Defect structures at thin film-substrate interfaces

We consider the loss of lattice coherence at a planar interface between a thin film and substrate. Coherence is determined locally at the interface by a relative deformation gradient at the interface. We construct an interfacial free energy density fxs such that a fully coherent interface is a global minimizer fxs, and there are symmetry related local minima of fxs corresponding to line defects at the interface. By considering both the...