Study of electrolytic laminated ferroelectric thin films from electroded substrates

Abstract

An electrolytic process is described to peel off ferroelectric thin films from electroded substrates. This procedure was used to study the evolution of stress in ferroelectric calcium-modified lead titanate thin films. Stresses developed during the different steps of the preparation of the film on the substrate were calculated from curvature radii of the deposited films after each step. During the film preparation, the substrate was permanently deformed by the generated stresses. This was shown by curvature of the substrate after the electrolytic separation of the film. The laminated film liberated a large amount of stresses, as deduced from the lattice parameters of the deposited and laminated film, obtained by x-ray diffraction. The moderate residual stress that the laminated film maintained could be associated with intrinsic defects of the film.