Dielectric behaviors of Pb1-3x/2LaxTiO3 derived from mechanical activation

Abstract

Pb1-3x/2LaxTiO3 was synthesized by mechanical activation of constituent oxides to investigate the origin of ultrahigh relative permittivity for lanthanum-doped lead titanate. With increasing La doping their sintered density, grain size and relative permittivity demonstrated a steady increase. The relative permittivity showed an initial rise and a peak at 4h of annealing, upon thermal annealing in oxygen and then a steady fall with further increase in annealing time. The results show that prolonged annealing in nitrogen generated oxygen vacancies, in addition to PbO loss, which played an important role in affecting the relative permittivity.