Structural studies on sols for PZT thin films

Crack-free transparent thin films of ferroelectric Pb(Zr_0.3,Ti_0.7)O₃ (PZT) with the perovskite structure were prepared by spin-coating a solution of complex alkoxides, followed by drying and then firing at the temperatures less than 500 °C. The preparation of stock solution, drying, and firing of films was described. The coatings with selective orientations have been prepared by using selective processing parameters. The influence of low-temperature processing steps on texture development will be reported. The formation and growth of polymeric particles in the hydrolysis and condensation of PZT sol-gel precursor solutions have been investigated by using photon correlation spectroscopy (PCS), small angle x-ray scattering (SAXS) and by measuring their rheological properties. It has been possible to follow the growth of the particles in the sol by the different techniques used from initial values of <4 nm up to ca 100 nm. It has been shown that the particles are rods rather than spheres. The effects of particle shape and solution chemistry on the crystal phase formation and texture development will be discussed.