Pulsed laser deposition of nanocrystalline lead zirconate titanate thin films

Nanocrystalline ferroelectric thin films are obtained by pulsed laser deposition from a target prepared by sintering at approximately 700 degrees C nanosized powders of Pb(Zr0.52Ti0.48)O-3 (PZT) With 1% weight addition of Nb2O5. The powder was prepared by spray-drying and it was calcinated at 500 degrees C. Film deposition is performed on Si(100) and Au/Si(100) substrates in a reactive oxygen atmosphere using a pulsed Nd-YAG laser with energy 0.3 J/pulse, wavelength 1064 nm, pulse duration 10 ns and frequency 10 Hz. The film samples are investigated by scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and dielectric measurements. The crystallite dimension of PZT films has been found through morphological analysis to be about 30-40 nm. A broadening of the dielectric constant peak at the ferroelectric transition temperature due to finite-size effects is observed. The critical coefficient gamma in the Curie-Weiss law is found to be 1.85 which is indicative of a partially diffused phase transition.