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arXiv · 1805.02435

High-temperature thermoelectric properties of half-Heusler phases Er$_{1-x}$Ho$_x$NiSb

Kamil Ciesielski·Karol Synoradzki·Izabela Wolańska·Paweł Stuglik·Dariusz Kaczorowski
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Abstract

Polycrystalline samples of Er$_{1-x}$Ho$_x$NiSb ($x$ = 0, 0.2, 0.3, 0.5, 0.7, 0.8, 1) were characterized by means of x-ray powder diffraction (XRD), scanning electron microscopy (SEM), and optical metallography. The results proved the formation of half-Heusler alloys in the entire composition range. Their electrical transport properties (resistivity, thermoelectric power) were studied in the temperature interval 350-1000 K. The measured electrical resistivity spanned between 5 and 25 $\mu \Omega$m. The maximum thermopower of 50-65 $\mu$V/K was observed at temperatures 500-650 K. Replacing Ho for Er resulted in a non-monotonous variation of the thermoelectric power factor ($PF = S^2/\rho$). The largest $PF$ of 4.6 $\mu$WcmK$^{-2}$ was found at 660 K for Er$_{0.5}$Ho$_{0.5}$NiSb. This value is distinctly larger than PF determined for the terminal phases ErNiSb and HoNiSb.

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Kamil Ciesielski, Karol Synoradzki, Izabela Wolańska, Paweł Stuglik, Dariusz Kaczorowski. 2018-05-07. High-temperature thermoelectric properties of half-Heusler phases Er$_{1-x}$Ho$_x$NiSb. https://arxiv.org/abs/1805.02435

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