The preparation of a novel layered lead titanate and its conversion to theperovskite lead titanate PbTiO3

A novel layered lead titanate with the approximate composition PbTiO2(CO3)( 0.3) (NO3)(0.35)(OH) has been synthesized hydrothermally under acidic condi tions. The structure has been solved and refined from X-ray and neutron pow der diffraction data in the space group P -3 1 m, with cell dimensions a = 5.1787(5) Angstrom and c = 8.5222(7) Angstrom. The titanate layers possess a gibbsite-like structure: lead cations and oxyanions such as carbonate and nitrate are included between the layers. Upon heating the solid loses wate r, carbon dioxide and nitrogen dioxide and converts via a poorly crystallin e intermediate phase to the perovskite PbTiO3. The conversion is complete b y 550 degreesC; continued heating results in an increase in crystallinity. (C) 2001 Elsevier Science Ltd. All rights reserved.