Writing and reading perpendicular magnetic recording media patterned by a focused ion beam

We have written and read bit patterns on arrays of square islands cut with a focused ion beam into granular perpendicular magnetic recording media. Us ing a static write-read tester, we have written square-wave bit patterns on arrays of islands with sizes between 60 and 230 nm, matching the recording linear density to the pattern period. These measurements reveal the onset of single-domain behavior for islands smaller than 130 nm, in agreement wit h magnetic force microscope images. The recording performance of patterned regions is systematically compared to that of unpatterned regions. (C) 2001 American Institute of Physics.