Morphological evolution of PbTiO₃ microstructures synthesized by topochemical microcrystal conversion

PbTiO₃ (PT) microstructures were fabricated by topochemical microcrystal conversion (TMC) and their morphological evolution was investigated with variation of synthesis temperature and relative molar ratio of reactants. Using molten salt synthesis, Aurivillius phase of PbBi₄Ti₄O₁₅ (PBiT) synthesized at 1050°C was prepared as precursor. Large plate-like PT microstructures with lengths of hundreds of micrometer were optimally obtained when the relative ratio (x) of (PbCO₃)₂·Pb(OH)₂ to PBiT in reactants was 6. In addition, relatively homogeneous PT platelets were achieved at the annealing temperature of 1050°C by TMC; these materials are probably suitable for use in templated grain growth. However, a Pb-deficient secondary phase of PbTi₃O₇ formed in cases of low x values of less than 4 and low annealing temperatures of less than 1050°C. The porous PT pellets, orthogonally assembled by numerous PT platelets, were achieved by increasing temperature to 1100°C. Further increase in temperature to 1150°C could lead to partial formation of denser PT blocks.