Synthesis of barium-zinc-titanate ceramics

The influence of mechanical activation, combined with subsequent thermal treatment, on the crystal structure, microstructure and dielectric properties of BaZn2Ti4O11 samples was studied. Mixtures of BaCO3, ZnO and TiO2 powders, with a molar ratio of 1:2:4, were mechanically activated for 20, 40 and 80 min in a planetary ball mill. The resulting powders were compacted into pellets and isothermally sintered at 1250 C for 2 h with a heating rate of 10 C/min. XRD of the obtained powders and sintered samples was performed to investigate changes of the phase composition. The microstructure of the sintered samples was examined by SEM. The photoacoustic phase and amplitude spectra of sintered samples were measured as a function of the laser beam modulating frequency using a transmission detection configuration. Fitting of experimental data enabled determination of photoacoustic properties, including thermal diffusivity. Based on the results, correlation between thermal diffusivity and experimental conditions, and microstructural characteristics, are discussed.