Effect of Hydrothermal Conditions on the Phase Evolution of Lead Titanate

Lead titanate (PbTiO3) powder was prepared from lead nitrate (Pb(NO3)(2)) and titania (TiO2) by hydrothermal route. Phase formation process was investigated by observing the phases formed in various experimental conditions like different KOH concentration, reaction temperature and time. PbTiO3 powder was fabricated when the KOH concentration was 0.8 M or higher. An intermediate compound, PbTi0.8 O-2.6, was formed at first by a reaction between PbO and TiO2 and changed into PbTiO3 powder with a perovskite crystal structure. A PbTiO3 phase was formed in a shorter time when a KOH concentration was increased from 0.8 M to 8 M because a driving force for a PbTiO3 formation was increased due to an increase in a degree of supersaturation. And TiO2 (rutile) and 3PbO center dot H(2)0 were observed at room temperature in a 0.8 M KOH solution and TiO2(rutile) and PbO (litharge) in a 8 M KOH. A PbTiO3 phase was also formed in a shorter time at a higher reaction temperature as a reaction temperature influenced the rates for a dissolution and a precipitation.