CRYSTALLIZATION BEHAVIOR AND PHASE COEXISTENCE AT MORPHOTROPHIC PHASEBOUNDARIES IN PZT THIN-FILMS PREPARED BY SOL-GEL PROCESSING

Pb(Zr0.53Ti0.47)O-3 (PZT) thin films, prepared by sol-gel techniques a nd deposited on to Si/SiO2/Ti/Pt substrates, have been subjected to th ermal annealing in a range of temperatures from 550-800 degrees C. The crystallization behaviour and phase coexistence (tetragonal and rhomb ohedral) were studied by X-ray diffraction. According to the values of the {110} peak intensity and {110} peak values, the crystallization f ull-width at half-maximum was more complete at higher temperatures (75 0, 800 degrees C). At a fixed Zr/Ti ratio close to the morphotropic ph ase boundary, the lattice parameters of the two phases changed with th e annealing temperature. However, the tetragonality degree had relativ ely low values and the angular rhombohedral distortion was associated with a narrow angular range. The phase coexistence and the variation o f the lattice parameters could be explained by the titanium diffusion through the platinum layer. Thus the formation of a {011} titanium ric h layer at Pt-PZT interface will supply a titanium excess for the nucl eation and growth of textured PZT grains.