Coherent fcc stacking in epitaxial Co/Cu superlattices

Abstract

A series of epitaxial Co/Cu superlattices has been grown on GaAs(110) substrates by molecular-beam epitaxy. Detailed analysis of x-ray diffuse scattering scans along Co (101\ifmmode\bar\else\textasciimacron\fi{}l) reveals metastable fcc stacking of Co, with stacking coherence extending across Co layers at thicknesses below 20 A\r{}, while coherent interfaces are obtained at Co thickness up to 40 A\r{}. We discuss possible mechanisms for stabilizing the stacking sequence.