High temperature electrical properties study of Sr₂(Fe,Ti)O₆ double perovskite materials using impedance spectroscopy method

The structure, thermal, and electrical properties of double perovskite material Sr₂(Fe,Ti)O₆ at high temperature have been studied. This material was synthesized by a solid state reaction method. X-ray diffraction characterization at room temperature for all samples shows a single phase and having a structure of cubic double perovskite with Pm3m space group. The variation of Fe and Ti atoms are seen in an increasing of lattice parameter and grain size which is found between 30 nm and 80 nm. The electrical properties as a function of temperature and frequency are characterized by using RLC-meter with impedance spectroscopy method. The impedance data are presented in Nyquist and Bode plot resulting in the equivalent circuit and its parameters. The equivalent circuit shows the effect of grain and grain boundary in the electrical properties of materials. DC conductivity of Sr₂(Fe,Ti)O₆ as a function of temperature was explained by using Arrhenius equation. The value of the activation energy which is evaluated from dc conductivity as a function of temperature shows the effect of grain and grain boundary. The activation energy exhibits of oxygen vacancy in Sr₂(Fe,Ti)O₆ which is also supported by morphology of Sr₂(Fe,Ti)O₆ is characterized by field emission scanning electron microscopy (FESEM).