Transport and thermoelectric properties of melt spinning synthesized M2FeNiSb2 (M = Ti, Hf) double half Heusler alloys

• Published in: Materials research bulletin Vol. 164; p. 112246
• Main Authors: Hassan, Mohamed Asran, El-Khouly, A., Elsehly, E.M., Almutib, Eman N, Elshamndy, Samah K., Serhiienko, I., Argunov, E.V., Sedegov, A., Karpenkov, D., Pashkova, D., Gorshenkov, M., Novitskii, A., Voronin, A., Kostishyn, V., Khovaylo, V., Adam, A.M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2023
• Subjects: Heusler alloys; Melt spinning; Spark plasma sintering; Thermal conductivity; Thermoelectric materials; Heusler alloys; Thermoelectric materials; Thermal conductivity; Melt spinning; Spark plasma sintering
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2023.112246

•P-type Hf2FeNiSb2 and Ti2FeNiSb2, prepared by melt spinning method.•The samples sintered with spark plasma.•Thermoelectric properties were studied as functions of temperature from 300 K to 900 K.•Morphology and grain sizes were examined by SEM analysis.•The maximum seebeck coefficient was obtained for Ti2FeNiSb2 with a value of 293µV/K at 575 K.•The maximum zT value at 874 K was achieved for Hf2FeNiSb2 sample. In this study, we report on structural and thermoelectric properties of novel Heusler compounds Hf2FeNiSb2 and Ti2FeNiSb2. Polycrystalline samples were successfully synthesized by arc melting and melt spinning techniques and consolidated by spark plasma sintering method. The studied compounds were found to crystallize in a face centered cubic crystal structure, as can be judged by superstructural reflections, clearly seen on the X-ray diffraction patterns. Morphology and grain sizes were examined by SEM analysis, showing homogeneity and high density of grains in the synthesized samples. Electrical conductivity and Seebeck coefficient were investigated in a range of temperatures between 300 and 900 K. Thermal conductivity was measured in the same temperature range and found to be significantly lower than that previously reported for related half-Heusler alloys such as TiCoSb. The thermoelectric figure of merit of the concerned Hf2FeNiSb2 and Ti2FeNiSb2 samples was found at 0.082 and 0.027, respectively, at 874 K. [Display omitted]