THE STRESS STATE AND DOMAIN STRUCTURE OF EPITAXIAL PbZr_(0.5)Ti_(0.8)O_3 FILMS ON (001) SrTiO_3 WITH AND WITHOUT La_(0.5)Sr_(0.5)CoO_3 ELECTRODE LAYER

摘要

The domain structure of the 400 nm thick PbZr_(0.2)Ti_(0.8)O_3 (PZT) films with different electrode layer configurations was investigated by x-ray diffraction and transmission electron microscopy. The c-domain fractions of the PZT films with no electrode layer, with a 50 nm electrode layer between the film and the substrate, and with 50 nm electrode layers on top and bottom of the PZT film were found to be equal. This means that depolarizing fields do not affect the polydomain structure of the film. Calculations of the in-plane strains based on the lattice parameters of the La_(0.5)Sr_(0.5)CoO_3 (LSCO) layer in the above configurations led to the conclusion that the bottom electrode layer is coherently strained to match the substrate.