STABILIZATION OF A FACE-CENTERED-CUBIC MN STRUCTURE WITH THE AG LATTICE-PARAMETER

We have studied the structure of epitaxial Mn sandwiches made of simil ar to 1 monolayer (ML) Ag/3 ML Mn/Ag(100) by using photoemission metho ds and low-energy electron diffraction (LEED). Epitaxial films of 3 ML Mn grown on Ag(100) at room temperature (RT) are found to have a body -centered-tetragonal (bet) structure. Yet, upon deposition of similar to 1 ML Ag, remarkable changes occur in the Mn film. X-ray photoelectr on diffraction data reveal that the Mn layer relaxes towards a face-ce ntered-cubic (fee) structure with the lattice parameter of Ag. This im plies an exceptionally large atomic volume for a 3d transition metal a s well as unusual electronic and magnetic properties. Actually, an evo lution towards more atomic-like behaviour is clearly evidenced by vale nce band and Mn3s core level photoemission data.