Study of electrical properties of Sc doped BaFe_(12)O_(19) ceramic using dielectric, impedance, modulus spectroscopy and AC conductivity

摘要

We present dielectric, complex impedance, modulus spectroscopy and AC conductivity studies of the compound BaFe_(10)Sc_2O_(19) as a function of temperature and frequency to understand the conduction mechanism. The variation in complex dielectric constant with frequency and temperature were analyzed on the basis of Maxwell-Wagner-Koop's theory and charge hopping between ferrous and ferric ions. The complex impedance spectroscopy study shows only grain contribution whereas complex modulus plot shows two semicircular arcs which indicate both grain and grain boundary contributions in conduction mechanism. AC conductivity has also been evaluated which follows the Jonscher's law. The activation energy calculated from temperature dependence of DC conductivity comes out to be E_a～0.31eV.