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1.
We have measured the thermal conductivity of Bi2Te3-Sb2Te3-Gd2Te3 solid solutions at temperatures from ~80 to 300 K and have determined the electronic and lattice components of their total thermal conductivity and the contributions of Sb2Te3 and Gd2Te3 to their thermal resistance. The results indicate that heat in these materials is transported largely by phonons and that three-phonon processes play a key role in determining the lattice thermal conductivity of the solid solutions. 相似文献
2.
The Pb-Bi-Te system has been studied in the composition region PbTe-Bi2Te3-Te at temperatures from 300 to 430 K using emf measurements on reversible concentration cells of the type
( - )PbTe(s)|liquid electrolyte, Pb2 + |(Pb - Bi - Te)(s)( + ).( - )PbTe(s)|liquid electrolyte, Pb^{2 + } |(Pb - Bi - Te)(s)( + ). 相似文献
3.
L. E. Shelimova O. G. Karpinskii T. E. Svechnikova E. S. Avilov M. A. Kretova V. S. Zemskov 《Inorganic Materials》2004,40(12):1264-1270
A number of tetradymite-like layered compounds in the PbTe-Bi2Te3 and PbTe-Sb2Te3 systems were prepared by a vertical Bridgman process, and their crystal structures were investigated by x-ray diffraction using single-crystal cleaved specimens. The atomic positional parameters and bond distances in PbBi4Te7 were determined. In the pseudobinary system PbTe-Sb2Te3, two new compounds were identified, PbSb2Te4 and PbSb4Te7, isostructural with PbBi2Te4 and PbBi4Te7, respectively. The positional parameters, site occupancies, and bond distances in the structure of PbSb2Te4 were determined. The room-temperature thermoelectric power of the grown ingots was measured along their length. All of the Sb compounds studied were found to be p-type, in contrast to the compounds of the PbTe–Bi2Te3 system.Translated from Neorganicheskie Materialy, Vol. 40, No. 12, 2004, pp. 1440–1447.Original Russian Text Copyright © 2004 by Shelimova, Karpinskii, Svechnikova, Avilov, Kretova, Zemskov. 相似文献
4.
This paper systematizes phase-diagram data for the Tl-TlCl(Br)-Te systems and presents their 500-K subsolidus phase diagrams. Tl5Te2Cl and Tl5Te2Br (Tl5Te3 structure) are shown to be nonstoichiometric compounds with wide homogeneity ranges, which have been accurately determined using emf measurements, x-ray diffraction, and microhardness tests. Using emf data for reversible concentration cells with a thallium electrode, we have evaluated the partial thermodynamic functions of the thallium in the alloys studied, the standard thermodynamic functions of formation of Tl5Te2Cl and Tl5Te2Br, and their standard entropies. The crystal chemistry of these phases of variable composition is discussed in relation to the Tl5Te3 structure. 相似文献
5.
Using differential thermal analysis and x-ray diffraction, we have shown that the Bi2Te3-Bi2Se3 system contains a continuous series of solid solutions in a narrow temperature range and a compound of composition Bi2Te2Se below the solidus line. The liquidus and solidus lines determined using zone-melted samples differ little from those reported in the literature for equilibrium samples. The Bi2Te3?x Se x solid-solution phase extends to ~-14 mol % Bi2Se3 (Bi2Te2.58Se0.42). The thermoelectric power of the alloys drops sharply near the boundary of the two-phase region. Within the homogeneity range of Bi2Te2Se (33.3 mol % Bi2Se3), the thermoelectric power factor has a minimum, while the thermoelectric power has a small maximum. 相似文献
6.
We have optimized the compositions of thermoelectric materials based on Sb2Te3-Bi2Te3 solid solutions using Czochralski-grown single crystals. The thermoelectric performance of Sb2Te3-Bi2Te3 solid solutions containing 0–100 mol % Bi2Te3 and Bi2Te3-Sb2Te3-Bi2-Bi2Se3 solid solutions containing 2, 4, or 7 mol % Bi2Se3 has been investigated. The Bi2Se3-doped crystals are found to have higher thermoelectric figures of merit compared to the undoped crystals. The optimal crystal compositions are selected for different temperatures in the range 100–400 K. 相似文献
7.
Phase equilibria in the Tl5Te3-Tl9BiTe6-Tl5Te2I system, containing ternary structural analogs of Tl5Te3, have been studied by differential thermal analysis, X-ray diffraction, microhardness tests, and emf measurements using concentration
cells with a thallium electrode. A number of T-x sections, the 760- and 800-K sections, and the liquidus and solidus projections of the phase diagram are constructed, and
the composition dependences of lattice parameters, microhardness, and emf are obtained. The results demonstrate that, despite
the presence of a liquid-liquid miscibility gap, the system contains a continuous series of solid solutions isostructural
with Tl5Te3. 相似文献
8.
L. D. Ivanova L. I. Petrova Yu. V. Granatkina V. S. Zemskov O. B. Sokolov S. Ya. Skipidarov N. I. Duvankov 《Inorganic Materials》2009,45(2):123-128
Extruded n-type materials based on Bi2Te3-Bi2Se3 alloys containing 6 to 40 mol % Bi2Se3 have been investigated using microstructural analysis and thermoelectric measurements at room temperature and in the range 100–400 K. Their electrical properties have been compared to those of single-crystal analogs. Compositions have been found at which the extruded materials offer the highest thermoelectric performance in different temperature ranges. 相似文献
9.
The (0001) surface morphology of Bi2Te3〈M〉 (M = Cu, Ni) layered crystals has been studied using atomic force microscopy (AFM) and scanning electron microscopy. Two-
and three-dimensional AFM images reveal charge transport paths through inhomogeneities created by nanostructured elements
(5–20 nm) in the Te(1)-Te(1) interlayer spaces. The nanoparticle distribution in the (0001) plane is similar to the arrangement
of model two-dimensional percolation clusters on a square lattice. The carrier mobility in Bi2Te3〈0.5 wt % Ni〉 crystals varies anomalously between 80 and 120 K. 相似文献
10.
L. E. Shelimova T. E. Svechnikova P. P. Konstantinov O. G. Karpinskii E. S. Avilov M. A. Kretova V. S. Zemskov 《Inorganic Materials》2007,43(2):125-131
Single crystals of the ternary layered compounds PbSb2Te4 (p-type) and PbBi4Te7 (n-type) have been grown by Czochralski pulling with melt supply through a floating crucible. The in-plane and out-of-plane thermoelectric power, electrical conductivity, and thermal conductivity of the PbSb2Te4 and PbBi4Te7 crystals and related alloys have been measured in the temperature range 85–340 K. The results attest to a significant thermoelectric anisotropy in the crystals, especially in the p-type material PbSb2Te4. 相似文献
11.
Caterina Lamuta Anna Cupolillo Antonio Politano Ziya S. Aliev Mahammad B. Babanly Evgueni V. Chulkov 《Nano Research》2016,9(4):1032-1042
Bismuth telluride (Bi2Te3) is one of the most important commercial thermoelectric materials. In recent years, the discovery of topologically protected surface states in Bi chalcogenides has paved the way for their application in nanoelectronics. Determination of the fracture toughness plays a crucial role for the potential application of topological insulators in flexible electronics and nanoelectromechanical devices. Using depth-sensing nanoindentation tests, we investigated for the first time the fracture toughness of bulk single crystals of Bi2Te3 topological insulators, grown using the Bridgman-Stockbarger method. Our results highlight one of the possible pitfalls of the technology based on topological insulators.
12.
Inhomogeneous State of the Bi<Subscript>2</Subscript>Te<Subscript>3</Subscript> Doped with Manganese
V. Sakhin E. Kukovitskii N. Garif’yanov Yu. Talanov G. Teitel’baum 《Journal of Superconductivity and Novel Magnetism》2017,30(1):63-67
Basing on electron spin resonance (ESR) data for Bi2Te3 doped by Mn ions we argue that this compound can be inhomogeneous and consists of two components with the different structures. Its main phase Bi 2?x Mn x Te 3 is intertwined with the microscopical inclusions of MnBi phase. The integral volume of these intermetal clusters is less than 1 % but nevertheless they exert the serious impact on the dynamic magnetic properties of the entire system. These inclusions are ferromagnetic with the Curie temperature of 630 K, while the main bulk phase Bi 2?x Mn x Te 3 has x= 0.05 orders at T c= 10 K (qualitatively this twophase picture is valid not only for this given x). Below this temperature two ferromagnetic phases coexist. Since the integral spontaneous polarization in MnBi phase is averaged out due to its random orientations in different clusters the time-reversal symmetry of Bi 2Te 3 doped by Mn ions is violated only at the low-temperature ferromagnetic transition. 相似文献
13.
Composite Bi2Te3/SiO2 nanoparticles of the core-shell type have been synthesized for the first time with a view to creating bulk composites possessing high thermoelectric figure of merit (conversion efficiency). It is suggested that bulk composited based on Bi2Te3/SiO2 nanoparticles will provide a combination of low lattice heat conduction due to SiO2 insulator and rather high electric conduction due to charge-carrier tunneling via dielectric spacers between adjacent Bi2Te3 semiconductor grains. The electric resistance of the composite increases with increasing temperature in the range of 130–300 K. This temperature dependence can be described in terms of a tunneling conduction model. 相似文献
14.
M. A. Abdullaev I. K. Kamilov D. Kh. Magomedova P. P. Khokhlachev 《Inorganic Materials》2007,43(12):1279-1283
Thermal annealing in oxygen has been used to produce photosensitive, rectifying In2O3/CuInSe2 structures. The optimal annealing temperature and time are 600–650 K and 40–60 min, respectively. 相似文献
15.
The Sn-Bi-Te system has been studied in the composition region SnTe-Bi2Te3-Te at temperatures from 300 to 430 K using emf measurements on reversible concentration cells of the type
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