The Properties Research Of L1₀(Superlattice Structures) Co-Pt Thin Films By An Electro-Deposition Process For Ultra-High Density Magnetic Recording Media

Co-Pt nano-structured alloy films with the high coercivity and high uniaxial magnetocrystalline anisotropy have attract abroad attention.A grate deal of research has been on the synthesis of nano-structured Co-Pt alloy films.The Co-Pt alloy thin films have been successfully synthesized on the substrate of copper and single crystal Si(110) wafer by electrodeposition from the alkaline plating bath containing ammonium tartrate as complexing agent and by subsequent annealing.Cathodic polarization curve results show that the codepositing potential of two metal ions was closed by complexing agent of the ammonium tartrate.Atomic absorption spectroscopy results show that the Co-Pt alloy compositions can be readily controlled by adjusting the metal ions ratio in the plating bath and current density.X-ray diffraction results show that the as-deposited Co-Pt alloy films contain a disordered face-central cubic(fcc) structure.By annealing at 700℃,the Co-Pt alloy film on the Cu substrate was melted by Cu substrate because of the thermal diffusion effect.The Co-Pt alloy film with disorderded phase structure transform to be Ll₀ ordered phase structure by annealing at 700℃.Magnetic research results show that the Co-Pt alloy thin film with disordered face-central cubic(fcc) structure show low perpendicular coercivity.The Ll₀ ordered Co-Pt alloy thin films exhibit high uniaxial magnetocrystalline anisotropy.