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Title: Maximum magnitude in bias-dependent spin accumulation signals of CoFe/MgO/Si on insulator devices

We study in detail how the bias voltage (V{sub bias}) and interface resistance (RA) depend on the magnitude of spin accumulation signals (|ΔV| or |ΔV|/I, where I is current) as detected by three-terminal Hanle measurements in CoFe/MgO/Si on insulator (SOI) devices with various MgO layer thicknesses and SOI carrier densities. We find the apparent maximum magnitude of spin polarization as a function of V{sub bias} and the correlation between the magnitude of spin accumulation signals and the shape of differential conductance (dI/dV) curves within the framework of the standard spin diffusion model. All of the experimental results can be explained by taking into account the density of states (DOS) in CoFe under the influence of the applied V{sub bias} and the quality of MgO tunnel barrier. These results indicate that it is important to consider the DOS of the ferromagnetic materials under the influence of an applied V{sub bias} and the quality of tunnel barrier when observing large spin accumulation signals in Si.
Authors:
; ; ; ;  [1] ;  [2] ;  [3]
  1. Corporate Research and Development Center, Toshiba Corporation, 1 Komukai Toshiba-cho, Kawasaki, Kanagawa 212-8582 (Japan)
  2. Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan)
  3. Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aramaki-aza-Aoba, Sendai, Miyagi 980-8579 (Japan)
Publication Date:
OSTI Identifier:
22267786
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 24; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BUILDUP; CARRIER DENSITY; CORRELATIONS; DIFFUSION BARRIERS; ELECTRIC POTENTIAL; FERROMAGNETIC MATERIALS; MAGNESIUM OXIDES; SIGNALS; SPIN; SPIN ORIENTATION; THICKNESS; TUNNELS; VENTILATION BARRIERS