Realisation of magnetically and atomically abrupt half-metal/semiconductor interface: Co2FeSi0.5Al0.5/Ge(111): Co2FeSi0.5Al0.5/Ge(111)

TY - JOUR

T1 - Realisation of magnetically and atomically abrupt half-metal/semiconductor interface: Co2FeSi0.5Al0.5/Ge(111)

T2 - Co2FeSi0.5Al0.5/Ge(111)

AU - Nedelkoski, Zlatko

AU - Kuerbanjiang, Balati

AU - Glover, Stephanie E

AU - Sanchez, Ana M.

AU - Kepaptsoglou, Demie

AU - Ghasemi, Arsham

AU - Burrows, Christopher W

AU - Yamada, Shinya

AU - Hamaya, Kohei

AU - Ramasse, Quentin M

AU - Hasnip, Philip J

AU - Hase, Thomas

AU - Bell, Gavin R.

AU - Hirohata, Atsufumi

AU - Lazarov, Vlado K

N1 - © The Author(s) 2016

PY - 2016/11/21

Y1 - 2016/11/21

N2 - Halfmetal-semiconductor interfaces are crucial for hybrid spintronic devices. Atomically sharp interfaces with high spin polarisation are required for efficient spin injection. In this work we show that thin film of half-metallic full Heusler alloy Co2FeSi0.5Al0.5 with uniform thickness and B2 ordering can form structurally abrupt interface with Ge(111). Atomic resolution energy dispersive X-ray spectroscopy reveals that there is a small outdiffusion of Ge into specific atomic planes of the Co2FeSi0.5Al0.5 film, limited to a very narrow 1 nm interface region. First-principles calculations show that this selective outdiffusion along the Fe-Si/Al atomic planes does not change the magnetic moment of the film up to the very interface. Polarized neutron reflectivity, x-ray reflectivity and aberration-corrected electron microscopy confirm that this interface is both magnetically and structurally abrupt. Finally, using first-principles calculations we show that this experimentally realised interface structure, terminated by Co-Ge bonds, preserves the high spin polarization at the Co2FeSi0.5Al0.5/Ge interface, hence can be used as a model to study spin injection from half-metals into semiconductors.

AB - Halfmetal-semiconductor interfaces are crucial for hybrid spintronic devices. Atomically sharp interfaces with high spin polarisation are required for efficient spin injection. In this work we show that thin film of half-metallic full Heusler alloy Co2FeSi0.5Al0.5 with uniform thickness and B2 ordering can form structurally abrupt interface with Ge(111). Atomic resolution energy dispersive X-ray spectroscopy reveals that there is a small outdiffusion of Ge into specific atomic planes of the Co2FeSi0.5Al0.5 film, limited to a very narrow 1 nm interface region. First-principles calculations show that this selective outdiffusion along the Fe-Si/Al atomic planes does not change the magnetic moment of the film up to the very interface. Polarized neutron reflectivity, x-ray reflectivity and aberration-corrected electron microscopy confirm that this interface is both magnetically and structurally abrupt. Finally, using first-principles calculations we show that this experimentally realised interface structure, terminated by Co-Ge bonds, preserves the high spin polarization at the Co2FeSi0.5Al0.5/Ge interface, hence can be used as a model to study spin injection from half-metals into semiconductors.

U2 - 10.1038/srep37282

DO - 10.1038/srep37282

M3 - Article

C2 - 27869132

SN - 2045-2322

VL - 6

SP - 37282

JO - Scientific Reports

JF - Scientific Reports

M1 - 37282

ER -