Cation distribution and site occupancy of nanoscale Cu2+-Er3+ substituted strontium hexaferrites via Raman and Mössbauer spectroscopy

Abstract

In this research, we report on the cation distribution and site occupancy of Cu2+ and Er3+ ions in the hexagonal lattice of M-type strontium hexagonal ferrites with chemical composition Sr1-xCuxFe12-yEryO19 (x=0.0, 0.1, 0.2, and y=0.0, 0.4, 0.5) fabricated using sol-gel autocombustion technique. Raman analysis of the synthesized samples was conducted based on the group theory analysis of hexagonal ferrites based on the D6h symmetry. The Raman active modes based on the mode assignment and symmetry and were typical of M-type hexaferrite. Mössbauer spectroscopy shows the density of the s electron cloud at the 12k, 4f2, and 4f1 is affected by Cu2+-Er3+ substitution which indicate that all the five sexets originate from Fe3+ ion with high spin and that Er3+ ion (with d10 orbitals) occupies Fe3+ ion position at 12k, 4f2, 2a, and 2b sites in different proportion based on the Ligand theory.