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.
F. Bezzi, A. L. Costa, D. Piazza, A. Ruffini, S. Albonetti, C. Galassi (2005). PZT Material by Spray Drying: from powder synthesis to electromechanical properties. JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 25 (13), 3323-3334 [10.1016/j.jeurceramsoc.2004.08.027].
PZT Material by Spray Drying: from powder synthesis to electromechanical properties
BEZZI, FEDERICA;ALBONETTI, STEFANIA;
2005
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
