English

On the structure and electronic properties of Fe$_2$V$_{0.8}$W$_{0.2}$Al thin films

Materials Science 2020-12-02 v2

Abstract

A very large thermoelectric figure of merit ZT = 6 at 380 K has recently been reported in Fe2_2V0.8_{0.8}W0.2_{0.2}Al under thin-film form (Hinterleitner et al., Nature 576 (2019) 85). Under this form, Fe2_2V0.8_{0.8}W0.2_{0.2}Al experimentally crystallizes in a disordered A2 crystal structure, different from its bulk-form structure (L21). First principles calculations of the electronic structure performed in A2-Fe2_2V0.8_{0.8}W0.2_{0.2}Al supercells generated by the Special Quasi-random Structure (SQS) method are thus reported here. These calculations unambiguously indicate that A2-Fe2_2V0.8_{0.8}W0.2_{0.2}Al is a ferromagnetic metal at 0 K, displaying a small Seebeck coefficient at 400 K (< 30 microV/K). The present results contradict the scenario of the occurrence of a deep pseudo-gap at the Fermi level, previously invoked to justify ZT = 6 in Fe2_2V0.8_{0.8}W0.2_{0.2}Al thin films.

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Cite

@article{arxiv.2006.11003,
  title  = {On the structure and electronic properties of Fe$_2$V$_{0.8}$W$_{0.2}$Al thin films},
  author = {E. Alleno and A. Berche and J. -C. Crivello and A. Diack Rasselio and P. Jund},
  journal= {arXiv preprint arXiv:2006.11003},
  year   = {2020}
}