Noise origin in Co/Pd multilayer media for perpendicular magnetic recording

Medium noise from Co/Pd multilayer media prepared at different conditions have been studied. For sputter-deposition preparation, a large transition noise was observed in the sample prepared at a sputtering Ar gas pressure of 1 Pa, and it was significantly reduced by raising the sputtering gas pressure to 70 Pa. For evaporation-deposition preparation, the main type of medium noise was the DC erase noise, and it was reduced by preparing the samples at higher pressure through introducing air. The above improvements in medium noise for sputter- and evaporation-deposited Co/Pd multilayer media resulted from the reduction in the magnetic domain size when the gas pressures during preparation were increased