Pt-Cr Alloy Intermediate Layer for CoCrPt-SiO $_2$ Granular Perpendicular Recording Media

We studied Pt-Cr binary alloys as a possible material for the intermediate layer (IML) in CoCrPt-SiO 2 perpendicular recording media. We investigated the magnetic properties, structural properties, and recording performance of CoCrPt-SiO 2 media with Pt-Cr alloy IMLs as a function of the Cr composition in the Pt-Cr IMLs. The CoCrPt-SiO 2 media exhibited the best recording performance at the Cr composition from 20 to 30 at.%, where the structural and magnetic defects in the CoCrPt-SiO 2 layers appeared to be minimized. Plan-view transmission electron microscopy images revealed that the addition of Cr into a Pt IML reduces the size of the crystal grains in the IML and promotes the formation of the oxide grain boundary in the CoCrPt-SiO 2 layers.