium ion conductor disposed so as to separate the first solution from the second solution, such that the first conductive solution, the second conductive solution, and the solid lithium ionic conductor define a circuit, where when the circuit is closed, lithium from the lithium polyaromatic hydrocarbon complex in the first conductive solution dissociates from the lithium polyaromatic hydrocarbon complex, migrates through the solid lithium ionic conductor, and associates with the cathodic complex of the second conductive solution, and a current is generated.

Lithium in the barium stars

International Nuclear Information System (INIS)

Pinsonneault, M.H.; Sneden, C.

1984-01-01

New high-resolution spectra of the lithium resonance doublet have provided lithium abundances or upper limits for 26 classical and mild barium stars. The lithium lines always are present in the classical barium stars. Lithium abundances in these stars obey a trend with stellar masses consistent with that previously derived for ordinary K giants. This supports the notion that classical barium stars are post-core-He-flash or core-He-burning stars. Lithium contents in the mild barium stars, however, often are much smaller than those of the classical barium stars sometimes only upper limits may be determined. The cause for this difference is not easily understood, but may be related to more extensive mass loss by the mild barium stars. 45 references

Differential roles for medial prefrontal and medial temporal cortices in schema-dependent encoding : from congruent to incongruent

NARCIS (Netherlands)

van Kesteren, Marlieke T R; Beul, Sarah F; Takashima, Atsuko; Henson, Richard N; Ruiter, Dirk J; Fernández, Guillén

2013-01-01

Information that is congruent with prior knowledge is generally remembered better than incongruent information. This effect of congruency on memory has been attributed to a facilitatory influence of activated schemas on memory encoding and consolidation processes, and hypothesised to reflect a shift

A Combined Thermodynamics & Computational Method to Assess Lithium Composition in Anode and Cathode of Lithium Ion Batteries

International Nuclear Information System (INIS)

Zhang, Wenyu; Jiang, Lianlian; Van Durmen, Pauline; Saadat, Somaye; Yazami, Rachid

2016-01-01

With aim to address the open question of accurate determination of lithium composition in anode and cathode at a defined state of charge (SOC) of lithium ion batteries (LIB), we developed a method combining electrochemical thermodynamic measurements (ETM) and computational data fitting protocol. It is a common knowledge that in a lithium ion battery the SOC of anode and cathode differ from the SOC of the full-cell. Differences are in large part due to irreversible lithium losses within cell and to electrode mass unbalance. This implies that the lithium composition range in anode and in cathode during full charge and discharge cycle in full-cell is different from the composition range achieved in lithium half-cells of anode and cathode over their respective full SOC ranges. To the authors knowledge there is no unequivocal and practical method to determine the actual lithium composition of electrodes in a LIB, hence their SOC. Yet, accurate lithium composition assessment is fundamental not only for understanding the physics of electrodes but also for optimizing cell performances, particularly energy density and cycle life.

Kinetics Tuning the Electrochemistry of Lithium Dendrites Formation in Lithium Batteries through Electrolytes

International Nuclear Information System (INIS)

Tao, Ran; Bi, Xuanxuan; The Ohio State University, Columbus, OH; Li, Shu; Yao, Ying

2017-01-01

Lithium batteries are one of the most advance energy storage devices in the world and have attracted extensive research interests. However, lithium dendrite growth was a safety issue which handicapped the application of pure lithium metal in the negative electrode. In this paper, two solvents, propylene carbonate (PC) and 2-methyl-tetrahydrofuran (2MeTHF), and four Li"+ salts, LiPF_6, LiAsF_6, LiBF_4 and LiClO_4 were investigated in terms of their effects on the kinetics of lithium dendrite formation in eight electrolyte solutions. The kinetic parameters of charge transfer step (exchange current density, j_0, transfer coefficient, α) of Li"+/Li redox system, the mass transfer parameters of Li"+ (transfer number of Li"+, t_L_i_+, diffusion coefficient of Li"+, D_L_i_+), and the conductivity (κ) of each electrolyte were studied separately. The results demonstrate that the solvents play a critical role in the measured j_0, t_L_i_+, D_L_i_+, and κ of the electrolyte, while the choice of Li"+ salts only slightly affect the measured parameters. Finally, the understanding of the kinetics will gain insight into the mechanism of lithium dendrite formation and provide guidelines to the future application of lithium metal.

Structure and reactivity of lithium amides. /sup 6/Li, /sup 13/C, and /sup 15/N NMR spectroscopic studies and colligative measurements of lithium diphenylamide and lithium diphenylamide-lithium bromide complex solvated by tetrahydrofuran

Energy Technology Data Exchange (ETDEWEB)

DePue, J.S.; Collum, D.B.

1988-08-03

/sup 6/Li, /sup 13/C, and /sup 15/N NMR spectroscopic studies of lithium diphenylamide in THF/hydrocarbon solutions (THF = tetrahydrofuran) detected two different species. /sup 6/Li and /sup 15/N NMR spectroscopic studies of (/sup 6/Li, /sup 15/N)lithium diphenylamide showed the species observed at low THF concentrations to be a cyclic oligomer. Structural analogies provided strong support for a dimer while colligative measurements at 0/degrees/C indicated the dimer to be di- or trisolvated. On the basis of the observed mass action effects, the species appearing at intermediate THF concentrations is assigned as a contact or solvent-separated ion-paired monomer. Lithium diphenylamide forms a 1:1 adduct with lithium bromide at low THF concentrations. A combination of /sup 6/Li-/sup 15/N double labeling studies and colligative measurements supports a trisolvated cyclic mixed dimer structure. Although detailed spectroscopic studies at elevated THF concentrations were precluded by high fluctionality, the similarity of the /sup 13/C chemical shifts of lithium diphenylamide in the presence and absence of lithium bromide provide indirect evidence that the mixed dimer undergoes a THF concentration dependent dissociation to the monomeric amide and free lithium bromide. 24 references, 9 figures, 2 tables.

Equilibrium dissociation pressures of lithium hydride and lithium deuteride

International Nuclear Information System (INIS)

Smith, H.M.; Webb, R.E.

1977-12-01

The equilibrium dissociation pressures of plateau composition lithium hydride and lithium deuteride have been measured from 450 to 750 0 C. These data were used to derive the relationship of dissociation pressure with temperature over this range and to calculate several thermodynamic properties of these materials. Thermodynamic properties determined included the enthalpy, entropy, and free energy of formation; the enthalpy and entropy of fusion; and the melting points

Overhauser effect in metallic lithium; Effet Overhauser dans le lithium metallique

Energy Technology Data Exchange (ETDEWEB)

Gueron, J.; Ryter, Ch. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Saclay (France)

1960-07-01

The Overhauser effect has been observed: a) at ordinary temperatures, by measuring the increase in the nuclear resonance signal of Li{sup 7}; b) at the temperature of liquid helium, by observing the electron resonance shift due to the secular part of the electron-nucleus coupling. The metallic lithium particles are produced by irradiating lithium hydride with thermal neutrons. Reprint of a paper published in Physical Review Letters, vol. 3, no. 7, 1959, p. 338-340 [French] L'effet Overhauser est mis en evidence: a) a la temperature ordinaire, en mesurant l'augmentation du signal de resonance nucleaire du Li{sup 7}; b) a la temperature de l'helium liquide, en observant le deplacement de la raie de resonance electronique du a la partie seculaire du couplage electron-noyau. Les particules de lithium metallique sont produites par irradiations aux neutrons thermiques de l'hydrure de lithium Li{sup 7}. Reproduction d'un article publie dans Physical Review Letters, vol. 3, no. 7, 1959, p. 338-340.

CRITIC-I: Instrumented lithium oxide irradiation: Part 1, Lithium oxide fabrication and characteristics

International Nuclear Information System (INIS)

Applegate, D.S.; Poeppel, R.B.

1987-06-01

Fine-grained, sinterable lithium oxide powder was prepared by high-temperature vacuum calcination of molten lithium carbonate. The product was ball milled, cold pressed, and fired in an oxygen atmosphere. The fired density, grain size, and surface roughness varied widely with firing schedule. Most variations were attributed to moisture content. Rings of high-density, sintered lithium oxide will be used in an in-reactor experiment to measure tritium release. 2 refs., 8 figs., 1 tab

Serum lithium levels and suicide attempts: a case-controlled comparison in lithium therapy-naive individuals.

Science.gov (United States)

Kanehisa, Masayuki; Terao, Takeshi; Shiotsuki, Ippei; Kurosawa, Keiko; Takenaka, Ryuichi; Sakamoto, Teruo; Shigemitsu, Osamu; Ishii, Nobuyoshi; Hatano, Koji; Hirakawa, Hirofumi

2017-11-01

Several epidemiological studies have shown the inverse association of lithium levels in drinking water and suicide rates; however, it is necessary to perform a clinical study dealing with individual patients. We analyzed 199 patients including 31 patients with suicide attempts, 21 patients with self-harm, and 147 control patients. All were transferred to a university emergency department suffering from intoxication or injury, were aged 20 or more years, and were alive at the start of the study. The exclusion criteria consisted of suffering from schizophrenia and a past or present history of lithium therapy. These exclusions were applied because it is difficult to determine whether their suicide attempt was induced by the intent to end their life or by psychotic symptoms such as auditory hallucinations, and if the patient had received lithium therapy, the association between the small amount of lithium taken from drinking water and food and serum lithium levels cannot be detected. There was a significant difference (p = 0.043) between the three groups whereby patients with suicide attempts had significantly lower lithium levels than control patients (p = 0.012) in males but not females. Multivariate logistic regression analysis with adjustment for age and gender revealed that patients with suicide attempts had significantly lower lithium levels than control patients (p = 0.032, odds ratio 0.228, 95% CI 0.059-0.883). The limitations of the present study are the nature of observational research which cannot reveal a causal relationship and the relatively small number of subjects. The present findings suggest that higher serum lithium levels may be protective against suicide attempts in lithium therapy-naive individuals.

Recovery of lithium from the effluent obtained in the process of spent lithium-ion batteries recycling

DEFF Research Database (Denmark)

Guo, Xueyi; Cao, Xiao; Huang, Guoyong

2017-01-01

A novel process of lithium recovery as lithium ion sieve from the effluent obtained in the process of spent lithium-ion batteries recycling is developed. Through a two-stage precipitation process using Na2CO3 and Na3PO4 as precipitants, lithium is recovered as raw Li2CO3 and pure Li3PO4...... of Na2CO3 is used to prepare LiMn2O4 as lithium ion sieve, and the tolerant level of sodium on its property is studied through batch tests of adsorption capacity and corrosion resistance. When the weight percentage of Na2CO3 in raw Li2CO3 is controlled less than 10%, the Mn corrosion percentage of LiMn2......O4 decreases to 21.07%, and the adsorption capacity can still keep at 40.08 mg g-1. The results reveal that the conventional separation sodium from lithium may be avoided through the application of the raw Li2CO3 in the field of lithium ion sieve....

Differential roles for medial prefrontal and medial temporal cortices in schema-dependent encoding: from congruent to incongruent.

Science.gov (United States)

van Kesteren, Marlieke T R; Beul, Sarah F; Takashima, Atsuko; Henson, Richard N; Ruiter, Dirk J; Fernández, Guillén

2013-10-01

Information that is congruent with prior knowledge is generally remembered better than incongruent information. This effect of congruency on memory has been attributed to a facilitatory influence of activated schemas on memory encoding and consolidation processes, and hypothesised to reflect a shift between processing in medial temporal lobes (MTL) towards processing in medial prefrontal cortex (mPFC). To investigate this shift, we used functional magnetic resonance imaging (fMRI) to compare brain activity during paired-associate encoding across three levels of subjective congruency of the association with prior knowledge. Participants indicated how congruent they found an object-scene pair during scanning, and were tested on item and associative recognition memory for these associations one day later. Behaviourally, we found a monotonic increase in memory performance with increasing congruency for both item and associative memory. Moreover, as hypothesised, encoding-related activity in mPFC increased linearly with increasing congruency, whereas MTL showed the opposite pattern of increasing encoding-related activity with decreasing congruency. Additionally, mPFC showed increased functional connectivity with a region in the ventral visual stream, presumably related to the binding of visual representations. These results support predictions made by a recent neuroscientific framework concerning the effects of schema on memory. Specifically, our findings show that enhanced memory for more congruent information is mediated by the mPFC, which is hypothesised to guide integration of new information into a pre-existing schema represented in cortical areas, while memory for more incongruent information relies instead on automatic encoding of arbitrary associations by the MTL. © 2013 Elsevier Ltd. All rights reserved.

Lithium protects ethanol-induced neuronal apoptosis

International Nuclear Information System (INIS)

Zhong Jin; Yang Xianlin; Yao Weiguo; Lee Weihua

2006-01-01

Lithium is widely used for the treatment of bipolar disorder. Recent studies have demonstrated its neuroprotective effect. Ethanol is a potent neurotoxin that is particularly harmful to the developing nervous system. In this study, we evaluated lithium's neuroprotection against ethanol-induced apoptosis. Transient exposure of infant mice to ethanol caused apoptotic cell death in brain, which was prevented significantly by administering a low dose of lithium 15 min later. In cultured cerebellar granule neurons, ethanol-induced apoptosis and activation of caspase-3/9, both of which were prevented by lithium. However, lithium's protection is not mediated by its commonly known inhibition of glycogen synthase3β, because neither ethanol nor lithium has significant effects on the phosphorylation of Akt (ser473) or GSK3β (ser9). In addition, the selective GSK-3β inhibitor SB-415286 was unable to prevent ethanol-induced apoptosis. These data suggest lithium may be used as a potential preventive measure for ethanol-induced neurological deficits

Solid solution lithium alloy cermet anodes

Science.gov (United States)

Richardson, Thomas J.

2013-07-09

A metal-ceramic composite ("cermet") has been produced by a chemical reaction between a lithium compound and another metal. The cermet has advantageous physical properties, high surface area relative to lithium metal or its alloys, and is easily formed into a desired shape. An example is the formation of a lithium-magnesium nitride cermet by reaction of lithium nitride with magnesium. The reaction results in magnesium nitride grains coated with a layer of lithium. The nitride is inert when used in a battery. It supports the metal in a high surface area form, while stabilizing the electrode with respect to dendrite formation. By using an excess of magnesium metal in the reaction process, a cermet of magnesium nitride is produced, coated with a lithium-magnesium alloy of any desired composition. This alloy inhibits dendrite formation by causing lithium deposited on its surface to diffuse under a chemical potential into the bulk of the alloy.

Congruent reduction and mode conversion in 4-dimensional plasmas

International Nuclear Information System (INIS)

Friedland, L.; Kaufman, A.N.

1987-04-01

Standard eikonal theory reduces, to N=1, the order of the system of equations underlying wave propagation in inhomogeneous plasmas. The condition for this remarkable reducibility is that only one eigenvalue of the unreduced NxN dispersion matrix D(k,x) vanishes at a time. If, however, two or more eigenvalues of D become simultaneously small, the geometric optics reduction scheme becomes singular. These regions are associated with linear mode conversion, and are described by higher order systems. A new reduction scheme based on congruent transformations of D is developed, and it is shown that, in ''degenerate'' plasma regions, a partial reduction of order is possible. The method comprises a constructive step-by-step procedure, which, in the most frequent (doubly) degenerate case, yields a second order system, describing the pairwise mode conversion problems, the solution of which in general geometry has been found recently

Therapeutic Drug Monitoring of Lithium

DEFF Research Database (Denmark)

Mose, Tina; Damkier, Per; Petersen, Magnus

2015-01-01

BACKGROUND: Serum lithium is monitored to ensure levels within the narrow therapeutic window. This study examines the interlaboratory variation and inaccuracy of lithium monitoring in Denmark. METHODS: In 16 samples consisting of (1) control materials (n = 4), (2) pooled patient serum (n = 5......), and (3) serum from individual patients (n = 7), lithium was measured in 19 laboratories using 20 different instruments. The lithium concentrations were targeted by a reference laboratory. Ion-selective electrode (n = 5), reflective spectrophotometric (RSM, n = 5), and spectrophotometric (n = 10) methods...... of >12%. Seven of these instruments had a systematic positive or negative bias and more so at lower lithium concentrations. Three poorly calibrated instruments were found in the ion-selective electrode group, 3 in the spectrophotometric group, and 2 in the RSM group. The instruments using reflectance...

Electrodeposition of high-density lithium vanadate nanowires for lithium-ion battery

Science.gov (United States)

Hua, Kang; Li, Xiujuan; Fang, Dong; Yi, Jianhong; Bao, Rui; Luo, Zhiping

2018-07-01

Lithium vanadate nanowires have been electrodeposited onto a titanium (Ti) foil by a direct current electrodeposition without template. The morphology, crystal structure, and the effects of deposition voltage, temperature and time on the prepared samples were tested and presented. The as-prepared lithium vanadate nanowires/Ti composite can be used as electrode for lithium-ion battery. Electrochemical measurements showed that the electrode displayed a specific discharge capacitance as high as 235.1 mAh g-1 after 100 cycles at a current density of 30 mA g-1. This research provides a new pathway to explore high tap density vanadates nanowires on metals with enhanced electrochemical performance.

Anomalous Lithium Adsorption Propensity of Monolayer ...

Indian Academy of Sciences (India)

longer life cycle, thus an ideal candidate to replace the conventional ... tion in the development of lithium ion batteries as they ... interaction of graphene with lithium based on density ... aromatic hydrocarbons.30 Lithium doping increases.

Oxygen-Rich Lithium Oxide Phases Formed at High Pressure for Potential Lithium-Air Battery Electrode.

Science.gov (United States)

Yang, Wenge; Kim, Duck Young; Yang, Liuxiang; Li, Nana; Tang, Lingyun; Amine, Khalil; Mao, Ho-Kwang

2017-09-01

The lithium-air battery has great potential of achieving specific energy density comparable to that of gasoline. Several lithium oxide phases involved in the charge-discharge process greatly affect the overall performance of lithium-air batteries. One of the key issues is linked to the environmental oxygen-rich conditions during battery cycling. Here, the theoretical prediction and experimental confirmation of new stable oxygen-rich lithium oxides under high pressure conditions are reported. Three new high pressure oxide phases that form at high temperature and pressure are identified: Li 2 O 3 , LiO 2 , and LiO 4 . The LiO 2 and LiO 4 consist of a lithium layer sandwiched by an oxygen ring structure inherited from high pressure ε-O 8 phase, while Li 2 O 3 inherits the local arrangements from ambient LiO 2 and Li 2 O 2 phases. These novel lithium oxides beyond the ambient Li 2 O, Li 2 O 2 , and LiO 2 phases show great potential in improving battery design and performance in large battery applications under extreme conditions.

Equilibrium lithium-ion transport between nanocrystalline lithium-inserted anatase TiO2 and the electrolyte.

Science.gov (United States)

Ganapathy, Swapna; van Eck, Ernst R H; Kentgens, Arno P M; Mulder, Fokko M; Wagemaker, Marnix

2011-12-23

The power density of lithium-ion batteries requires the fast transfer of ions between the electrode and electrolyte. The achievable power density is directly related to the spontaneous equilibrium exchange of charged lithium ions across the electrolyte/electrode interface. Direct and unique characterization of this charge-transfer process is very difficult if not impossible, and consequently little is known about the solid/liquid ion transfer in lithium-ion-battery materials. Herein we report the direct observation by solid-state NMR spectroscopy of continuous lithium-ion exchange between the promising nanosized anatase TiO(2) electrode material and the electrolyte. Our results reveal that the energy barrier to charge transfer across the electrode/electrolyte interface is equal to or greater than the barrier to lithium-ion diffusion through the solid anatase matrix. The composition of the electrolyte and in turn the solid/electrolyte interface (SEI) has a significant effect on the electrolyte/electrode lithium-ion exchange; this suggests potential improvements in the power of batteries by optimizing the electrolyte composition. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhancing the effectiveness of antismoking messages via self-congruent appeals.

Science.gov (United States)

Chang, Chingching

2009-01-01

A self-congruent effect model was applied to understand adolescents' responses to antismoking advertising that referred to the self or others. Experiment 1 showed that self-referring ads generated more negative smoking attitudes than other-referring ads among adolescents with independent self-construals, whereas other-referring ads generated more negative smoking attitudes than self-referring ads among adolescents with interdependent self-construals. A survey further showed that smokers rated themselves higher on a measure of independent self-construal than nonsmokers. Experiment 2 then found that self-referring ads are more effective than other-referring ads for smokers, who have independent self-construals. Findings supported the idea that health communication campaign designers can maximize message effectiveness by developing different messages for different target segments of the population based on their self-construals.

Observation and analysis of nanodomain textures in dielectric relaxor lead magnesium niobate

International Nuclear Information System (INIS)

Bursill, L.A.; Qian, Hua; Peng, Julin; Fan, X.D.

1995-01-01

High-resolution (0.2nm) images are used to locate chemical domains occurring with length scales of 1-5nm in the dielectric relaxor lead magnesium niobate (PMN). The experimental HRTEM images are analysed using computer-simulations and image matching in order to clarify and characterize the nature of the chemical ordering. Madelung electrostatic energy calculations are used to rank a set of structural models for possible ordered and disordered distributions of Nb and Mg over the B-sites of perovskite ABO 3 . Next, the chemical domain textures are modelled using next-nearest-neighbour Ising (NNNI) models and Monte Carlo methods. This results in a preferred model for the B-site distribution (the extended NNN-Ising model), which is used for image simulations. Both HRTEM many-beam bright-and dark-field and single-beam dark-field TEM images are obtained and compared with the experimental images. The final result is a realistic atomic model for the Nb, Mg distribution of PMN. 42 refs., 2 tabs., 10 figs

Emotion Recognition from Congruent and Incongruent Emotional Expressions and Situational Cues in Children with Autism Spectrum Disorder

Science.gov (United States)

Tell, Dina; Davidson, Denise

2015-01-01

In this research, the emotion recognition abilities of children with autism spectrum disorder and typically developing children were compared. When facial expressions and situational cues of emotion were congruent, accuracy in recognizing emotions was good for both children with autism spectrum disorder and typically developing children. When…

With Their Help: How Community Members Construct a Congruent Third Space in an Urban Kindergarten Classroom

Science.gov (United States)

Quigley, Cassie F.

2013-01-01

Through the use of narrative enquiry, this paper tells the story of how a kindergarten teacher in an all-girls' school incorporates family and community members' involvement to the construction of the congruent Third Space present in the classroom, and the ways the girls respond to this involvement, thereby providing a successful model for other…

Recovery of lithium and cobalt from waste lithium ion batteries of mobile phone

Energy Technology Data Exchange (ETDEWEB)

Jha, Manis Kumar, E-mail: mkjha@nmlindia.org; Kumari, Anjan; Jha, Amrita Kumari; Kumar, Vinay; Hait, Jhumki; Pandey, Banshi Dhar

2013-09-15

Graphical abstract: Recovery of valuable metals from scrap batteries of mobile phone. - Highlights: • Recovery of Co and Li from spent LIBs was performed by hydrometallurgical route. • Under the optimum condition, 99.1% of lithium and 70.0% of cobalt were leached. • The mechanism of the dissolution of lithium and cobalt was studied. • Activation energy for lithium and cobalt were found to be 32.4 kJ/mol and 59.81 kJ/mol, respectively. • After metal recovery, residue was washed before disposal to the environment. - Abstract: In view of the stringent environmental regulations, availability of limited natural resources and ever increasing need of alternative energy critical elements, an environmental eco-friendly leaching process is reported for the recovery of lithium and cobalt from the cathode active materials of spent lithium-ion batteries of mobile phones. The experiments were carried out to optimize the process parameters for the recovery of lithium and cobalt by varying the concentration of leachant, pulp density, reductant volume and temperature. Leaching with 2 M sulfuric acid with the addition of 5% H{sub 2}O{sub 2} (v/v) at a pulp density of 100 g/L and 75 °C resulted in the recovery of 99.1% lithium and 70.0% cobalt in 60 min. H{sub 2}O{sub 2} in sulfuric acid solution acts as an effective reducing agent, which enhance the percentage leaching of metals. Leaching kinetics of lithium in sulfuric acid fitted well to the chemical controlled reaction model i.e. 1 − (1 − X){sup 1/3} = k{sub c}t. Leaching kinetics of cobalt fitted well to the model ‘ash diffusion control dense constant sizes spherical particles’ i.e. 1 − 3(1 − X){sup 2/3} + 2(1 − X) = k{sub c}t. Metals could subsequently be separated selectively from the leach liquor by solvent extraction process to produce their salts by crystallization process from the purified solution.

The ethical dimensions of delivering culturally congruent nursing and health care.

Science.gov (United States)

Zoucha, R; Husted, G L

2000-01-01

This article discusses the ethical parameters of giving culturally congruent care to individual patients by health care professionals. Leininger's Cultural Care Diversity and Universality theory (Leininger, 1995) is used to demonstrate the importance of culture in a person's life and Husted's and Husted's (1995) bioethical theory is used to create a mind-set of ethical interaction and to direct the analysis of a bioethical dilemma involving cultural differences between persons of the same culture, a depressed Mexican-American woman and her husband. The differences between transculturalism and multiculturalism are explored. We defend the position that a patient's culture is only a useful tool in caring for a patient if the individual person is made the primary focus of care.

RECOVERY OF LITHIUM FROM WASTE MATERIALS

Directory of Open Access Journals (Sweden)

JITKA JANDOVÁ

2012-03-01

Full Text Available In this study, processes based on roasting-leaching-crystallization steps and condensation-precipitation steps for Li2CO3 separation from spent Li/MnO2 batteries and lithium-containing wastewaters were developed and verified on a laboratory scale. Spent Li/MnO2 batteries were roasted under reduced pressure at 650°C, which split the castings and deactivated the batteries by reduction of LiMnO2 and MnO2 with residual lithium metal and graphite to form MnO and Li2CO3. The resultant lithium carbonate was selectively solubilised in water with manganese remaining in the leach residue. Li2CO3 of 99.5 % purity was obtained after evaporation of 95 % water. Processing of lithium-containing alkaline wastewaters from the production of liquid rubber comprises condensation up to lithium concentration of 12-13 g/l Li and a two-step precipitation of lithium carbonate using CO2 as a precipitation agent. Sparingly soluble Li2CO3 was produced in the second step at 95°C, whilst most impurities remain in the solution. Obtained lithium carbonate products contained on average more than 99.5 % Li2CO3. The lithium precipitation efficiency was about 90 %.

77 FR 28259 - Mailings of Lithium Batteries

Science.gov (United States)

2012-05-14

... POSTAL SERVICE 39 CFR Part 111 Mailings of Lithium Batteries AGENCY: Postal Service TM . ACTION... international mailing of lithium batteries and devices containing lithium batteries. This prohibition also extends to the mailing of lithium batteries to and from an APO, FPO, or DPO location. However, this...

Properties of lithium and its handling

International Nuclear Information System (INIS)

Asada, Takashi; Kano, Shigeki; Tachi, Toshiaki; Kawai, Masataka

2000-09-01

Lithium is one of good coolants because of high boiling point (1317degC), small specific gravity (0.47 at 600degC) and large specific heat (1 cal/g/degC). Therefore if lithium will be used in fast reactor for coolant, the heat efficiency of reactor will largely increase. Here the fundamental properties of lithium and the results of examination on chemical reaction, combustion and extinction are shown. These examinations were also carried out on sodium to compare with lithium. The differences between both are that lithium reacts more moderately with water, not explosive, and is not combustible but after ignition burns at higher temperature and longer. (author)

Module of lithium divertor for KTM tokamak

Energy Technology Data Exchange (ETDEWEB)

Lyublinski, I., E-mail: yublinski@yandex.ru [FSUE ' Red Star' , Moscow (Russian Federation); Vertkov, A.; Evtikhin, V.; Balakirev, V.; Ionov, D.; Zharkov, M. [FSUE ' Red Star' , Moscow (Russian Federation); Tazhibayeva, I. [IAE NNC RK, Kurchatov (Kazakhstan); Mirnov, S. [TRINITI, Troitsk, Moscow Region (Russian Federation); Khomiakov, S.; Mitin, D. [OJSC Dollezhal Institute, Moscow (Russian Federation); Mazzitelli, G. [ENEA RC Frascati (Italy); Agostini, P. [ENEA RC Brasimone (Italy)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Problems of PFE degradation, tritium accumulation and plasma pollution can be overcome by the use of liquid lithium-metal with low Z. Black-Right-Pointing-Pointer Capillary-porous system (CPS) - new material in which liquid lithium fill a solid matrix from porous material. Black-Right-Pointing-Pointer Lithium divertor module for KTM tokamak is under development. Black-Right-Pointing-Pointer Lithium filled tungsten felt is offered as the base plasma facing material of divertor. Black-Right-Pointing-Pointer Results of this project addresses to the progress in the field of fusion neutrons source and fusion energy source creation. - Abstract: Activity on projects of ITER and DEMO reactors has shown that solution of problems of divertor target plates and other plasma facing elements (PFEs) based on the solid plasma facing materials cause serious difficulties. Problems of PFE degradation, tritium accumulation and plasma pollution can be overcome by the use of liquid lithium-metal with low Z. Application of lithium will allow to create a self-renewal and MHD stable liquid metal surface of the in-vessel devices possessing practically unlimited service life; to reduce power flux due to intensive re-irradiation on lithium atoms in plasma periphery that will essentially facilitate a problem of heat removal from PFE; to reduce Z{sub eff} of plasma to minimally possible level close to 1; to exclude tritium accumulation, that is provided with absence of dust products and an opportunity of the active control of the tritium contents in liquid lithium. Realization of these advantages is based on use of so-called lithium capillary-porous system (CPS) - new material in which liquid lithium fill a solid matrix from porous material. The progress in development of lithium technology and also activity in lithium experiments in the tokamaks TFTR, T-11M, T-10, FTU, NSTX, HT-7 and stellarator TJ II permits of solving the problems in development of

Effect of impurities on the performance of lithium intended for lithium/thionyl chloride battery manufacture

Energy Technology Data Exchange (ETDEWEB)

Hagan, W P; Hampson, N A; Packer, R K

1988-09-01

The elemental impurities in four different, commercially-available lithium samples have been determined. Cells consisting of these lithium samples as anodes and pressed acetylene black as cathodes were discharged at 20 C and at 70 C at a rate of 50 mA/sq cm. The passivating films remaining on the lithium surface after discharge were examined using electron microscopy and their elemental compositions determined using the surface sensitive technique of X-ray photoelectron spectroscopy. Performance characteristics (voltage and capacity) of test cells consisting, in part, of the different lithium samples are discussed in terms of impurity concentrations determined by secondary ion mass spectrometry and atomic absorption spectroscopy. The permeability and electronic conductivity of the LiCl passivating films are adduced as two possible reasons for the variations in capacity and on-load voltage of the different lithium samples. 25 references.

Tritium sorption in lithium-bismuth and lithium-aluminum alloys

International Nuclear Information System (INIS)

Talbot, J.B.; Smith, F.J.; Land, J.F.; Barton, P.

1976-01-01

The sorption of tritium by molten lithium-bismuth, Li-Bi (15 at.% lithium), and solid equiatomic lithium-aluminum, Li-Al, was investigated to evaluate the potential application of both materials in controlled thermonuclear reactors. The solubility of tritium in molten Li-Bi is less than 0.1 ppb at 500 - 700 0 C and tritium partial pressures of 10 -1 - 10 -3 Torr. Therefore, extraction of tritium from molten Li 2 BeF 4 salt with Li-Bi is not practical. The solubility of hydrogen in solid Li-Al (50 - 50 at.%) at 500 0 C follows Sieverts' Law; the Sieverts' constant was measured to be 1.9 (+-0.1) X 10 4 Torrsup(1/2)/atomic fraction. Tritium sorption in Li-Al ranged from 0.01 to 7 ppm at 400 - 600 0 C at respective tritium partial pressures of 0.14 - 0.52 Torr. (Auth.)

Deposition of lithium on a plasma edge probe in TFTR -- Behavior of lithium-painted walls interacting with edge plasmas

Energy Technology Data Exchange (ETDEWEB)

Hirooka, Y. [Univ. of California, San Diego, La Jolla, CA (United States); Ashida, K. [Toyama Univ. (Japan); Kugel, H. [Princeton Univ., NJ (United States)] [and others

1998-05-01

Recent observations have indicated that lithium pellet injection wall conditioning plays an important role in achieving the enhanced supershot regime in TFTR. However, little is understood about the behavior of lithium-coated limiter walls, interacting with edge plasmas. In the final campaign of TFTR, a cylindrical carbon fiber composite probe was inserted into the boundary plasma region and exposed to ohmically-heated deuterium discharges with lithium pellet injection. The ion-drift side probe surface exhibits a sign of codeposition of lithium, carbon, oxygen, and deuterium, whereas the electron side essentially indicates high-temperature erosion. It is found that lithium is incorporated in these codeposits in the form of oxide at the concentration of a few percent. In the electron side, lithium has been found to penetrate deeply into the probe material, presumably via rapid diffusion through interplane spaces in the graphite crystalline. Though it is not conclusive, materials mixing in the carbon and lithium system appears to be a key process in successful lithium wall conditioning.

Low pressure lithium condensation

International Nuclear Information System (INIS)

Wadkins, R.P.; Oh, C.H.

1985-01-01

A low pressure experiment to evaluate the laminar film condensation coefficients of lithium was conducted. Some thirty-six different heat transfer tests were made at system pressures ranging from 1.3 to 26 Pa. Boiled lithium was condensed on the inside of a 7.6-cm (ID), 409 stainless-steel pipe. Condensed lithium was allowed to reflux back to the pool boiling region below the condensing section. Fourteen chromel/alumel thermocouples were attached in various regions of the condensing section. The thermocouples were initially calibrated with errors of less than one degree Celsius

Lithium Pharmacogenetics: Where Do We Stand?

Science.gov (United States)

Pisanu, Claudia; Melis, Carla; Squassina, Alessio

2016-11-01

Preclinical Research Bipolar disorder (BPD) is a chronic and disabling psychiatric disorder with a prevalence of 0.8-1.2% in the general population. Although lithium is considered the first-line treatment, a large percentage of patients do not respond sufficiently. Moreover, lithium can induce severe side effects and has poor tolerance and a narrow therapeutic index. The genetics of lithium response has been largely investigated, but findings have so far failed to identify reliable biomarkers to predict clinical response. This has been largely determined by the highly complex phenotipic and genetic architecture of lithium response. To this regard, collaborative initiatives hold the promise to provide robust and standardized methods to disantenagle this complexity, as well as the capacity to collect large samples of patietnts, a crucial requirement to study the genetics of complex phenotypes. The International Consortium on Lithium Genetics (ConLiGen) has recently published the largest study so far on lithium response reporting significant associations for two long noncoding RNAs (lncRNAs). This result provides relevant insights into the pharmacogenetics of lithium supporting the involvement of the noncoding portion of the genome in modulating clinical response. Although a vast body of research is engaged in dissecting the genetic bases of response to lithium, the several drawbacks of lithium therapy have also stimulated multiple efforts to identify new safer treatments. A drug repurposing approach identified ebselen as a potential lithium mimetic, as it shares with lithium the ability to inhibit inositol monophosphatase. Ebselen, an antioxidant glutathione peroxidase mimetic, represents a valid and promising example of new potential therapeutic interventions for BD, but the paucity of data warrant further investigation to elucidate its potential efficacy and safety in the management of BPD. Nevertheless, findings provided by the growing field of pharmacogenomic

Lithium-Oxygen Batteries: At a Crossroads?

DEFF Research Database (Denmark)

Vegge, Tejs; García Lastra, Juan Maria; Siegel, Donald Jason

2017-01-01

In this current opinion, we critically review and discuss some of the most important recent findings in the field of rechargeable lithium-oxygen batteries. We discuss recent discoveries like the evolution of reactive singlet oxygen and the use of organic additives to bypass reactive LiO2 reaction...... intermediates, and their possible implications on the potential for commercialization of lithium-oxygen batteries. Finally, we perform a critical assessment of lithium-superoxide batteries and the reversibility of lithium-hydroxide batteries....

Lithium Ion Battery Anode Aging Mechanisms

Science.gov (United States)

Agubra, Victor; Fergus, Jeffrey

2013-01-01

Degradation mechanisms such as lithium plating, growth of the passivated surface film layer on the electrodes and loss of both recyclable lithium ions and electrode material adversely affect the longevity of the lithium ion battery. The anode electrode is very vulnerable to these degradation mechanisms. In this paper, the most common aging mechanisms occurring at the anode during the operation of the lithium battery, as well as some approaches for minimizing the degradation are reviewed. PMID:28809211

Lithium-ion batteries fundamentals and applications

CERN Document Server

Wu, Yuping

2015-01-01

Lithium-Ion Batteries: Fundamentals and Applications offers a comprehensive treatment of the principles, background, design, production, and use of lithium-ion batteries. Based on a solid foundation of long-term research work, this authoritative monograph:Introduces the underlying theory and history of lithium-ion batteriesDescribes the key components of lithium-ion batteries, including negative and positive electrode materials, electrolytes, and separatorsDiscusses electronic conductive agents, binders, solvents for slurry preparation, positive thermal coefficient (PTC) materials, current col

Recovery of lithium from the effluent obtained in the process of spent lithium-ion batteries recycling.

Science.gov (United States)

Guo, Xueyi; Cao, Xiao; Huang, Guoyong; Tian, Qinghua; Sun, Hongyu

2017-08-01

A novel process of lithium recovery as lithium ion sieve from the effluent obtained in the process of spent lithium-ion batteries recycling is developed. Through a two-stage precipitation process using Na 2 CO 3 and Na 3 PO 4 as precipitants, lithium is recovered as raw Li 2 CO 3 and pure Li 3 PO 4 , respectively. Under the best reaction condition (both the amounts of Na 2 CO 3 and Li 3 PO 4 vs. the theoretical ones are about 1.1), the corresponding recovery rates of lithium (calculated based on the concentration of the previous stage) are 74.72% and 92.21%, respectively. The raw Li 2 CO 3 containing the impurity of Na 2 CO 3 is used to prepare LiMn 2 O 4 as lithium ion sieve, and the tolerant level of sodium on its property is studied through batch tests of adsorption capacity and corrosion resistance. When the weight percentage of Na 2 CO 3 in raw Li 2 CO 3 is controlled less than 10%, the Mn corrosion percentage of LiMn 2 O 4 decreases to 21.07%, and the adsorption capacity can still keep at 40.08 mg g -1 . The results reveal that the conventional separation sodium from lithium may be avoided through the application of the raw Li 2 CO 3 in the field of lithium ion sieve. Copyright © 2017 Elsevier Ltd. All rights reserved.

Crystal growth and characterization of europium doped lithium strontium iodide scintillator as an ionizing radiation detector

Science.gov (United States)

Uba, Samuel

High performance detectors used in the detection of ionizing radiation is critical to nuclear nonproliferation applications and other radiation detectors applications. In this research we grew and tested Europium doped Lithium Strontium Iodide compound. A mixture of lithium iodide, strontium iodide and europium iodide was used as the starting materials for this research. Congruent melting and freezing temperature of the synthesized compound was determined by differential scanning calorimetry (DSC) using a Setaram Labsys Evo DSC-DTA instrument. The melting temperatures were recorded at 390.35°C, 407.59°C and freezing temperature was recorded at 322.84°C from a graph of heat flow plotted against temperature. The synthesized material was used as the charge for the vertical Bridgeman growth, and a 6.5 cm and 7.7cm length boule were grown in a multi-zone transparent Mullen furnace. A scintillating detector of thickness 2.53mm was fabricated by mechanical lapping in mineral oil, and scintillating response and timing were obtained to a cesium source using CS-137 isotope. An energy resolution (FWHM over peak position) of 12.1% was observed for the 662keV full absorption peak. Optical absorption in the UV-Vis wavelength range was recorded for the grown crystal using a U-2900 UV/VIS Spectrophotometer. Absorption peaks were recorded at 194nm, 273nm, and 344nm from the absorbance spectrum, various optical parameters such as absorption coefficient, extinction coefficient, refractive index, and optical loss were derived. The optical band gap energy was calculated using Tauc relation expression at 1.79eV.

Operation of the lithium pellet injector

International Nuclear Information System (INIS)

Khlopenkov, K.V.; Sudo, S.; Sergeev, V.Yu.

1996-05-01

A lithium pellet injection requires an accurate handling with lithium and special technique of loading the pellets. Thus, the technology for this has been developed based on the following conditions: 1) Because of chemical activity of lithium it is necessary to operate in a glove-box with the noble gas atmosphere (He, Ar, etc.). 2) A special procedure of replacing the glove-box atmosphere allows to achieve high purity of the noble gas. 3) When making the pellets it is better to keep the clean lithium in the liquid hexane so as to maintain lithium purity. 4) The pressure of the accelerating gas for Li pellets should be not less than 30 atm. (author)

Technology roadmap for lithium ion batteries 2030; Technologie-Roadmap Lithium-Ionen-Batterien 2030

Energy Technology Data Exchange (ETDEWEB)

Thielmann, Axel; Isenmann, Ralf; Wietschel, Martin [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany)

2010-07-01

The technology roadmap for lithium ion batteries 2030 presents a graphical representation of the cell components, cell types and cell characteristics of lithium ion batteries and their connection with the surrounding technology field from today through 2030. This is a farsighted orientation on the way into the future and an implementation of the ''Roadmap: Batterieforschung Deutschland'' of the BMBF (Federal Ministry of Education and Science). The developments in lithium ion batteries are identified through 2030 form today's expert view in battery development and neighbouring areas. (orig.)

Novel iron-cobalt derivatised lithium iron phosphate nanocomposite for lithium ion battery cathode

CSIR Research Space (South Africa)

Ikpo, CO

2013-01-01

Full Text Available Described herein is the electrochemical study conducted on lithium ion battery cathode material consisting of composite of lithium iron phosphate (LiFePO(sub4), iron-cobalt derivatised carbon nanotubes (FeCo-CNT) and polyaniline (PA) nanomaterials...

49 CFR 173.185 - Lithium cells and batteries.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Lithium cells and batteries. 173.185 Section 173... Class 7 § 173.185 Lithium cells and batteries. (a) Cells and batteries. A lithium cell or battery, including a lithium polymer cell or battery and a lithium-ion cell or battery, must conform to all of the...

Lithium. Effects on excitable cell membranes

NARCIS (Netherlands)

Ploeger, Egbert Johan

1974-01-01

LITHIUM: Effects on excitable cell membranes. Lithium salts have been used in the treatment of manic-depressive psychosis for many years but their mechanism of action is not well understood. Many workers assume that the action of lithium on catecholamine metabolism and/or on electrolyte distribution

Effect of AgCl NPs: Physical, thermal, absorption and luminescence properties

Science.gov (United States)

Nurhafizah, H.; Rohani, M. S.

2017-06-01

Silver nanoparticles (AgCl NPs) are embedded in Er3+/Nd3+ co-doped lithium niobate tellurite glasses of the form (68-x)TeO2-15Li2CO3-15Nb2O5-1Er2O3-1Nd2O3-(x)AgCl with x = 1,2 and 3 mol% via conventional melt-quenching technique. The physical properties such as density, ionic packing density, refractive index and electronic polarizability are computed utilizing the usual method. The existence of AgCl NPs with an average size of 3.7 nm is confirmed using TEM analysis. Moreover, the thermal stability and Hruby criterion of the glass decreases as the AgCl NPs content increases. The direct optical band gap are found decrease as the AgCl NPs content increase, but both indirect optical band gap and Urbach energy are found increases as AgCl NPs content increases. The luminescence spectra shows two strong emission which is the purple emission at 436 nm and red emission at 724 nm which also been observed has strong quenching due to the AgCl NPs, Er3+/Nd3+ dopant and modifier, lithium niobate which possessed magnetic penetration. These glass compositions may be potential for various applications such as solid state devices including laser.

Lithium Battery Diaper Ulceration.

Science.gov (United States)

Maridet, Claire; Taïeb, Alain

2016-01-01

We report a case of lithium battery diaper ulceration in a 16-month-old girl. Gastrointestinal and ear, nose, and throat lesions after lithium battery ingestion have been reported, but skin involvement has not been reported to our knowledge. © 2015 Wiley Periodicals, Inc.

Tritium recovery from lithium oxide pellets

International Nuclear Information System (INIS)

Bertone, P.C.; Jassby, D.L.

1984-01-01

The TFTR Lithium Blanket Module is an assembly containing 650 kg of lithium oxide that will be used to test the ability of neutronics codes to model the tritium breeding characteristics of limited-coverage breeding zones in a tokamak. It is required that tritium concentrations as low as 0.1 nCi/g bred in both metallic lithium samples and lithium oxide pellets be measured with an uncertainty not exceeding +- 6%. A tritium assay technique for the metallic samples which meets this criterion has been developed. Two assay techniques for the lithium oxide pellets are being investigated. In one, the pellets are heated in a flowing stream of hydrogen, while in the other, the pellets are dissolved in 12 M hydrochloric acid

Size effects in lithium ion batteries

International Nuclear Information System (INIS)

Yao Hu-Rong; Yin Ya-Xia; Guo Yu-Gao

2016-01-01

Size-related properties of novel lithium battery materials, arising from kinetics, thermodynamics, and newly discovered lithium storage mechanisms, are reviewed. Complementary experimental and computational investigations of the use of the size effects to modify electrodes and electrolytes for lithium ion batteries are enumerated and discussed together. Size differences in the materials in lithium ion batteries lead to a variety of exciting phenomena. Smaller-particle materials with highly connective interfaces and reduced diffusion paths exhibit higher rate performance than the corresponding bulk materials. The thermodynamics is also changed by the higher surface energy of smaller particles, affecting, for example, secondary surface reactions, lattice parameter, voltage, and the phase transformation mechanism. Newly discovered lithium storage mechanisms that result in superior storage capacity are also briefly highlighted. (topical review)

NSTX plasma operation with a Liquid Lithium Divertor

Energy Technology Data Exchange (ETDEWEB)

Kugel, H.W., E-mail: hkugel@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Allain, J.P. [Purdue University, West Lafayette, IN 47907 (United States); Bell, M.G.; Bell, R.E.; Diallo, A.; Ellis, R.; Gerhardt, S.P. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Heim, B. [Purdue University, West Lafayette, IN 47907 (United States); Jaworski, M.A.; Kaita, R.; Kallman, J.; Kaye, S.; LeBlanc, B.P. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Maingi, R.; McLean, A. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Menard, J.; Mueller, D. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Nygren, R. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Ono, M.; Paul, S.F. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); and others

2012-10-15

Highlights: Black-Right-Pointing-Pointer NSTX 2010 experiments tested the effectiveness of maintaining the deuterium retention properties of a static liquid lithium molybdenum divertor surface when refreshed by lithium evaporation as an approximation to a flowing liquid lithium surface. Black-Right-Pointing-Pointer Noteworthy improvements in plasma performance with the plasma strike point on the liquid lithium molybdenum divertor were obtained similar to those obtained previously with lithiated graphite. The role of lithium impurities in this result is discussed. Black-Right-Pointing-Pointer Inspection of the liquid lithium molybdenum divertor after the Campaign indicated mechanical damage to supports, and other hardware resulting from forces following plasma current disruptions. - Abstract: NSTX 2010 experiments were conducted using a molybdenum Liquid Lithium Divertor (LLD) surface installed on the outer part of the lower divertor. This tested the effectiveness of maintaining the deuterium retention properties of a static liquid lithium surface when refreshed by lithium evaporation as an approximation to a flowing liquid lithium surface. The LLD molybdenum front face has a 45% porosity to provide sufficient wetting to spread 37 g of lithium, and to retain it in the presence of magnetic forces. Lithium Evaporators were used to deposit lithium on the LLD surface. At the beginning of discharges, the LLD lithium surface ranged from solid to liquefied depending on the amount of applied and plasma heating. Noteworthy improvements in plasma performance were obtained similar to those obtained previously with lithiated graphite, e.g., ELM-free, quiescent edge, H-modes. During these experiments with the plasma outer strike point on the LLD, the rate of deuterium retention in the LLD, as indicated by the fueling needed to achieve and maintain stable plasma conditions, was the about the same as that for solid lithium coatings on the graphite prior to the installation of the

Gas absorption and discharge behaviors of lead-lithium

International Nuclear Information System (INIS)

Sakabe, Toshiro; Yokomine, Takehiko; Kunugi, Tomoaki; Kawara, Zensaku; Ueki, Yoshitaka; Tanaka, Teruya

2014-01-01

Highlights: • The absorption of argon in the lead-lithium is comparable with that of helium even at the solid state. • For the molten state of lead-lithium, the absorption of argon could be larger than that of helium. • It is observed that the argon tends to desorb when the phase change of lead-lithium occurs. • It is observed from the TPD-MS analysis that the argon tends to desorb when the phase change of lead-lithium occurs. - Abstract: The absorption of rare gas in the lead-lithium has been quite low and the gas is used as a cover-gas to control the environment of experiment. In our previous thermo-fluid experiment by using lithium-lead, it was found the cover gas pressure enclosed in the very leak tight container of lithium-lead was decreased with time, that is, the gas-absorption of the solid lithium-lead occurred at room temperature under atmospheric pressure. The variation of pressure exceeded the retention of argon in lead-lithium which is expected by the published data. Therefore, we aim to confirm those phenomena under well-controlled experimental condition by using argon, nitrogen and helium. According to the results of gas exposure tests, the absorption of argon in the lead-lithium is comparable with that of helium even at the solid state. For the molten state of lead-lithium, the absorption of argon could be larger than that of helium. It is also observed from the TPD-MS analysis that the argon tends to desorb when the phase change of lead-lithium occurs. If the retention of argon in the lead-lithium cannot be ignored, the problem of Ar-41 activity should be taken into consideration as well as the problem of argon bubble in the lead-lithium

Preliminary experimental study of liquid lithium water interaction

International Nuclear Information System (INIS)

You, X.M.; Tong, L.L.; Cao, X.W.

2015-01-01

Highlights: • Explosive reaction occurs when lithium temperature is over 300 °C. • The violence of liquid lithium water interaction increases with the initial temperature of liquid lithium. • The interaction is suppressed when the initial water temperature is above 70 °C. • Steam explosion is not ignorable in the risk assessment of liquid lithium water interaction. • Explosion strength of liquid lithium water interaction is evaluated by explosive yield. - Abstract: Liquid lithium is the best candidate for a material with low Z and low activation, and is one of the important choices for plasma facing materials in magnetic fusion devices. However, liquid lithium reacts violently with water under the conditions of loss of coolant accidents. The release of large heats and hydrogen could result in the dramatic increase of temperature and pressure. The lithium–water explosion has large effect on the safety of fusion devices, which is an important content for the safety assessment of fusion devices. As a preliminary investigation of liquid lithium water interaction, the test facility has been built and experiments have been conducted under different conditions. The initial temperature of lithium droplet ranged from 200 °C to 600 °C and water temperature was varied between 20 °C and 90 °C. Lithium droplets were released into the test section with excess water. The shape of lithium droplet and steam generated around the lithium were observed by the high speed camera. At the same time, the pressure and temperature in the test section were recorded during the violent interactions. The preliminary experimental results indicate that the initial temperature of lithium and water has an effect on the violence of liquid lithium water interaction.

Preliminary experimental study of liquid lithium water interaction

Energy Technology Data Exchange (ETDEWEB)

You, X.M.; Tong, L.L.; Cao, X.W., E-mail: caoxuewu@sjtu.edu.cn

2015-10-15

Highlights: • Explosive reaction occurs when lithium temperature is over 300 °C. • The violence of liquid lithium water interaction increases with the initial temperature of liquid lithium. • The interaction is suppressed when the initial water temperature is above 70 °C. • Steam explosion is not ignorable in the risk assessment of liquid lithium water interaction. • Explosion strength of liquid lithium water interaction is evaluated by explosive yield. - Abstract: Liquid lithium is the best candidate for a material with low Z and low activation, and is one of the important choices for plasma facing materials in magnetic fusion devices. However, liquid lithium reacts violently with water under the conditions of loss of coolant accidents. The release of large heats and hydrogen could result in the dramatic increase of temperature and pressure. The lithium–water explosion has large effect on the safety of fusion devices, which is an important content for the safety assessment of fusion devices. As a preliminary investigation of liquid lithium water interaction, the test facility has been built and experiments have been conducted under different conditions. The initial temperature of lithium droplet ranged from 200 °C to 600 °C and water temperature was varied between 20 °C and 90 °C. Lithium droplets were released into the test section with excess water. The shape of lithium droplet and steam generated around the lithium were observed by the high speed camera. At the same time, the pressure and temperature in the test section were recorded during the violent interactions. The preliminary experimental results indicate that the initial temperature of lithium and water has an effect on the violence of liquid lithium water interaction.

131I therapy of Graves' disease using lithium

International Nuclear Information System (INIS)

Sato, Kenshi

1983-01-01

Lithium is known to cause goiter and hypothyroidism. In the mechanism of goitrogenesis, there is general agreement that lithium inhibits the release of the thyroid hormones from the thyroid gland without significantly impairing other thyroid functions. The present study was undertaken, therefore, to investigate the usefulness of lithium in the radioiodine treatment of Graves' disease. Nine patients with Graves' disease who were all, except one, previously treated with antithyroid drugs were studied. 600 mg of lithium carbonate were administered daily to investigate the effects on thyroidal 131 I uptake, disappearance rate of 131 I from the prelabeled thyroid and the serum concentrations of thyroid hormones. Lithium showed no significant effect on the thyroidal 131 I uptake when the 24 hour thyroidal 131 I uptakes were determined both before and during lithium treatment in the five cases. On the other hand, lithium clearly prolonged the mean value of effective half-lives of 131 I to approximately 8 days vs. 5.1 days before lithium treatment (p 4 and T 3 levels significantly decreased during lithium treatment, from 21.3 to 12.4μg/dl (n=9, p 131 I for the Graves' disease can be reduced by using lithium, the radiation exposure to the total body is decreased. Moreover, it is possible to perform the 131 I therapy while improving the thyrotoxicosis with lithium. Finally, it is concluded that lithium is a very useful drug to be combined with the 131 I therapy of Graves' disease. (author)

The effect of impurities on the performance of lithium intended for lithium/thionyl chloride battery manufacture

Science.gov (United States)

Hagan, W. P.; Hampson, N. A.; Packer, R. K.

The elemental impurities in four different, commercially-available lithium samples have been determined. Cells consisting of these lithium samples as anodes and pressed acetylene black as cathodes were discharged at 20 °C and at 70 °C at a rate of 50 mA cm -2. The passivating films remaining on the lithium surface after discharge were examined using electron microscopy and their elemental compositions determined using the surface sensitive technique of X-ray photoelectron spectroscopy. Performance characteristics (voltage and capacity) of test cells consisting, in part, of the different lithium samples are discussed in terms of impurity concentrations determined by secondary ion mass spectrometry and atomic absorption spectroscopy. The permeability and electronic conductivity of the LiCl passivating films are adduced as two possible reasons for the variations in capacity and on-load voltage of the different lithium samples.

Lithium extractive metallurgy

International Nuclear Information System (INIS)

Josa, J.M.; Merino, J.L.

1985-01-01

The Nuclear Fusion National Program depends on lithium supplies. Extractive metallurgy development is subordinate to the localization and evaluation of ore resources. Nowadays lithium raw materials usable with present technology consist of pegmatite ore and brine. The Instituto Geologico y Minero Espanol (IGME) found lepidolite, ambligonite and spodrimene in pegmatite ores in different areas of Spain. However, an evaluation of resources has not been made. Different Spanish surface and underground brines are to be sampled and analyzed. If none of these contain significant levels of lithium, the Junta de Energia Nuclear (JEN) will try an agreement with IGME for ENUSA (Empresa Nacional del Uranio, S.A.) to explore pegmatite-ore bodies from different locations. Different work stages, laboratory tests, pilots plants tests and commercial plant, are foreseen, if the deposits are found. (author)

Probing quantum effects in lithium

Science.gov (United States)

Deemyad, Shanti; Zhang, Rong

2018-05-01

In periodic table lithium is the first element immediately after helium and the lightest metal. While fascinating quantum nature of condensed helium is suppressed at high densities, lithium is expected to adapt more quantum solid behavior under compression. This is due to the presence of long range interactions in metallic systems for which an increase in the de-Boer parameter (λ/σ, where σ is the minimum interatomic distance and λ is the de-Broglie wavelength) is predicted at higher densities [1,2]. Physics of dense lithium offers a rich playground to look for new emergent quantum phenomena in condensed matter and has been subject of many theoretical and experimental investigations. In this article recent progress in studying the quantum nature of dense lithium will be discussed.

Reactivity of lithium exposed graphite surface

International Nuclear Information System (INIS)

Harilal, S.S.; Allain, J.P.; Hassanein, A.; Hendricks, M.R.; Nieto-Perez, M.

2009-01-01

Lithium as a plasma-facing component has many attractive features in fusion devices. We investigated chemical properties of the lithiated graphite surfaces during deposition using X-ray photoelectron spectroscopy and low-energy ion scattering spectroscopy. In this study we try to address some of the known issues during lithium deposition, viz., the chemical state of lithium on graphite substrate, oxide layer formation mechanisms, Li passivation effects over time, and chemical change during exposure of the sample to ambient air. X-ray photoelectron studies indicate changes in the chemical composition with various thickness of lithium on graphite during deposition. An oxide layer formation is noticed during lithium deposition even though all the experiments were performed in ultrahigh vacuum. The metal oxide is immediately transformed into carbonate when the deposited sample is exposed to air.

Waveguide Cavity Resonator as a Source of Optical Squeezing

Science.gov (United States)

Stefszky, M.; Ricken, R.; Eigner, C.; Quiring, V.; Herrmann, H.; Silberhorn, C.

2017-04-01

We present the generation of continuous-wave optical squeezing from a titanium-in-diffused lithium niobate waveguide resonator. We directly measure 2.9 ±0.1 dB of single-mode squeezing, which equates to a produced level of 4.9 ±0.1 dB after accounting for detection losses. This device showcases the current capabilities of this waveguide architecture and precipitates more complicated integrated continuous-wave quantum devices in the continuous-variable regime.

Integrated optical circuit engineering IV; Proceedings of the Meeting, Cambridge, MA, Sept. 16, 17, 1986

Science.gov (United States)

Mentzer, Mark A.; Sriram, S.

The design and implementation of integrated optical circuits are discussed in reviews and reports. Topics addressed include lithium niobate devices, silicon integrated optics, waveguide phenomena, coupling considerations, processing technology, nonlinear guided-wave optics, integrated optics for fiber systems, and systems considerations and applications. Also included are eight papers and a panel discussion from an SPIE conference on the processing of guided-wave optoelectronic materials (held in Los Angeles, CA, on January 21-22, 1986).

Ultrafast Phase Comparator for Phase-Locked Loop-Based Optoelectronic Clock Recovery Systems

DEFF Research Database (Denmark)

Gomez-Agis, F.; Oxenløwe, Leif Katsuo; Kurimura, S.

2009-01-01

The authors report on a novel application of a chi((2)) nonlinear optical device as an ultrafast phase comparator, an essential element that allows an optoelectronic phase-locked loop to perform clock recovery of ultrahigh-speed optical time-division multiplexed (OTDM) signals. Particular interest...... is devoted to a quasi-phase-matching adhered-ridge-waveguide periodically poled lithium niobate (PPLN) device, which shows a sufficient high temporal resolution to resolve a 640 Gbits OTDM signal....

Membranes in Lithium Ion Batteries

Science.gov (United States)

Yang, Min; Hou, Junbo

2012-01-01

Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed. PMID:24958286

Membranes in Lithium Ion Batteries

Directory of Open Access Journals (Sweden)

Junbo Hou

2012-07-01

Full Text Available Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed.

Anode materials for lithium-ion batteries

Science.gov (United States)

Sunkara, Mahendra Kumar; Meduri, Praveen; Sumanasekera, Gamini

2014-12-30

An anode material for lithium-ion batteries is provided that comprises an elongated core structure capable of forming an alloy with lithium; and a plurality of nanostructures placed on a surface of the core structure, with each nanostructure being capable of forming an alloy with lithium and spaced at a predetermined distance from adjacent nanostructures.

Characterization of lithium evaporators for LTX

Science.gov (United States)

Nieto-Perez, M.; Majeski, R.; Timberlake, J.; Lundberg, D.; Kaita, R.; Arevalo-Torres, B.

2010-11-01

The presence of lithium on the internal components of fusion devices has proven to be beneficial for reactor performance. The Lithium Tokamak Experiment (LTX) will be the first experimental fusion device operating with a significant portion of its internal surface coated with lithium. One of the key capabilities in the device is the reliable production of lithium films inside the reactor. This task is accomplished with the use of lithium evaporators, specially designed for LTX using resistively heated yttria crucibles. In the present work, results from the operation of one of these evaporators on a separate test stand are presented. Deposition measurements at different power levels were performed using a quartz crystal deposition monitor, and temperature distributions in the evaporator crucible and its content were obtained using an infrared camera and a dip-in thermocouple probe. Modeling of the evaporation cloud was done with the raytracing software OptiCAD, and comparisons between the computations and the temperature and flux measurements were performed, in order to accurately predict spatial lithium deposition rates in different locations of the LTX device.

Monitoring and toxicity evaluation of phytoplankton on lithium manganese oxide adsorbents at lithium recovery pilot plant field.

Science.gov (United States)

Yoon, H. O.; Kim, J. A.; Kim, J. C.; Chung, K. S.; Ryu, J. H.

2015-12-01

For recovery of rare mineral resources such as lithium or boron from seawater, the lithium adsorbent material have been made by Korea Institute of Geoscience and Mineral Resources (KIGAM) and pilot plant was conducted in Okgye Harbor, Gangneung, Korea. The application of lithium adsorbent in pilot plant, it is important to consider the impact on the marine environment. Especially phytoplankton communities are important marine microorganism to represent marine primary product. At the same time, phytoplankton is possible to induce the decrease of lithium recovery rate due to cause of biofouling to surfaces of lithium adsorbents. Therefore long-term and periodic monitoring of phytoplankton is necessary to understand the environmental impact and biofouling problems near the lithium pilot plant. The abundance and biomass of phytoplankton have been evaluated through monthly interval sampling from February 2013 to May 2015. Abundance and species diversity of phytoplankton went up to summer from winter. When lithium adsorbents were immersing to seawater, eco-toxicities of released substances were determined using Microtox with bioluminescence bacteria Vibrio fischeri. The adsorbents were soaked in sterilized seawater and aeration for 1, 3, 5, 7, 10 and 14 days intervals under controlled temperature. Maximum EC50 concentration was 61.4% and this toxicity was showed in more than 10 days exposure.

Novel Approach for in Situ Recovery of Lithium Carbonate from Spent Lithium Ion Batteries Using Vacuum Metallurgy.

Science.gov (United States)

Xiao, Jiefeng; Li, Jia; Xu, Zhenming

2017-10-17

Lithium is a rare metal because of geographical scarcity and technical barrier. Recycling lithium resource from spent lithium ion batteries (LIBs) is significant for lithium deficiency and environmental protection. A novel approach for recycling lithium element as Li 2 CO 3 from spent LIBs is proposed. First, the electrode materials preobtained by mechanical separation are pyrolyzed under enclosed vacuum condition. During this process the Li is released as Li 2 CO 3 from the crystal structure of lithium transition metal oxides due to the collapse of the oxygen framework. An optimal Li recovery rate of 81.90% is achieved at 973 K for 30 min with a solid-to-liquid ratio of 25 g L -1 , and the purity rate of Li 2 CO 3 is 99.7%. The collapsed mechanism is then presented to explain the release of lithium element during the vacuum pyrolysis. Three types of spent LIBs including LiMn 2 O 4 , LiCoO 2 , and LiCo x Mn y Ni z O 2 are processed to prove the validity of in situ recycling Li 2 CO 3 from spent LIBs under enclosed vacuum condition. Finally, an economic assessment is taken to prove that this recycling process is positive.

Control of Internal and External Short Circuits in Lithium Ion and Lithium Batteries, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA has identified needs for compact high-energy-density primary and secondary batteries. Lithium and Lithium Ion cells, respectively, are meeting these needs for...

LITHIUM TOXICITY IN ELDERLY-A CASE REPORT AND DISCUSSION

Directory of Open Access Journals (Sweden)

Mariana D. Arnaoudova

2014-07-01

Full Text Available Background: The therapeutic effect of Lithium as a mono therapy or as an augmenting agent in a variety of medical and psychiatric disorders is under doubt. However, lithium is associated with a number of adverse effects. Method and objective: A review of the literature on lithium use in older adults and a case report presentation. Summary of results: The literature, concerning current uses of Lithium in older patients, especially for patients with neurologic or cognitive impairments is limited due to the lack of well-designed, large clinical trials. Elderly patients are at higher risk to develop neurotoxicity in the course of lithium therapy. We present a case of 66 years old female patient, suffering bipolar disorder, who developed lithium toxicity and was admitted at the gerontopsychiatric department due to a confusional state, tremor and gait abnormality. Lithium toxicity was suspected when sufficient information about previous medical history of lithium therapy has been obtained. Lithium level found to be 1.69mmol/L. The patient has developed intoxication during maintenance therapy with a lithium dosage which had been unchanged for months. Conclusion: Elderly patients require lower doses of Lithium to achieve similar serum concentrations as those in younger adults. Neurotoxicity could be suspected at serum lithium levels which are considered therapeutic in younger adults. When prescribing lithium agents in elderly we should consider age-related changes in pharmacokinetics. The best way to prevent lithium toxicity is to control the serum concentration regularly during therapy.

Lithium pellet production (LiPP): A device for the production of small spheres of lithium

Science.gov (United States)

Fiflis, P.; Andrucyzk, D.; Roquemore, A. L.; McGuire, M.; Curreli, D.; Ruzic, D. N.

2013-06-01

With lithium as a fusion material gaining popularity, a method for producing lithium pellets relatively quickly has been developed for NSTX. The Lithium Pellet Production device is based on an injector with a sub-millimeter diameter orifice and relies on a jet of liquid lithium breaking apart into small spheres via the Plateau-Rayleigh instability. A prototype device is presented in this paper and for a pressure difference of ΔP = 5 Torr, spheres with diameters between 0.91 < D < 1.37 mm have been produced with an average diameter of D = 1.14 mm, which agrees with the developed theory. Successive tests performed at Princeton Plasma Physics Laboratory with Wood's metal have confirmed the dependence of sphere diameter on pressure difference as predicted.

Solid composite electrolytes for lithium batteries

Science.gov (United States)

Kumar, Binod; Scanlon, Jr., Lawrence G.

2000-01-01

Solid composite electrolytes are provided for use in lithium batteries which exhibit moderate to high ionic conductivity at ambient temperatures and low activation energies. In one embodiment, a ceramic-ceramic composite electrolyte is provided containing lithium nitride and lithium phosphate. The ceramic-ceramic composite is also preferably annealed and exhibits an activation energy of about 0.1 eV.

Mathematical modeling of the lithium deposition overcharge reaction in lithium-ion batteries using carbon-based negative electrodes

International Nuclear Information System (INIS)

Arora, P.; Doyle, M.; White, R.E.

1999-01-01

Two major issues facing lithium-ion battery technology are safety and capacity grade during cycling. A significant amount of work has been done to improve the cycle life and to reduce the safety problems associated with these cells. This includes newer and better electrode materials, lower-temperature shutdown separators, nonflammable or self-extinguishing electrolytes, and improved cell designs. The goal of this work is to predict the conditions for the lithium deposition overcharge reaction on the negative electrode (graphite and coke) and to investigate the effect of various operating conditions, cell designs and charging protocols on the lithium deposition side reaction. The processes that lead to capacity fading affect severely the cycle life and rate behavior of lithium-ion cells. One such process is the overcharge of the negative electrode causing lithium deposition, which can lead to capacity losses including a loss of active lithium and electrolyte and represents a potential safety hazard. A mathematical model is presented to predict lithium deposition on the negative electrode under a variety of operating conditions. The Li x C 6 vertical bar 1 M LiPF 6 , 2:1 ethylene carbonate/dimethyl carbonate, poly(vinylidene fluoride-hexafluoropropylene) vert b ar LiMn 2 O 4 cell is simulated to investigate the influence of lithium deposition on the charging behavior of intercalation electrodes. The model is used to study the effect of key design parameters (particle size, electrode thickness, and mass ratio) on the lithium deposition overcharge reaction. The model predictions are compared for coke and graphite-based negative electrodes. The cycling behavior of these cells is simulated before and after overcharge to understand the hazards and capacity fade problems, inherent in these cells, can be minimized

Hydrogen storage capacity of lithium-doped KOH activated carbons

International Nuclear Information System (INIS)

Minoda, Ai; Oshima, Shinji; Iki, Hideshi; Akiba, Etsuo

2014-01-01

Highlights: • The hydrogen adsorption of lithium-doped KOH activated carbons has been studied. • Lithium doping improves their hydrogen adsorption affinity. • Lithium doping is more effective for materials with micropores of 0.8 nm or smaller. • Lithium reagent can alter the pore structure, depending on the raw material. • Optimizing the pore size and functional group is needed for better hydrogen uptake. - Abstract: The authors have studied the hydrogen adsorption performance of several types of lithium-doped KOH activated carbons. In the case of activated cokes, lithium doping improves their hydrogen adsorption affinity from 5.02 kg/m 3 to 5.86 kg/m 3 at 303 K. Hydrogen adsorption density increases by around 17% after lithium doping, likely due to the fact that lithium doping is more effective for materials with micropores of 0.8 nm or smaller. The effects of lithium on hydrogen storage capacity vary depending on the raw material, because the lithium reagent can react with the material and alter the pore structure, indicating that lithium doping has the effect of plugging or filling the micropores and changing the structures of functional groups, resulting in the formation of mesopores. Despite an observed decrease in hydrogen uptake, lithium doping was found to improve hydrogen adsorption affinity. Lithium doping increases hydrogen uptake by optimizing the pore size and functional group composition

Chemical processing of liquid lithium fusion reactor blankets

International Nuclear Information System (INIS)

Weston, J.R.; Calaway, W.F.; Yonco, R.M.; Hines, J.B.; Maroni, V.A.

1979-01-01

A 50-gallon-capacity lithium loop constructed mostly from 304L stainless steel has been operated for over 6000 hours at temperatures in the range from 360 to 480 0 C. This facility, the Lithium Processing Test Loop (LPTL), is being used to develop processing and monitoring technology for liquid lithium fusion reactor blankets. Results of tests of a molten-salt extraction method for removing impurities from liquid lithium have yielded remarkably good distribution coefficients for several of the more common nonmetallic elements found in lithium systems. In particular, the equilibrium volumetric distribution coefficients, D/sub v/ (concentration per unit volume of impurity in salt/concentration per unit volume of impurity in lithium), for hydrogen, deuterium, nitrogen and carbon are approx. 3, approx. 4, > 10, approx. 2, respectively. Other studies conducted with a smaller loop system, the Lithium Mini-Test Loop (LMTL), have shown that zirconium getter-trapping can be effectively used to remove selected impurities from flowing lithium

Interdisciplinary: Cultural competency and culturally congruent education for millennials in health professions.

Science.gov (United States)

Hawala-Druy, Souzan; Hill, Mary H

2012-10-01

The increasingly diverse multicultural and multigenerational student population in the United States requires that educators at all levels develop cultural knowledge, awareness, and sensitivity to help diverse learners fulfill their potential and to avoid cultural misunderstandings that can become obstacles or barriers to learning. The purpose of this study was to design and implement eclectic, creative, evidence-based interdisciplinary educational activities, along with culturally congruent teaching strategies, within a semester-long university course that promoted positive and culturally competent learning outcomes for culturally diverse, largely millennial students. The interdisciplinary course would prepare health professional students with the requisite knowledge and skills, through transformative learning that produces change agents, to provide culturally congruent and quality team-based care to diverse populations. This was a qualitative and quantitative study, which measured students' level of cultural awareness, competence, and proficiency pre and post the educational intervention. Instruments used for data collection included the Inventory for Assessing The Process of Cultural Competence-Student Version (IAPCC-SV) by Campinha-Bacote, course evaluations, students' feedback, and portfolio reflections. The study was conducted at a private academic institution located in the Mid-Atlantic region and the sample population included inter-professional students (N=106) from various health professions including nursing, pharmacy, and allied health sciences. Results from the pre- and post-test IAPCC-SV survey revealed that mean scores increased significantly from pre-test (60.8) to post-test (70.6). Thus, students' levels of cultural competency (awareness, knowledge, skills, desire, encounter) improved post-educational intervention, indicating that the teaching methods used in the course might be applied on a larger scale across the university system to cater to the

Instrinsic defect energies of lithium hydride and lithium deuteride crystals

International Nuclear Information System (INIS)

Pandey, R.; Stoneham, A.M.

1985-01-01

A theoretical study has been made of the defect structure of lithium hydride and lithium deuteride. A potential model is obtained describing the statics and dynamics of these crystals. Intrinsic defect energies are calculated using the Harwell HADES program which is based on a generalised Mott-Littleton method. The results are in good agreement with the experimental data, and suggest that the vacancy and interstitial migration mechanisms of anions and cations are all comparable in their contribution to ionic conduction. (author)

Does lithium protect against dementia?

DEFF Research Database (Denmark)

Kessing, Lars Vedel; Forman, Julie Lyng; Andersen, Per Kragh

2010-01-01

OBJECTIVE: To investigate whether treatment with lithium in patients with mania or bipolar disorder is associated with a decreased rate of subsequent dementia. METHODS: Linkage of register data on prescribed lithium in all patients discharged from psychiatric health care service with a diagnosis...... exposed to lithium (50.4%), 1,781 to anticonvulsants (36.7%), 4,280 to antidepressants (88.1%), and 3,901 to antipsychotics (80.3%) during the study period. A total of 216 patients received a diagnosis of dementia during follow-up (103.6/10,000 person-years). During the period following the second...... prescription of lithium, the rate of dementia was decreased compared to the period following the first prescription. In contrast, the rates of dementia during multiple prescription periods with anticonvulsants, antidepressants, or antipsychotics, respectively, were not significantly decreased compared...

Starting lithium prophylaxis early v. late in bipolar disorder

DEFF Research Database (Denmark)

Kessing, Lars Vedel; Vradi, Eleni; Andersen, Per Kragh

2014-01-01

BACKGROUND: No study has investigated when preventive treatment with lithium should be initiated in bipolar disorder. AIMS: To compare response rates among patients with bipolar disorder starting treatment with lithium early v. late. METHOD: Nationwide registers were used to identify all patients...... with a diagnosis of bipolar disorder in psychiatric hospital settings who were prescribed lithium during the period 1995-2012 in Denmark (n = 4714). Lithium responders were defined as patients who, following a stabilisation lithium start-up period of 6 months, continued lithium monotherapy without being admitted...... to hospital. Early v. late intervention was defined in two ways: (a) start of lithium following first contact; and (b) start of lithium following a diagnosis of a single manic/mixed episode. RESULTS: Regardless of the definition used, patients who started lithium early had significantly decreased rates of non...

Lithium technologies for edge plasma control

International Nuclear Information System (INIS)

Sergeev, Vladimir Yu.; Kuteev, Boris V.; Bykov, Aleksey S.; Krylov, Sergey V.; Skokov, Viacheslav G.; Timokhin, Vladimir M.

2012-01-01

Highlights: ► We have investigated two new modes of operation been in T-10 limiter tokamak experiments with a novel rotary feeder of lithium dust. ► The observed decreases of bolometer and D β signals, with increase of the electron density during the lithium dust injection, reveal the effects of the first wall conditioning. ► The lithium technology may provide inherent safety mission for major disruption mitigation in a tokamak reactor, which requires demonstration in contemporary tokamak experiments. - Abstract: We have investigated two new modes of operation been in T-10 limiter tokamak experiments with a novel rotary feeder of lithium dust. Quasi steady-state mode I and pulse mode II of dust delivery were realized in both OH and OH + ECRH disruption free plasmas at the lithium flow rate up to 2 × 10 21 atoms/s. A higher flow rate in mode II with injection rate of ∼5 × 10 21 atoms/s caused a series of minor disruptions, which was completed by discharge termination after the major disruption. The observed decreases of bolometer and D β signals, with increase of the electron density during the lithium dust injection, reveal the effects of the first wall conditioning. The lithium technology may provide inherent safety pathway for major disruption mitigation in a tokamak reactor, which requires demonstration in contemporary tokamak experiments.

Lithium-mediated protection against ethanol neurotoxicity

Directory of Open Access Journals (Sweden)

Jia Luo

2010-06-01

Full Text Available Lithium has long been used as a mood stabilizer in the treatment of manic-depressive (bipolar disorder. Recent studies suggest that lithium has neuroprotective properties and may be useful in the treatment of acute brain injuries such as ischemia and chronic neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and amyotrophic lateral sclerosis. One of the most important neuroprotective properties of lithium is its anti-apoptotic action. Ethanol is a neuroteratogen and fetal alcohol spectrum disorders (FASD are caused by maternal ethanol exposure during pregnancy. FASD is the leading cause of mental retardation. Ethanol exposure causes neuroapoptosis in the developing brain. Ethanol-induced loss of neurons in the central nervous system underlies many of the behavioral deficits observed in FASD. Excessive alcohol consumption is also associated with Wernicke–Korsakoff syndrome and neurodegeneration in the adult brain. Recent in vivo and in vitro studies indicate that lithium is able to ameliorate ethanol-induced neuroapoptosis. Lithium is an inhibitor of glycogen synthase kinase 3 (GSK3 which has recently been identified as a mediator of ethanol neurotoxicity. Lithium’s neuroprotection may be mediated by its inhibition of GSK3. In addition, lithium also affects many other signaling proteins and pathways that regulate neuronal survival and differentiation. This review discusses the recent evidence of lithium-mediated protection against ethanol neurotoxicity and potential underlying mechanisms.

Stable lithium electrodeposition in salt-reinforced electrolytes

KAUST Repository

Lu, Yingying; Tu, Zhengyuan; Shu, Jonathan; Archer, Lynden A.

2015-01-01

© 2015 Elsevier B.V. Development of high-energy lithium-based batteries that are safe remains a challenge due to the non-uniform lithium electrodeposition during repeated charge and discharge cycles. We report on the effectiveness of lithium bromide

Observation and analysis of nanodomain textures in dielectric relaxor lead magnesium niobate

Energy Technology Data Exchange (ETDEWEB)

Bursill, L A; Qian, Hua; Peng, Julin; Fan, X D

1995-10-01

High-resolution (0.2nm) images are used to locate chemical domains occurring with length scales of 1-5nm in the dielectric relaxor lead magnesium niobate (PMN). The experimental HRTEM images are analysed using computer-simulations and image matching in order to clarify and characterize the nature of the chemical ordering. Madelung electrostatic energy calculations are used to rank a set of structural models for possible ordered and disordered distributions of Nb and Mg over the B-sites of perovskite ABO{sub 3}. Next, the chemical domain textures are modelled using next-nearest-neighbour Ising (NNNI) models and Monte Carlo methods. This results in a preferred model for the B-site distribution (the extended NNN-Ising model), which is used for image simulations. Both HRTEM many-beam bright-and dark-field and single-beam dark-field TEM images are obtained and compared with the experimental images. The final result is a realistic atomic model for the Nb, Mg distribution of PMN. 42 refs., 2 tabs., 10 figs.

Outcome of lithium prophylaxis: a prospective follow-up of affective disorder patients assigned to high and low serum lithium levels

DEFF Research Database (Denmark)

Vestergaard, Per; Licht, Rasmus Wentzer; Brodersen, Anders Torp

1998-01-01

The purpose of the study was to examine the outcome of long-term lithium treatment in consecutively admitted affective disorder patients assigned to high and low serum lithium levels. A total of 91 patients were diagnosed according to DSM-III criteria and randomly allocated to two open treatment...... groups in which prophylactic lithium was administered in high (serum lithium 0.8-1.0 mmol L-1) and low (serum lithium 0.5-0.8 mmol L-1) doses, respectively. The patients were followed for 2 years or until discontinuation of lithium treatment or readmission to hospital for recurrence of affective illness....... The main outcome of the treatment groups was compared with Kaplan-Meier survival curves and by Cox regression analysis. A total of 31 patients (34%) completed 24 months of prophylactic lithium treatment without recurrence and readmission to hospital. In total, 18 patients (20%) suffered a recurrence...

Lithium containing manganese dioxide (composite dimensional manganese oxide-CDMO) as a cathod active material for lithium secondary batteries

Energy Technology Data Exchange (ETDEWEB)

Furukawa, Nobuhiro; Noma, Toshiyuki; Teraji, Kazuo; Nakane, Ikuo; Yamamoto, Yuji; Saito, Toshihiko (Sanyo Electric Co., Ltd., Osaka, Japan)

1989-06-05

Manganese dioxide containing lithium ions in a solid matrix was investigated in the lithium nonaqueous cell. Li/sub x/MnO/sub 2+{delta}/ material prepared, with the thermal treatment, by the solid state reaction of manganese dioxide and lithium hydroxide, 7 to 3 in molar ratio, at the temperature of 375{sup 0}C in air for 20 hours, exhibited the rechargeability in the lithium nonaqueous cell. A discharging and changing cycle test, 0.14 or 0.26e/Mn in each of both the discharge and charge, was also made, with the use of a flat type cell, to demonstrate it in performance. Synthetic Li/sub x/MnO/sub 2+{delta}/ was discussed, in advantageous use for the secondary lithium cell, based on the discharging and charging characteristics. As a conclusion of the foregoing, composite dimensional manganese oxide is expected to be good as active material of positive electrode for the secondary lithium cell use. 11 refs., 11 figs., 3 tabs.

Process for recovering tritium from molten lithium metal

Science.gov (United States)

Maroni, Victor A.

1976-01-01

Lithium tritide (LiT) is extracted from molten lithium metal that has been exposed to neutron irradiation for breeding tritium within a thermonuclear or fission reactor. The extraction is performed by intimately contacting the molten lithium metal with a molten lithium salt, for instance, lithium chloride - potassium chloride eutectic to distribute LiT between the salt and metal phases. The extracted tritium is recovered in gaseous form from the molten salt phase by a subsequent electrolytic or oxidation step.

Balancing surface adsorption and diffusion of lithium-polysulfides on nonconductive oxides for lithium-sulfur battery design.

Science.gov (United States)

Tao, Xinyong; Wang, Jianguo; Liu, Chong; Wang, Haotian; Yao, Hongbin; Zheng, Guangyuan; Seh, Zhi Wei; Cai, Qiuxia; Li, Weiyang; Zhou, Guangmin; Zu, Chenxi; Cui, Yi

2016-04-05

Lithium-sulfur batteries have attracted attention due to their six-fold specific energy compared with conventional lithium-ion batteries. Dissolution of lithium polysulfides, volume expansion of sulfur and uncontrollable deposition of lithium sulfide are three of the main challenges for this technology. State-of-the-art sulfur cathodes based on metal-oxide nanostructures can suppress the shuttle-effect and enable controlled lithium sulfide deposition. However, a clear mechanistic understanding and corresponding selection criteria for the oxides are still lacking. Herein, various nonconductive metal-oxide nanoparticle-decorated carbon flakes are synthesized via a facile biotemplating method. The cathodes based on magnesium oxide, cerium oxide and lanthanum oxide show enhanced cycling performance. Adsorption experiments and theoretical calculations reveal that polysulfide capture by the oxides is via monolayered chemisorption. Moreover, we show that better surface diffusion leads to higher deposition efficiency of sulfide species on electrodes. Hence, oxide selection is proposed to balance optimization between sulfide-adsorption and diffusion on the oxides.

The lithium-ion accumulators in Japan; Les accumulateurs lithium-ion au Japon

Energy Technology Data Exchange (ETDEWEB)

Lazzari, O

2006-07-15

This document takes stock on the different technologies of lithium based batteries developed in Japan as the materials used to produce their different elements. The today tendencies of the japanese researches are discussed. The applications of the lithium-ion are presented. A list of the main public and private laboratories in the domain and the research programs is provided. (A.L.B.)

Advances in simulating non-congruent phase transitions of hyperstoichiometric uranium dioxide fuel

International Nuclear Information System (INIS)

Welland, M.J.; Thompson, W.T.; Lewis, B.J.

2007-01-01

A model is being developed to simulate UO 2 at very high temperatures incorporating the effects of non-congruent phase transitions. In particular, the melting transformation and the possible 'Λ-transition' is being investigated to help support the design and analysis of experimental work being conducted as part of nuclear safety research. This work includes the interpretation of the behaviour of operating CANDU fuel under upset conditions, where centerline melting may potentially occur (particularly if the fuel is oxidized). The model presented here numerically solves a system of coupled nonlinear differential equations as derived from fundamental principles. The results of the model present here compare well against laser flash experiments in recently published literature. (author)

Determination of reduction yield of lithium metal reduction process

International Nuclear Information System (INIS)

Choi, In Kyu; Cho, Young Hwan; Kim, Taek Jin; Jee, Kwang Young

2004-01-01

Metal reduction of spent oxide fuel is the first step for the effective storage of spent fuel in Korea as well as transmutation purpose of long-lived radio-nuclides. During the reduction of uranium oxide by lithium metal to uranium metal, lithium oxide is stoichiometrically produced. By determining the concentration of lithium oxide in lithium chloride, we can estimate that how much uranium oxide is converted to uranium metal. Previous method to determine the lithium oxide concentration in lithium chloride is tedious and timing consuming. This paper describe the on-line monitoring method of lithium oxide during the reduction process

Lithium - no shortage in supply

International Nuclear Information System (INIS)

Anon.

1987-01-01

Over the last five years the face of the lithium industry has changed with new sources coming onto the market. The result of developments in supply is a buyers' market and, in the absence of major consumer developments, all things point to an increasing severely overcrowded market through the turn of the decade. As such lithium is likely to maintain charismatic appeal as developments unfold. This article provides an overview of the world's lithium industry and looks at the various market uses and potential. (author)

Lithium Resources and Production: Critical Assessment and Global Projections

Directory of Open Access Journals (Sweden)

Steve H. Mohr

2012-03-01

Full Text Available This paper critically assesses if accessible lithium resources are sufficient for expanded demand due to lithium battery electric vehicles. The ultimately recoverable resources (URR of lithium globally were estimated at between 19.3 (Case 1 and 55.0 (Case 3 Mt Li; Best Estimate (BE was 23.6 Mt Li. The Mohr 2010 model was modified to project lithium supply. The Case 1 URR scenario indicates sufficient lithium for a 77% maximum penetration of lithium battery electric vehicles in 2080 whereas supply is adequate to beyond 2200 in the Case 3 URR scenario. Global lithium demand approached a maximum of 857 kt Li/y, with a 100% penetration of lithium vehicles, 3.5 people per car and 10 billion population.