Co-Cr thin films have been studied extensively as leading candidates for perpendicular recording media. The enhancement of the magnetic properties (saturation magnetization and coercivity) in rfsputtered Co-Cr films has been reported by several investigators. Concurrent work has revealed similar improvements in the magnetic properties of annealed Co-Cr films produced by magnetron sputtering. Honda et al. propose that compositional inhomogeneities in annealed films give rise to these properties changes. In this work, we have employed X-ray photoelectron spectroscopy (XPS) to investigate compositional changes in annealed Co-Cr layers of thickness 10-200 nm.Films were deposited from a Co-22wt%Cr alloy target onto glass (Coming Type 7059) substrates using a Varian DC Magnetron ("S" gun) sputtering system. Sputtering conditions included an argon pressure of lmTorr and room temperature substrates. The sputtering rate was 0.25 nm/sec. Annealing was performed at 360°C in a vacuum (10-6 Torr) in incremental times up to 49 hours.
