Preparation and characterization of perovskite Pb(Mg1/3Nb2/3)O3-PbTiO3 by a modified polymerized complex process

Relaxor-based ferroelectrics, 0.65Pb(Mg1/3Nb2/3)O-3-0.35PbTiO(3) (PMN-PT) with a pyrochlore-free phase, was prepared by a modified polymerized complex process. The reactive columbite (MgNb2O6) phase was synthesized by the polymerized complex method at 1050 degrees C for 4 h with 3wt% excess MgO. Lead acetate and tetrebutyl titanate were used to synthesize pyrochlore-free PMN-PT powder via the columbite route, from 800 degrees C to 900 degrees C, in air for 4 h. X-ray diffraction and scanning electron microscopy were used to detect the perovskite phase evolution and the presence of the pyrochlore phase in PMN-PT. The formation of perovskite PMN-PT is a function of the time and temperature conditions of the precursor calcinations, and an optimum condition for the thermal decomposition of the precursor was determined to avoid the fort-nation of the pyrochlore phase.