A versatile method for exploring the magnetooptical properties of polar saturated and unsaturated ferromagnetic metallic thin films

Abstract

Abstract Polar unsaturated ferromagnetic thin films are promising for low-power and high-speed nonvolatile resistive and optical memories. Here we measure the magnetooptical (MO) response of polar unsaturated Co90Fe10 and Co40Fe40B20 thin films in the spectral range from 400 nm to 1000 nm using vector MO generalized ellipsometry (VMOGE) in an out-of-plane applied magnetic field of ±0.4 T where magnetization of the ferromagnetic (FM) thin film is not saturated. Using magnetooptical simulation software (MagOpS®), we extract the complex MO coupling constant ( Q ) of the polar unsaturated FM thin films from difference spectra of VMOGE data recorded in a polar configuration at Hz = +0.4 T and Hz = −0.4 T. The presented approach opens a path to determine Q of both polar saturated and polar unsaturated FM thin films for simulating the MO properties of application-relevant optical memory multilayer structures.