High-performance half-Heusler thermoelectric materials Hf1−x ZrxNiSn1−ySby prepared by levitation melting and spark plasma sintering

✍ Scribed by Cui Yu; Tie-Jun Zhu; Rui-Zhi Shi; Yun Zhang; Xin-Bing Zhao; Jian He

• Book ID: 103998802
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 797 KB
• Volume: 57
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2009.02.026

✦ Synopsis

Half-Heusler thermoelectric materials Hf 1Àx Zr x NiSn 1Ày Sb y (x = 0, 0.25, 0.4, 0.5; y = 0.02, 0.04, 0.06) have been prepared by levitation melting followed by spark plasma sintering or hot pressing. X-ray diffraction analysis and scanning electron microscopy observation show that single-phased half-Heusler compounds without compositional segregations have been obtained by levitation melting in a timeefficient manner. A small amount of Sb doping can improve the electrical power factor but undesirably increases the thermal conductivity due to the increased carrier thermal conductivity. The isoelectronic substitution of Zr for Hf substantially decreased the lattice thermal conductivity. A state-of-the-art ZT value of 1.0 has been attained at 1000 K for the levitation-melted and spark-plasma-sintered Hf 0.6 Zr 0.4 NiSn 0.98 Sb 0.02 , which is one of the highest achieved ZT values for half-Heusler thermoelectric alloys.