PZT Material by Spray Drying: from powder synthesis to electromechanical properties

A PZT niobium doped material (PZTN) was developed from precursor powders obtained by spray drying of a water solution of Zr and Pb nitrates, Ti isopropoxide and Nb-ammonium complex. The thermo - oxidative process as well as the phase evolution were analysed. The morphology of powders were investigated as a funtction of the spray drying conditions. The stoichiometry of the systems was checked at each stage of the process and no fluctuation was detected. The obtained powders had a spherical, hollow and porous structure and were transformed into a pure perovskite phase at 550 °C. The samples, sintered at 1100°C for 2h in air showed 98% relative density at a densification T 100°C lower than following the conventional mixed oxide route1. The green and final densities were improved introducing a grinding step and high pressure cold isostatic consolidation. Some sintered samples were fully densified by hot isostatic pressing (1100°C, 300 bars) post-treatment, obtaining pore free structures. The electrical characterization showed comparable or better properties than those obtained with the mixed oxide method.