SPECTRUM ANALYSIS OF RECORDED MAGNETIZATION USING MAGNETIC FORCE MICROSCOPY

Spectrum analyses of recorded magnetization were performed using magne tic force microscopic (MFM) images to quantitatively analyze the relat ionship between the magnetization structure and the reproduced signal output. Repeated one-dimensional Fourier analyses were performed on an MFM image along the recording direction of the disk medium for a cert ain width with a pitch of about 70 nm. The dependence of MFM signal in tensity on wavelength was obtained through Fourier transformation. Dif ferences in the noise characteristics of CoCrTa media with different C r compositions were investigated. Several peaks in the Fourier-transfo rmed spectrum are related to the magnetic cluster size and/or the magn etic cross-linking distance between neighboring recorded bits. The mag netic interactions were found to extend up to about 0.5 mu m and 1 mu m for magnetically recorded CoCr16Ta4 and CoCr10Ta4 media, respectivel y.