Above room temperature complex impedance analysis of properties of La0.33Sr0.67Mn0.33Ti0.67O3± perovskite

La0.33Sr0.67Mn0.33Ti0.67O3 +/- perovskite was prepared by the standard solid state reaction at 1773K. The sample crystallizes in the cubic structure. The electrical properties of the sample have been investigated above room temperature in 293-373K range with varying frequency between 10(2) and 10(6) Hz using complex impedance analysis. The sample exhibit a metal-semiconductor transition temperature at T-MS= 303K. The conductance curves were well fitted by Jonscher power law G() = G(dc) + A(n), which shows that with increasing temperature, the exponent (n) decreases below T-MS, and increases above T-MS. The activation energy deduced from the analysis of the conductance curves matches very well with the value estimated from the relaxation time indicating that relaxation process and electrical conductivity are attributed to the same defect. Nyquist plots of impedance show semicircle arcs for sample and an electrical equivalent circuit has been proposed to explain the impedance results.