Ab initio phonon properties of half-Heusler NiTiSn, NiZrSn and NiHfSn - Université de Lorraine Access content directly
Journal Articles Journal of Physics: Condensed Matter Year : 2015

Ab initio phonon properties of half-Heusler NiTiSn, NiZrSn and NiHfSn

Abstract

A theoretical investigation of phonon properties from first-principles calculations is carried out for the half-Heusler compounds Ni X Sn, ##IMG## [http://ej.iop.org/images/0953-8984/27/42/425401/cmaa030bieqn001.gif] X=\textTi , Zr and Hf. The crystal structures are optimised via ab initio calculations within the framework of density functional theory. The phonon properties are retrieved from harmonic and anharmonic interatomic force constants calculations using the finite size displacements method and many-body perturbation theory. A solution to the linearized phonon Boltzmann transport equation is then used to compute the ab initio thermal conductivities. For X    =   Ti, Zr and Hf, we found 15.4, 13.3 and 15.8 W m −1 K −1 at 300 K, respectively. Thanks to a spectral analysis of the velocities and lifetimes we were able appreciate the differences in the thermal conductivities between the three compounds under study. Our results provide insights to understand the behaviour of the thermal conductivity and therefore to improve the thermoelectric figure of merit for such materials.
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Dates and versions

hal-01417584 , version 1 (15-12-2016)

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Luc Andrea, Gilles Hug, Laurent Chaput. Ab initio phonon properties of half-Heusler NiTiSn, NiZrSn and NiHfSn. Journal of Physics: Condensed Matter, 2015, 27 (42), pp.425401. ⟨10.1088/0953-8984/27/42/425401⟩. ⟨hal-01417584⟩
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