Thermal Characterization of PZT Ceramics Obtained by Mechanically Activated Mixed Oxides Using Different Pb Sources

In this study, three sets of PZT samples with compositions 57/43 and 55/45 (rhombohedral phase), 53/47 and 51/49 (tetragonal phase) prepared by mechanochemical activation of powder mixtures (during 4 h of milling) and thermal treatment (sintered at 1200 A degrees C for 4 h) were thermally characterized. The three sets of compositions were prepared using different Pb sources (A-PbO, B-PbO2, and C-Pb3O4). The thermal characterization of sintered samples was carried out by photoacoustic spectroscopy and differential scanning calorimetry, to obtain the thermal diffusivity and specific heat (c (p) ). The DSC thermograms also allowed the determination of the Curie temperature, and the thermal conductivity was calculated combining the results of the thermal diffusivity, specific heat, and density. The samples obtained with Pb3O4 showed a theoretical density higher than 95 %, whereas those obtained from PbO2 precursors showed a lower densification rate (around 89 %). The samples obtained with Pb3O4 with compositions 53/47 and 51/49 also showed the highest values of thermal diffusivity (7.3 +/- 0.4) x 10(-7)m(2)center dot s(-1) and (6.6 +/- 0.3) x 10(-7)m(2)center dot s(-1), respectively.