Reaction sequence in the formation of perovskite Pb(ZrO0.48Ti0.52)O3-Pb(Nb2/3Ni1/3)O3 solid solution:: Dynamic heat-treatment

The sequence of the solid state reactions in the PbO-ZrO2-TiO2Nb2O5-NiO system has been investigated. The oxide mixing route utilised in sample preparation was selected in order to determine the basic reaction path in the formation of the PZT-PNN perovskite phase. It has been established that the main intermediate phases formed prior to PZT-PNN are PbTiO3 and pyrochlore Pb-Nb-based phases. The sequence in the pyrochlore formation was from tetragonal Pb3Nb2O8 (500 degrees C) to rhombohedral Pb2Nb2O7 (600-750 degrees C) and finally to cubic Pb3Nb4O13 (650-850 degrees C). The formation of the perovskite phase proceeded from mutual solubility of PbTiO3 and pyrochlore Pb3Nb4O13 phases, accompanied by dissolving of residuals (PbZrO3 and NiO) in the perovskite solid solution for med. (C) 1998 Elsevier Science Limited. All rights reserved.