A study of ACSN comparison between spin-stand and magnetic force microscopy

Characterizing media noise and then improving media signal-to-noise ratio (SNR) are important issues for successfully implementing perpendicular recording technology. In this work, the measurements of the autocorrelation signal-to-noise (ACSN) have been conducted using both spin-stand testing and magnetic force microscopy (MFM) method. The ACSN was measured as a function of the linear density so as to analyze the media noise origins. The results obtained from two different methods show a good correlation if a saturation effect of the GMR read sensor is taken into consideration, indicating that the saturation process of GMR readers could actually improve the ACSN values at low linear density situations.