Nanostructured Thermoelectric Skutterudite Co1−xNixSb3 Alloys

2008 ◽  
Vol 8 (8) ◽  
pp. 4003-4006 ◽  
Author(s):  
Qinyu He ◽  
Qing Hao ◽  
Xiaowei Wang ◽  
Jian Yang ◽  
Yucheng Lan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Grain Boundary ◽  
Direct Current ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Hot Press ◽  
Ni Doping ◽  
Strong Electron ◽  
Dimensionless Figure Of Merit ◽  
Electron Phonon Scattering

Nanostructured Ni-doped skutterudites Co1−xNixSb3 (with x ranging from 0.01 to 0.09) were prepared by ball milling and direct-current induced hot press. It was found that the thermal conductivity was reduced due to strong electron–phonon scattering from Ni-doping as well as phonon scattering from the increased grain boundary of the nanostructures. A maximum dimensionless figure-of-merit of 0.7 was obtained in Co0.91Ni0.09Sb3 at 525 °C.

Synthesis and thermoelectric properties of tantalum-doped ZrNiSn half-Heusler alloys

2014 ◽  
Vol 07 (03) ◽  
pp. 1450032 ◽  
Author(s):  
Degang Zhao ◽  
Min Zuo ◽  
Zhenqing Wang ◽  
Xinying Teng ◽  
Haoran Geng
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Acoustic Phonon ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Heusler Alloys ◽  
Hot Press ◽  
Arc Melting ◽  
Hot Press Sintering

The Ta -doped ZrNiSn half-Heusler alloys, Zr 1-x Ta x NiSn , were synthesized by arc melting and hot-press sintering. Microstructure of Zr 1-x Ta x NiSn compounds were analyzed and the thermoelectric (TE) properties of Zr 1-x Ta x NiSn compounds were measured from room temperature to 823 K. The electrical conductivity increased with increasing Ta content. The Seebeck coefficient of Zr 1-x Ta x NiSn compounds was sharply decreased with increasing Ta content. The Hall mobility was proportional to T-1.5 above 673 K, indicating that the acoustic phonon scattering was predominant in the temperature range. The thermal conductivity was effectively depressed by introducing Ta substitution. The figure of merit of ZrNiSn compounds was improved due to the decreased thermal conductivity and increased electrical conductivity. The maximum ZT value of 0.60 was achieved for Zr 0.97 Ta 0.03 NiSn sample at 823 K.

scholarly journals Enhancement of thermoelectric properties of La-doped SrTiO 3 bulk by introducing nanoscale porosity

2019 ◽  
Vol 6 (10) ◽  
pp. 190870 ◽  
Author(s):  
Al Jumlat Ahmed ◽  
Sheik Md. Kazi Nazrul Islam ◽  
Ridwone Hossain ◽  
Jeonghun Kim ◽  
Minjun Kim ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Bulk Sample ◽  
Ionic Surfactant ◽  
Dimensionless Figure Of Merit ◽  
Maximum Value ◽  
Wide Scale ◽  
La Doped

Electron-doped SrTiO 3 is a well-known n -type thermoelectric material, although the figure of merit of SrTiO 3 is still inferior compared with p -type metal oxide-based thermoelectric materials due to its high lattice thermal conductivity. In this study, we have used a different amount of the non-ionic surfactant F127 during sample preparation to introduce nanoscale porosities into bulk samples of La-doped SrTiO 3 . It has been observed that the porosities introduced into the bulk sample significantly improve the Seebeck coefficient and reduce the thermal conductivity by the charge carrier and phonon scattering respectively. Therefore, there is an overall enhancement in the power factor (PF) followed by a dimensionless figure of merit ( zT ) over a wide scale of temperature. The sample 20 at% La-doped SrTiO 3 with 600 mg of F127 surfactant (SLTO 600F127) shows the maximum PF of 1.14 mW m −1 K −2 at 647 K which is 35% higher than the sample without porosity (SLTO 0F127), and the same sample (SLTO 600F127) shows the maximum value of z T is 0.32 at 968 K with an average enhancement of 62% in zT in comparison with the sample without porosity (SLTO 0F127).

scholarly journals Electronic and Thermal Transport Properties of Complex Structured Cu-Bi-Se Thermoelectric Compound with Low Lattice Thermal Conductivity

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jae-Yeol Hwang ◽  
Hyeona Mun ◽  
Jung Young Cho ◽  
Sang Sun Yang ◽  
Kyu Hyoung Lee ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Thermal Properties ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Dimensionless Figure Of Merit ◽  
Impurity Doping ◽  
Electron Carriers ◽  
Mass Fluctuation

Monoclinic Cux+yBi5−ySe8structure has multiple disorders, such as randomly distributed substitutional and interstitial disorders by Cu as well as asymmetrical disorders by Se. Herein, we report the correlation of electronic and thermal properties with the structural complexities of Cux+yBi5−ySe8. It is found that the interstitial Cu site plays an important role not only to increase the electrical conductivity due to the generation of electron carriers but also to reduce the thermal conductivity mainly due to the phonon scattering by mass fluctuation. With impurity doping at the interstitial Cu site, an extremely low lattice thermal conductivity of 0.32 W·m−1·K−1was achieved at 560 K. These synergetic effects result in the enhanced dimensionless figure of merit (ZT).

Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Substitution Effect ◽  
Dimensionless Figure Of Merit ◽  
The Matrix ◽  
Mass Fluctuation

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).

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

2019 ◽  
Vol 34 (02) ◽  
pp. 2050019 ◽  
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.

Electron–phonon interaction in P-, As-, and Sb-doped germanium in the intermediate concentration region

1980 ◽  
Vol 58 (9) ◽  
pp. 1268-1274 ◽  
Author(s):  
V. Radhakrishnan ◽  
P. C. Sharma
Keyword(s):  
Thermal Conductivity ◽  
Conduction Band ◽  
Phonon Scattering ◽  
Metallic State ◽  
Deformation Potential ◽  
Concentration Region ◽  
Electron Phonon Interaction ◽  
Impurity Atoms ◽  
Intermediate Concentration ◽  
Electron Phonon Scattering

The electron–phonon scattering, in the analysis of low temperature thermal conductivity of n-type germanium, is studied in the intermediate donor concentration region. At low concentrations, below metal–insulator transition, the donor electrons are bound to the impurity atoms, and at high concentrations they are free in conduction band. The properties in the intermediate concentration are explained by Mikoshiba's "inhomogeneity model". According to this model, the electrons are in a mixed state both in non-metallic and metallic state. The electron concentrations in the non-metallic and metallic regions are calculated for each sample and the theory of both bound electron–phonon scattering and free electron–phonon scattering are applied. This theory of mixed electron–phonon scattering explains the thermal conductivity results of P-, As-, and Sb-doped germanium samples between 1 and 20 K for intermediate donor concentrations from 1.1 × 1017 to 5.6 × 1017 cm−3. The values of density-of-states effective mass are kept constant (= 0.22) without variation with temperature. The values of shear and dilatation-deformation potential constants are obtained from our calculations. The values of shear-deformation potential for the electrons in the bound region are found to be between 14 and 16 eV, while the values of dilatation-deformation potential are between 1 and 3.5 eV for the electrons in the conduction band and these values are in agreement with the experimentally measured values.

scholarly journals Graphene inclusion induced ultralow thermal conductivity and improved figure of merit in p-type SnSe

Nanoscale ◽  
2020 ◽  
Vol 12 (24) ◽  
pp. 12760-12766 ◽  
Author(s):  
Lei Chen ◽  
Weiyao Zhao ◽  
Meng Li ◽  
Guangsai Yang ◽  
Sheik Md Kazi Nazrul Islam ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
P Type

Polycrystalline SnSe sample with graphene embedded in realized the enhancement of phonon scattering and achieved ultralow thermal conductivity.

Synthesis and Thermoelectric Properties of Co4-XFeXSb12-YSnY Skutterudites

2011 ◽  
Vol 695 ◽  
pp. 65-68 ◽  
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.

Thermoelectric Properties of Binary-Phased Nanocomposites

2014 ◽  
Vol 809-810 ◽  
pp. 3-8
Author(s):  
Peng Xian Lu
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Hot Press ◽  
Point Temperature ◽  
Disordered Structure ◽  
Maximum Value ◽  
Hot Press Process

In order to increase the electrical conductivity greatly but maintain a large Seebeck coefficient and a low thermal conductivity simultaneously, the binary-phased LaCeFe3CoSb12-Sb nanocomposites composed of LaCeFe3CoSb12skutterudite nanospheres and semimetal Sb microsized ribbons were fabricated via a hydro/solvo thermal route. The results suggest that the Sb powders result in a disordered structure during a hot-press process at its melting-point temperature and the disordered structure has been partly preserved into the room-temperature materials successfully. The Sb microsized ribbons enhance the electrical conductivity of the binary-phased materials largely, meanwhile the disordered structure increases the Seebeck coefficient obviously even though the thermal conductivity is also increased slightly. Consequently, the figure of merit of the binary-phased materials is improved significantly and the maximum value of 1.54 at 773 K has been realized for the LaCeFe3CoSb15material.

Sign in / Sign up

Export Citation Format

Share Document