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Pressure-dependent phase transition of 2D layered silicon telluride(Si2le3)and manganese intercalated silicon telluride

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Nano Research 2019年第9期12卷 2373-2377页

作者： Virginia L. Johnson Auddy Anilao Kristie J. Koski Department of Chemistry University of CaliforniaDavisDavisCA 95616USA

Two-dimensional(2D)layered silicon telluride(SizTes)nanocrystals were compressed to 12 GPa using diamond anvil cell techniques.Optical measurements show a color change from transparent red to opaque black indicating a semiconductor-to-metal phase transition.Raman scattering was used to observe the stiffening of the crystal lattice and subsequent phase behavior.A possible phase transition was observed.at 9.5±0.5 GPa evidenced by the disappearance of the Atg stretching mode.SizTes was intercalated with elemental manganese to^1 at.%.Intercalation lowers the pressure of the proposed phase transition to 7.5±1 GPa.Raman modes show both phonon stiffening and phonon softening,suggesting negative linear compressibility.These results provide fundamental insight into the high-pressure optical phonon behavior of silicon telluride and illuminate how a specific electron-donating intercalant can chemically alter pressure-dependent optical phonon behavior.

关键词： silicon telluride Si2Te3 high pressure diamond anvil cell two-dimensional(2D)layered material

Modeling Nd^(3+)-Yb^(3+)-Tm^(3+)-Er^(3+) Codoped telluride Glass Fiber for 0.4 to 2.0 μm Emission Spectra

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Journal of Shanghai Jiaotong university(Science) 2018年第3期23卷 352-359页

作者： NKONDE Sampa 姜淳 State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronic EngineeringShanghai Jiao Tong University

The modeling of rare-earth-doped fiber amplifier is accomplished by utilizing the rate and propagation equations of distinct levels for a laser medium. A complex theoretical model for neodymium(Nd^(3+)), erbium(Er^(3+)),thulium(Tm^(3+)) and ytterbium(Yb^(3+)) codoped telluride glass fiber covering 0.4—2.0 μm emission spectra is presented. The emission spectra of Nd^(3+)-Er^(3+)-Tm^(3+)-Yb^(3+)codoped telluride fiber are realized with the excitation of both 808 and 980 nm lasers pumped at 500 mW. Numerical methods are used to calculate the emission spectra covering 0.4—2.0 μm. With the Nd^(3+), Tm^(3+)and Yb^(3+)ion concentrations fixed at 2 × 1020 ion/m^3, the Er^(3+)ion concentration optimized to 8 × 10^(20) ion/m^3 and the fiber length spanning from 0.5 to 2 m, a peak amplified spontaneous emission(ASE) power of 19.8 mW is attainable, and a minimum ASE power of 7.96 mW can also be achieved. The analytical techniques and results indicate that when a telluride codoped fiber with suitable ion concentrations of Nd^(3+), Er^(3+), Tm^(3+)and Yb^(3+)is excited by both 980 and 808 nm pump lasers, 0.4—2.0 μm emission spectra are attainable for vast optical applications.

关键词： telluride codoped fiber rare-earth-doped fiber optical communication

Anisotropic transport in a possible quasi-one-dimensional topological candidate:TaNi_(2)Te_(3)

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钨科技(英文) 2023年第3期5卷 325-331页

作者： Yi Liu Chun-Qiang Xu Wen-He Jiao Ping-Gen Cai Bin Li Wei Zhou Bin Qian Xue-Fan Jiang Kalaivaman R Raman Sankar Xiang-Lin Ke Guang-Han Cao Xiao-Feng Xu Department of Applied Physics Zhejiang University of TechnologyHangzhou 310023China Department of Physics and Astronomy Michigan State UniversityEast LansingMI 48824-2320USA School of Physics and Key Laboratory of MEMS of the Ministry of Education Southeast UniversityNanjing 211189China Department of Physics Zhejiang University of Science and TechnologyHangzhou 310023China New Energy Technology Engineering Laboratory of Jiangsu Province and School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Department of Physics Changshu Institute of TechnologyChangshu 215500China Institute of Physics Academia SinicaTaipei 11529China Department of Physics Zhejiang UniversityHangzhou 310027China

We report on the solid-state synthesis and the strongly anisotropic transport properties of the ternary telluride TaNi_(2)Te_(3),whose three orthogonal resistivity coefficients exhibit a large ratio of 1.4:1:2294(14:1:2303) at 300 K(2 K),thereby demonstrating its quasi-one-dimensional(q1D) electronic structure.The Kohler’ s rule in different current/field configurations shows a moderate violation.Its one dimensionality manifests itself in the needle-like shape of crystal,the large anisotropic resistivity and the flat Fermi surface normal to the chain direction.Moreover,the first-principles calculations also provide evidence for the existence of the nontrivial topological carriers in this q1D system.Our calculation demonstrates that TaNi_(2)Te_(3) is a strong topological nontrivial material with topological indices(1;1 0 1) and its nontrivial topology is also evidenced from its bulk-surface correspondence.Our study may therefore offer a new platform for engineering the topologically nontrivial phase in low-dimensional materials,in analogy to the recently discovered q1D topological TaNiTe_(5).

关键词： Topological materials-Quasi-one-dimensionality telluride

Construction of Desirable NiCoTe_(2) Nanosheet Arrays on a Carbon Cloth Substrate as a Positive Electrode Material for a High-Performance Asymmetric Supercapacitor

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Transactions of Tianjin University 2022年第2期28卷 153-161页

作者： Mi Xiao Meilian Zhao Tianrui Wang Tingwu Zhao Xu Niu Key Laboratory of the Ministry of Education on Smart Power Grids School of Electrical and Information EngineeringTianjin UniversityTianjin 300072China

Nickel–cobalt tellurides are deemed as promising electrode materials for energy storage devices due to their superior conductivity and theoretical specific capacitance.Here,NiCoTe_(2)was successfully fabricated on carbon cloth by facile electrodeposition and hydrothermal synthesis,which can directly serve as a binderless electrode.The NiCoTe_(2)with interconnected nanosheet arrays on a conductive carbon substrate showed a high specific capacitance(924 F/g at 1 A/g)and robust longterm cycling stability(89.6%retention after 5000 cycles).In addition,the assembled NiCoTe_(2)//activiated carbon hybrid supercapacitor achieved a high energy and power density with a short charging time(42.26 Wh/kg at a power density of 760.96 W/kg).This work provides a novel idea to produce bimetallic nickel–cobalt telluride nanosheet array electrodes for high-performance hybrid supercapacitors.

关键词： NiCoTe_(2) Hydrothermal telluride Supercapacitor Electrode Asymmetric capacitor

Fabrication and Characterization of PLD-Grown Bismuth telluride (Bi2Te3) and Antimony telluride (Sb2Te3) Thermoelectric Devices

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Journal of Electronics Cooling and Thermal Control 2017年第3期7卷 63-77页

作者： Ibrahim M.Abdel-Motaleb Syed M.Qadri Department of Electrical Engineering Northern Illinois UniversityDeKalbILUSA

We report on the fabrication and characterization of multi-leg bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) thermoelectric devices. The two materials were deposited, on top of SiO2/Si substrates, using Pulsed Laser Deposition (PLD). The SiO2 layer was used to provide insulation between the devices and the Si wafer. Copper was used as an electrical connector and a contact for the junctions. Four devices were built, where the Bi2Te3 and Sb2Te3 were deposited at substrate temperatures of 100°C, 200°C, 300°C and 400°C. The results show that the device has a voltage sensitivity of up to 146 μV/K and temperature sensitivity of 6.8 K/mV.

关键词： Thermoelectric Devices Bismuth telluride Bi2Te3 Antimony telluride Sb2Te3 Pulsed Laser Deposition PLD Seebeck Effect

Electrochemical Deposition and Optimization of Thermoelectric Nanostructured Bismuth telluride Thick Films

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Engineering（科研） 2011年第6期3卷 659-667页

作者： Hesham M. A. Soliman Abdel-Hady B. Kashyout 不详

Bismuth telluride thick films are suitable for thermoelectric (TE) devices covering large areas and operating at small-to-moderate temperature differences (20 - 200 K). High efficiency and high coefficient of performance (COP) are expected to be achieved by using thick films in some cooling applications. Bismuth telluride thick films fabrication have been achieved with Galvanostatic and Potentionstatic deposition. Stoichiometric bismuth telluride thick film was obtained by Galvanostatic deposition at current density of 3.1 mAcm-2. Bismuth telluride films with average growth rate of 10 μmh-1 and different composition were obtained. Effects of current density and composition of electrolyte in Galvanostatic deposition were studied. The current density affected the film compactness, where films deposited at lower current density were more compact than those deposited at higher current density. The morphology of the films did not depend on the current density, but chemical composition was observed when different composition of electrolyte was used. Effects of distance between electrodes, composition of electrolyte solution, and stirring in Potentionstatic deposition were studied. The shorter the distance between electrodes, the higher the electric field, thus the higher current density was applied and the deposited film was less compact. The current density increased more rapidly with stirring during electrodeposition which leads to less compact film. Through this study, films electrode-posited from solution containing 0.013 M Bi(NO3)3.5 H2O, 0.01 M TeO2 and 1 M HNO3 at 3.1 mA cm-2 for 6 hours without stirring and with interelectrode distance of 4.5 cm were free-standing with average film thickness of 60 μm and optimum film composition of Bi2Te3. The crystallite size of the later films was found to be around 4.3 nm using Scherrer’s equation from XRD patterns. Also, negative Seebeck coefficient for the same samples was revealed with an average value of -82 μV.K-1.

关键词： Bismuth telluride Thermoelectric Electrodeposition Nanostructure Thick Film

一种超快的碲化法用于非常规相控碲化钯小纳米颗粒的合成

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Science China Materials 2022年第7期65卷 1853-1860页

作者：韩艺张燕云张新义孙玉垚蔡雯雯李镇江赖建平王磊 Key Laboratory of Eco-Chemical Engineering Key Laboratory of Optic-electric Sensing and Analytical Chemistry of Life ScienceTaishan Scholar Advantage and Characteristic Discipline Team of Eco-Chemical Process and TechnologyCollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China Shandong Engineering Research Center for Marine Environment Corrosion and Safety Protection College of Environment and Safety EngineeringQingdao University of Science and TechnologyQingdao 266042China College of Materials Science and Engineering Qingdao University of Science and TechnologyQingdao 266042China

本研究发展了一种超快的碲化方法,可以在碳纳米管上快速制备非常规相控碲化钯小纳米颗粒.这种碲化方法只需要一台家用微波炉,整个过程非常快(60秒),简单,不含表面活性剂,可规模化生产.通过在相同条件下仅调整前驱体Te粉的使用量,可以精... 详细信息

本研究发展了一种超快的碲化方法,可以在碳纳米管上快速制备非常规相控碲化钯小纳米颗粒.这种碲化方法只需要一台家用微波炉,整个过程非常快(60秒),简单,不含表面活性剂,可规模化生产.通过在相同条件下仅调整前驱体Te粉的使用量,可以精确调控合成小尺寸(约5.5 nm)、高产率(约90%)的六方结构PdTe/CNT和菱方结构Pd_(20)Te_7/CNT.其中,六方结构的PdTe/CNT在甘油氧化反应(GOR)和乙二醇氧化反应(EGOR)中表现出卓越的性能.具体来说,六方结构的PdTe/CNT在甘油氧化反应中,最高电流密度可达2.72 A mg_(Pd)^(-1),比菱方结构Pd_(20)Te_7/CNT的最高电流密度高1.9倍,比Pd/CNT最高电流密度高2.8倍,超过了目前文献中报道过的大多数催化剂.同时,六方结构的PdTe/CNT在乙二醇氧化反应中比活性达到3.65 A mg_(pd)^(-1),比菱方结构的Pd_(20)Te_7/CNT和Pd/CNT分别高2.1倍和3.9倍.我们希望这项工作可以为小尺寸非常规相控碲化物催化剂的制备提供新的碲化方法指导,并为相控材料的应用提供启发.

关键词： scalable production phase-controlled catalysts telluride fuel cell

Approaching the minimum lattice thermal conductivity of p-type SnTe thermoelectric materials by Sb and Mg alloying

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Science Bulletin 2019年第14期64卷 1024-1030页

作者： Tiezheng Fu Jiazhan Xin Tiejun Zhu Jiajun Shen Teng Fang Xinbing Zhao State Key Laboratory of Silicon Materials and School of Materials Science and EngineeringZhejiang University

SnTe, as the nontoxic analogue to high-performance PbTe thermoelectric material, has captured the worldwide interest recently. Many triumphant instances focus on the strategies of band convergence, resonant doping, and nano-precipitates phonon scattering. Herein, the p-type SnTe-based materials Sn0.85-xSb0.15MgxTe (x=0-0.10) are fabricated and a combined effect of Sb and Mg is investigated. Sb alloying tunes the hole carrier concentration of SnTe and decreases the lattice thermal conductivity. Mg alloying leads to a nearly hundredfold rise of disorder parameter due to the large mass and strain fluctuations, and as a consequence the lattice thermal conductivity decreases further down to ~0.64Wm^-1K^-1 at 773K, close to the theoretical minimum of the lattice thermal conductivity (~0.50Wm^-1K^-1) of SnTe. In conjunction with the enhancement of the Seebeck coefficient caused by band convergence due to Mg alloying, the maximum zTmax reaches ~1.02 and the device zTdevice of ~0.50 at 773K for Sn0.79Sb0.15Mg0.06Te, suggesting this SnTe-based composition has a promising potential in intermediate temperature thermoelectric applications.

关键词： Tin telluride Thermoelectric materials Point defect scattering Band convergence

Transverse magnetoresistance peculiarities of thermoelectric Lu-doped Bi_2Te_3 compound due to strong electrical disorder

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Journal of Rare Earths 2019年第3期37卷 292-298页

作者： Oleg Ivanov Maxim Yaprintsev Elena Danshina Belgorod State University Belgorod State Technological University named after V.G.Shukhov

The n-type thermoelectric Bi_(1.9)Lu_(0.1)Te_3 was prepared by microwave-solvothermal method and spark plasma sintering. The magnetic field and temperature dependences of transverse magneto resistance measured within temperature 2-200 K interval allow finding the peculiarities characteristic for strongly disordered and inhomogeneous semiconductors. The first peculiarity is due to appearance of linear-inmagnetic field contribution to the total magneto resistance reflected in a crossover from quadratic magnetoresistance at low magnetic fields to linear magneto resistance at high magnetic fields. The linear magnetoresistance can result from the Hall resistance picked up from macroscopically distorted current paths due to local variations in stoichiometry of the compound studied. The second peculiarity is that both linear magnetoresistance magnitude and crossover field are functions of carrier mobility which is in agreement with the Parish and Littlewood model developed for disordered and inhomogeneous semiconductors. An increase in the mobility due to a decrease in temperature is accompanied by an increase in the magnetoresistance magnitude and a decrease in the crossover field. Finally, the third peculiarity is related to the remarkable deviation of the total magnetoresistance measured at various temperatures from the Kohler's rule. Presence of strong inhomogeneity and disorder in the Bi_(1.9)Lu_(0.1)Te_3 structure concluded from the magnetoresistance peculiarities can be responsible for the remarkable reduction in the total thermal conductivity of this compound.

关键词： Bismuth telluride Linear positive magnetoresistance Semiconductors Thermoelectric material Carrier mobility Kohler’s rule