Microstructure and thermoelectric performance evaluation of p-type (Bi, Sb)2Te3 materials synthesized using mechanical alloying and spark plasma sintering process

Author(s):  
Hamta Mansouri ◽  
Seyed Abdolkarim Sajjadi ◽  
Abolfazl Babakhani ◽  
Yasaman Saberi
2017 ◽  
Vol 5 (31) ◽  
pp. 7845-7852 ◽  
Author(s):  
Yao Yao ◽  
Bo-Ping Zhang ◽  
Jun Pei ◽  
Yao-Chun Liu ◽  
Jing-Feng Li

A series of single-phased Cu2S1−xSex bulks were prepared by using mechanical alloying (MA) combined with spark plasma sintering (SPS). Our results suggest that the TE properties of Cu2S can be greatly enhanced by simultaneously increasing PF and decreasing κ via doping a sole Se element.


2003 ◽  
Vol 793 ◽  
Author(s):  
Lidong Chen ◽  
Jun Jiang ◽  
Xun Shi

ABSTRACTThermoelectric performance of polycrystalline materials is greatly influenced by their microstructures including grain sizes, grain boundaries, grain orientations in anisotropic compounds, etc. The material microstructures are sensitive to the preparation processes and the starting materials. In the present study, n-type and p-type Bi2Te3-based sintered materials with highly preferred grain orientations have been fabricated through a spark plasma sintering (SPS) technique, by controlling the particle sizes of the starting powder and other sintering process parameters. The obtained textured Bi2Te3-based materials show a high mechanical strength as 80MPa in bending strength, which is 7 to 8 times as that of the melted ingot materials, and a significant anisotropy in thermoelectric transport properties. The optimal figure of merit (ZT) of the sintered materials in the direction perpendicular to the pressing direction (with c-axis preferred orientation) is comparable to that of the zone-melted ingots in the same crystallographic orientation.


2006 ◽  
Vol 6 (11) ◽  
pp. 3429-3432
Author(s):  
Chung-Hyo Lee ◽  
Seong-Hee Lee ◽  
Sung-Yong Chun ◽  
Sang-Jin Lee

A mixture of pure Mg and Si powders with an atomic ratio 2:1 has been subjected to mechanical alloying (MA) at room temperature to prepare the Mg2Si thermoelectric material. Mg2Si intermetallic compound with a grain size of 50 nm can be obtained by MA of Mg66.7Si33.3 powders for 60 hours and subsequently annealed at 620 °C. Consolidation of the MA powders was performed in a spark plasma sintering (SPS) machine using graphite dies up to 800–900 °C under 50 MPa. The shrinkage of consolidated samples during SPS was significant at about 250 °C and 620 °C. X-ray diffraction data shows that the SPS compact from 60 h MA powders consolidated up to 800 °C consists of only nanocrystalline Mg2Si compound with a grain size of 100 nm.


2016 ◽  
Vol 703 ◽  
pp. 70-75 ◽  
Author(s):  
Zhen Ye Zhu ◽  
Shi Lei Guo

High dense p-type Si95Ge5 doped with nanoSi70Ge30B5particles thermoelectric materials were firstly fabricated by mechanical alloying (MA) and spark plasma sintering (SPS) method. The effects of different nanoSi70Ge30B5 doping content on the thermoelectric and phase properties were studied. A dimensionless thermoelectric figure-of-merit (ZT) of 0.47 at 710K in p-type nanocomposite bulk silicon germanium (SiGe) alloys is achieved. The enhancement of ZT is due to a large reduction of thermal conductivity caused by the increased grain boundaries of the numerous nanograins that effectively scatter long wavelength phonons.


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