CoSm-based high-coercivity thin films for longitudinal recording

In order to produce thin media with high intrinsic coercivity, we studied a number of CoSm films produced by rf-diode sputtering. We determined an optimized set of sputtering parameters for films sputtered both on glass and NiP-coated Al substrates with and without Cr underlayers. While the coercivity of the films depended strongly on argon pressure, the 〈110〉 texture of the Cr underlayer remained unaffected by it. The 〈110〉 texture of Cr changed to 〈200〉 texture at temperatures ≥300 °C, and the coercivity of the film was significantly reduced. Under optimal conditions we obtained intrinsic coercivities ≳2400 Oe for films with thickness <20 nm.