High Temperature Thermoelectric Property of Sr-Filled Skutterudite SryCo4Sb12

2007 ◽  
Vol 336-338 ◽  
pp. 842-845
Author(s):  
Xue Ying Zhao ◽  
Xun Shi ◽  
Li Dong Chen ◽  
Sheng Qiang Bai ◽  
Wen Bing Zhang ◽  
...  

Sr-filled skutterudite compounds SryCo4Sb12 (y=0-0.20) were synthesized by melting method. XRD and EPMA results revealed that the obtained samples are single skutterudite phase with homogeneous chemical composition. The lattice parameters increase linearly with increasing Sr content in the range of y=0-0.20. The thermal conductivity, electrical conductivity and Seebeck coefficient were measured in the temperature range of 300-850K. The measurement of Hall effect was performed by Van de Pauw method at room temperature. The obtained Sr-filled skutterudite exhibits n-type conduction. The absolute value of the Seebeck coefficient of SryCo4Sb12 decreases with the increase of Sr content. The electrical conductivity increases with the increase of Sr content. The lattice thermal conductivity of SryCo4Sb12 is significantly depressed as compared with unfilled CoSb3. The maximum dimensionless thermoelectric figure of merit is 0.7 for Sr0.20Co4Sb12 at 850K. Further optimization of chemical composition would improve the thermoelectric performance.

2015 ◽  
Vol 16 (1) ◽  
pp. 62-67
Author(s):  
O. M. Matkivsky

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.


2000 ◽  
Vol 626 ◽  
Author(s):  
Takaaki Koga ◽  
Stephen B. Cronin ◽  
Mildred S. Dresselhaus

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.


2020 ◽  
Vol 62 (4) ◽  
pp. 537
Author(s):  
А.В. Сотников ◽  
В.В. Баковец ◽  
Michihiro Ohta ◽  
А.Ш. Агажанов ◽  
С.В. Станкус

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.


2014 ◽  
Vol 602-603 ◽  
pp. 906-909 ◽  
Author(s):  
Yao Chun Liu ◽  
Jun Fu Liu ◽  
Bo Ping Zhang ◽  
Yuan Hua Lin

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.


2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).


2003 ◽  
Vol 793 ◽  
Author(s):  
Y. Amagai ◽  
A. Yamamoto ◽  
C. H. Lee ◽  
H. Takazawa ◽  
T. Noguchi ◽  
...  

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.


Author(s):  
А.А. Шабалдин ◽  
П.П. Константинов ◽  
Д.А. Курдюков ◽  
Л.Н. Лукьянова ◽  
А.Ю. Самунин ◽  
...  

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.


Author(s):  
Ч.И. Абилов ◽  
М.Ш. Гасанова ◽  
Н.Т. Гусейнова ◽  
Э.К. Касумова

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.


2008 ◽  
Vol 368-372 ◽  
pp. 547-549
Author(s):  
Jun Jiang ◽  
Ya Li Li ◽  
Gao Jie Xu ◽  
Ping Cui ◽  
Li Dong Chen

In the present study, n-type (Bi2Se3)x(Bi2Te3)1-x crystals with various chemical compositions were fabricated by the zone melting method. Thermoelectric properties, including Seebeck coefficient (α), electrical conductivity (σ) and thermal conductivity (κ), were measured in the temperature range of 300-500 K. The influence of the variations of Bi2Te3 and Bi2Se3 content on thermoelectric properties was studied. The increase of Bi2Se3 content (x) caused an increase in carrier concentration and thus an increase of σ and a decrease of α. The maximum figure of merit (ZT = α2σT/κ) of 0.87 was obtained at about 325 K for the composition of 93%Bi2Te3-7%Bi2Se3 with doping TeI4.


Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 140 ◽  
Author(s):  
Ji Hoon Kim ◽  
Seunggun Yu ◽  
Sang Won Lee ◽  
Seung-Yong Lee ◽  
Keun Soo Kim ◽  
...  

Recently, two-dimensional tungsten disulfide (WS2) has attracted attention as a next generation thermoelectric material due to a favorable Seebeck coefficient. However, its thermoelectric efficiency still needs to be improved due to the intrinsically low electrical conductivity of WS2. In the present study, thermoelectric properties of WS2 hybridized with highly conductive single-walled carbon nanohorns (SWCNHs) were investigated. The WS2/SWCNH nanocomposites were fabricated by annealing the mixture of WS2 and SWCNHs using a high-frequency induction heated sintering (HFIHS) system. By adding SWCNHs to WS2, the nanocomposites exhibited increased electrical conductivity and a slightly decreased Seebeck coefficient with the content of SWCNHs. Hence, the maximum power factor of 128.41 μW/mK2 was achieved for WS2/SWCNHs with 0.1 wt.% SWCNHs at 780 K, resulting in a significantly improved thermoelectric figure of merit (zT) value of 0.027 compared to that of pristine WS2 with zT 0.017.


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