Size Effect for Lead Zirconium Titanate Nanopowders with Pb(Zr0.3Ti0.7)O₃Composition

This paper focuses on the size effect for lead zirconate titanate. Pb(Zr 0.3 Ti 0.7 )O 3 (PZT30) nanopowders with different sizes were prepared by chemical solution deposition. The crystal sizes of the prepared samples were determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The crystal structures were identified by XRD. The c/a ratio or tetragonality for PZT30 nanocrystals was 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 E(1TO) and A 1 (1TO) at around 25 nm, suggesting the existence of the critical size for PZT30 nanopowders. The intrinsic dielectric constant which was calculated from the phonon mode shift by using the Lyddane-Sachs-Teller (LST) relation increased with decreasing crystal size. The temperature dependence of Raman spectra clearly revealed that T c for PZT30 nanopowder shifted due to the size effect.