GROWTH TEMPERATURE-DEPENDENCE OF LONG-RANGE ALLOY ORDER AND MAGNETIC-PROPERTIES OF EPITAXIAL FEXPT1-X (X-SIMILAR-OR-EQUAL-TO-0.5) FILMS

The structural and magnetic properties of 1000-Angstrom-thick epitaxia l FexPt1-x(001) alloy films, grown by molecular beam epitaxy with x si milar or equal to 0.5, have been studied as a function of growth tempe rature, X-ray diffraction analysis showed that the long-range order pa rameter increased from near Zero for films grown at 100 degrees C to a maximum of 0.93 in films grown at 500 degrees C. Over this range the magnetic easy axis changed from in-plane to perpendicular and the pola r Kerr rotation increased strongly. Spontaneous long-range ordering in these films has an activation energy similar to 0.2 eV, consistent wi th an energy barrier for surface and step down diffusion. (C) 1996 Ame rican Institute of Physics.