Magneto-Optical Observation of Magnetic Domains in Rubbing Surface of a Ferrite Head

A magneto-optical microscope was used to observe in-plane magnetic domains. The magnetic contrast caused by the longitudinal Kerr rotation was optimized by adjusting an analyzer and a phase compensator. The contrast in the raw image detected by a CCD video camera was much improved by an image processor. Closure domains were clearly observed in both single layered and double layered permalloy thin square films. The magnetic domain wall was found to be Neel wall like. The observation revealed that the multidomain state is still stable in a 3 μm wide double layered permalloy film. Magnetic domains in rubbing surface of a ferrite head were successfully observed for the first. The magnetization reversal was expanded from near the head gap with reproducibility, when a coil current was increased in a direction opposite to the previous saturation current. A magnetization model was proposed to explain apparent hysteresis.