Electrical Investigation of the Oblique Hanle Effect in Ferromagnet/Oxide/Semiconductor Contacts

Abstract

We have investigated the electrical Hanle effect with magnetic fields applied at an oblique angle (θ) to the spin direction (the oblique Hanle effect, OHE) in CoFe/MgO/semiconductor (SC) contacts by employing a three-terminal measurement scheme. The electrical oblique Hanle signals obtained in CoFe/MgO/Si and CoFe/MgO/Ge contacts show clearly different line shapes depending on the spin lifetime of the host SC. Notably, at moderate magnetic fields, the asymptotic values of the oblique Hanle signals (in both contacts) are consistently reduced by a factor of cos^2(θ) irrespective of the bias current and temperature. These results are in good agreement with predictions of the spin precession and relaxation model for the electrical oblique Hanle effect. At high magnetic fields where the magnetization of CoFe is significantly tilted from the film plane to the magnetic field direction, we find that the observed angular dependence of voltage signals in the CoFe/MgO/Si and CoFe/MgO/Ge contacts are well explained by the OHE, considering the misalignment angle between the external magnetic field and the magnetization of CoFe.

19 pages, 8 figures

References in corpus (3)

• Electrical Detection of Spin Accumulation at a Ferromagnet-Semiconductor Interface
• Comment: "Electrical injection and detection of spin accumulation in silicon at 500 K with magnetic metal / silicon dioxide contacts" [Nature Commun. 2:245 doi:10.1038/ncomms125 (2011)]
• Oblique Hanle Effect in Semiconductor Spin Transport Devices

Cited by in corpus (3)

• Magnetic-Field-Modulated Resonant Tunneling in Ferromagnetic-Insulator-Nonmagnetic junctions
• Thermal spin injection and accumulation in CoFe/MgO tunnel contacts to n-type Si through Seebeck spin tunneling
• Spin accumulation detection of FMR driven spin pumping in silicon-based metal-oxide-semiconductor heterostructures