Coupling of two types of polar regions in Na0.5Bi0.5TiO3: An impedance spectroscopic study

Polycrystalline Na0.5Bi0.5TiO3(NBT) system has been synthesized by solid-state reaction method. The dielectric and microstructural conduction mechanism has been investigated with the help of impedance spectroscopic technique. From microstructural conduction mechanism results, it is perceived that, two short range and two long range conduction/relaxation processes are evolved in different temperature and frequency zones. The dynamics of four relaxation/conduction processes are analyzed by considering the variation of activation energy (E-a) of each relaxation/conduction process in different temperature zone and represented by a model. In this model, coupling of two polar regions in different temperature and frequency zones has been systematically discussed.