High-temperature Thermoelectric Properties of the Ca1-xBixMnO3 System

2002 ◽  
Vol 17 (5) ◽  
pp. 1092-1095 ◽  
Author(s):  
Gaojie Xu ◽  
Ryoji Funahashi ◽  
Ichiro Matsubara ◽  
Masahiro Shikano ◽  
Yuqin Zhou

Polycrystalline samples of Ca1-xBixMnO3 (0.02 ≤ x ≤ 0.20) were studied by means of x-ray diffraction, electrical resistivity (ρ), thermoelectric power (S), and thermal conductivity (κ) at high temperature. Bi doping leads to the lattice parameters a, b, and c increasing. And the ρ and the absolute value of S decrease rapidly with Bi doping. The largest power factor, S2/ρ, is obtained in the x = 0.04 sample, which is 3.6×10−4 Wm−1 K−2 at 400 K. The figures of merit (Z = S2/ρκ) for this sample and 1.0×10−4 and 0.86 × 10−4 K−1 at 600 and 1000 K, respectively.

2015 ◽  
Vol 29 (27) ◽  
pp. 1550189
Author(s):  
Q. R. Hou ◽  
B. F. Gu ◽  
Y. B. Chen

In this paper, we report a large enhancement in the thermoelectric power factor in CrSi2 film via Si:B (1 at.% B content) addition. The Si:B-enriched CrSi2 films are prepared by co-sputtering CrSi2 and heavily B-doped Si targets. Both X-ray diffraction patterns and Raman spectra confirm the formation of the crystalline phase CrSi2. Raman spectra also indicate the crystallization of the added Si:B. With the addition of Si:B, the electrical resistivity [Formula: see text] decreases especially at low temperatures while the Seebeck coefficient [Formula: see text] increases above 533 K. As a result, the thermoelectric power factor, [Formula: see text], is greatly enhanced and can reach [Formula: see text] at 583 K, which is much larger than that of the pure CrSi2 film.


2007 ◽  
Vol 1044 ◽  
Author(s):  
Veronique Da Ros ◽  
Juliusz Leszczynski ◽  
Bertrand Lenoir ◽  
Anne Dauscher ◽  
Christophe Candolfi ◽  
...  

AbstractThe preparation of partially filled n-type InxCo4Sb12 skutterudite compounds has been recently reported. The results were particularly promising, the materials exhibiting a ZT value far higher than one at moderated temperature. In this paper, we propose to investigate another way to tune the electrical and thermal properties by substituting Co atoms by Ni atoms in InxCo4Sb12. InxCo4-yNiySb12 polycrystalline samples have been prepared by a conventional metallurgical route. Structural analyses have been carried out by X-ray diffraction. The chemical composition and micro-homogeneity have been checked by electron probe microanalysis. Measurements of the electrical resistivity, thermoelectric power and thermal conductivity have been performed between 300 and 800 K. The influence of the presence of Ni on the thermoelectric properties of InxCo4Sb12 compounds is presented and discussed.


2005 ◽  
Vol 886 ◽  
Author(s):  
Julio E. Rodriguez

ABSTRACTMeasurements of Seebeck coefficient, S(T) and electrical resistivity, ρ(T) on polycrystalline La2−xSrxCuO4+d(LSCO) (0<x≤0.2) samples are reported. The Seebeck coefficient is positive in whole measured temperature range (77K and 300K) and it decreases with Sr content. At room temperature S(T) changes from 400 μ/K for the samples with the lowest levels of Sr to 30 μV/K for the samples with the highest Sr levels. The behavior of S(T) fits to Heikes model, which describes the behavior of Seebeck coefficient in systems where the correlated hopping is present. With the Sr content, the electrical resistivity changes its behavior from semiconducting to metallic and it took values from 2.4 to 10−3Ωcm. From S(T) and rho(T) measurements the thermoelectric power factor, PF was obtained. The maximum values for PF were about 5 μW/K2cm in the samples where x= 0.03, which are comparable to the typical values for conventional thermoelectric semiconductors. The structural and morphological properties of the samples were studied by x-ray diffraction analysis and Scanning Electron Microscopy (SEM) respectively. The behavior of transport properties opens de possibility of considering this family of perovskite-compounds as a thermoelectric material which works below room temperature.


2008 ◽  
Vol 476 (1-2) ◽  
pp. 60-68 ◽  
Author(s):  
Fabien Bruneseaux ◽  
Elisabeth Aeby-Gautier ◽  
Guillaume Geandier ◽  
Julien Da Costa Teixeira ◽  
Benoît Appolaire ◽  
...  

2017 ◽  
Vol 23 (3) ◽  
pp. 257 ◽  
Author(s):  
Katsuhiko Nishimura ◽  
Takahiro Namiki ◽  
Tsuyoshi Ikeno ◽  
Yuichi Yamamoto ◽  
Wayne D. Hutchison

<p class="AMSmaintext1"><span lang="EN-GB">Magnetic and transport properties of cold rolled SUS304 stainless steels were investigated via measurements of X-ray diffraction, magnetization, thermoelectric power (TEP), thermal conductivity and electrical resistivity from 300 K down to low temperatures.   Saturation magnetizations at 300 K were 1.6, 37.5, 72.6 and 105.6 emu/g for rolled thickness reduction ratios of 0, 33, 50 and 75%, respectively.  The thermoelectric power (TEP) values at 300 K were found to be -1.3, -0.4, 1.6 and 2.9 </span><span lang="EN-GB">m</span><span lang="EN-GB">V/K for the reduction ratios of 0, 33, 50 and 75%, respectively.  Least-squares fits of the experimental data predicted a saturation magnetization of 141 emu/g and a thermoelectric power of 4.3 </span><span lang="EN-GB">m</span><span lang="EN-GB">V/K for SUS304 in the martensite phase at 300 K.</span></p>


2016 ◽  
Vol 09 (01) ◽  
pp. 1650008 ◽  
Author(s):  
Le Deng ◽  
Li Bin Wang ◽  
Jie Ming Qin ◽  
Xiao Peng Jia ◽  
Hong An Ma

We prepared InxPbxCo4Sb[Formula: see text] by high-pressure and high-temperature (HPHT) method. Samples were characterized by X-ray diffraction (XRD), electron microprobe analysis and thermoelectric properties measurements. The Seebeck coefficient, electrical resistivity and thermal conductivity of InxPbxCo4Sb[Formula: see text] samples were all performed in the temperature range of 323–723[Formula: see text]K. With the increasing synthetic pressure, the Seebeck coefficient of In[Formula: see text]Pb[Formula: see text]Co4Sb[Formula: see text] samples, which synthesized between 1.5 GPa–2.3 GPa, showed an obvious increase while the thermal conductivity exhibited a substantial reduction.


2013 ◽  
Vol 357-360 ◽  
pp. 1353-1357
Author(s):  
Xiao Li Ji ◽  
Zhuo Chen

High-temperature foam ceramics were produced from sludge, Zhongxiang porcelain sand, shale and sand, with addition of SiC 0.15%~0.40% as foaming agent, respectively, sintered at 1130°C~1160°C. The phase composition and micro structure of sintered samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and density, compressive strength and thermal conductivity were evaluated. The results showed that the main phase of amorphous phase plagioclase in sintered samples and interior of samples with a large number of uniformly distributed closed pores, rose sintering temperature and increased SiC addition leading to pores size enlarged and density, compressive strength and thermal conductivity diminished.


2017 ◽  
Vol 31 (28) ◽  
pp. 1750261 ◽  
Author(s):  
Yiping Jiang ◽  
Xiaopeng Jia ◽  
Hongan Ma

The skutterudite CoSb[Formula: see text]Te[Formula: see text]Sn[Formula: see text] compound was synthesized successfully by high pressure and high temperature (HPHT) method using Co, Sb, Te and Sn powder as raw materials. The effects of pressure on its structure and the thermoelectric properties are investigated systematically from 300 K to 800 K. The electrical resistivity and the absolute value of the Seebeck coefficient for the sample increases with rising synthetic pressure. The thermal conductivity of the sample decreases with synthetic pressure and temperature rising in the range of 300–800 K. In this study, the maximum dimensionless figure of merit (ZT) value of 1.17 has been achieved at 793 K, 3 GPa for this thermoelectric material.


2006 ◽  
Vol 20 (29) ◽  
pp. 4885-4890
Author(s):  
R. SELVA VENNILA ◽  
S. REZA GHORBANI ◽  
N. VICTOR JAYA

High pressure-high temperature electrical resistivity study on composition-controlled Nd 0.9 Ca 0.1 Ba 2 Cu 3 O 7-δ high T c superconductor (HTSC) is carried out by a four-probe technique using Bridgman anvils. A simple heating coil arrangement is used for heating the samples. Electrical resistivity behavior under pressure (up to a maximum of 8 GPa) at various temperatures (up to a maximum of 523 K) were studied and reported in this paper. Simulation of energy dispersive X-ray diffraction confirms substitution of calcium at the Nd site of Nd -123. Variation of the electrical resistivity under pressure is compared with that of the structural changes and the bulk modulus was determined.


2014 ◽  
Vol 787 ◽  
pp. 210-214 ◽  
Author(s):  
Yi Li ◽  
Jian Liu ◽  
Chun Lei Wang ◽  
Wen Bin Su ◽  
Yuan Hu Zhu ◽  
...  

The thermoelectric properties of Sr0.61Ba0.39Nb2O6 ceramics, reduced in various conditions, were investigated in the temperature range from 323K to 1073K. Both the electrical resistivity and the absolute Seebeck coefficient decreased with the deepening degree of oxygen-reduction. However, the decrease of the electrical resistivity had a major influence on the thermoelectric power factor. Therefore, the more heavily reduced sample can gain the higher value of thermoelectric power factor. It has been observed that the thermal conductivity increased with the deepening degree of oxygen-reduction, which indicates that the scattering of the oxygen vacancies produced by reduction does not play a dominant role in the thermal conduction. In spite of the increase of the thermal conductivity, the oxygen-reduction still promoted the thermoelectric figure of merit via the increase of the thermoelectric power factor. And the most heavily reduced Sr0.61Ba0.39Nb2O6 ceramic has the highest thermoelectric figure of merit (~0.18 at 1073 K) among all the samples.


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