Rietveld refinement, optical, dielectric and ac conductivity studies of Ba-doped SrSnO3.

The samples SrSnO₃ (SBS0) and Sr_0.98Ba_0.02SnO₃ (SBS2) were synthesized using sol–gel route, followed by calcination at 1073 K. Rietveld refinement analysis of XRD data shows orthorhombic phase under Pbnm space group. Lattice parameters, volume and density of the doped sample were found to be higher than undoped, due to higher ionic radii of Ba²⁺. Further, the Raman spectrum of samples was carried out to study the local structure. Optical properties of samples show intense absorption in UV range and transparent in visible to NIR region. The direct bandgap of samples was found to be 3.88 eV and 3.97 eV for SBS0 and SBS2, respectively, reflecting the semiconducting nature of a sample. Dielectric properties of the sample were explained in terms of interfacial and orientational polarization. Temperature-dependent conductivity analysis of the sample reflected an Arrhenius-type charge transport, with two conduction regions in SBS2 and single conduction in SBS0. In the present case, the activation energy value represents a mixed ionic and electronic conductivity of the sample, making it a promising candidate for mixed ionic and electronic conductor device application. [ABSTRACT FROM AUTHOR]