采用电弧熔炼法和放电等离子体烧结法, 制备了稀土掺杂的金属间化合物Zr1-xLaxNiSn (x = 0.05, 0.1, 0.15, 0.2, 0.3, 0.4) 和Zr0.98R0.02NiSn0.98X0.02(R = La, Ce; X = Sb, Bi). 用X射线衍射仪分析研究了它们的晶体结构随稀土替代量演化的规律. 在室温到700 K的范围内, 对其热电特性进行了评价. 研究结果表明, 代换量x小于0.15时, 稀土原子可以进入晶格形成单相化合物. 代换量x大于0.15的样品中含有非half-Heusler的第二相, 且含量随x增大而增加. 少量稀土掺杂可以有效地降低材料的热导率而保持良好的电输运特性. 在575 K, Zr0.98La0.02NiSn0.98Sb0.02的热电优值达到0.5.
Intermetallic compounds Zr1-xLaxNiSn (x = 0.05, 0.1, 0.15, 0.2, 0.3, 0.4) and Zr0.98R0.02NiSn0.98X0.02(R = La, Ce; X=Sb, Bi) were synthesized using arc melting and spark plasma sintering (SPS) techniques. The changes of their crystal structures were analyzed by using X-ray diffractometer. Thermoelectric properties were evaluated in the temperature range of 300 to 925 K. For x≤0.15, single-phase samples can be obtained. With x > 0.15, a non-half-heusler phase formed. The content of the second phase increases with x. For the samples with x≤0.15, rare-earth doping can effectively reduce the thermal conductivity while keeping good electrical transport. The maximum value of ZT was obtained in Zr0.98La0.02NiSn0.98Sb0.02, which reaches 0.5 at 575K.
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