Room temperature electrical spin injection into GaAs by an oxide spin injector

Area of Science:

• Materials Science
• Condensed Matter Physics
• Semiconductor Physics

Background:

• Spintronics devices rely on spin injection, manipulation, and detection.
• Conventional metallic magnets have been used for spin injection into semiconductors.
• Material compatibility with existing semiconductor technology is crucial.

Purpose of the Study:

• To demonstrate electrical spin injection from an oxide magnetic material (Fe3O4) into GaAs.
• To investigate spin injection using a MgO tunnel barrier at room temperature.
• To establish a platform for room-temperature oxide-based spintronics devices.

Main Methods:

• Utilized a 3-terminal Hanle measurement technique.
• Employed Fe3O4/MgO heterostructures for spin injection.
• Investigated spin injection into both n-GaAs and p-GaAs.

Main Results:

• Achieved electrical spin injection from Fe3O4 into n-GaAs at room temperature.
• Measured a spin relaxation time (τ) of ~0.9 ns for n-GaAs at 300 K.
• Observed a spin relaxation time (τ) of ~0.32 ns for p-GaAs at 300 K.
• Demonstrated enhanced spin injection efficiency with increasing MgO barrier thickness.

Conclusions:

• Fe3O4/MgO system enables efficient room-temperature spin injection into GaAs.
• The study provides a viable platform for developing oxide-based spintronics.
• Oxide magnetic materials offer a promising alternative for spintronics applications compatible with semiconductor technology.