Analysis of two-dimensional medium noise and magnetic cluster with MFM for Co82Cr13Ta5 longitudinal magnetic recording media

A method of obtaining two-dimensional medium noise characters by subtracting signal elements from MFM data is proposed and applied to investigating the medium noise and magnetic cluster of Cos,Cr,,Ta, longitudinal magnetic recording media. The method gives detailed information about magnetic cluster appearance, magnetic cluster size, signal deformations and different performances of medium noise at different recording densities. Furthermore, the magnetic cluster size is found to increase from similar to 100 to similar to 500 nm with increasing recording density. The recording density dependence of noise intensity and signal output obtained by MFM analysis is investigated and the noise intensity shows a linear increment depending on the magnetic cluster size. (C) 1998 Elsevier Science B.V. All rights reserved.