Abstract
The structure and the magnetic properties of Co- Pt alloy thin films were investigated under various sputtering conditions. Co-Pt films below 15 at%Pt had hcp structure and above 30 at%Pt fcc structure. The films of 15∼30 at%Pt indicated both of the hcp and fcc phases. Perpendicular magnetization was realized in the range of 20∼40 at%Pt. Substrate bias of −50 V improved the orientation of fcc [111] axis normal to the film plane and increased perpendicular anisotropy energy Ku. There was also a correlation between the orientation of the crystallites and Ku in the case of varying Ar gas pressure PAr. This suggested that perpendicular anisotropy of Co-Pt films arises from magnetocrystalline anisotropy. Although the perpendicular coercivity was small in these films, it increased by a factor of 2 with addition of 10 at%Cr.
