Effect of Nonmagnetic Underlayer on Structural and Magnetic Properties of CoCr-alloy Thin Film Media

Abstract

Microstructures of CoCr-alloy thin film media were investigated by cross-sectional transmission electron microscopy focussing on the initial growth region of the magnetic layer grown on nonmagnetic underlayers. An introduction of nonmagnetic hcp-CoCrRu layer between an hcp-CoCrPt recording layer and an hcp- or a bcc-underlayer improved the crystallographic quality of the initial growth region. Coercivity and squareness of thin film media increased by realizing good hetero-epitaxy between the nonmagnetic and the magnetic hcp-layers.