Tailoring the structural, optical, electrical and multiferroic properties of Sm1-xRxFeO3 (x = 0.0 and 0.5; R = Pr, Nd, and Gd) and their synergistic photocatalytic activity

Abstract

In this work, nanocrystalline Sm1-xRxFeO3 (x = 0.0 and 0.5; RPr, Nd, and Gd) samples have been synthesized via auto-combustion method and characterized to understand their microstructural, optical, electrical and multiferroic properties. X-ray diffraction data in combination with the FTIR spectra revealed the monophase and distorted orthorhombic configuration of all the samples with Pbnm space group. Rietveld refinement displayed a reduction in the bond length as well as the bond angle in the Sm0.5Gd0.5FeO3 sample. Raman spectra exhibit compressive strain in Sm0.5Gd0.5FeO3 nanoparticles; this finding is further supported by the XRD analysis. UV–visible spectroscopy manifests a reduction in the optical energy bandgap on moving Gd to Pr in Sm0.5R0.5FeO3 system. Transmission electron microscopy (TEM) images in combination with energy dispersive x-ray (EDX) spectra reveal the non-uniform surface morphology with the agglomerated nature of nanoparticles and affirm the elemental compositions of all the samples. The room temperature P-E and M − H loops infer the multiferroic nature of all samples. Electron paramagnetic resonance (EPR) analysis divulges the weakening of the super-exchange interactions in Sm0.5R0.5FeO3 system. DC electrical resistivity measurements reflect semiconductor-like behaviour in all prepared samples. The dielectric behaviour of the samples is in accordance with the “universal dielectric response” model. The temperature-dependent dielectric measurements of all prepared samples have been performed at 1 kHz to determine the Néel temperature (TN). The photocatalytic investigation depicts the superior photocatalytic response of Sm0.5Pr0.5FeO3 nanoparticles under solar-light irradiation through the synergism of semiconductor-photocatalyzed oxidation and heterogeneous Fenton-like reaction.