Size effect for lead zirconate titanate nano-particles with PZT (40/60) composition

This paper focuses on the size effect of lead zirconate titanate. Pb (Zr0.4 Ti0.6) O3 (PZT40) nano-partilces with different sizes were prepared by the sol–gel method. The crystal size and structure were determined by X-ray diffraction. As a result the c/a ration (terragonality) was close to 1 with decreasing particle size. Raman spectra for PZT40 nano-particle of various sizes have been observed to exhibit a decrease in the soft mode at around 35 nm, suggesting the existence of a critical size of the PZT40 particle. The temperature dependence of Raman spectra clearly revealed that the Curie temerature for PZT40 nano-partilces shifted toward lower temperatures due to the size effect. The intrinsic dielectric onstants of PZT40 nano-particles calculated by the Laddne–Saches–Teller relation increased with decreasing particle size. These results show that Raman scattering is a powerful tool to investigate forrelectric materials.