Effect of Particle Size on the Structural and Magnetic Properties of Nanocrystalline Zinc Ferrite

Abstract

ZnFe₂O₄ is one of the most important technological material having applications in radio engineering, radio technology, semiconductors, bio-medical applications etc. ZnFe₂O₄ when in bulk form shows paramagnetic behavior at room temperature. When ZnFe₂O₄ is synthesized by some techniques it was possible to see the ferromagnetic behavior. Also, ZnFe₂O₄ in nanocrystalline form exhibit different magnetic properties. Therefore in the present work we intend to present the properties of particle size behavior of ZnFe2O4 nanoparticles. ZnFe₂O₄ nanoparticles were synthesized by oxalic acid based precursor method. The obtained ZnFe₂O₄ nano powders were thermally annealed from 300 to 600 °C. The structural and magnetic characterization were measured using X-ray diffraction (XRD), scanning electron microscope (SEM), IR measurements and vibrating sample magnetometer (VSM). XRD patterns clearly showed the formation of zinc ferrite. The particle size was observed to increase from 19 to 35 nm with increasing annealing temperature. The lattice constants were observed to decrease with increasing particle size. The nanoparticles size were confirmed using SEM measurements. IR measurements were carried to confirm the phase formation of ZnFe₂O₄ nanoparticles. The Infrared spectra showed the characteristic features of vibrational bands corresponding to spinel ferrite. Room temperature ferromagnetic properties were observed for zinc ferrite having particle sizes 19 and 21 nm. For the particle size 29 and 35 nm it showed paramagnetic nature. The magnetic properties of zinc ferrite nanoparticles were observed to be dependent on the particle size.

Keywords: Nanoferrites Zn ferrite Structural properties Magnetic properties