Correlation between magnetic properties and phase-separated microstructure of electroless CoNiP perpendicular magnetic recording media

Abstract

Correlation between magnetic and structural properties of electroless-deposited CoNiP films for the use of perpendicular magnetic recording media was studied, focusing upon their phase-separated structure in nanometer scale. The media with various perpendicular coercivity, Hc(⊥), were examined and it was clarified that higher Hc(⊥) medium showed a clearer phase-separated condition, which was confirmed by the selective chemical-etching technique. It was strongly indicated that such a structure plays an important role in attaining a high Hc(⊥) and in forming an hcp structure in a film with a Ni-rich average composition.