The results of Monte Carlo simulations of the structure and energetics of Ni thin films grown on Ag(100) are discussed. Despite a 13.9% lattice mismatch, layer-by-layer growth of pseudomorphic Ni is favored over an incommensurate Ni(111) structure, up to approximately ∼ 3.2 ML Ni. Reconstruction or clustering of the Ni overlayer is seen at submonolayer to monolayer coverages. The pseudomorphic multilayer film has a tetragonal structure due to the expansive intralayer strain inducing a compressive interlayer stress. The tetragonal Ni(100) overlayer appears metastable, since allowing interdiffusion via exchange of Ni and Ag atoms leads to a thermodynamically favored Ag/Ni/Ag(100) sandwich structure. A buckled, close-packed Ni(111) thin film structure is preferred at higher coverages and is found to inhibit interdiffusion of Ag atoms. A direct commensurate-incommensurate phase transition is never observed.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry