Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8955417 | Journal of Materials Science & Technology | 2018 | 6 Pages |
Abstract
The porous p-type Bi0.4Sb1.6Te3 bulks containing irregularly and randomly oriented pores were obtained by artificially controlling the relative density of sintered samples during resistance pressing sintering process. It is demonstrated that the thermoelectric performances are significantly affected by the porous structure, especially for the electrical and thermal conductivity due to the enhanced carrier scattering and phonon scattering. The increasing porosity resulted in the obvious decrease in electrical and thermal conductivity, and little change in Seebeck coefficients. It is encouraging that the reduction of thermal conductivity can compensate for the deterioration of electrical performance, leading to the enhancement in thermoelectric figure of merit (ZT). The maximum ZT value of 1.0 was obtained for the sample with a relative density of 90% at 333â¯K. Unfortunately, the increase in porosity also brought in obvious degradations in Vickers hardness from 51.71 to 27.74â¯HV. It is worth mentioning that although the Vickers hardness of the sample with a relative density of 90% decreased to 40.12â¯HV, it was still about twice as high as that of the zone melting sample (21.25â¯HV). To summarize, introducing pores structure into bulks properly not only enhances the ZT value of Bi2Te3 based alloys, but also reduces the use of raw materials and saves production cost.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Chemistry
Authors
Jie Hu, Xi'An Fan, Chengpeng Jiang, Bo Feng, Qiusheng Xiang, Guangqiang Li, Zhu He, Yawei Li,