近年，垂直磁気記録媒体の更なる高密度化に対rnする要求は益々，高まっている．高密度化を実現するrnためには，メディアノイズの低減，高い熱安定性，飽rn和記録の間に存在するトリレンマを克服することが不rn可欠である．%L1_1 type Co-Pt ordered alloy films with a large uniaxial magnetic anisotropy, K_u, of the order of 10~7 erg/cm~3 were successfully fabricated at relatively low substrate temperatures of 270-390℃ using ultra-high vacuum sputter film deposition. L1_1 type ordered Co-Pt films, with the <111> direction (easy axis of magnetization) perpendicular to the film plane, were fabricated on MgO(111) single crystal substrates and glass disks. The ordered structure was formed in a wide Pt content region of 40-75 at%, and Kx showed a maximum at around 50% Pt content. The values of the order parameter, S, and K_u for L1_1 type Co5o Pt 5o films increased as the substrate temperature, Ts, increased. Kx reached about 3.7×10~7 erg/cm~3 (S=0.54) at Ts=360℃ for the single crystal films deposited on MgO(111) substrates, indicating a potential increase in Ka by enhancing the ordering. The values of Ku for polycrystalline films deposited on glass disks were smaller than those for the single crystal films on MgO(111) substrates, however, K_u reached 1.9×10~7 erg/cm~3 at Ts=360℃. The experimental demonstrate the potential of L1_1 type Co_(50)Pt_(50) films for use in data storage applications, because of their very high K_u, comparable to L1_0-type Fe_(50)Pt_(50) films, the relatively low fabrication temperature, and good controllability of the grain orientation.
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