Strain control of Urbach energy in Cr-doped PrFeO3

Abstract

Polycrystalline samples of PrFe1−x CrxO3 having average particle size of ~90 nm have been prepared by wet chemical route. The structural phase purity of the prepared samples is confirmed by powder X-ray diffraction followed by Rietveld refinements. It is observed that with Cr doping, the Urbach energy (E u) increases. The E u is measure of the various disorders present in the sample, such as chemical and structural. To understand the contribution to the E u due to chemical and structural disorders, we have probed the chemical and structural disorders in the samples by elemental mappings and through X-ray diffraction experiments, respectively. Elemental mapping confirms chemical homogeneity of prepared samples. It is observed that with Cr doping the crystallographic strain increases and Urbach energy shows the similar scaling.