Atomic Reordering and Lattice Mismatch - (Meta) Stability in Heteroepitaxial Layers.

We report the first evidence of lattice mismatch stain induced atomic reordering within a single crystalline epilayer in a film-substrate structure. The Raman activity of Zn sub 3 As sub 2 layers, grown by molecular beam epitaxy on InP and GaAs, confirms an ordered migration of specific Zn atoms over atomic distances. It is shown thermodynamically, that the structural change is consistent with a strain driven and stabilized anion reordering. This phenomenon could represent a means to stabilize novel heteroepitaxial structures.