Quantification of local remanence magnetization in perpendicular magnetic recording film by scanning interference electron microscopy

Abstract

The local remanence magnetization of perpendicular magnetic recording bit patterns has been quantified by scanning interference electron microscopy. When two coherent probes run across each bit, the interference image contrast changes periodically with a unit of h/e (h: Planck’s constant, e: electron charge). Our numerical analysis shows that the magnetic field effect on the image contrast is less than 1/1000 that of the magnetization under the experimental conditions. This allows the local remanence magnetization of the film to be determined accurately by averaging the periodic contrast change measured over repetitive bit patterns. From the interference image of bit patterns on a Co (0.4 nm)/Pt (1.2 nm)×18 layered film, a value of 1.4×10−8 T m was obtained as the product of the remanence and the film thickness.