Characterization of nanostructured PZT prepared by chemical routes

Nanostructured, crystalline Pb(Zr0.52Ti0.48)O-3 (crystallite size 8-10 nm) ceramic powders were synthesized at low temperature by the hydroxide co-precipitation and aqueous solution method (water bath technique). The phase and surface morphology characterizations were carried out by XRD, SEM, and TEM analyses. XRD powder pattern exhibited the presence of a major tetragonal and a minor rhombohedral crystalline phase indicating the mixed phase composition in both the samples. SEM-EDS analysis revealed good homogeneity of the materials. From evolution of the Raman spectra the spectroscopic signature of the corresponding phases was determined. Detailed dielectric measurements (between 30 degrees C to 500 degrees C) were obtained to analyze a complete set of impedance-related functions such as dielectric constant (epsilon), loss factor (tan delta), dielectric modulus (M), and conductivity (sigma). Similar to the normal ferroelectric (FE) materials, the dielectric constant (epsilon) of synthesized PZTs was found to be increasing gradually with temperature and attains a maxima (epsilon(max)) at the Curie temperature (T-c). The peaks in the dielectric constant plots are attributed to the phase transition associated with the change from tetragonal to rhombohedral structures. The higher dielectric constant of the PZT prepared by hydroxide co-precipitation make it more suitable for various applications.