INVESTIGATION OF THERMAL, STRUCTURAL, OPTICAL AND MAGNETIC PROPERTIES OF ZnFe2O4 and Zn0.75Cu0.25Al0.1Fe1.9O4 MAGNETIC MATERIALS

Abstract

In the present study, ZnFe2O4 and Zn0.75Cu0.25Al0.1Fe1.9O4 ferrite nanoparticles were synthesized by Solid state reaction method. The thermal, structural, optical and magnetic properties of these ferrites were investigated. For this purpose, thermal Analysis, powder x-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Ultraviolet visible (UV-vis) spectroscopy and electron spin resonance (ESR) spectroscopy characterization techniques were utilized. The TGA/DTA analysis measurement used for measuring changes in the mass of a sample as a function of temperature or time and measurement of the difference in temperature. The investigation identifies that 11.48% and 12.077% total weight loss of ZnFe2O4 and Zn0.75Cu0.25Al0.1Fe1.9O4 compounds respectively were detected when the compound is heated from room temperature to 1000℃. The XRD analysis reveals that both the synthesized samples possessed cubic spinel structure with Fd-3m space groups. Different structural parameters were investigated from the obtained XRD analysis. The average crystallite sizes were found to be 30.07, 35.40 and 36.85 nm, for ZnFe2O4 and Zn0.75Cu0.25Al0.1Fe1.9O4, respectively. This confirms the nano crystalline nature of both synthesized materials. From FT-IR spectroscopy study, two strong absorbation spectral bands of ZnFe2O4 were 578.5cm-1 and 389.9cm-1 and also two strong bands of Zn0.75Cu0.25Al0.1Fe1.9O4 were 584.9cm-1 and 396cm-1 which are responsible for the formation of the synthesized materials, were identified. The optical bandgap was found to be 2.785 and 2.773 eV for ZnFe2O4 and Zn0.75Cu0.25Al0.1Fe1.9O4 ferrite, respectively. From the ESR spectroscopic investigation, the ESR spectrum of ZnFe2O4 and Zn0.75Cu0.25Al0.1Fe1.9O4 ferrite at room temperature shows wide line width ∆HPP133mT and 3.68 effective g value and wide line width ∆HPP177mT and 3.37 g-values were identified respectively , which indicates that dipole interactions are dominant in both synthesized ferrite particles.