Microwave assisted synthesis and characterization of Fe3+-O-Fe3+ sublattice magnetic moment influencing ferromagnetism exhibited erbium orthoferrite sublattice (ErFeO3) perovskite nanopowders

Abstract

In this work, we report the systematic experimental synthesis and characterization of rare earth Erbium metal incorporated orthoferrite (EOF) nanoparticles (NPs) via microwave-assisted technique. The instrument micro-oven was used to induce exothermic heating inside the sample which causes the formation of ErFeO3 nano-crystallites. The unit cell structure of Erbium substituted orthoferrite nano-crystallite is studied by using experimental results and computational techniques by simulating the orthorhombic phase. Crystal lattice structure and its direct and reciprocal parameters are analysed by performing the Rietveld refinement process on the Powder X-ray diffraction pattern (P-XRD) data which confirms the fabricated unit cell structure belongs to the orthorhombic-cubic phase (spacegroup: Pbnm) with slightly induced distortion in bond distance between atoms. From FTIR fingerprint region of metal oxides, the vibrational frequency of harmonically oscillating Er-O groups in ErFeO3 unit cells was observed at (414 and 420 cm−1) and this value is consistent with the theoretical vibrational frequencies of Er-O (424.0410 and 426.5122 cm−1) calculated based on the Hooks law by considering the Er-O groups as a harmonic system. Similarly, the observed and calculated vibrational frequencies of Fe-O groups are found at (536, 570 and 576 cm−1) and (530.2621, 531.4341 and 549.7296 cm-1) respectively. The band gap of the ErFeO3 is found to be 2.1 eV. Weak Ferromagnetic property is observed in MH plot for the synthesized EOF nanoparticles due to formation of lower bond angle of Fe3+-O-Fe3+ sublattice with 140.5782° and 147.6881°. SEM image of ErFeO3 is confirmed the spherically distributed nano-crystallites with size ranging from 62 to 166 nm. In this research, Match (v3) and VESTA open-source programs are used for the Rietveld refinement process and to calculate bond distance between atoms in the unit cell.