The dependence of media noise on the magnetic cluster size for Co based thin film media fabricated under ultra clean sputtering process

The media noise performance is discussed quantitatively in connection with magnetic microstructure for Co based thin film media fabricated under Ultra Clean (UC) process. Results are summarized as follows: (1) The media noise decreases by reducing the dispersion of magnetic field strength at transition, (2) The dispersion of magnetic field strength at transition is suppressed by the reduction of magnetic cluster size, and (3) The grain size reduction and the decrement of intergranular magnetic coupling play an important role for the improvement of recording performance though the reduction of magnetic cluster size.