Impedance studies of La^sub 0.6^Gd^sub 0.1^Sr^sub 0.3^Mn^sub 0.9^In^sub 0.1^O^sub 3^ manganite prepared by the sol-gel method

A systematic study of complex impedance analysis and dielectric properties of La0.6Gd0.1Sr0.3Mn0.9In0.1O3manganite are carried out. Our sample is prepared using the sol-gel method. The impedance spectrum analysis was fitted by adequate equivalent circuits involving the contributions of grain and grain boundaries in the conduction mechanism. The imaginary part of the complex impedance (Z″) frequency dependence revealed one relaxation peak. The dielectric constant shows a normal behavior. The real part (ε′) and loss tangent have been explained on the basis of space charge polarization according to Maxwell-Wagner's two layer model and Koops phenomenological theory. The conductivity curves have been investigated by the Jonscher universal power law: σ=σAC+σDC. The conduction process is found to be dominated by a thermally activated small polaron hopping (SPH) model.