Magnetic recording on FePt and FePtB intermetallic compound media

Abstract

Near-contact recording on high-coercivity FePt intermetallic compound media using a high B/sub sat/ write element was investigated. Untextured FePt media were prepared by magnetron sputtering on ZrO/sub 2/ disks at a substrate temperature of 450/spl deg/C, with postannealing at 450/spl deg/C for 8 h. Both multilayer and cosputtered precursors produced the ordered tetragonal L1/sub 0/ phase with high coercivity between 5 and 12 kOe. To improve readback noise and decrease magnetic domain size, FePtB media were subsequently prepared by cosputtering. Overwrite, roll-off, signal-to-noise ratio (SNR), and nonlinear transition shift (NLTS) were measured by both metal-in-gap and merged magneto-resistive heads. FePtB media showed NLTS similar to that of commercial CoCrPtTa longitudinal media, but 5 dB lower SNR. By operating recording transducers in near contact, reasonable values of overwrite (>30 dB) could be obtained.