Abstract
This study focuses on the size effect for lead zirconate titanate. Pb(Zr0.3Ti0.7)O3(PZT30) nanopowders with different sizes were prepared by chemical solution deposition. The crystal size of the prepared samples was determined by X-ray diffraction (XRD) and transmission electon microscope (TEM). The crystal structures were identified by XRD. The c/a ratio for PZT30 nanocrystals close to 1 with decreasing crystal size. Raman spectra for PZT30 nanocrystals with various grain sizes have been observed to show the sudden decrease in the soft mode frequencies of E(1TO) and A1(1TO) at around 25 nm, suggesting the existence of the critical size for PZT30 nanopowders. The intrinsic dielectric constant calculated from the phonon mode shift by using LST relation increased with decreasing crystal size. The temperature dependence of raman spectra clearly revealed that Tc for PZT30 nanopowder shifted by the size effect.
