Enhance perpendicular magnetic anisotropy of Co3Pt thin film by inserting a Pt underlayer

The HCP structural Co₃Pt thin film has large magnetocrystalline anisotropy constant (K_u ~ 10⁷ erg/ cm³)[1], relatively lower ordering temperature (<; 400C), good thermal stability, and the lower amount of Pt content, thus becoming a substitute material to replace the ordered L1₀ FePt and CoPt phase films for ultrahigh-density magnetic recording media. However, it is difficult to obtain perpendicular magnetic anisotropy (PMA) of Co₃Pt thin films as the film is sputtered on amorphous glass substrate directly. In order to enhance the PMA of the film, inserting an underlayer between magnetic layer and substrate is quite effective method [2-3]. Some efforts have demonstrated that adoption of Pt underlayer can enhance the PMA and magnetic properties of Co₃Pt thin films [4-5]. Nevertheless, there is less research to discuss the reason that why Pt layer could improve the PMA and magnetic properties of Co₃Pt thin films. In this study, we inserted a textured Pt (111) underlayer between magnetic Co₃Pt thin film and glass substrate for study the mechanism to build up the PMA of Co₃Pt film. This work demonstrated that the PMA of Co₃Pt film can be improved by inserting a 10nm-thick Pt underlayer. The growth structure of the films plays an important role to enhance the magnetic properties.