Effect of ion beam patterning on the write and read performance of perpendicular granular recording media

We have used a static write-read tester to study the reading and writing of bit patterns on arrays of square bits cut with a focused ion beam into granular perpendicular recording media. We have written square-wave bit patterns on arrays of magnetically isolated islands with periods between 80-248 nm, with the recording linear density matched to this pattern period. These measurements clearly reveal the onset of single domain behavior of the islands for periods <130 nm. We report on variations of read-back signals with this period for bits written in-phase and out-of-phase with the patterning (where bits are written in the center of the islands and lines, respectively). We also present results and analysis on the effect of patterning and phase on the transition position jitter