Orientation dependence of the heteroepitaxial growth of Ni films on Pd

Abstract

Molecular-dynamics simulation based on many-particle potentials calculated in terms of the embedded-atom method was performed to study growth of Ni films on singular (001), (110), and (111) surfaces of a Pd single crystal at a temperature T = 1000 K. Upon the growth of a Ni film on (001)Pd and (110)Pd surfaces, there is formed a heterostructure consisting of a Pd substrate, a single-layer epitaxially stabilized solidsolution phase, and a film of an Ni-Pd solid solution. At the initial stages of the film growth, the lattice misfit is compensated via elastic deformation; with increasing average thickness of the film, there occurs a relaxation of the elastic deformation: in the (001)Pd-Ni heterosystem, via the formation of misfit dislocations; in the (110)Pd-Ni heterosystem, via misfit dislocations and point defects (in the [\(1\bar 10\)] direction) as well as via partial dislocations (in the [001] direction). Upon the growth of an Ni film on the (111)Pd surface, no intermixing of the components occurs; already at the initial stages of growth, the islands (clusters) are not deformed; the matching at the interphase boundary is incoherent.