Electrical spin injection from highly spin polarized Co2CrAl Heusler alloy into non-magnetic p-Si semiconductor

To obtain a larger spin signal for use in graphene-based spintronic devices, the spin injection efficiency needs to be enhanced. Previously researchers can increase the efficiency by inserting a tunnel barrier such as Al2O3or MgO between ferromagnet and graphene. However, the key value in spin transport is still very low because of the conductance mismatch as well as the limit to fabricate a high-quality tunnel barrier at the junction surface. Here we use a highly spin-polarized ferromagnetic material—Heusler alloy Co2MnGe as a substitutional scheme without the tunnel barrier. The spin injection efficiency of our Co2MnGe (111)/graphene junction can be as high as 73% which is much higher than 1% of ferromagnet/graphene or 30% of ferromagnet/oxide/graphene using first-principles study. The large spin polarization can be explicated by analyzing the transmission spectrum at the nonequilibrium state.

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ELECTRICAL SPIN INJECTION FROM AN IRON-RICH IRON–PLATINUM THIN FILM INTO GALLIUM ARSENIDE

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863508003993 ◽

2008 ◽

Vol 17 (01) ◽

pp. 105-109

Author(s):

ASAWIN SINSARP ◽

TAKASHI MANAGO ◽

FUMIYOSHI TAKANO ◽

HIRO AKINAGA

Keyword(s):

Magnetic Field ◽

Thin Film ◽

Optical Measurement ◽

Light Emitting Diode ◽

Spin Injection ◽

Light Emitting ◽

Iron Platinum ◽

Spin Polarized ◽

Out Of Plane ◽

Electrical Spin

We fabricated an FePt / MgO tunneling junction ( Fe 55 atomic %) on a GaAs -based light-emitting-diode structure. The out-of-plane magnetization of the FePt thin film was confirmed by a magneto-optical measurement. The electrical spin injection from FePt into GaAs at room temperature was studied using the technique of spin-polarized electroluminescence. The spin polarization of the injected electrons under the magnetic field of 1 T was at least 6.0%. The remnant polarization at 0 T, which indicates the spin injection without a magnetic field, was at least 3.3%.

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Electrical Spin Injection and Transport in Semiconductor Spintronic Devices

MRS Bulletin ◽

10.1557/mrs2003.216 ◽

2003 ◽

Vol 28 (10) ◽

pp. 740-748 ◽

Cited By ~ 36

Author(s):

B.T. Jonker ◽

S.C. Erwin ◽

A. Petrou ◽

A.G. Petukhov

Keyword(s):

Resonant Tunneling ◽

Spin Injection ◽

Polarized Light ◽

Semiconductor Heterostructures ◽

Light Emitting ◽

Spintronic Devices ◽

Tunneling Diode ◽

Spin Polarized ◽

Interband Tunneling ◽

Electrical Spin

AbstractSemiconductor heterostructures that utilize carrier spin as a new degree of freedom offer entirely new functionality and enhanced performance over conventional devices. We describe the essential requirements for implementing this technology, focusing on the materials and interface issues relevant to electrical spin injection into a semiconductor. These are discussed and illustrated in the context of several prototype semiconductor spintronic devices, including spin-polarized light-emitting diodes and resonant tunneling structures such as the resonant interband tunneling diode.

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