Dielectric behavior of Fe-ion-doped BaTiO₃ nanoparticles

Abstract

Iron-ion-doped barium titanate (BaTiO₃) nanoparticles have been synthesized through a chemical route using polyvinyl alcohol. The polymer serves as a surfactant to encapsulate the cationic species in divided groups during the reaction that confines the size and morphology of the specimen. The concentration of Fe³⁺ varies from 0 to 2 mol % in the specimens. The results from x-ray diffractograms and transmission electron micrographs show that the particle diameters in the specimen lie in the range 29 to 49 nm. It is seen that the ferroelectric-paraelectric phase transition temperature (T_c) varies with the composition and the dielectric permittivity in doped specimens is enhanced by an order of magnitude compared to undoped barium titanate ceramics. The dielectric permittivity shows maxima in the specimen containing 0.3 mol % of dopant concentration. The dielectric behavior of the specimens is explained in terms of the change in crystalline structure of the specimens.