Exchange coupling optimization on CoPtCrO perpendicular media

CoPtCrO is an ideal system to study the influence of exchange on the performance of granular perpendicular media. By changing the oxygen ratio during the deposition process, loop shape and thus inter-granular exchange can be controlled. Noise measurements show there is an optimum exchange coupling which reduces the total media noise in the system. Numerical simulations using the experimental media parameters were found to reproduce the measured loop shapes and noise behavior. The optimization of exchange coupling was found to be a key factor in the design of low noise CoPtCrO perpendicular media.