STUDY OF ULTRATHIN FE FILMS ON PD(111), AG(111) AND AL(111)

The growth of epitaxial Fe films of 1 to 10 layer equivalents (LE) on Pd{111} Al{111} and Ag{111} has been studied with quantitative low-energy electron diffraction and Auger electron spectroscopy. On Pd{111}, both at room temperature and at 200-degrees-C, the growth starts with pseudomorphic layers which may involve intermixing of Fe and Pd. At both temperatures. when the coverage reaches 6 LE, the Fe films develop into large bcc {110} domains related to the substrate by the Kurdjumov-Sachs orientation. On Ag{111} Fe grows initially in a very similar manner to Fe on Ag{001}, i.e., by way of small islands of bcc Fe. These islands then grow into bcc Fe{110} domains in the Nishiyama-Wasserman orientation. On Al{111} Fc behaves differently, despite the fact that the lattice mismatch for Fe on Al{111} is nearly identical to that for Fe on Ag{111}: for coverages of less than 1 LE the surface region becomes completely disordered and no LEED pattern is visible.