Growth of Columnar Co 3 Pt Strucrure with Ru Buffer Layer at Room Temperature

Abstract

Magnetic Co3Pt films were sputtered on a Ru(0002)/Pt(111) bilayer on glass substrate at room temperature. The effects of a Ru buffer layer thickness (t nm) on magnetic properties and microstructures were studied. AFM surface roughness results revealed that the root mean square roughness (Rrms) of the Ru/Pt bilayer surface is smaller than 1.5 nm. Granular Ru topography was observed as t is larger than 7 nm, which played an important role in influencing the magnetic properties and microstructures of Co3Pt thin film. In this study, Ru(0002) grew along the Pt(111) underlayer and then became a template for epitaxially growing Co3Pt(0002) film, in order to enhance the perpendicular magnetic anisotropy (PMA). Maximum Hc were obtained as t=15, due to the columnar structure formed in the whole Co3Pt/Ru/ Pt film. It demonstrates that a Ru buffer layer is helpful to enhance the PMA of Co3Pt magnetic thin film and increase out-of-plane squareness (S⊥) and Hc.