Electrical conductivity and complex impedance analysis of 20% Ti-doped La0.7Sr0.3MnO3 perovskite

The electrical conductance of 20% Ti-doped La0.7Sr0.3MnO3 (LSMO) was measured using admittance spectroscopy over a wide temperature and frequency ranges. The impedance plane plot shows semicircle arcs at different temperatures and an electrical equivalent circuit has been proposed to explain the impedance results. Activation energy inferred from conductance spectrum matches very well with the value estimated from relaxation time indicating that relaxation process and conductivity have the same origin. The electrical conductance of La0.7Sr0.3Mn0.8Ti0.2O3 is found to be dependent on temperature and frequency. Also, the electronic conduction appears to be dominated by thermally activated hopping of small polaron (SPH) at high temperatures and by variable range hopping (VRH) at low temperatures.