Impedance analysis of 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 ceramic

Abstract

0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 ceramic was prepared by citrate gel method. The electrical property of this compound was investigated using impedance spectroscopy. The appearance of grain and grain boundary is evident at higher temperature (≥425 °C). The depression of semicircle in the impedance plot and the value of full width half maximum (FWHM) of the peaks in the modulus plot show that the compound exhibits non-Debye relaxation process. The impedance analysis further provided the value of relaxation frequency, which is a characteristic intrinsic property of the material. The temperature variation of the bulk conductivity indicated an Arrhenius type of thermally activated process, showing a linear variation upto 425 °C and above which it is dominated by grain boundary conduction, which was evident from the slope change at 425 °C. The temperature coefficients of the resistance (α) were derived being equal to −1.4 × 10−2 C−2 at 400 °C. The low value of exponent (s) indicates the presence of asymmetric charge defects.