Spin transport and accumulation in n{sup +}-Si using Heusler compound Co{sub 2}FeSi/MgO tunnel contacts

Journal Article · Mon Aug 31 04:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4929888· OSTI ID:22489202

Ishikawa, Mizue; Sugiyama, Hideyuki; Inokuchi, Tomoaki; Saito, Yoshiaki ^[1]; Hamaya, Kohei ^[2]

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1. Corporate Research and Development Center, Toshiba Corporation, 1 Komukai-Toshiba-cho, Kawasaki, Kanagawa 212-8582 (Japan)
2. Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka City, Osaka 560-8531 (Japan)

We investigate spin transport and accumulation in n{sup +}-Si using Heusler compound Co{sub 2}FeSi/MgO/Si on insulator (SOI) devices. The magnitudes of the non-local four- and three-terminal Hanle effect signals when using Heusler compound Co{sub 2}FeSi/MgO/SOI devices are larger than when using CoFe/MgO/SOI devices, whereas the preparation methods of MgO layers on SOI are exactly same in both devices. Different bias voltage dependencies on the magnitude of spin accumulation signals are also observed between these devices. Especially, Co{sub 2}FeSi/MgO/SOI devices show large spin accumulation signals compared with CoFe/MgO/SOI devices in the low bias voltage region less than ∼1000 mV in which the increase of the spin polarization is expected from the estimation of the density of states in Heusler compound Co{sub 2}FeSi and CoFe under spin extraction conditions. These results indicate that the species of ferromagnetic material definitely affects the magnitude and behavior of the spin signals. The use of highly polarized ferromagnets such as Heusler compounds would be important for improving the spin polarization and the magnitude of spin signals through Si channels.

• OSTI ID: 22489202
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 9 Vol. 107; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DENSITY OF STATES
ELECTRIC POTENTIAL
FERROMAGNETIC MATERIALS
LAYERS
MAGNESIUM OXIDES
NITROGEN IONS
SIGNALS
SPIN
SPIN ORIENTATION