scholarly journals Морфология и термоэлектрические свойства керамики твердых растворов γ-Gd-=SUB=-x-=/SUB=-Dy-=SUB=-1-x-=/SUB=-S-=SUB=-1.5-y-=/SUB=-

2020 ◽  
Vol 62 (4) ◽  
pp. 537
Author(s):  
А.В. Сотников ◽  
В.В. Баковец ◽  
Michihiro Ohta ◽  
А.Ш. Агажанов ◽  
С.В. Станкус
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Specific Surface ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Temperature Dependences

The temperature dependences of Seebeck coefficient, electrical conductivity (Т=300–873K), thermal conductivity and figure of merit (Т=300–770K) of polycrystalline samples of solid solutions based on gadolinium and dysprosium sulfides with γ-GdxDy1-xS1.49 (x=0.1, 0.2, 0.3, 0.4) composition were studied. It was established that samples morphological features, namely, the specific surface area of crystallites causing a change in the number of deformation centers determines the thermal conductivity of -GdxDy1-xS1.49, and it was found that there is an anomalous decrease in thermal conductivity for composition with х = 0.2. For this composition the lowest values of Seebeck coefficient -371 mkV/K at 873K, electrical resistivity 880 mkΩ∙m at 873K and thermal conductivity 0.68 ± 0.03 W/m·K at 770K were obtained, in this case the thermoelectric figure of merit reaches ZT = 0.23.

scholarly journals Термоэлектрические свойства твердых растворов (CuInSe-=SUB=-2-=/SUB=-)-=SUB=-1-x-=/SUB=-(In-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-)-=SUB=-x-=/SUB=-

2022 ◽  
Vol 56 (1) ◽  
pp. 38
Author(s):  
Ч.И. Абилов ◽  
М.Ш. Гасанова ◽  
Н.Т. Гусейнова ◽  
Э.К. Касумова
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Charge Carriers ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Mobility Of Charge Carriers ◽  
Temperature Dependences ◽  
Thermoelectric Coefficient

The results of studying the temperature dependences of electrical conductivity, thermoelectric coefficient, Hall mobility of charge carriers, total and electronic thermal conductivity, as well as phonon thermal resistance of alloys of (CuInSe2)1-x(In2Te3)x solid solutions at x=0.005 and 0.0075 are presented. The values ​​of these parameters for certain temperatures were used to calculate the values ​​of the thermoelectric figure of merit of the indicated compositions. It turned out that as the temperature rises, the thermoelectric figure of merit tends to grow strongly, from which it can be concluded that these materials can be used in the manufacture of thermoelements.

Thermoelectric Properties of Semiconducting Intermetallic Compounds: FeGa3and RuGa3

2003 ◽  
Vol 793 ◽  
Author(s):  
Y. Amagai ◽  
A. Yamamoto ◽  
C. H. Lee ◽  
H. Takazawa ◽  
T. Noguchi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
High Seebeck Coefficient

ABSTRACTWe report transport properties of polycrystalline TMGa3(TM = Fe and Ru) compounds in the temperature range 313K<T<973K. These compounds exhibit semiconductorlike behavior with relatively high Seebeck coefficient, electrical resistivity, and Hall carrier concentrations at room temperature in the range of 1017- 1018cm−3. Seebeck coefficient measurements reveal that FeGa3isn-type material, while the Seebeck coefficient of RuGa3changes signs rapidly from large positive values to large negative values around 450K. The thermal conductivity of these compounds is estimated to be 3.5Wm−1K−1at room temperature and decreased to 2.5Wm−1K−1for FeGa3and 2.0Wm−1K−1for RuGa3at high temperature. The resulting thermoelectric figure of merit,ZT, at 945K for RuGa3reaches 0.18.

scholarly journals Thermoelectric Lead Telluride with ZnO Nanoparticles

2015 ◽  
Vol 16 (1) ◽  
pp. 62-67
Author(s):  
O. M. Matkivsky
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Figure Of Merit ◽  
Lead Telluride ◽  
Thermoelectric Figure Of Merit ◽  
X Ray Diffraction ◽  
Thermoelectric Figure ◽  
X Ray ◽  
Zno Powder

An X-ray diffraction structural study and measurement of Seebeck coefficient (S), the electrical conductivity (σ) and thermal conductivity (χ) for Lead Telluride with nanoinclusions of ZnO. The calculated value of the specific thermoelectric power (S2σ) and thermoelectric figure of merit (ZT). It was established that the addition of ZnO powder Nanodispersed diameter grains (40-60) nm PbTe reduces the thermal conductivity of the material, and at 0.5 wt.% ZnO to an increase of lead telluride thermoelectric figure of merit to ZT≈1,3.

scholarly journals Влияние температуры спекания на термоэлектрические свойства соединения Bi-=SUB=-1.9-=/SUB=-Gd-=SUB=-0.1-=/SUB=-Te-=SUB=-3-=/SUB=-

2019 ◽  
Vol 53 (5) ◽  
pp. 620
Author(s):  
М.Н. Япрынцев ◽  
А.Е. Васильев ◽  
О.Н. Иванов
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Elemental Composition ◽  
Figure Of Merit ◽  
Sintering Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Total Thermal Conductivity ◽  
Thermoelectric Figure ◽  
Antisite Defects

AbstractThe regularities of the influence of the sintering temperature (750, 780, 810, and 840 K) on the elemental composition, crystal-lattice parameters, electrical resistivity, Seebeck coefficient, total thermal conductivity, and thermoelectric figure of merit of the Bi_1.9Gd_0.1Te_3 compound are investigated. It is established that the elemental composition of the samples during high-temperature sintering varies due to intense tellurium evaporation, which can lead to the formation of various point defects (vacancies and antisite defects) affecting the majority carrier (electron) concentration and mobility. The sintering temperature greatly affects the electrical resistivity of the samples, while the influence on the Seebeck coefficient and total thermal conductivity is much weaker. The largest thermoelectric figure of merit ( ZT ≈ 0.55) is observed for the sample sintered at 750 K.

Carrier Pocket Engineering for the Design of Low Dimensional Thermoelectrics with High Z3DT

2000 ◽  
Vol 626 ◽  
Author(s):  
Takaaki Koga ◽  
Stephen B. Cronin ◽  
Mildred S. Dresselhaus
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Engineering Model ◽  
Thermoelectric Figure ◽  
Model Calculations ◽  
Low Dimensional ◽  
Good Agreement

ABSTRACTThe concept of carrier pocket engineering applied to Si/Ge superlattices is tested experimentally. A set of strain-symmetrized Si(20Å)/Ge(20Å) superlattice samples were grown by MBE and the Seebeck coefficient S, electrical conductivity σ, and Hall coefficient were measured in the temperature range between 4K and 400K for these samples. The experimental results are in good agreement with the carrier pocket engineering model for temperatures below 300K. The thermoelectric figure of merit for the entire superlattice, Z3DT, is estimated from the measured S and σ, and using an estimated value for the thermal conductivity of the superlattice. Based on the measurements of these homogeneously doped samples and on model calculations, including the detailed scattering mechanisms of the samples, projections are made for δ-doped and modulation-doped samples [(001) oriented Si(20Å)/Ge(20Å) superlattices] to yield Z3DT ≈ 0.49 at 300K.

scholarly journals Термоэлектрические свойства твердого раствора n-Mg-=SUB=-2-=/SUB=-(SiGe)-=SUB=-0.8-=/SUB=-Sn-=SUB=-0.2-=/SUB=-

2019 ◽  
Vol 53 (5) ◽  
pp. 612
Author(s):  
Г.Н. Исаченко ◽  
А.Ю. Самунин ◽  
П.П. Константинов ◽  
А.А. Касьянов ◽  
А. Масалимов
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Magnesium Silicide ◽  
Thermoelectric Figure Of Merit ◽  
High Concentration ◽  
Thermoelectric Figure ◽  
Lower Figure ◽  
Temperature Dependences

AbstractHigh values of the thermoelectric figure of merit ( ZT = 1.5) in Mg_2Si–Mg_2Sn solid solutions are caused by a low thermal conductivity and a complex band structure, which is optimal at the ratio of solid-solution components of 40% Mg_2Si and 60% Mg_2Sn. However, the presence of magnesium stannide in a high concentration impairs the mechanical properties and chemical stability of the material limiting its application at high temperatures. Magnesium silicide has a higher stability but a lower figure of merit. The figure of merit is much lower in Mg_2Si-rich solid solutions and amounts to ZT ~ 1. The possibility of increasing ZT in the Mg_2Si_0.8Sn_0.2 solid solution with the additional inclusion of Mg_2Ge in small quantities is investigated here. Samples of Mg_2(Si_1 –_ x Ge_ x )_0.8Sn_0.2 ( x < 0.03) solid solution are prepared by hot pressing. The temperature dependences of the coefficients of the thermoelectric power, electrical conductivity, and thermal conductivity are measured in the range of 300–800 K. An increase in the thermoelectric figure of merit to ZT = 1.1 is shown at T = 800 K in the Mg_2Si_0.78Ge_0.02Sn_0.2〈Sb〉 solid solution.

Thermoelectric Properties of Ni Doped P-Type BiCuSeO Oxyselenides

2014 ◽  
Vol 602-603 ◽  
pp. 906-909 ◽  
Author(s):  
Yao Chun Liu ◽  
Jun Fu Liu ◽  
Bo Ping Zhang ◽  
Yuan Hua Lin
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Layer Structure ◽  
Thermoelectric Figure Of Merit ◽  
Ni Doping ◽  
Thermoelectric Figure ◽  
P Type

We report on the effect of Ni doping on the thermoelectric properties of p-type BiCuSeO oxyselenide, with layer structure composed of conductive (Cu2Se2)2-layers alternately stacked with insulating (Bi2O2)2+layers along c axis. After doping with Ni, enhanced electrical conductivity coupled with a moderate Seebeck coefficient leads to a power factor of ~231 μwm-1K-2at 873 K. Coupled to low thermal conductivity, ZT at 873 K is increased from 0.35 for pristine BiCuSeO to 0.39 for Bi0.95Ni0.05CuSeO. However, the efficiency of Ni doping in the insulating (Bi2O2)2+layer is low, and this doping only leads to a limited increase of the hole carriers concentration. Therefore Ni doped BiCuSeO has relatively low electrical conductivity which makes its thermoelectric figure of merit much lower than that of Ca, Sr, Ba and Pb doped BiCuSeO.

scholarly journals Термоэлектрические свойства нанокомпозитного Bi-=SUB=-0.45-=/SUB=-Sb-=SUB=-1.55-=/SUB=-Te-=SUB=-2.985-=/SUB=- с микрочастицами SiO-=SUB=-2-=/SUB=-

2019 ◽  
Vol 53 (6) ◽  
pp. 751
Author(s):  
А.А. Шабалдин ◽  
П.П. Константинов ◽  
Д.А. Курдюков ◽  
Л.Н. Лукьянова ◽  
А.Ю. Самунин ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Electrical Conductivity ◽  
Wide Temperature Range ◽  
Figure Of Merit ◽  
Nanostructured Material ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Efficiency ◽  
Thermoelectric Figure ◽  
P Type

AbstractNanocomposite thermoelectrics based on Bi_0.45Sb_1.55Te_2.985 solid solution of p -type conductivity are fabricated by the hot pressing of nanopowders of this solid solution with the addition of SiO_2 microparticles. Investigations of the thermoelectric properties show that the thermoelectric power of the nanocomposites increases in a wide temperature range of 80–420 K, while the thermal conductivity considerably decreases at 80–320 K, which, despite a decrease in the electrical conductivity, leads to an increase in the thermoelectric efficiency in the nanostructured material without the SiO_2 addition by almost 50% (at 300 K). When adding SiO_2, the efficiency decreases. The initial thermoelectric fabricated without nanostructuring, in which the maximal thermoelectric figure of merit ZT = 1 at 390 K, is most efficient at temperatures above 350 K.

scholarly journals N-Type Bismuth Telluride Nanocomposite Materials Optimization for Thermoelectric Generators in Wearable Applications

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1529 ◽  
Author(s):  
Amin Nozariasbmarz ◽  
Jerzy S. Krasinski ◽  
Daryoosh Vashaee
Keyword(s):  
Thermal Conductivity ◽  
Power Generation ◽  
Seebeck Coefficient ◽  
Figure Of Merit ◽  
Microwave Cavity ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Efficient Operation ◽  
High Seebeck Coefficient ◽  
Body Heat

Thermoelectric materials could play a crucial role in the future of wearable electronic devices. They can continuously generate electricity from body heat. For efficient operation in wearable systems, in addition to a high thermoelectric figure of merit, zT, the thermoelectric material must have low thermal conductivity and a high Seebeck coefficient. In this study, we successfully synthesized high-performance nanocomposites of n-type Bi2Te2.7Se0.3, optimized especially for body heat harvesting and power generation applications. Different techniques such as dopant optimization, glass inclusion, microwave radiation in a single mode microwave cavity, and sintering conditions were used to optimize the temperature-dependent thermoelectric properties of Bi2Te2.7Se0.3. The effects of these techniques were studied and compared with each other. A room temperature thermal conductivity as low as 0.65 W/mK and high Seebeck coefficient of −297 μV/K were obtained for a wearable application, while maintaining a high thermoelectric figure of merit, zT, of 0.87 and an average zT of 0.82 over the entire temperature range of 25 °C to 225 °C, which makes the material appropriate for a variety of power generation applications.

Thermoelectric Properties of a Wide–Gap Chalcopyrite Compound AgInSe2

2012 ◽  
Vol 519 ◽  
pp. 188-192 ◽  
Author(s):  
P.Z. Ying ◽  
H. Zhou ◽  
Y.L. Gao ◽  
Y.Y. Li ◽  
Y.P. Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Chemical Compositions ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Remarkable Improvement ◽  
Wide Gap ◽  
Chalcopyrite Compound

Here we report the thermoelectric properties of a wide–gap chalcopyrite compound AgInSe2, and observed the remarkable improvement in electrical conductivity σ, due to the bandgap (Eg = 1.12 eV) reduction compared to In2Se3. The improvement in σ is directly responsible for the enhancement of thermoelectric figure of merit ZT, though the thermal conductivity is much higher at 500 ~ 724 K. The maximum ZT value is 0.34 at 724 K, increasing by a factor of 4, indicating that this chalcopyrite compound is of a potential thermoelectric candidate if further optimizations of chemical compositions and structure are made.

Sign in / Sign up

Export Citation Format

Share Document