Title :
Influence of orientation ratio on reverse erase-edge noise and track-edge dipole distribution
Author :
Bennett, Wayne R. ; Zhang, Bing ; Richter, Hans J.
Author_Institution :
Magnon, Palo Alto, CA, USA
fDate :
5/1/1998 12:00:00 AM
Abstract :
The cross-track profile of media noise is measured on a precision spinstand for oriented and nonoriented media. These data are correlated with magnetic force microscopy (MFM) images to determine the location of track-edge noise with high spatial resolution. A significant component of track-edge noise is located in a narrow band at the edge of bits recorded in opposition to the previously saturation-erased direction. This reverse erase-edge noise (REEN) increases as orientation ratio increases. The magnitude and distribution of REEN is consistent with a reverse-dc-erase mechanism. δM data indicate a greater influence of magnetostatic and/or exchange coupling for the oriented media. Together with larger on-track reverse-dc-erase noise and higher supralinear transition noise, these results suggest enhanced collective magnetization reversal for the oriented media relative to the nonoriented media. MFM images also reveal the presence of narrow magnetic-dipolar strips at the track edges. These dipolar strips are generated by cross-track components of the head field. The track-edge dipole moment decreases as orientation ratio increases due to preferential alignment of easy axes along the down-track direction. These dipoles contribute to base line shift and are not a significant source of media noise
Keywords :
exchange interactions (electron); magnetic force microscopy; magnetic moments; magnetic recording noise; magnetisation reversal; cross-track components; cross-track profile; down-track direction; easy axes; enhanced collective magnetization reversal; exchange coupling; head field; high spatial resolution; magnetic force microscopy; magnetostatic coupling; media noise; narrow magnetic-dipolar strips; nonoriented media; on-track reverse-dc-erase noise; orientation ratio; oriented media; precision spinstand; reverse erase-edge noise; reverse-dc-erase mechanism; saturation-erased direction; supralinear transition noise; track-edge dipole distribution; track-edge dipole moment; track-edge noise; Magnetic force microscopy; Magnetic forces; Magnetic moments; Magnetic noise; Magnetostatics; Noise measurement; Saturation magnetization; Signal to noise ratio; Spatial resolution; Strips;
Journal_Title :
Magnetics, IEEE Transactions on