Moiré patterns and coherent double-positioning boundaries in {111} epitaxial gold films

Abstract
The double-positioning structure of discontinuous evaporated {111} gold layers grown on MoS2 substrates has been studied in detail. The two twin-related orientations of the deposit are nucleated independently on the substrate. At a later stage of growth, after coalescence has occurred, deposit islands are seen to contain both of the orientations, separated by a double-positioning boundary. It is shown, by a detailed analysis of moiré patterns formed between the Au and MoS2 crystals, that double-positioning boundaries frequently lie parallel to the substrate surface and so exist as coherent twin boundaries.