Thermoelectric properties of Nb-doped Sr1−x (La0.5Na0.5) x TiO3 perovskites

Abstract We report the thermal conductivity (κ) of perovskite Sr1−x(La0.5Na0.5)xTiO3 (0 ≤ x ≤ 1) and the thermoelectric properties of Nb-doped samples for x = 0.1 and 0.2. The κ of the solid solution shows a distinct minimum near the cubic-tetragonal phase boundary at x = 0.2, where the value becomes close to the minimum theoretical κ. Nb doping to x = 0.2 retains the high power factor found in Nb-doped SrTiO3, but also raises the κ to result in a thermoelectric figure of merit of 0.24 at 773 K.

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High Power Factor and Thermoelectric Figure of Merit in Sb2Si2Te6 through Synergetic Effect of Ca Doping

Chemistry of Materials ◽

10.1021/acs.chemmater.1c02895 ◽

2021 ◽

Author(s):

Tian Xu ◽

Abubakar-Yakubu Haruna ◽

Zheng Ma ◽

Wang Li ◽

Jinmeng Li ◽

...

Keyword(s):

Power Factor ◽

High Power ◽

Figure Of Merit ◽

Synergetic Effect ◽

Thermoelectric Figure Of Merit ◽

Thermoelectric Figure ◽

Ca Doping ◽

High Power Factor

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Is LiI a Potential Dopant Candidate to Enhance the Thermoelectric Performance in Sb-Free GeTe Systems? A Prelusive Study

Energies ◽

10.3390/en13030643 ◽

2020 ◽

Vol 13 (3) ◽

pp. 643 ◽

Cited By ~ 13

Author(s):

Bhuvanesh Srinivasan ◽

David Berthebaud ◽

Takao Mori

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Properties ◽

Power Factor ◽

Figure Of Merit ◽

Lattice Thermal Conductivity ◽

Short Communication ◽

Thermoelectric Figure Of Merit ◽

Thermoelectric Figure ◽

Plasma Sintering ◽

Spark Plasma

As a workable substitute for toxic PbTe-based thermoelectrics, GeTe-based materials are emanating as reliable alternatives. To assess the suitability of LiI as a dopant in thermoelectric GeTe, a prelusive study of thermoelectric properties of GeTe1−xLiIx (x = 0–0.02) alloys processed by Spark Plasma Sintering (SPS) are presented in this short communication. A maximum thermoelectric figure of merit, zT ~ 1.2, was attained at 773 K for 2 mol% LiI-doped GeTe composition, thanks to the combined benefits of a noted reduction in the thermal conductivity and a marginally improved power factor. The scattering of heat carrying phonons due to the presumable formation of Li-induced “pseudo-vacancies” and nano-precipitates contributed to the conspicuous suppression of lattice thermal conductivity, and consequently boosted the zT of the Sb-free (GeTe)0.98(LiI)0.02 sample when compared to that of pristine GeTe and Sb-rich (GeTe)x(LiSbTe2)2 compounds that were reported earlier.

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Effects of Ge Doping on the Charge Transport and Thermoelectric Properties of Permingeatites Cu3Sb1−yGeySe4

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2021.59.6.422 ◽

2021 ◽

Vol 59 (6) ◽

pp. 422-429

Author(s):

Ji-Hee Pi ◽

Go-Eun Lee, ◽

Il-Ho Kim

Keyword(s):

Thermal Conductivity ◽

Charge Transport ◽

Thermoelectric Properties ◽

Power Factor ◽

Figure Of Merit ◽

Thermoelectric Figure Of Merit ◽

Lorenz Number ◽

Degenerate Semiconductor ◽

Thermoelectric Figure ◽

Ge Doping

Permingeatites Cu3Sb1−yGeySe4 (0 ≤ y ≤ 0.14) were synthesized by mechanical alloying and hot pressing. The charge-transport parameters (Hall coefficient, carrier concentration, mobility, and Lorenz number) and thermoelectric properties (electrical conductivity, Seebeck coefficient, power factor, thermal conductivity, and figure of merit) were examined with respect to the Ge doping level. A single permingeatite phase with a tetragonal structure was obtained without subsequent heat treatment, but a small amount of the secondary phase Cu2GeSe3 was found for the specimens with y ≥ 0.08. All hot-pressed compacts exhibited a relative density of 97.5%–98.3%. The lattice constants of the a-axis and c-axis were decreased by the substitution of Ge at the Sb sites. As the Ge content increased, the carrier concentration increased from 5.2 × 1018 to 1.1 × 1020 cm−3, but the mobility decreased from 92 to 25 cm2·V−1·s−1. The Lorenz number of the undoped Cu3SbSe4 implied a non-degenerate semiconductor behavior, ranging from (1.57–1.56) × 10−8 V2·K−2 at 323–623 K. The thermoelectric figure of merit was 0.39 at 623 K, resulting from a power factor of 0.49 mW·m−1·K−2 and a thermal conductivity of 0.76 W·m−1·K−1. However, the Lorenz numbers of the Gedoped specimens indicated degenerate semiconductor characteristics, increasing to (1.63–1.94) × 10−8 V2·K−2 at 323–623 K. The highest thermoelectric figure of merit of 0.65 was at 623 K for Cu3Sb0.86Ge0.14Se4, resulting from the significantly improved power factor of 0.93 mW·m−1·K−2 and the thermal conductivity of 0.89W·m−1·K−1. As a result, the thermoelectric properties were remarkably enhanced by doping Ge into the Sb sites of the permingeatite.

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Effects of Oxygen-Reduction on Thermoelectric Properties of Sr0.61Ba0.39Nb2O6 Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.787.210 ◽

2014 ◽

Vol 787 ◽

pp. 210-214 ◽

Cited By ~ 1

Author(s):

Yi Li ◽

Jian Liu ◽

Chun Lei Wang ◽

Wen Bin Su ◽

Yuan Hu Zhu ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Oxygen Reduction ◽

Thermoelectric Power ◽

Thermoelectric Properties ◽

Power Factor ◽

Figure Of Merit ◽

Thermoelectric Figure Of Merit ◽

Thermoelectric Figure ◽

Thermoelectric Power Factor

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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Influence of multi-sintering on the thermoelectric properties of Bi2Sr2Co2Oy ceramics

Modern Physics Letters B ◽

10.1142/s0217984920500190 ◽

2019 ◽

Vol 34 (02) ◽

pp. 2050019 ◽

Cited By ~ 2

Author(s):

Y. Zhang ◽

M. M. Fan ◽

C. C. Ruan ◽

Y. W. Zhang ◽

X.-J. Li ◽

...

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Phonon Scattering ◽

Sintered Sample ◽

Thermoelectric Figure Of Merit ◽

Thermoelectric Figure ◽

The Third ◽

Ceramic Samples ◽

Optimum Formula

[Formula: see text] ceramic samples have a structure similar to phonon glass electronic crystals, and their thermoelectric properties can be effectively adjusted through repeated grinding and sintering. The results show that multi-sintering can make their grain refined and increase their grain boundary, which will effectively increase density and phonon scattering. Finally, multi-sintering can reduce the resistivity and thermal conductivity, thus obviously improve thermoelectric figure of merit [Formula: see text] of [Formula: see text]. The optimum [Formula: see text] value of 0.26 is achieved at 923 K by the third sintered sample.

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Effects of Ce filling fraction and Fe content on the thermoelectric properties of Co-rich CeyFexCo4−xSb12

Journal of Materials Research ◽

10.1557/jmr.2001.0109 ◽

2001 ◽

Vol 16 (3) ◽

pp. 837-843 ◽

Cited By ~ 66

Author(s):

Xinfeng Tang ◽

Lidong Chen ◽

Takashi Goto ◽

Toshio Hirai

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Single Phase ◽

Lattice Thermal Conductivity ◽

Hole Concentration ◽

Thermoelectric Figure Of Merit ◽

Thermoelectric Figure ◽

Filling Fraction ◽

Fe Content

Single-phase filled skutterudite compounds, CeyFexCo4−xSb12 (x = 0 to 3.0, y = 0 to 0.74), were synthesized by a melting method. The effects of Fe content and Ce filling fraction on the thermoelectric properties of CeyFexCo4−xSb12 were investigated. The lattice thermal conductivity of Ce-saturated CeyFexCo4−xSb12, y being at the maximum corresponding to x, decreased with increasing Fe content (x) and reached its minimum at about x = 1.5. When x was 1.5, lattice thermal conductivity decreased with increasing Ce filling fraction till y = 0.3 and then began to increase after reaching the minimum at y = 0.3. Hole concentration and electrical conductivity of Cey Fe1.5Co2.5Sb12 decreased with increasing Ce filling fraction. The Seebeck coefficient increased with increasing Ce filling fraction. The greatest dimensionless thermoelectric figure of merit T value of 1.1 was obtained at 750 K for the composition of Ce0.28Fe1.52Co2.48Sb12.

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

Физика и техника полупроводников ◽

10.21883/ftp.2019.06.47721.30 ◽

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.

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Thermoelectric Properties of CoSb3-based Skutterudite Compounds

MRS Proceedings ◽

10.1557/proc-1267-dd03-02 ◽

2010 ◽

Vol 1267 ◽

Author(s):

Adul Harnwunggmoung ◽

Ken Kurosaki ◽

Hiroaki Muta ◽

Shinsuke Yamanaka

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Room Temperature ◽

Lattice Thermal Conductivity ◽

Filling Ratio ◽

Thermoelectric Figure Of Merit ◽

Thermoelectric Figure ◽

Alloy Scattering ◽

Skutterudite Compound

AbstractCoSb3 is known as a skutterudite compound that could exhibit high thermoelectric figure of merit. However, the thermal conductivity of CoSb3 is relatively high. In order to enhance the thermoelectric performance of this compound, we tried to reduce the thermal conductivity of CoSb3 by substitution of Rh for Co and by Tl-filling into the voids. The polycrystalline samples of (Co,Rh)Sb3 and Tl-filled CoSb3 were prepared and the thermoelectric properties such as the Seebeck coefficient, electrical resistivity, and thermal conductivity were measured in the temperature range from room temperature to 750 K. The Rh substitution for Co reduced the lattice thermal conductivity, due to the alloy scattering effect. The minimum value of the lattice thermal conductivity was 4 Wm-1K-1 at 750 K obtained for (Co0.7Rh0.3)Sb3. Also the lattice thermal conductivity rapidly decreased with increasing the Tl-filling ratio. T10.25Co4Sb12 exhibited the best ZT values; the maximum ZT was 0.9 obtained at 600 K.

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Thermoelectric Properties of a Wide–Gap Chalcopyrite Compound AgInSe2

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.519.188 ◽

2012 ◽

Vol 519 ◽

pp. 188-192 ◽

Cited By ~ 11

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.

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