HIGH ANISOTROPY L1(0) THIN-FILMS FOR LONGITUDINAL RECORDING

Bulk L1(0) phase materials, such as CoPt and FePt, are known for their high magnetocrystalline anisotropy and magnetic moment, properties th at are also desirable for high density magnetic recording media, This work reports the preparation, microstructural characterization, magnet ic properties, and magnetic recording performance of L1(0) phase thin (25 Angstrom to 200 Angstrom) films. The samples are prepared by sputt er deposition and ex-situ anneal, The microstructural characterization is by transmission electron microscopy and x-ray diffraction, High ma gnetocrystalline anisotropy is apparently maintained for even the thin nest films, where coercivity, Hc, > 10,000 Oe is observed for a 25 Ang strom sample, The Hc of films prepared for magnetic recording measurem ents is considerably less to ensure that test patterns could be writte n, Samples for recording measurements were obtained by a reduction in anneal temperature or the codeposition of an oxide with the L1(0) phas e material to limit grain growth during anneal.