Effect of Sr substitution on rare earth mangnaites: EuMnO3

Abstract

An effort is made to study the effect of Sr (divalent atom) substitution in an otherwise antiferromagnetic insulator EuMnO3. A series of samples have been prepared through solid state reaction route from the high purity constituent materials. The structural characterization is carried out by XRD with Retieveld analysis. Most of the samples in the series crystallises under orthorhombic structures with Pnma space group. With increasing concentration of Sr, the sample tends to more symmetric in nature. The SEM imaging renders the proper granular structures of the samples in the series. Moreover, a detail investigation is carried out for the transport features of the materials. The temperature dependence of resistivity shows unique features with varied concentrations of the Sr. With a lower concentrations favours the insulating state of the materials to that of semiconducting with increasing the content of Sr on the rare earth side of the parent manganite. The features are described in terms of the double exchange model with the support of structural parameters calculated for each material.