PHASE INFORMATION IN THE CRYSTAL TRUNCATION RODS

A simple method to extract information on the phases of the diffracted amplitudes of overlayers on substrates is presented. It is based on the assumption that the substrate structure is known as well as the phases of the diffracted amplitudes of the substrate crystal truncation rods. By measuring the diffracted intensity after depositing an overlayer on the substrate it is possible, under some circumstances, to infer the phase of the diffracted amplitude from the overlayer. This may be of use in some particular experimental situations. Several examples are presented: Sb/Ge(111), epitaxial growth of Ge(111) and GaAs(100) and growth of an fcc (111) crystal.