Structural and electrical characteristics of double perovskite: Sr2FeMoO6

Sr2FeMoO6 ceramic material has been prepared by a mixed oxide reaction route. Analysis of structural, micro-structural and electrical characteristics of the material has been analyzed in the limit of frequency (1 kHz-1 MHz) and temperature (25-400 degrees C). From the preliminary X-ray structural analysis, the structure of the material is found to be tetragonal. The frequency dependence of dielectric constant has been explained by Maxwell-Wagner effect. There is no anomaly observed in the temperature dependent dielectric analysis. The analysis of the Nyquist plot suggests the existence of only grain effect and the sample shows both characteristics of negative and positive temperature coefficient of resistance (NTCR and PTCR). The frequency and temperature dependence of ac conductivity obeys Jonschor's power law. The analysis of temperature dependence of frequency exponent suggest that the conduction mechanism is follow the overlapping large polaron tunneling (OLPT) and correlated barrier hopping (CBH) conduction phenomena and the activation energy has also been calculated by using Arrhenius equation. The occurrence conduction phenomenon belongs to space charge limited conduction process. The observed low-leakage current density from J-E characteristics curve may be applicable for high temperature applications.