Magnetic reversal phenomena of perpendicular magnetic islands fabricated by block copolymer lithography

Templated block copolymer lithography has been proposed as a method of fabricating patterned magnetic media. This paper discusses the magnetic properties of perpendicular CoCrPt magnetic uniaxial islands in a range of sizes (5–15nm thick, 20–35nm diameter) fabricated by this method. Sputter-deposited films of perpendicular CoCrPt films were patterned in a series of reactive and ion beam etches. The magnetic islands maintain the perpendicular magnetization from the film, but show increased coercivity (800–1650Oe) as compared to the film (150Oe). Time-scale-dependent magnetic measurements show switching volumes (V*) on the order of the physical volume of the dots (∼5000nm3), suggesting that the dots switch their magnetization coherently and independently of each other. Last, we demonstrate selectively removable topographic templates for imposing long-range order to the system.