Ru/Ru-oxide interlayers for CoCrPtO perpendicular recording media

Abstract

A novel Ru/Ru-oxide interlayer structure was investigated to improve intergranular decoupling in a magnetic layer. The effect of this interlayer on the microstructure, and magnetic properties of CoCrPtO perpendicular media is reported. By using a Ru-oxide layer on a conventional Ru layer, the interlayer grain size was 11 nm. The resulting vertical c-axis dispersion of the interlayer was less than 3/spl deg/ with no disruption in epitaxial growth throughout the Ru/Ru-oxide and Ru-oxide/magnetic layer interfaces. Grain clusters in the CoCrPtO magnetic layer were observed to match one-to-one with interlayer grains, and were well isolated from each other by nonmagnetic oxide phase grain boundaries. A high coercivity (over 6.9 kOe) and a nucleation field of -2.8 kOe were obtained with this Ru (26 nm)/Ru-oxide (2 nm) interlayer structure.