Ru x Cr 1−x / Ta underlayer for Co-alloy perpendicular magnetic recording

Abstract

The effects of the RuxCr1−x/Ta underlayer on the microstructural and magnetic properties of CoCrPtB perpendicular films were investigated. The hcp RuxCr1−x (0002) texture was observed to grow perpendicular to the film plane with narrow rocking curves of 2°–3°. High-resolution transmission electron microscopy indicated epitaxial growth of the CoCrPtB on top of the RuxCr1−x/Ta underlayer. In-plane x-ray diffraction scans indicate that as the Cr atomic composition increases in the RuxCr1−x underlayer, the a-lattice parameter was found to contract more closely matching the CoCrPtB a-lattice parameter [measured with (112̄0)]. In addition, the rocking curves for the CoCrPtB (0002)-texture induced by the (0002) textured RuxCr1−x buffer showed narrowing peaks (4.5°–3.5°) as the Cr concentration increased from 0% to 40%.