Enhanced thermoelectric and mechanical properties in textured n-type Bi2Te3 prepared by spark plasma sintering
Enhanced thermoelectric and mechanical properties in textured n-type Bi2Te3 prepared by spark plasma sintering
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DOI：
10.1016/j.solidstatesciences.2007.10.022
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发表时间：
2008-05-01
影响因子：
3.5
通讯作者：
Liu, W. S.
中科院分区：
文献类型：
--
作者：
Zhao, L. D.;Zhang, B. -P.;Liu, W. S.
采用火花等离子烧结（SPS）方法制备了n型Bi2Te3热电材料，并通过SPS热锻工艺制备了晶粒取向优良的Bi2Te3体块。研究了取向度和热锻温度对热电性能的影响。增大取向度可以降低电阻率，提高热锻温度可以提高塞贝克系数，从而使功率因数从热锻前（423 K）的2.1 mW/mK(2)显著提高到热锻后（733 K）的3.1 mW/mK(2)。733 K热锻后的ZT最大值在423 K时达到1.18。该数值比热锻前提高了20%，但热锻后的导热系数略有提高。经热锻后，其抗弯强度由原来的62 MPa提高到120 MPa。(C) 2007 Elsevier Masson SAS。版权所有。
n-Type Bi2Te3 thermoelectric materials were prepared by spark plasma sintering (SPS) using mechanically alloyed powders, and fine-grained Bi2Te3 bulks with preferred grain orientation have been fabricated by SPS as a hot-forging process. The effects of orientation degree and hot-forging temperature on thermoelectric properties were investigated. The electrical resistivity was reduced by increasing orientation degree, the Seebeck coefficient was increased by raising hot-forging temperature, and consequently the power factor was significantly increased from 2.1 mW/mK(2), measured at 423 K, before hot-forging to 3.1 mW/mK(2) after hot-forging at 733 K. The maximum ZT value after hot-forging at 733 K reached 1.18 measured at 423 K. This value was 20% higher than that before hot-forging, although the corresponding thermal conductivity was a little increased after hot-forging. The bending strength was greatly enhanced from 62 MPa to 120 MPa after the hot-forging. (C) 2007 Elsevier Masson SAS. All rights reserved.