Fine control of L10 ordering and grain growth kinetics by C doping in FePt films

We present the results on highly anisotropic oriented face-centered-tetragonal ordered equiatomic FePt thin films embedded in a C matrix prepared by cosputtering technique on MgO (100) substrates at 400 °C. We have found that doping of C in FePt alloy films is an effective and appropriate way to control the L10 ordering and growth of grain size down to 4 nm. Room-temperature magnetic measurements reveal that perpendicular magnetic anisotropy exists for these films with C concentration up to 25 vol %. These films are very promising and the results are of relevance for ultrahigh-density magnetic recording media.