Study of aliovalent modification on dielectric and ac conductivity properties in lead titanate nanoceramics

Substitution of aliovalent ions on Pb and Ti sites of ferroelectric lead titanate nanoceramics has been carried out by using a novel mechanical activation followed by a conventional solid-state reaction technique to modify the dielectric and electric properties. The Optimization of calcinations and sintering temperatures has been checked by thermal gravimetric analysis and repeated firing. High resolution X-ray diffractogram (HRXRD) analysis of some aspects of crystal structure showed that single phase compounds were formed exhibiting a tetragonal structure. The ferroelectric phase-transition of PLMT materials is studied using dielectric measurements. A shift in the transition temperature towards the lower-temperature side with increased doping concentration has been noticed. The electrical conductivity calculated from impedance data has been observed to increase as a function of Mn concentration. Conduction and charge carrier behaviors were studied based on study of frequency and temperature dependence of ac conductivity. The low temperature conductivity mechanism shows frequency dependence.