Laser-Written Domain Observation Using High Resolution Lorentz Microscopy

Abstract

-The performance of future generations of MO (Magneto-Optical) recording media will depend more strongly on domain edge features because of pulse width modulation (PWM) encoding requirements and higher domain densities. DirElct observation of these features would help greatly in correlating media performance to domain characteristics. This paper describes domain observation using Lorentz transmission electron microscopy (TEM) with a new sample preparation method; domains were dynamically written in thin films deposited on a large salt crystal substrate. Domains written both in a SiNlTbFeCo/SiN thin film stack and in a SiNlTbFeCo/SiN/AI-Cr thin film stack were examined and compared. Some relationships between domains and writing conditions were found. A resolution of near 10 nm was reached. It was also found that domain walls and microstructures, which are most likely columnar structures, were observed at the same time using high resolution Lorentz TEM.