Fabrication of Mg2Si from a Reused-silicon Source and its Thermoelectric Characteristics

2007 ◽  
Vol 1044 ◽  
Author(s):  
Masayasu Akasaka ◽  
Tsutomu Iida ◽  
Youhiko Mito ◽  
Takeru Omori ◽  
Yohei Oguni ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Silicon Source ◽  
Figures Of Merit ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type ◽  
Type Sample

AbstractPolycrystalline Mg2Si was fabricated from a reused-Silicon source, based on Si sludge, using Spark Plasma Sintering technique. The n-type and p-type dopants, bismuth (Bi) and silver (Ag), respectively, were incorporated into the Mg2Si. The thermoelectric properties were estimated from 300 to 873K. The power factors of undoped and Bi-doped samples from the reused-Si source were comparable to those from a solar grade Si source (99.99999%). The power factor was estimated to be 2.5 × 10-5 W/cmK2 for the Bi-doped sample from the reused-Si source. However, the power factor of the Ag-doped, p-type sample from the reused-Si source was lower than that from solar grade Si source. The dimensionless figures of merit of samples from the resused-Si source were slightly lower than those from a solar grade Si source. The dimensionless figure of merit was estimated to be 0.53 at 812 K for Bi-doped sample from the reused-Si source.

Fabrication of Bi-Te Based Thermoelectric Semiconductors by Using Hybrid Powders

2005 ◽  
Vol 297-300 ◽  
pp. 875-880
Author(s):  
Cheol Ho Lim ◽  
Ki Tae Kim ◽  
Yong Hwan Kim ◽  
Dong Choul Cho ◽  
Young Sup Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Single Crystals ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Bending Strength ◽  
Mixing Ratio ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

P-type Bi0.5Sb1.5Te3 compounds doped with 3wt% Te were fabricated by spark plasma sintering and their mechanical and thermoelectric properties were investigated. The sintered compounds with the bending strength of more than 50MPa and the figure-of-merit 2.9×10-3/K were obtained by controlling the mixing ratio of large powders (PL) and small powders (PS). Compared with the conventionally prepared single crystal thermoelectric materials, the bending strength was increased up to more than three times and the figure-of-merit Z was similar those of single crystals. It is expected that the mechanical properties could be improved by using hybrid powders without degradation of thermoelectric properties.

scholarly journals Development of Spark Plasma Syntering (SPS) technology for preparation of nanocrystalline p-type thermoelctrics based on (BiSb)2Te3

2020 ◽  
Vol 21 (4) ◽  
pp. 628-634
Author(s):  
O. Kostyuk ◽  
B. Dzundza ◽  
M. Maksymuk ◽  
V. Bublik ◽  
L. Chernyak ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Antimony Telluride ◽  
Bismuth Antimony Telluride ◽  
Thermoelectric Figure ◽  
Temperature Range ◽  
Plasma Sintering ◽  
Different Temperatures ◽  
Spark Plasma ◽  
P Type

Bismuth antimony telluride is the most commonly used commercial thermoelectric material for power generation and refrigeration over the temperature range of 200–400 K. Improving the performance of these materials is a complected balance of optimizing thermoelectric properties. Decreasing the grain size of Bi0.5Sb1.5Te3 significantly reduces the thermal conductivity due to the scattering phonons on the grain boundaries. In this work, it is shown the advances of spark plasma sintering (SPS) for the preparation of nanocrystalline p-type thermoelectrics based on Bi0.5Sb1.5Te3 at different temperatures (240, 350, 400oC). The complex study of structural and thermoelectric properties of Bi0.5Sb1.5Te3 were presented. The high dimensionless thermoelectric figure of merit ZT ~ 1 or some more over 300–400 K temperature range for nanocrystalline p-type Bi0.5Sb1.5Te3 was obtained.

Preparation and Thermoelectric Properties of Bi-Doped Mg2Si Nanocomposites

2009 ◽  
Vol 66 ◽  
pp. 17-20 ◽  
Author(s):  
Mei Jun Yang ◽  
Wei Jun Luo ◽  
Qiang Shen ◽  
Hong Yi Jiang ◽  
Lian Meng Zhang
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Heavy Doping ◽  
Nanocomposite Structures

Nanocomposites and heavy doping both are regarded as effective way to improve materials’ thermoelectric properties. 0.7at% Bi-doped Mg2Si nanocomposites were prepared by spark plasma sintering. Results of thermoelectric properties tests show that the doping of Bi atom effectively improves the electrical conductivity of Mg2Si，and the nanocomposite structures are helpful to reduce thermal conductivity and increase Seebeck coefficient, hence improving the thermoelectric performance. A maximum dimensionless figure of merit of 0.8 is obtained for the Bi-doped Mg2Si nanocomposite with 50 wt % nanopowder inclusions at 823K, about 63% higher than that of Bi-doped Mg2Si sample without nanopowder inclusions and 119% higher than that of microsized Mg2Si sample without Bi-doped, respectively.

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

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 643 ◽  
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.

Investigating the key role of carrier transport mechanism in SnSe nanoflakes with enhanced thermoelectric power factor

2021 ◽  
Author(s):  
Srikanth Mandava ◽  
Neeta Bisht ◽  
Anjali Saini ◽  
Mukesh Kumar Bairwa ◽  
Khasimsaheb Bayikadi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ab Initio ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Temperature Range ◽  
Carrier Scattering ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

Abstract A novel SnSe nanoake system is explored for its thermoelectric properties from both experiments and ab initio study. The nanoakes of the low temperature phase of SnSe (Pnma) are synthesized employing a fast and efficient refluxing method followed by spark plasma sintering at two different temperatures. We report an enhanced power factor (12 W/mK2 - 67 W/mK2 in the temperature range 300 K-600 K) in our p-type samples. We find that the prime reason for a high PF in our samples is a significantly improved electrical conductivity (1050 S/m - 2180 S/m in the temperature range 300 K-600 K). From our ab initio band structure calculations accompanied with the models of temperature and surface dependent carrier scattering mechanisms, we reveal that an enhanced electrical conductivity is due to the reduced carrier-phonon scattering in our samples. The trans- port calculations are performed using the Boltzmann transport equation within relaxation time approximation. With our combined experimental and theoretical study, we demonstrate that the thermoelectric properties of p-type Pnma-SnSe could be improved by tuning the carrier scattering mechanisms with a control over the spark plasma sintering temperature.

Thermoelectric Properties of La-doped BaSi2 and (Ba,Sr)Si2 Solid Solutions

2007 ◽  
Vol 1044 ◽  
Author(s):  
Kohsuke Hashimoto ◽  
Ken Kurosaki ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Electrical Resistivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
La Doped

AbstractWe studied the thermoelectric properties of BaSi2 and SrSi2. The polycrystalline samples were prepared by spark plasma sintering (SPS). The electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ) were measured above room temperature. The maximum values of the dimensionless figure of merit (ZT) were 0.01 at 954 K for BaSi2 and 0.09 at 417 K for SrSi2. We tried to enhance the ZT values of BaSi2 and SrSi2 by prepareing and characterizing La-doped BaSi2 and (Ba,Sr)Si2 solid solution.

scholarly journals Fabrication and Thermoelectric Properties of Graphene/Bi2Te3Composite Materials

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Beibei Liang ◽  
Zijun Song ◽  
Minghui Wang ◽  
Lianjun Wang ◽  
Wan Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Conductivity Measurement ◽  
Testing Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma

Graphene/Bi2Te3thermoelectric materials were prepared by spark plasma sintering (SPS) using hydrothermal synthesis of the powders as starting materials. The X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) were used to investigate the phase composition and microstructure of the as-prepared materials. Electrical resistivity, Seebeck coefficient, and thermal conductivity measurement were applied to analyze the thermoelectric properties. The effect of graphene on the performance of the thermoelectric materials was studied. The results showed that the maximum dimensionless figure of merit of the graphene/Bi2Te3composite with 0.2 vol.% graphene was obtained at testing temperature 475 K, 31% higher than the pure Bi2Te3.

Preparation and High Temperature Thermoelectric Properties of [Ca2(Co0.65Cu0.35)2O4]0.624CoO2 Compound

2007 ◽  
Vol 336-338 ◽  
pp. 805-808 ◽  
Author(s):  
Xiao Ya Li ◽  
Yun Yu ◽  
Dong Li Wang ◽  
Li Dong Chen
Keyword(s):  
High Temperature ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Conduction Mechanism ◽  
Sol Gel ◽  
Hopping Conduction ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Thermoelectric Energy ◽  
Spark Plasma

[Ca2(Co0.65Cu0.35)2O4]0.624CoO2 polycrystalline samples were prepared using sol-gel method followed by spark plasma sintering. Thermoelectric properties of the samples were examined from room temperature to 1000K. The temperature dependence of electrical conductivity shows that the hole hopping conduction mechanism is dominant for the samples. The activation energy of hopping conduction is 0.11 eV. At the temperature of about 1000K, the electrical resistivity is 7.1m cm, the thermopower is 160 μVK-1, the thermal conductivtity is 2.94Wm-1K-1 and dimensionless figure of merit reaches 0.12. These results indicate [Ca2(Co0.65Cu0.35)2O4]0.624CoO2 is a potential material for high temperature thermoelectric energy conversion.

Thermoelectric properties of undoped p-type CoSb3 prepared by vertical Bridgman crystal growth and spark plasma sintering

2006 ◽  
Vol 415 (1-2) ◽  
pp. 251-256 ◽  
Author(s):  
Satoru Furuyama ◽  
Tsutomu Iida ◽  
Shinsuke Matsui ◽  
Masayasu Akasaka ◽  
Keishi Nishio ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Plasma Sintering ◽  
Vertical Bridgman ◽  
Spark Plasma ◽  
Bridgman Crystal Growth ◽  
P Type

The Influence of RuO2 Addition on the Thermoelectric Properties of BiSbTe Alloys

2012 ◽  
Vol 512-515 ◽  
pp. 1651-1654 ◽  
Author(s):  
Yu Kun Xiao ◽  
Zhi Xiang Li ◽  
Jun Jiang ◽  
Sheng Hui Yang ◽  
Ting Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Combined Process ◽  
Plasma Sintering ◽  
The Matrix ◽  
Spark Plasma ◽  
Xrd Patterns ◽  
Factor Α ◽  
P Type

P-type BiSbTe/RuO2 composite was fabricated using a combined process of melting and spark plasma sintering. The XRD patterns showed that RuO2 reacted with the matrix for the RuO2 content of 1.0 wt% and 4.0 wt% samples. The measured thermoelectric properties showed that the highest electrical conductivity was obtained for the sample with 2.0 wt% RuO2. The power factor (α2σ/κ) decreased with the increase of RuO2 below 450 K. The lattice thermal conductivity was lower than that of BiSbTe over the whole temperature range for BiSbTe/2.0 wt% RuO2.

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