Characterization of Magnetic Thin Films and Spintronic Devices Using Magneto-optic Kerr Microscopy

The magneto-optical Kerr microscopy, which allows to observe the magnetic domain structure with high sensitivity, relatively high resolution, and high dynamic performance, is becoming a basic instrument to study the properties of magnetic materials or spintronic devices. Thanks to advantages such as configuration flexibility and high compatibility with magnetic fields, electric tests, and cryogenics, a series of typical experimental research based on magneto-optical Kerr microscopy has been developed to study problems mainly involving magnetic domain morphology and dynamics. This review summarizes some classical experimental methods based on Kerr microscopy developed in recent years and their applications on material studies or spintronics device development, including the qualitative and quantitative study of defects in magnetic material, the measurement of magnetic parameters including saturation magnetization, the Heisenberg exchange stiffness, and Dzyaloshinskii–Moriya interactions, the analysis of the spin-transfer torque, or spin–orbit torque-induced magnetic dynamic in spintronic devices.