Film structure and magnetic properties of Multilayered Co/Au films

抄録

Multilayered Co/Pt, Co/Pd and Co/Au films exhibit large perpendicular magnetic anisotropy. They have attracted attention as new materials for next-generation high-density magneto-optical recording media, and are being studied for applications in other areas besides. The coercivities of as sputtered m ultilayered Co/Pt and Co/Pd films are small but increase to 2〜3 kOe with the annealing at 300℃ in air. In this paper, the structure and magnetic properties and effects of the annealing in air on the multilayered Co/Au sputtering films have been studied. The dual-source rf magnetron sputtering method was employed in fabricating the films, using Ar as the sputtering gas, The thicknesses of Co layer and Au layer of the Co/Au films were 8.4Å and 18.2Å, respectively, and the total thickness was 3000Å. The uniaxial magnetic anisotropy constant (Ku) and the coercivity/ (Hc) of the films as sputtered was 7.8×10^5 erg/cm^3 and 50 Oe, respectively. The values of Ku and Hc increased with the annealing temperature and Ku and Hc showed at 200℃ 2.6×10^6erg/cm^3 and 150 Oe, respectively. The low-angle X-ray peak and the satellite peak intensities increased alter the 200℃ annealing. At the higher temperature than 250℃, Ku decreased and showed the minus values, and the oxidation of Co layer, the disorderization of the multilayered structure, and the segregation of Au and Co_3O_4 occured. This results show that the multilayered structure of Co/Au films is less stable than those of Co/Pt and Co/Pd films.