skip to main content

Title: The effect of atomic structure on interface spin-polarization of half-metallic spin valves: Co{sub 2}MnSi/Ag epitaxial interfaces

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.
Authors:
; ; ; ;  [1] ; ;  [2] ;  [3] ;  [4] ;  [5]
  1. Department of Physics, University of York, York YO10 5DD (United Kingdom)
  2. Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)
  3. Department of Applied Physics, Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-05, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)
  4. Department of Electronics, University of York, York YO10 5DD (United Kingdom)
  5. (Japan)
Publication Date:
OSTI Identifier:
22486127
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DENSITY FUNCTIONAL METHOD; ELECTRON MICROSCOPY; EPITAXY; FERMI LEVEL; INTERFACES; LAYERS; POLARIZATION; SPIN; SPIN ORIENTATION; SWITCHES; VALVES