Patterning of granular magnetic media with a focused ion beam to produce single-domain islands at <140 Gbit/in/sup 2/

Abstract

We have used a focused ion beam to directly pattern thin-film granular perpendicular Co/sub 70/Cr/sub 18/Pt/sub 12/ media. By cutting trenches /spl sim/6 nm deep in the /spl sim/20 nm media, we have produced square arrays of magnetically isolated islands with periods in the range 65-500 nm. At periods below /spl sim/130 nm we observe only single magnetic domains, which exhibit a rough "checker-board" pattern upon ac demagnetization. We have patterned at densities of over 140 Gbit/in/sup 2/.