Effect of Interlayers Upon Texture and Magnetic Properties in Co Alloy Multilayer Films for Longitudinal Magnetic Recording

Abstract

ABSTRACTCoCrNi bilayer films with Cr, Ti and Zr interlayers were deposited by DC magnetron sputtering onto ultra densified amorphous carbon substrates and characterized using cross-section transmission electron microscopy and vibrating sample magnetometry. The films are polycrystalline with a columnar microstructure. In the Cr interlayer case there is layer-to-layer epitaxy throughout a given column. Magnetic measurements snowed a simple in-plane easy axis magnetic hysteresis loop. In the Zr and Ti interlayer cases epitaxy within a column was lost beginning with the first CoCrNi/(Zr/Ti) interface, resulting in a magnetic layer consisting of two crystallographically unrelated CoCrNi films. Magnetic measurements revealed a complex step-structure hysteresis loop for this case. Annealing the Zr interlayer film led to a significant growth of the amorphous layer due to a solid state amorphization reaction between the Zr and CoCrNi, which was accompanied by a decrease in the saturation magnetization.