Novel laminated antiferro-magnetically coupled soft magnetic underlayer for perpendicular recording media

The magnetic characteristics of novel laminated antiferro-magnetically coupled soft magnetic underlayers (AFG SULs) were investigated. The Co/Ru/Co structure is used as a basic unit for SULs. The anti ferro-magnetically coupled soft underlayer with the structure of Glass/Ta (2 nm)/Cu (1.5 nm)/IrMn (8 nm)/Co90Fe10 (25 nm)/Ru (1 nm)/ Co90Fe10 (25 nm) showed significantly large exchange-bias fields of upper CoFe (123 Oe) and lower CoFe (160 Oe). Moreover, excellent thermal stability of exchange-bias field of AFC-SUL was also confirmed, demonstrating its potential for the applications of double-layered perpendicular recording media. (C) 2004 Elsevier B.V. All rights reserved.