The effect of atomic structure on interface spin-polarization of half-metallic spin valves: Co{sub 2}MnSi/Ag epitaxial interfaces
- Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-05, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)
- Department of Electronics, University of York, York YO10 5DD (United Kingdom)
Using density functional theory calculations motivated by aberration-corrected electron microscopy, we show how the atomic structure of a fully epitaxial Co{sub 2}MnSi/Ag interfaces controls the local spin-polarization. The calculations show clear difference in spin-polarization at Fermi level between the two main types: bulk-like terminated Co/Ag and Mn-Si/Ag interfaces. Co/Ag interface spin-polarization switches sign from positive to negative, while in the case of Mn-Si/Ag, it is still positive but reduced. Cross-sectional atomic structure analysis of Co{sub 2}MnSi/Ag interface, part of a spin-valve device, shows that the interface is determined by an additional layer of either Co or Mn. The presence of an additional Mn layer induces weak inverse spin-polarisation (−7%), while additional Co layer makes the interface region strongly inversely spin-polarized (−73%). In addition, we show that Ag diffusion from the spacer into the Co{sub 2}MnSi electrode does not have a significant effect on the overall Co{sub 2}MnSi /Ag performance.
- OSTI ID:
- 22486127
- Journal Information:
- Applied Physics Letters, Vol. 107, Issue 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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