CONTROL OF THE AXIS OF CHEMICAL ORDERING AND MAGNETIC-ANISOTROPY IN EPITAXIAL FEPT FILMS

Growth of epitaxial films of the L1(0) phase of FePt, with the tetrago nal c axis along either the film normal or in-plane, is described. Fil ms were grown by coevaporation of Fe and Pt, under ultrahigh vacuum co nditions, onto a seed film of Pt grown on MgO or SrTiO3 substrates. Th e perpendicular or in-plane orientation of the c axis was controled by selecting the (001) or (110) substrate plane, respectively. Nearly co mplete chemical ordering was achieved for growth at 500 degrees C for both orientations. Magnetic and magneto-optical characterization of th ese films confirmed the huge magnetic anisotropy expected for this pha se. In the most highly ordered films, anisotropy fields in excess of 1 20 kOe were measured. (C) 1996 American Institute of Physics.