Magnetic Recording Near the Grain Size Limit

The writing quality of magnetic recording improves with increasing sharpness of the written transitions. Ultimately, the transition sharpness is limited by the grains themselves, and no longer depends on the head field gradient. In this study, we varied the head field gradient by changing the head-media spacing and characterized the write quality by transition jitter and equalized signal-to-noise (eSNR) measurements. Consistent with a recording in the grain size limit, we discovered that the write quality did not improve with smaller head to medium spacings. We also found that the measured values for the jitter and the eSNR are close to what is estimated for grain size limited recording.