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Mn films with a thickness of 2–15 monolayers (ML) have been deposited, in ultra-high vacuum, on a Ag(001) single crystal and analyzed by low energy electron diffraction (LEED) and X-ray photoelectron diffraction (XPD). When a 12 ML film is deposited at room temperature (RT), a ∼3 ML-thick diffuse interface is formed, and Ag segregation occurs on top of an epitaxial body centered tetragonal (bct) Mn layer. If the same amount of Mn is deposited at 80 K in order to block interdiffusion, the film grows in a polycrystalline α-Mn phase. Annealing the sample at 300 K does not markedly change its structure. However, when a 3 ML template of Mn is first deposited on the substrate kept at 80 K, and then 9 ML at 300 K, the data show that the film is pseudomorphic and adopts an epitaxial bct phase, and that the system exhibits an abrupt interface.

We have studied the structure of epitaxial Mn sandwiches made of ∼ 1 monolayer (ML) Ag/3 ML Mn/Ag(100) by using photoemission methods 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 (bct) structure. Yet, upon deposition of ∼ 1 ML Ag, remarkable changes occur in the Mn film. X-ray photoelectron diffraction data reveal that the Mn layer relaxes towards a face-centered-cubic (fcc) structure with the lattice parameter of Ag. This implies an exceptionally large atomic volume for a 3d transition metal as well as unusual electronic and magnetic properties. Actually, an evolution towards more atomic-like behaviour is clearly evidenced by valence band and Mn3s core level photoemission data.

Thin Cr films (∼20 A) deposited in vacuum at 300 K on a Cu(001) single crystal have been annealed at various temperatures and analyzed by angle resolved ultraviolet photoemission, X-ray photoemission, X-ray photoelectron diffraction and low energy electron diffraction. The data show that Cu segregation occurs above 425 K, resulting in an atomic monolayer wetting the whole Cr film. At 775 K, the Cr overlayer collapses and the Cu(001) substrate surface becomes partly uncovered.

We have investigated the crystallographic structure of ultra-thin Mn films deposited at room temperature on a clean Ag(100) single crystal, using angle-resolved ultra-violet photoemission, X-ray photoelectron diffraction (XPD) and low-energy electron diffraction. The evolution of the Ag 4d valence band shows deviations from simple layer by layer growth. These results, combined with the XPD data, indicate that by ∼1–1.5 monolayers of Mn a two layers thick Mn-rich epitaxial MnAg alloy is formed that continues the face centered cubic lattice of the Ag substrate.