Impedance and a.c. conductivity studies on Ba(Nd_(0.2)Ti_(0.6)Nb_(0.2))O_3 ceramic prepared through conventional and microwave sintering route

摘要

Electrical conduction studies on Ba(Nd_(0.2)Ti_(0.6)Nb_(0.2))O_3 ceramic samples prepared through conventional and microwave sintering route are presented in this paper. D.C. and a.c. conductivities of these samples as a function of temperature from 300-900 K have been studied. Two types of conduction processes are evident from the frequency dependant conductivity plots, i.e. low-frequency conduction due to short-range hopping and high-frequency conduction due to the localized relaxation (reorientational) hopping mechanism. Grain and grain boundary contributions to the conductivity in these samples are obtained from impedance/admittance measurements via equivalent circuit modelling.