High-temperature thermoelectric properties of W-substituted CaMnO3

2013 ◽  
Vol 1490 ◽  
pp. 3-8 ◽  
Author(s):  
Dimas S. Alfaruq ◽  
James Eilertsen ◽  
Philipp Thiel ◽  
Myriam H Aguirre ◽  
Eugenio Otal ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Soft Chemistry ◽  
Absolute Seebeck Coefficient

AbstractThe thermoelectric properties of W-substituted CaMn1-xWxO3-δ (x = 0.01, 0.03; 0.05) samples, prepared by soft chemistry, were investigated from 300 K to 1000 K and compared to Nb-substituted CaMn0.98Nb0.02O3-δ. All compositions exhibit both an increase in absolute Seebeck coefficient and electrical resistivity with temperature. Moreover, compared to the Nb-substituted sample, the thermal conductivity of the W-substituted samples was strongly reduced. This reduction is attributed to the nearly two times greater mass of tungsten. Consequently, a ZT of 0.19 was found in CaMn0.97W0.03O3-δ at 1000 K, which was larger than ZT exhibited by the 2% Nb-doped sample.

The thermoelectric properties of CoSb3 compound doped with Te and Sn synthesized at different pressure

2017 ◽  
Vol 31 (28) ◽  
pp. 1750261 ◽  
Author(s):  
Yiping Jiang ◽  
Xiaopeng Jia ◽  
Hongan Ma
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Raw Materials ◽  
Absolute Value ◽  
Dimensionless Figure Of Merit

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.

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.

Thermoelectric Properties of Doped Iron Disilicide

2000 ◽  
Vol 626 ◽  
Author(s):  
Jun-ichi Tani ◽  
Hiroyasu Kido
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Measured Temperature ◽  
Iron Disilicide ◽  
Measured Temperature Range ◽  
Temperature Range

ABSTRACTIn order to investigate the thermoelectric properties of Re-doped β-FeSi2 (Fe1-xRexSi2), Ir-doped β-FeSi2 (Fe1-xIrxSi2), and Pt-doped β-FeSi2 (Fe1-xPtxSi2), the electrical resistivity, the Seebeck coefficient, and the thermal conductivity of these samples have been measured in the temperature range between 300 and 1150 K. Fe1-xRexSi2 is p-type, while Fe1-xIrxSi2 and Fe1-xPt xSi2 are n-type over the measured temperature range. The solubility limits of dopant are estimated to be 0.2at% for Fe1-xRexSi2, 0.5at% for Fe1-xIrxSi2, and 1.9at% for Fe1-xPtxSi2. A maximum ZT value of 0.14 was obtained for Fe1-xPt xSi2 (x=0.03) at the temperature 847 K.

High-temperature thermoelectric properties of n-type BayNixCo4−xSb12

2001 ◽  
Vol 16 (12) ◽  
pp. 3343-3346 ◽  
Author(s):  
X. F. Tang ◽  
L. M. Zhang ◽  
R. Z. Yuan ◽  
L. D. Chen ◽  
T. Goto ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Electron Concentration ◽  
Lattice Thermal Conductivity ◽  
Filling Fraction ◽  
Ni Content ◽  
Increasing Temperature

Effects of Ba filling fraction and Ni content on the thermoelectric properties of n-type BayNixCo4−xSb12 (x = 0−0.1, y = 0−0.4) were investigated at temperature range of 300 to 900 K. Thermal conductivity decreased with increasing Ba filling fraction and temperature. When y was fixed at 0.3, thermal conductivity decreased with increasing Ni content and reached a minimum value at about x = 0.05. Lattice thermal conductivity decreased with increasing Ni content, monotonously (y ≤ 0.1). Electron concentration and electrical conductivity increased with increasing Ba filling fraction and Ni content. Seebeck coefficient increased with increasing temperature and decreased with increasing Ba filling fraction and Ni content. The maximum ZT value of 1.25 was obtained at about 900 K for n-type Ba0.3Ni0.05Co3.95Sb12.

Thermoelectric properties of S-doped Cu2Se materials synthesized by high-pressure and high-temperature method

2019 ◽  
Vol 34 (01) ◽  
pp. 2050006
Author(s):  
Lisha Xue ◽  
Chao Fang ◽  
Weixia Shen ◽  
Manjie Shen ◽  
Wenting Ji ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Thermoelectric Properties ◽  
Composition Change ◽  
Selenium Compounds ◽  
Competitive Effects ◽  
Temperature Method ◽  
Pressure Synthesis

High-pressure technique is an effective route to synthesize thermoelectric materials and tune transport properties simultaneously. In this work, S-doped copper–selenium compounds [Formula: see text], [Formula: see text] were successfully synthesized by high-pressure and high-temperature (HPHT) technology in just 30 min. [Formula: see text] samples show layered morphology composed of abundant pores and lattice defects. The appropriate S introduction ([Formula: see text] and 0.03) can effectively enhance Seebeck coefficient and reduce the thermal conductivity of [Formula: see text]. Compared with the pure [Formula: see text] sample, [Formula: see text] exhibits a 30% lower thermal conductivity, but the decline of power factor by the distinctly increased electrical resistivity at high temperature results in a smaller zT at temperature [Formula: see text] K. The variations of thermoelectric properties are resulted from the competitive effects between S-doping and actual composition change (Cu:S). It indicates that S-doping is not so effective in improving the zT value of [Formula: see text] materials by high-pressure synthesis.

Effect of Ho Doping on the High-Temperature Thermoelectric Properties of Ca3Co4O9-Based Oxides

2011 ◽  
Vol 228-229 ◽  
pp. 947-950
Author(s):  
Tao Zhu ◽  
Jun Min Zhou
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Solid Reaction

Ca3-xHoxCo4O9 (x=0.0, 0.15, 0.3, 0.45) samples were prepared using solid reaction and the effect of Ho doping on their high thermoelectric properties were investigated. The substitution of Ho for Ca resulted in an increase of both thermopower and electrical resistivity which could be attributed to the decrease of hole concentrations. The Ho-doped samples had lower thermal conductivity than Ca3Co4O9 due to their lower electronic and lattice thermal conductivity. The largest ZT values were attained in Ca2.7Ho0.3Co4O9 sample.

Effect of TiO2 additive on thermoelectric properties of SrTiO3

2019 ◽  
Vol 13 (02) ◽  
pp. 2051001
Author(s):  
Wei-Ying Yang ◽  
Ke-Xian Wang ◽  
Zheng Cao ◽  
Hao-Yang Yu ◽  
Xiao-Bo Ma ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Strontium Titanate ◽  
Thermoelectric Properties ◽  
Waste Heat ◽  
Molar Ratio ◽  
Composite Powders ◽  
The Impact

Strontium titanate ([Formula: see text] has the advantages of being non-toxic, environmentally friendly and high-temperature stable, and has potential application in waste heat power generation at medium and high temperature. To explore the impact of TiO2 on the thermoelectric properties of SrTiO3, we synthesized TiO2/La10Nbb10-STO composite powders by hydrothermal method using precursor solution of 10[Formula: see text]mol.% La and 10[Formula: see text]mol.% Nb co-doped STO (La10Nb10-STO) containing TiO2 nanopowders with different molar ratio. After cold pressing and sintering, composite bulk materials were obtained, and their microstructure and thermoelectric transport properties were analyzed. With the increasing TiO2, although the thermal conductivity of TiO2/La10Nb10-STO composite decreased and the Seebeck coefficient increased, the minimum thermal conductivity and the maximum Seebeck coefficient were 2.54[Formula: see text][Formula: see text][Formula: see text] and 215[Formula: see text][Formula: see text]V[Formula: see text][Formula: see text], respectively, at 1000[Formula: see text]K, but the power factor decreased at high temperature due to the apparent decrease of electrical conductivity, resulting in the ZT values being lower than that of La0Nb10-STO without TiO2 addition at high temperature. Significantly, the addition of TiO2 can improve the thermoelectric performance of strontium titanate at low temperature. This approach is expected to improve the ZT of SrTiO3-based thermoelectric material through additional controlling of electrical conductivity.

Thermoelectric Properties of Carbon Nanotubes Added n-type CoSb3 Compound

2011 ◽  
Vol 1314 ◽  
Author(s):  
Takashi Itoh ◽  
Masashi Tachikawa
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Phonon Scattering ◽  
Pulse Discharge ◽  
Molar Ratios ◽  
Performance Reduction ◽  
Compound Matrix

ABSTRACTCobalt triantimonide compounds are well known as materials with good thermoelectric properties over temperature range of 550-900 K. For further improving thermoelectric performance, reduction of thermal conductivity is required. In this study, we attempted to disperse carbon nanotubes (CNTs) homogeneously into the n-type CoSb3 compound for lowering lattice thermal conductivity by the phonon scattering. Powders of Co, Ni, Sb and Te were blended with molar ratios of n-type Co0.92Ni0.08Sb2.96Te0.04 compound, and the compound was synthesized through a pulse discharge sintering (PDS) process. After coarsely grinding the synthesized compound, CNTs were mixed with the compound powder at different mass% (0, 0.01, 0.05 and 0.1 mass%). Then, the mixture was mechanically ground with a planetary ball milling equipment. The ground composite powder was compacted and sintered by PDS. Thermoelectric properties (Seebeck coefficient, electrical resistivity and thermal conductivity) of the sintered samples were measured. It was confirmed that the fibrous CNTs existed homogeneously in the compound matrix. The absolute value of Seebeck coefficient slightly decreased with increase of CNT content. The minimum thermal conductivity was obtained at addition of 0.01mass%CNT, and the electrical resistivity was a little increased with CNT content. The maximum ZT of 0.98 was achieved at 853 K in the 0.01mass%CNT-added sample.

Thermoelectric properties of InxPbxCo4Sb12 prepared by HPHT

2016 ◽  
Vol 09 (01) ◽  
pp. 1650008 ◽  
Author(s):  
Le Deng ◽  
Li Bin Wang ◽  
Jie Ming Qin ◽  
Xiao Peng Jia ◽  
Hong An Ma
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Substantial Reduction ◽  
X Ray Diffraction ◽  
X Ray

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.

Thermoelectric properties of Ba-Ge based Type-III Clathrate Compounds

2006 ◽  
Vol 980 ◽  
Author(s):  
Jung-Hwan Kim ◽  
Norihiko L. Okamoto ◽  
Kyosuke Kishida ◽  
Katsushi Tanaka ◽  
Haruyuki Inui
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Type Iii ◽  
Clathrate Compounds ◽  
Coefficient Increase ◽  
Excess Electrons ◽  
Anisotropic Deformation

AbstractThe crystal structures and thermoelectric properties of Ba-Ge based type-III clathrate compounds in Ba-Al-Ge and Ba-In-Ge systems have been investigated as a function of Al and In content. The absolute values of electrical resistivity and Seebeck coefficient increase, while that of lattice thermal conductivity decreases with increasing Al and In content. The increase in electrical resistivity and Seebeck coefficient is discussed in terms of the number of the excess electrons deduced from the Zintl concept, on the other hand, the decrease in lattice thermal conductivity is discussed in terms of an anisotropic deformation of the open-dodecahedron cage encapsulating Ba atom. High ZT values of 0.74 and 0.87 are obtained at 780 and 580 °C for Ba24Al12Ge88 and Ba24In16Ge84, respectively.

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