管式反应法制备Mg_2Sn基热电材料及其性能研究

Preparation of Mg_2Sn Based Thermoelectric Materials by a Tube Solid Reaction Method and Their Performance

采用Mg H2代替单质Mg粉与Sn粉进行固相反应制备Mg2Sn基热电材料,有效地避免了Mg单质的挥发和氧化。在300~750 K的温度区间内对其热电性能进行了测试、分析,并与文献中报道的Mg2Sn热电性能进行了对比。结果表明,所有试样在整个测温区间均显示出n型掺杂,并且随着温度的升高,呈现逐渐向p型转变的变化趋势。掺杂Y后Mg2Sn试样的Seebeck系数有所提高,综合电性能比文献报道提高了40%,并且在350 K时获得最大的ZT值（0.033）,是文献报道的Mg2Sn的ZT值（0.013）的近3倍。

Mg2Sn based thermoelectric（TE） materials were prepared by a low-temperature solid-state reaction between Mg H2 and Sn. Reaction between tin and magnesium hydride instead of pure magnesium minimizes the oxidation and volatilization of magnesium. The thermoelectric performance was measured over the temperature range 300~750 K. All samples indicate n-type conduction within the whole temperature region, while they show a tendency to be nearly p-type with the temperature increasing. The Seebeck coefficient of Y-doped Mg2 Sn has been enhanced, and the power factor has been 40% higher than the value of reference. The 0.2% Y-doped Mg2 Sn exhibits a maximum figure of merit ZT of 0.033 at 350 K, which is nearly 3 times of the value of reference.