L10 FePt-ZrO2 (001) nanostructured films with high aspect ratio columnar grains

In order to increase the signal-to-noise ratio of heat assisted magnetic recording, it is desirable to fabricate high magnetic anisotropy FePt media with small grain size and high aspect ratio (grain height to size ratio). In the present paper, we report that FePt media with small grain size and high aspect ratio were achieved by doping ZrO2 into FePt film grown on TiON intermediate layer. The grain size was around 5.6 nm, and the aspect ratio was as high as 2.6. It is believed that this originated from the ZrO2 (002) tetragonal crystalline phase epitaxially grown on TiON intermediate layer. With a 5 vol. % carbon doping into FePt-ZrO2 films, the perpendicular anisotropy was improved and the out-of-plane coercivity was around 23.2 kOe. Doping of crystalline phase material with certain required crystal structure may offer a method for fabrication of nanostructured thin films with high aspect ratio grains at high processing temperature.