Reactively evaporated Co thin film for tape media

The dependence of the magnetic properties of reactively evaporated Co on film thickness and oxygen pressure have been studied. The coercivity was found to be very sensitive to oxygen pressure, but the coercive squareness and coercivity peak at different values of oxygen pressure for the same thickness. An optimized 500 /spl Aring/ Co-O film deposited at an oxygen pressure of 1.6 /spl mu/torr, exhibits a coercivity of 2000 Oe, a coercive squareness S* of 0.7, an M/sub r/t of 2.2 memu/cm/sup 2/, a remanence squareness of 0.9 and an anisotropy constant of 3.5/spl times/10/sup 6/ erg/cc. Auger spectroscopy reveals an oxygen content of 30 at.% throughout the film thickness.