Microstructures and Recorded Magnetization Microstructures of Co-based Thin Film Recording Media

Abstract

Inter-relationships among medium microstructure, magnetization structure, and recording characteristics are investigated for Co-based longitudinal, perpendicular, and obliquely evaporated recording media. Two types of magnetization irregularities are observed. One is the magnetization transition irregularity which causes magnetic interference between neighboring recorded bits at high linear recording densities. The magnetization interference is the main source of the medium noise for longitudinal recording media. The second type of the magnetization irregularity exists inside the recorded bits which can be observed under all types of recording media. The size of the magnetization irregularity is several times greater than the average size of magnetic crystal grain. The size of the latter magnetization irregularity should be decreased well below the shortest bit length in order to decrease the medium noise and to improve the linear recording density characteristics.