Fabrication of L11 type Co-Pt ordered alloy films by sputter deposition

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 degrees C using ultrahigh 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 K-u showed a maximum at around 50 at. % Pt content. The values of the order parameter S and K-u for L1(1) type Co50Pt50 films increased as the substrate temperature T-s, increased. K-u reached about 3.7x10(7) erg/cm(3) (S=0.54) at T-s=360 degrees C for the single crystal films deposited on MgO(111) substrates, indicating a potential increase in K-u by enhancing the ordering. The values of K-u 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 x 10(7) erg/cm(3) at T-s=360 degrees C. The experimental results demonstrate the potential of L1(1) type Co50Pt50 films for use in data storage applications, because of their very high K-u, comparable to L1(0) type Fe50Pt50 films, the relatively low fabrication temperature, and good controllability of the grain orientation. (C) 2008 American Institute of Physics.