Titanium effects on the transport properties in La0.7Sr0.3Mn1-xTixO3

The transport properties of the samples La0.7Sr0.3Mn1-xTixO3 were investigated using admittance spectroscopy. In contrary to free compound, when titanium is introduced, the conductance becomes frequency and temperature dependent. From DC conductance study, electronic conduction is found to be dominated by thermally activated hopping and depending strongly on Ti content. Activation energy is deduced from the variation of conductance with temperature. This energy decreases from 168 to 143 meV when x increases from 0.05 to 0.20. The AC conductance spectrum is found to obey Jonscher universal power law. Finally, at ambient temperature, DC conductance decreases with the value of x and proves a clear effect of titanium in transport properties of the material. This decrease of conductance is explained by a reduction of Mn3+-O-Mn4+ network responsible for electrical conduction in perovskite.