Noise characteristics of Co-γFe2O3 perpendicular magnetic recording media

Abstract

The Co-γFe2O3 perpendicular recording thin film disks were prepared by annealing a CoO-Fe3O4 single layer deposited on a NiO underlayer in air in the temperature range from 260 °C to 350°C. Noise characteristics of the Co-γFe2O3 disks were measured using a MIG-type ring head. From a DC reverse erase noise measurement and a measurement of recording density dependence of medium noise, it was found that the Co-γFe2O3 disks show noise characteristics which is often seen in thin film media. The Co-γFe2O3 disks show the higher Sp-p/Nm,rms than various longitudinal recording media now on the market at high recording densities over 40 kFRPI.