Method of forming modified portion and magnetic recording member using this method

摘要

A member is prepared by forming a magnetic surface layer on a magnetic base member having a different composition from the surface layer. A laser beam is radiated onto the member so as to fuse the member and the surface layer, thereby forming a fused portion having magnetic properties. A modified portion is formed in a portion of the fused portion corresponding to the surface layer such that this portion has different permeability from other portions of the surface layer.