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First-principles calculations of finite temperature electronic structures and transport properties of Heusler alloy Co2MnSi

Authors :
Tetsuya Fukushima
Hikari Shinya
Hisazumi Akai
Hiroshi Katayama-Yoshida
Kazunori Sato
Akira Masago
S. Kou
Source :
Applied Physics Letters. 117:042402
Publication Year :
2020
Publisher :
AIP Publishing, 2020.

Abstract

In this study, we calculate the temperature-dependent electronic structures and transport properties of the Heusler alloy Co2MnSi on the basis of the Korringa–Kohn–Rostoker Green's function method combined with the coherent potential approximation (CPA). Temperature effects often have a significant influence on the spin-polarization properties of Heusler alloys. To incorporate the contributions of temperature effects, we first consider lattice vibrations and spin fluctuations. Using CPA, we can replace them with random displacements due to local phonons and local magnetic moment disorders, respectively. In the Co2MnSi Heusler alloy, we found that the band structures are smeared by the electron–phonon scattering process and the half-metallic property is eliminated by magnon excitations from the spin-up to spin-down states. Furthermore, we can estimate the electrical resistivity as a function of temperature in the scheme of linear response theory. Including the local phonon disorder, local moment disorder, and Mn–Co antisite disorder in CPA, we can reproduce the temperature-dependent resistivity observed by experiments.

Details

ISSN :
10773118 and 00036951
Volume :
117
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........ff4525be99af03ca34d2701b21e530b2
Full Text :
https://doi.org/10.1063/5.0017862