Patterned Perpendicular and Longitudinal Media: A Magnetic Recording Study

Isolated tracks of single-domain magnetic islands have been fabricated using focused ion beam lithography. Islands were fabricated in thin films having either perpendicular or longitudinal magnetic anisotropy, and in both cases writing and reading of individual islands was demonstrated using a static write/read tester. Additionally, we have investigated the synchronization requirements (write margin) needed for writing the different flavors of patterned media. We have found that the write margin is strongly dependent on the switching field distribution of the islands and on the head field gradient. In the presented study, the write margin is much larger for the longitudinal patterned media than for perpendicular patterned media.