Electrochemical post treatment of perpendicular magnetic recording media

摘要

A method of electrochemical post treatment to a continuous thin film magnetic medium designed for perpendicular recording comprising a substrate upon which is deposited a thin magnetic layer comprising acicular shaped crystalline magnetic particles with the crystallographic "c" axis of the crystal in each particle oriented parallel to the longitudinal axis of the particle acicula and the longitudinal axis of the acicular particles oriented substantially normal to the plane of said magnetic layer, the post treatment effectively increasing the separation between magnetic particles and thereby increasing their coercivity while decreasing their demagnetization field of the film. The method comprises the step of utilizing enhanced grain boundary reaction at the interganular boundary of the acicular particles to achieve particle separation effectively either by electrochemical charging by cathodic action in solution or electrochemical etching by anodic action in solution. The magnetic layer may be initially fabricated, for example, by an electrochemical plating, sputtering or vaccuum deposited method.