Efficient Spin-Orbit Torque Switching in a Perpendicularly Magnetized Heusler Alloy MnPtGe Single Layer.

Area of Science:

• Spintronics
• Materials Science
• Condensed Matter Physics

Background:

• Spin-orbit torque (SOT) enables electrical manipulation of magnetic moments for memory and logic devices.
• Existing SOT studies on heterostructures face challenges with interfacial thermal stability and high switching current density.

Purpose of the Study:

• To investigate the SOT switching behavior in polycrystalline Heusler alloy MnPtGe (MPG) single layers.
• To explore the potential of MPG films for efficient and high-density spintronic applications.

Main Methods:

• Deposition of highly textured MPG films with varying thicknesses onto silicon wafers.
• Electrical current pulse measurements to induce and verify magnetic switching.
• Magnetic optical measurements for confirmation of magnetization reversal.
• Analysis of SOT effective fields and dependence on film thickness.

Main Results:

• Reversible switching of perpendicular magnetization in MPG single layers achieved with low current density (4.1 × 10¹⁰ Am^-2).
• Switching mechanism attributed to inversion symmetry breaking from vertical composition gradients after annealing.
• SOT efficiency increases with film thickness, indicating bulk-like behavior.
• Observed memristive characteristics due to multidomain switching.
• Deterministic field-free switching demonstrated via in-plane symmetry breaking.

Conclusions:

• MnPtGe (MPG) is a suitable material for efficient magnetoresistive random-access memory (MRAM) and other spintronic devices.
• The observed phenomena pave the way for developing next-generation, high-density, and low-power spintronic technologies.