Direct observation of an incommensurate solid-solid interface

Abstract

Atomic structure at the epitaxial Al(111)/Si(111) interface has been studied using high-resolution transmission electron microscopy. Aside from the orientational ‘‘matching,’’ the interface appeared to be incommensurate. We have interpreted the observed phenomenon within the context of the well-known Frank–van dan Merwe dislocation theory for adsorbed overlayers. The result also suggests the intriguing possibility of growing dislocation-free and strain-free thin films.