Temperature-dependent spin polarization of Heusler Co2MnSi from the disordered local-moment approach: Effects of atomic disordering and nonstoichiometry

Journal article

Half-metallic ferromagnets have been widely investigated by first-principles density-functional theory (DFT) calculations, but extending such studies to investigate spin-polarization at finite temperatures is still challenging due to the difficulty of incorporating temperature effects appropriately. We present DFT calculations, based on a Green's function formulation, which include thermal effects via the disordered local-moment method to address this issue. The calculations are carried out for Heusler Co2MnSi alloys in order to investigate the temperature dependence of spin polarization, where atomic-disordering and nonstoichiometric effects are taken into account. Our results show that the spin polarization strongly depends on temperature and that a Co d-orbital effect plays a key role in this effect. Furthermore, we find that the temperature-dependent spin polarization of Co2MnSi can be improved by reducing the Co content and incorporating extra Mn.

Authors: Nawa, K; Kurniawan, I; Masuda, K; Miura, Y; Patrick, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review B
• Volume: 102
• Issue: 5
• Article number: 054424
• Publication date: 2020-08-18
• Acceptance date: 2020-07-24
• DOI: 10.1103/physrevb.102.054424
• EISSN: 2469-9969
• ISSN: 2469-9950
• Language: English
• Keywords: FFR