L1(0)-ordered high coercivity (FePt)Ag-C granular thin films for perpendicular recording

We report (FePt)Ag-C granular thin films for potential applications to ultrahigh density perpendicular recording media, that were processed by co-sputtering FePt, Ag, and C targets on MgO underlayer deposited on thermally oxidized Si substrates. (FePt)(1-x)Ag-x-yvol%C (0 < x < 0.2, 0 < y < 50) films were fabricated on oxidized silicon substrates with a 10 nm MgO interlayer at 450 degrees C. We found that the Ag additions improved the L1(0) ordering and the granular structure of the FePt-C films with the perpendicular coercivity ranging from 26 to 37 kOe for the particle size of 5-8 nm. The (FePt)(0.9)Ag-0.1-50vol%C film showed the optimal magnetic properties as well as an appropriate granular morphology for recording media, i.e., average grain size of D-av=6.1 nm with the standard deviation of 1.8 nm. (C) 2010 Elsevier B.V. All rights reserved.