SPS法制备的三元合金Ag0.405Sb0.532Te的热电性能

采用放电等离子烧结法(SPS)制备了三元合金Ag0.405Sb0.532Te,并研究了它的输运性能,即Seebeck系数、电导率和热导率。结果表明,当温度从316K上升到548K时,电导率从7.6×104S·m-1下降到6.6×104S·m-1。在438K以上,热导率随温度上升逐渐增加,低于438K时,热导率趋于稳定,约为0.86W·(K·m)-1。无量纲热电优值ZT在548K时取得最大值0.65,稍高于Ag0.365Sb0.558Te三元合金的0.61。与掺Ag的AgxBi0.5Sb1.5-xTe3(x=0～0.4)合金相比,热电性能得到了改善。并再次讨论了AgxBi0.5Sb1.5-xTe3合金中析出的第二相Ag-Sb-Te三元合金的作用机制。

Thermoelectric Properties of Ternary Alloy Ag0.405Sb 0.532Te Prepared by Spark Plasma Sintering

The ternary Ag_(0.405)Sb_(0.532)Te alloy was prepared by spark plasma sintering, and its transport properties involving Seebeck coefficients, electrical and thermal conductivities were evaluated. The results reveal that the electrical conductivity mildly decreases from 7.6(10~4 S·m~(-1) to 6.6(10~4 S·m~(-1) when the temperature increases from 316 K, to 548 K. Above 438 K, the thermal conductivity gradually increases with the increase of the temperature, and below 438 K, a relative stable value of about 0.86 W·K~(-1)·m~(-1) is obtained. The maximum thermoelectric figure of merit ZT is up to 0.65 at 548 K, a little higher than 0.61 of the ternary alloy Ag0.365Sb0.558Te. The thermoelectric properties have been improvement compared with the Ag-doped Ag_xBi_(0.5)Sb_(1.5-x)Te_3 alloys (x=0-0.4). The action mechanism of the second phase Ag-Sb-Te ternary alloy precipitated in the Ag_xBi_(0.5)Sb_(1.5-x)Te_3 alloys has been re-discussed.