Charge Transport and Thermoelectric Properties of Sn-Doped Tetrahedrites Cu12Sb4-ySnyS13

In this study, tetrahedrite compounds doped with Sn were prepared by mechanical alloying and hot pressing, and their charge transport and thermoelectric properties were analyzed. X-ray diffraction analysis revealed that both the synthetic powders and sintered bodies were synthesized as a single tetrahedrite phase without secondary phases. Densely sintered specimens were obtained with relatively high densities of 99.5%-100.0% of the theoretical density, and the component elements were distributed uniformly. Sn was successfully substituted at the Sb site, and the lattice constant increased from 1.0348 to 1.0364 nm. Positive signs of the Hall and Seebeck coefficients confirmed that the Sn-doped tetrahedrites were p-type semiconductors. The carrier concentration decreased from 1.28 × 1019 to 1.57 × 1018 cm-3 as the Sn content decreased because excess electrons were supplied by doping with Sn4+ at the Sb3+ site of the tetrahedrite. The Seebeck coefficient increased with increasing Sn content, and Cu12Sb3.6Sn0.4S13 exhibited maximum values of 238-270 µVK-1 at temperatures of 323-723 K. However, the electrical conductivity decreased as the amount of Sn doping increased. Thus, Cu12Sb3.9Sn0.1S13 exhibited the highest electrical conductivity of (2.24-2.40) × 104 Sm-1 at temperatures of 323-723 K. A maximum power factor of 0.73 mWm-1K-2 was achieved at 723 K for Cu12Sb3.9Sn0.1S13. Sn substitution reduced both the electronic and lattice thermal conductivities. The lowest thermal conductivity of 0.49-0.60 Wm-1K-1 was obtained at temperatures of 323-723 K for Cu12Sb3.6Sn0.4S13, where the lattice thermal conductivity was dominant at 0.49-0.57 Wm-1K-1. As a result, a maximum dimensionless figure of merit of 0.66 was achieved at 723 K for Cu12Sb3.9Sn0.1S13.

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Study on Phases and Thermoelectric Properties of Bulk Fe4Sb12 and Fe3CoSb12 Prepared by Milling and Sintering

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.121-126.1526 ◽

2011 ◽

Vol 121-126 ◽

pp. 1526-1529

Author(s):

Ke Gao Liu ◽

Jing Li

Keyword(s):

Thermoelectric Properties ◽

Impurity Phase ◽

Semiconductor Materials ◽

Thermal Constant ◽

X Ray Diffraction ◽

X Ray ◽

Seebeck Coefficients ◽

Maximum Value ◽

Type Semiconductor ◽

P Type

Bulk Fe4Sb12 and Fe3CoSb12 were prepared by sintering at 600 °C. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk samples are skutterudite with impurity phase FeSb2. The electric resistivities of the samples increase with temperature rising at 100~500 °C. The bulk samples are P-type semiconductor materials. The Seebeck coefficients of the bulk Fe4Sb12 are higher than those of bulk Fe3CoSb12 samples at 100~200 °C but lower at 300~500 °C. The power factor of the bulk Fe4Sb12 samples decreases with temperature rising while that of bulk Fe3CoSb12 samples increases with temperature rising at 100~500 °C. The thermal conductivities of the bulk Fe4Sb12 samples are relatively higher than those of and Fe3CoSb12, which maximum value is up to 0.0974 Wm-1K-1. The ZT value of bulk Fe3CoSb12 increases with temperature rising at 100~500 °C, the maximum value is up to 0.031.The ZT values of the bulk Fe4Sb12 samples are higher than those of bulk Fe3CoSb12 at 100~300 °C while lower at 400~500 °C.

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Synthesis and Thermoelectric Properties of Co4-XFeXSb12-YSnY Skutterudites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.695.65 ◽

2011 ◽

Vol 695 ◽

pp. 65-68 ◽

Cited By ~ 1

Author(s):

Kwan Ho Park ◽

Il Ho Kim

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Phonon Scattering ◽

Charge Compensation ◽

Fe Doping ◽

Sn Doping ◽

Double Doping

Co4-xFexSb12-ySny skutterudites were synthesized by mechanical alloying and hot pressing, and thermoelectric properties were examined. The carrier concentration increased by doping and thereby the electrical conductivity increased compared with intrinsic CoSb3. Every specimen had a positive Seebeck coefficient. Fe doping caused a decrease in the Seebeck coefficient but it could be enhanced by Fe/Sn double doping possibly due to charge compensation. The thermal conductivity was desirably very low and this originated from ionized impurity-phonon scattering. Thermoelectric properties were improved remarkably by Fe/Sn doping, and a maximum figure of merit, ZT = 0.5 was obtained at 723 K in the Co3FeSb11.2Sn0.8 specimen.

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Thermoelectric Properties of Co1-xNbxSb3 Prepared by Induction Melting

Materials Science Forum ◽

10.4028/www.scientific.net/msf.486-487.602 ◽

2005 ◽

Vol 486-487 ◽

pp. 602-605 ◽

Cited By ~ 1

Author(s):

J.B. Park ◽

S.-W. You ◽

K.W. Cho ◽

J.I. Lee ◽

Soon Chul Ur ◽

...

Keyword(s):

Electrical Conductivity ◽

Thermoelectric Properties ◽

Induction Melting ◽

Thermoelectric Power Factor ◽

Seebeck Coefficients ◽

Maximum Value ◽

High Temperature Maximum ◽

Higher Temperature ◽

Nb Doping ◽

P Type

Induction melting was attempted to prepare the undoped and Nb-doped CoSb3 compounds, and their thermoelectric properties were investigated. Single phase d-CoSb3 was successfully obtained by induction melting and subsequent annealing at 400°C for 2 hours in vacuum. The positive signs of Seebeck coefficients for all the specimens revealed that Nb atoms acted as p-type dopants by substituting Co atoms. Electrical conductivity decreased and then increased withincreasing temperature, indicating mixed behaviors of metallic and semiconducting conductions. Electrical conductivity increased by Nb doping, and it was saturated at high temperature. Maximum value of the thermoelectric power factor was shifted to higher temperature with the increasing amount of Nb doping, mainly originated from the Seebeck coefficient variation.

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Влияние легирования ванадием на термоэлектрические свойства сплавов Гейслера Fe-=SUB=-2-=/SUB=-Ti-=SUB=-1-x-=/SUB=-V-=SUB=-x-=/SUB=-Sn

Физика и техника полупроводников ◽

10.21883/ftp.2019.06.47727.36 ◽

2019 ◽

Vol 53 (6) ◽

pp. 777

Author(s):

А.И. Таранова ◽

А.П. Новицкий ◽

А.И. Воронин ◽

С.В. Таскаев ◽

В.В. Ховайло

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Experimental Study ◽

Seebeck Coefficient ◽

Transport Properties ◽

Thermoelectric Properties ◽

Pristine Sample ◽

Electrical Conductivity Behavior ◽

P Type ◽

Conductivity Behavior

In this work the results of an experimental study of Fe2Ti1-xVxSn alloys (x = 0; 0.06; 0.15; 0.2) are presented. According to the temperature dependencies of the electrical conductivity, Seebeck coefficient and thermal conductivity, it is established, that the studied compositions exhibit transport properties typical for semiconductors. The substitution of V at the Ti site leads to a change of the p-type electrical conductivity behavior to n-type; the pristine sample of Fe2TiSn has the best thermoelectric properties.

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Study on Phases and Thermoelectric Properties of Bulk FexCo4-xSb12 Sintered by MM-SPS

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.179-180.294 ◽

2011 ◽

Vol 179-180 ◽

pp. 294-297

Author(s):

Ke Gao Liu ◽

Shi Lei

Keyword(s):

Thermoelectric Properties ◽

Thermal Constant ◽

X Ray Diffraction ◽

Semiconducting Materials ◽

X Ray ◽

Seebeck Coefficients ◽

Plasma Sintering ◽

Electrical Resistivities ◽

Spark Plasma ◽

P Type

Bulk FexCo4-xSb12 with x varies from 0.1 to 2.0 were prepared by mechanical milling (MM) and spark plasma sintering (SPS). The phases of the products were characterized by X-ray diffraction (XRD) and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk FexCo4-xSb12 are skutterudite. The electrical resistivities of the products increase first and then decrease. The Seebeck coefficients ( ) are negative when x=0.1 at 100 °C and 200 °C while positive at 300~500 °C. The products with x=0.5~2.0 at 100~500 °C are P type semiconducting materials due to their positive values. The thermal conductivities of most samples increase first and then decrease with x increasing and the maximum is up to 0.39 Wm-1K-1 when x=1.0. The ZT values at 200~500 °C increase first and then decrease with x increasing when x=0.1~1.0 and x=1.0~2.0 respectively and the maximum ZT value is 0.196 when x=1.5 at 400 °C.

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THERMOELECTRIC PROPERTIES OF p-TYPE SKUTTERUDITES (Pr0.25Nd0.75)xFe3CoSb12 BY LEVITATION MELTING AND SPARK PLASMA SINTERING

Functional Materials Letters ◽

10.1142/s1793604713400067 ◽

2013 ◽

Vol 06 (05) ◽

pp. 1340006 ◽

Cited By ~ 2

Author(s):

JINGSHU XU ◽

CHENGUANG FU ◽

JIAN XIE ◽

XINBING ZHAO ◽

TIEJUN ZHU

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Spark Plasma Sintering ◽

Thermoelectric Properties ◽

Lattice Thermal Conductivity ◽

Levitation Melting ◽

Plasma Sintering ◽

Spark Plasma ◽

P Type

The p-type skutterudite compounds of ( Pr 0.25 Nd 0.75)x Fe 3 CoSb 12 (x = 0.67–0.78) have been successfully synthesized by levitation melting followed by annealing and spark plasma sintering. The thermoelectric properties have been characterized by the measurements of Seebeck coefficient, electrical conductivity and thermal conductivity in the temperature range from 300 K to 850 K. The improvement in the thermoelectric properties was realized due to the reduction in the lattice thermal conductivity when the voids were partially filled by Pr 0.25 Nd 0.75. The maximum ZT value of ~ 0.83 for ( Pr 0.25 Nd 0.75)0.76 Fe 3 CoSb 12 was obtained at 700 K.

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Thermoelectric Properties of Co1-xNbxSb3 Prepared by Induction Melting

Materials Science Forum ◽

10.4028/www.scientific.net/msf.486-487.554 ◽

2005 ◽

Vol 486-487 ◽

pp. 554-557

Author(s):

J.B. Park ◽

S.-W. You ◽

K.W. Cho ◽

J.I. Lee ◽

Soon Chul Ur ◽

...

Keyword(s):

Electrical Conductivity ◽

Thermoelectric Properties ◽

Induction Melting ◽

Thermoelectric Power Factor ◽

Seebeck Coefficients ◽

High Temperature Maximum ◽

Higher Temperature ◽

Nb Doping ◽

Increasing Temperature ◽

P Type

Induction melting was attempted to prepare the undoped and Nb-doped CoSb3 compounds, and their thermoelectric properties were investigated. Single phase d-CoSb3 was successfully obtained by induction melting and subsequent annealing at 400°C for 2 hours in vacuum. The positive signs of Seebeck coefficients for all the specimens revealed that Nb atoms acted as p-type dopants by substituting Co atoms. Electrical conductivity decreased and then increased with increasing temperature, indicating mixed behaviors of metallic and semiconducting conductions. Electrical conductivity increased by Nb doping, and it was saturated at high temperature. Maximum value of the thermoelectric power factor was shifted to higher temperature with the increasing amount of Nb doping, mainly originated from the Seebeck coefficient variation.

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Effect of CuO-TiO2 Eutectic on Thermal and Electrical Conductivities of CaCu3Ti4O12 Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.881.117 ◽

2016 ◽

Vol 881 ◽

pp. 117-122

Author(s):

Flavia dos Reis Gonçalves ◽

Daniel Thomazini ◽

Maria Virginia Gelfuso

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Laser Flash ◽

Eutectic Phase ◽

Flash Method ◽

Secondary Phases ◽

X Ray Diffraction ◽

X Ray ◽

Electrical Conductivities ◽

Diffraction Patterns

In this work, CaCuxTiyO12 ceramics (2.7 ≤ x ≤ 3.3 and 3.25 ≤ y ≤ 4.75), related to excess and deficiency of CuO-TiO2 eutectic phase have been synthesized by coprecipitation method. The crystalline phases in the ceramics were identified by X-ray diffraction patterns, and the pellets have mainly presented CCTO and also exhibited CuO, TiO2 and CaTiO3 as secondary phases. The thermal conductivity of the ceramics was determined using the laser flash method in the temperature range of 300-1000 K. It was observed a decrement in thermal conductivity values as the amount of the eutectic phase decreased. The electrical DC conductivity has been measured by the two-probe method from 300-1000 K and it has been noted that both grain size and amount of eutectic phase influenced the electrical conductivity results.

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Thermal Conductivity and Thermoelectric Properties of Novel Rare Earth Boron-Rich Cluster Compounds; Discovery of first undoped n-type B12 icosahedral compound

MRS Proceedings ◽

10.1557/proc-0886-f11-14 ◽

2005 ◽

Vol 886 ◽

Author(s):

Takao Mori

Keyword(s):

Thermal Conductivity ◽

Rare Earth ◽

Thermoelectric Properties ◽

Thermoelectric Materials ◽

Homologous Series ◽

Cluster Compounds ◽

Rich Cluster ◽

Boron Cluster ◽

Seebeck Coefficients ◽

P Type

ABSTRACTNovel rare earth boron icosahedral compounds are investigated as potential high temperature thermoelectric materials. REB50-type compounds and a homologous series of RE-B-C(N) compounds were synthesized and the thermal conductivity and thermoelectric properties measured. Seebeck coefficients in excess of 200 μV/K are observed at temperatures above 1000 K for the REB50-type compounds. Strikingly, n-type behavior was observed for REB22C2N and REB17CN. Up to now, non-doped B12 icosahedral compounds like boron carbide have all been p-type. The discovery of an n-type compound is extremely important in terms of the potential development of this class of compounds as viable thermoelectric materials. Low thermal conductivities of κ < 0.03 W/cm/K at room temperature was observed for these rare earth boron cluster compounds. In comparison among the homologous series in which there are rare earth and B6 octahedra layers separated by an increasing number of B12 icosahedra layers, we observe that the thermal conductivity actually increases as the number of boron cluster layers increases. We find that the rare earth B12 icosahedral cluster compounds in which RE atoms occupy voids among the clusters generally appear to have lower thermal conductivity than boron cluster compounds which do not contain RE atoms.

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