title: Controlling the half-metallicity of Heusler/Si(1 1 1) interfaces by a monolayer of Si-Co-Si.
abstract: By using first-principles calculations we show that the spin-polarization reverses its sign at atomically abrupt interfaces between the half-metallic Co2(Fe,Mn)(Al,Si) and Si(1 1 1). This unfavourable spin-electronic configuration at the Fermi-level can be completely removed by introducing a Si-Co-Si monolayer at the interface. In addition, this interfacial monolayer shifts the Fermi-level from the valence band edge close to the conduction band edge of Si. We show that such a layer is energetically favourable to exist at the interface. This was further confirmed by direct observations of CoSi2 nano-islands at the interface, by employing atomic resolution scanning transmission electron microscopy.
authors: Department of Physics, University of York, Heslington, York, YO10 5DD, UK.
authors: Zlatko
authors: Z
authors: Nedelkoski
authors: SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, UK.
authors: Demie
authors: D
authors: Kepaptsoglou
authors: Department of Physics, University of York, Heslington, York, YO10 5DD, UK.
authors: Arsham
authors: A
authors: Ghasemi
authors: Department of Physics, University of York, Heslington, York, YO10 5DD, UK.
authors: Barat
authors: B
authors: Achinuq
authors: Department of Physics, University of York, Heslington, York, YO10 5DD, UK.
authors: Philip J
authors: PJ
authors: Hasnip
authors: Department of Systems Innovation, Osaka University, Osaka 560-8531, Japan.
authors: Shinya
authors: S
authors: Yamada
authors: Department of Systems Innovation, Osaka University, Osaka 560-8531, Japan.
authors: Kohei
authors: K
authors: Hamaya
authors: SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, UK.
authors: Quentin M
authors: QM
authors: Ramasse
authors: Department of Electronics, University of York, York, YO10 5DD, UK.
authors: Atsufumi
authors: A
authors: Hirohata
authors: Department of Physics, University of York, Heslington, York, YO10 5DD, UK.
authors: Vlado K
authors: VK
authors: Lazarov