Controlled preparation of a magnetic thin film alloy: GdFe2 and GdFe3

Thin film systems of highly ordered alloys consisting of 3d transition metals and 4f rare earth metals were prepared without buffer layers on a W(1 1 0) substrate by controlling different stoichiometries. The topography of Gd–Fe systems was characterized by scanning tunneling microscopy and LEED, the electronic properties using the spectroscopic mode of the STM. The crystallographic arrangement does not coincide with the bulk Laves phase for GdFe2 due to the large lattice mismatch with the substrate. An increasing amount of Fe during the deposition enables the preparation of well-defined thin films of GdFe3.