Direct formation of ordered CoPt and FePt compound thin films by sputtering

Equiatomic CoPt and FePt alloy films were deposited by cosputtering at substrate temperatures between 25 and 640 °C. Those deposited at high temperatures (≥400 and ≥520 °C for FePt and CoPt, respectively) contained ordered intermetallic compounds with the L10 crystal structure while those deposited at lower temperatures were chemically disordered. Deposition on single crystal 001 MgO and 0001 Al2O3 resulted in 001 and 111 oriented films, respectively, for all deposition temperatures. Ordered alloys have out-of-plane magnetic easy axes and modified magneto-optic Kerr rotation spectra relative to the disordered case. A difference in the Kerr rotation spectrum is observed between ordered, but not disordered, 001 and 111 films.