TY - JOUR
T1 - The effect of atomic structure on interface spin-polarization of half-metallic spin valves:
T2 - Co2MnSi/Ag epitaxial interfaces
AU - Nedelkoski, Zlatko
AU - Hasnip, Philip J.
AU - Sanchez, Ana M.
AU - Kuerbanjiang, Balati
AU - Higgins, Edward
AU - Oogane, Mikihiko
AU - Hirohata, Atsufumi
AU - Bell, Gavin R.
AU - Lazarov, Vlado K.
PY - 2015/11/23
Y1 - 2015/11/23
N2 - Using density functional theory calculations motivated by aberration-corrected electron microscopy, we show how the atomic structure of a fully epitaxial Co2MnSi/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 Co2MnSi/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 Co2MnSi electrode does not have a significant effect on the overall Co2MnSi /Ag performance.
AB - Using density functional theory calculations motivated by aberration-corrected electron microscopy, we show how the atomic structure of a fully epitaxial Co2MnSi/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 Co2MnSi/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 Co2MnSi electrode does not have a significant effect on the overall Co2MnSi /Ag performance.
UR - http://www.scopus.com/inward/record.url?scp=84948446276&partnerID=8YFLogxK
U2 - 10.1063/1.4936630
DO - 10.1063/1.4936630
M3 - Article
AN - SCOPUS:84948446276
SN - 0003-6951
VL - 107
SP - 1
EP - 5
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 21
ER -