Photoelectron diffraction study on the epitaxial growth of SrF2 on Ge(111)-c(2x8)

The initial stages of epitaxy of SrF(2) on Ge(111)-c(2 X 8) have been studied by X-ray photoelectron diffraction (XPED). Forward-scattering peaks along the emitter-scatterer axes have been effectively used to determine the morphology of the overlayer. In addition, multiple-scattering analysis of the two-dimensional XPED patterns for the overlayer emission has provided the information on the average domain size of SrF(2) islands. The epitaxy of SrF(2) on Ge(111) has been characterized by (1) the 180 degrees azimuthal rotation of the overlayer relative to the substrate, (2) formation of small SrF(2) (111) islands of similar to 2 TL (triple-layer) in thickness at deposited coverages below 1 TL-equivalent, and (3) aggregation of the islands into relatively large domains with the average height of similar to 2 TL unchanged at coverages up to 2 TL-equivalent. (C) 1998 Elsevier Science B.V. All rights reserved.