Abstract Sb is a very effective dopant for ZrNiSn based half-Heusler alloys. The effect of Ti substitution on Zr0.75Hf0.25NiSn0.985Sb0.015 half-Heusler (HH) semiconductor alloys has been investigated to explore the structural modifications and composition variation. TixHf0.25 Zr0.75-xNiSn0.985Sb0.015 (x = 0, 0.15, 0.30, 0.45) alloys were synthesized by induction melting. A set of samples was also annealed for comparative studies. The samples were then sintered using plasma activated sintering (PAS) technique. XRD results confirmed the existence of ZrNiSn type HH compounds. Backscattered electron (BSE) images showed phase separations in the samples. Ti substitution improved the carrier concentration and electrical conductivity of the alloys. Moreover, thermal conductivity was also significantly reduced due to the enhanced phonon scattering. Consequently, a ZT value of 1.11 at 873 K was obtained for 30% Ti substituted (annealed) sample.

中文翻译：

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相分离Ti取代Zr0.75Hf0.25NiSn0.985Sb0.015半赫斯勒的热电性能

摘要 Sb 是一种非常有效的 ZrNiSn 基半赫斯勒合金掺杂剂。已经研究了 Ti 取代对 Zr0.75Hf0.25NiSn0.985Sb0.015 半赫斯勒 (HH) 半导体合金的影响，以探索结构修改和成分变化。TixHf0.25 Zr0.75-xNiSn0.985Sb0.015 (x = 0, 0.15, 0.30, 0.45)合金是通过感应熔炼合成的。一组样品也被退火用于比较研究。然后使用等离子体激活烧结 (PAS) 技术烧结样品。XRD 结果证实了 ZrNiSn 型 HH 化合物的存在。背散射电子 (BSE) 图像显示样品中的相分离。Ti取代提高了合金的载流子浓度和电导率。此外，由于声子散射增强，热导率也显着降低。