INFLUENCE OF RARE EARTH SUBSTITUTION ON THE MAGNETIC PROPERTIES OF SPINEL FERRITES

Abstract

Nano-size ferrites (NSF) are magnetic nanoparticles (MNPs) which have attractedgreat interest in the last decades owing to their high surface area-to-volume ratio,high saturation magnetization, initial permeability, etc. Nickel-copper-zinc ferritesare especially used in multi-layer chip inductors (MLCIs) which are found in mobilephones, camcorders, notebook computers, etc. MLCIs are composed of alternatinglayers of silver electrodes and soft ferrites. Thus, it is important to develop magneticcharacteristics in ferrites for requiring less ferrite layers and hence to obtain furtherminiaturized devices. The goal of our study is to investigate the effect of rare earthsubstitution of Ni-Cu-Zn ferrite nanoparticles. Ni-Cu-Zn NSFs substituted with rareearth metal (RE) ions Eu3+, Tb3+, and Dy3+ in varying concentrations were obtainedby a sonochemical method. We investigated the crystal structure, chemical bonding,morphology and magnetic characteristics of the Ni-Cu-Zn NSFs by X-ray powderdiffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanningelectron microscopy (SEM), and vibrating sample magnetometry (VSM),respectively. The phase purity of the samples was confirmed by the XRD analysis.Stretching vibrations of spinel ferrites were verified by the FT-IR analysis. VSMresults reveal that the rare earth substitution has a significant effect on the magneticproperties of the Ni-Cu-Zn NSFs.