四元Mg2Si0.27Ge0.05Sn0.65Sb0.03固溶体的热电性能

Thermoelectric performance of quaternary Mg2Si0.27Ge0.05Sn0.65Sb0.03 solid solutions

摘要:

通过氧化硼助熔剂法和放电等离子烧结技术制备了Mg_2(1+x)Si_0.27Ge_0.05Sn_0.65Sb_0.03 (x = 0.05, 0.08)四元固溶体热电材料。测量了在300 K - 800 K 的温度区间内测试了所有四元固溶体试样的塞贝克系数、电导率和热导率。研究结果表明随着温度的升高电导率单调降低而塞贝克系数单调升高,所有样品的晶格热导率明显高于通过Abeles模型计算所得到的理论值。最高无量纲热电优值出现在x=0.08样品中,在800 K时达到最高值1.0.

Abstract:

Single–phased Mg_2(1+x)Si_0.27Ge_0.05Sn_0.65Sb_0.03 (x = 0.05, 0.08) quaternary solid solutions were prepared by B₂O₃ flux method followed by spark plasma sintering (SPS). The electrical conductivity, Seebeck coefficient and thermal conductivity were measured from 300 K to 800 K. The results show that the electrical conductivity increases while the Seebeck coefficient decreases with temperature for these samples. The lattice thermal conductivities of all the samples are higher than the calculated value using the Abele model. A maximum ZT of 1.0 at 800 K was obtained in the sample with x = 0.08.