Current-induced magnetic switching with spin-orbit torque in an interlayer-coupled junction with a Ta spacer layer

Area of Science:

• Spintronics
• Materials Science
• Condensed Matter Physics

Background:

• Spin-orbit torque (SOT) offers an alternative to spin-transfer torque (STT) for magnetic switching.
• Deterministic SOT switching typically requires an external magnetic field to break symmetry.
• Previous work demonstrated field-free switching using Ru-mediated interlayer coupling.

Purpose of the Study:

• To investigate field-free current-induced magnetization switching in a Co/Ta/CoFe heterostructure.
• To explore the role of Ta as a spacer layer in mediating interlayer coupling for SOT.

Main Methods:

• Fabrication of Co/Ta/CoFe heterostructures with varying Ta layer thicknesses.
• Electrical characterization of current-induced magnetization switching.
• Analysis of switching behavior under varying external magnetic fields.

Main Results:

• Demonstrated zero-field current-induced switching of perpendicular magnetization in Co/Ta/CoFe.
• Identified Ta as a suitable spacer for achieving SOT switching due to weak interlayer coupling.
• Optimized Ta layer thickness (≈0.5 nm) for effective SOT-induced switching.
• Confirmed stability of the switching process against external magnetic fields.

Conclusions:

• Ta-mediated interlayer coupling enables efficient spin-orbit torque for field-free magnetization switching.
• The Co/Ta/CoFe system provides a robust platform for advanced spintronic devices.
• This approach overcomes the need for external magnetic fields, simplifying device design and operation.