Synthesis, XRD and EPR spectroscopic characterization of nano copper doped alumino zinc ferrite

Abstract

Copper doped zinc aluminium ferrites CuxZn1-x.(AlxFe2-x)O4 (x= 0.15,0.45, 0.75 and 0.90) are synthesized by the solid-state reaction route and characterized by XRD, TEM, EPR and Optical absorption spectroscopy techniques. The particle size is found to be 30 nm and the unit cell parameter “a” is calculated as 5.10 Å. The cation distributions are estimated from X-ray diffraction intensities of various planes. The theoretical lattice parameters, X-ray density, oxygen positional parameter and ionic radii, as well as bonds and lengths of the edges of the tetrahedral (A-) and octahedral (B-) sites, have been determined. The XRD studies have verified the quality of the synthesis of compounds and have shown the differences in the positions of the diffraction peaks due to the change in concentration of copper ions. Absence of EPR spectra at room temperature indicates that the sample is perfectly ferromagnetic. EPR results at low temperature indicate that the sample is paramagnetic, and that copper is placed in the tetragonal elongation (B) site with magnetically non-equivalent ions in the unit cell having strong exchange coupling between them. Nonlinear optical properties of the samples studied using 5 ns laser pulses at 532 nm employing the open aperture z-scan technique indicate that these ferrites are potential candidates for optical limiting applications.