Effect of sintering time on the particle size and dielectric properties of La-doped PbTiO3 ceramic nanoparticles

Nanoparticles of [Pb0.7 La0.2] TiO3 ceramics were prepared by conventional combustion technique from the oxides of PbO, La2O3 and TiO2 with different sintering time (ts) (2, 6, 10, 12, 16 and 20h) while keeping the calcination temperature at 1200 oC. Particle size of the samples was estimated between 25 to 65 nm through Scherrer formula and was found to increase with increasing sintering time (ts). Microstructural analysis of the samples was carried out using scanning electron microscope which showed that grain boundary increased with increasing sintering time (ts) while dislocations were reduced. The dielectric constant and Curie temperature of the samples was increased with increasing sintering time (ts), but the activation energy in both of ferroelectric and paraelectric (Ea) decreased with increasing ts . The diffusion coefficient (γ) decreased with increasing ts . In other words the optimum sintering time conditions was found.