Influence of seeding on the crystallisation kinetics of PbTiO3 from gel-derived precursors

Lead titanate has been prepared by a sol–gel method using titanium tetrabutoxide and lead acetate in stoichiometric proportion. It was found that the seeding with PbTiO3 nanoparticles (5 and 10 wt.%) into the precursor solution affects the crystallisation process. Thus, unseeded gel calcined at 380°C remained almost amorphous whereas 10 wt.% seeded gel was >70% crystallised. At 400°C, the 10 wt.% seeded sample was almost fully crystallised and the pyrochlore phase was not observed. The isothermal crystallisation kinetics for an unseeded and 5, 10 wt.% seeded PbTiO3 have been compared. The seeded one exhibited enhanced crystallisation kinetics and the activation energy for the PbTiO3 crystallisation was reasonably lowered (from 281 kJ/mol for unseeded to 121 kJ/mol for 10 wt.% seeded gel).