Growth temperature dependence of long-range alloy order and magnetic properties of epitaxial Fe_xPt_1-x (x≃0.5) films

The structural and magnetic properties of 1000-Å-thick epitaxial FexPt1-x(001) alloy films, grown by molecular beam epitaxy with x≃0.5, have been studied as a function of growth temperature. X-ray diffraction analysis showed that the long-range order parameter increased from near zero for films grown at 100°C to a maximum of 0.93 in films grown at 500°C. Over this range the magnetic easy axis changed from in-plane to perpendicular and the polar Kerr rotation increased strongly. Spontaneous long-range ordering in these films has an activation energy ∼0.2 eV, consistent with an energy barrier for surface and step down diffusion. © 1996 American Institute of Physics.