Dielectric properties of PZT prepared by two sol-gel methods

Lead zirconate titanate (PZT) has ferroelectrics properties. PZT powders were prepared by two different sol-gel methods. In one process, the precursor materials used were lead hydroxide, zirconium tetra-n-butoxide, and titanium tetraisopropoxide along with 2-methoxyethanol as a solvent. An amount of distilled water equivalent to the total molar concentration of Pb, Ti, and Zr was added to the above solution. In another process, the precursor materials used were lead acetate, zirconyl nitrate, and titanium tetra-n-butoxide. Distilled water and acetic acid were used as solvents. Triethyleneglycol was used in both the above processes as a chemical additive to modify the hydrolysis and condensation of the solution. Thermal gravimetric-differential thermal analysis was used to study the weight changes of the dried gels as a function of annealing temperature. Dried samples were heated for 1 h in the range of 673 to 1073 K in air atmosphere. The crystalline phases of calcined PZT powders were identified by X-ray diffraction analysis. The calcined powders were die-pressed at 30 MPa and pressed by CIP at 100 MPa. The pellets were sintered at 1173 K, 1273 K, and 1323 K and their relative dielectric constants were measured. The dielectric constants of PZT samples by the first method showed high values of about 15000 at 655 K.