Defect-driven antiferromagnetic domain walls in CuMnAs films

Area of Science:

• Materials Science
• Condensed Matter Physics
• Spintronics

Background:

• Efficient manipulation of antiferromagnetic (AF) domains and domain walls is crucial for developing ultrafast, high-density spintronic devices.
• The influence of magnetoelastic effects on AF domain structures is known, but the microscopic interplay with crystalline defects and strain is not well understood.

Purpose of the Study:

• To investigate the role of nanoscale crystalline defects in determining the antiferromagnetic domain structure in CuMnAs thin films.
• To elucidate the relationship between microtwin defects and the behavior of 180° and 90° domain walls.

Main Methods:

• Photoemission electron microscopy (PEEM)
• Scanning X-ray diffraction (XRD) imaging
• Micromagnetic simulations

Main Results:

• The antiferromagnetic domain structure in CuMnAs thin films is predominantly controlled by nanoscale structural twin defects.
• Microtwin defects spanning the film thickness and terminating at the surface dictate the location and orientation of domain walls.
• Both 180° and 90° domain walls are directly influenced by these microtwin defects.

Conclusions:

• Nanoscale crystalline defects, specifically microtwins, play a critical role in defining antiferromagnetic domains and domain walls in CuMnAs.
• This understanding provides a pathway for optimizing the performance of spintronic devices by controlling defect structures.