Deformation of oriented thin films on solid substrates
When a single crystal of a face centred cubic metal is deformed, the strain is accommodated by the movement of dislocations which results in the formation of localized slipped regions. If an oriented thin film of another face centred cubic metal is deposited on the surface, the way in which the film deforms is determined by the ability with which the mobile dislocations in the substrate can pass into and through the film. The mode of deformation of such surface films has been investigated by detaching from the substrate after deformation and examining them by transmission in the electron microscope. This has given information about the factors which influence the passage of dislocations across a boundary between two crystals which are in a parallel orientation but have different lattice parameters.