Growth and magnetic properties of epitaxial Au/Fe/Au and Ag/Fe/Au films on α-Al2O3

Nanoscale Fe(1 1 0) layers have been fabricated on α-Al2O3 using DC magnetron sputtering with Au(1 1 1) or Ag(1 1 1) as a buffer layer. Atomic force microscopy shows that Au(1 1 1) grows as a continuous layer and Ag(1 1 1) grows as nanoislands of irregular shapes and sizes. Magneto-optic Kerr effect shows that a 12 nm Fe(1 1 0) layer deposited on Au(1 1 1) at 295 K and on Ag(1 1 1) at 640 K is ferromagnetic at room temperature. In-plane magnetic anisotropy is observed for the Fe(1 1 0) layer on Au(1 1 1). The layer thickness, the surface coverage and the magnetization of the films have been determined by polarized neutron reflectometry.