Dielectric and Magnetic Properties of Rare-Earth Metal Ce-Doped ZnO Thin Films

Abstract

Ce-doped ZnO thin films were fabricated by sol–gel dip coating method with varying Ce concentrations of 1–5 at.wt.%. The influence of Ce doping on magnetic and dielectric properties has been investigated. Vibrating sample magnetometer results reveal that the Ce-doped ZnO material has a soft nature. The study of magnetic properties confirmed the ferromagnetic behavior at room temperature for all the synthesized thin films. The localized states of Ce atoms are the main contribution to the magnetic moment. Crystallinity of thin films is highly dependent on the magnetic properties. The increased percentage of Ce reduces the saturation magnetization and coercivity. By using an impedance analyzer, variation in the results of dielectric constant, dielectric loss and AC conductivity of prepared thin films at room temperature as a function of frequency ranges from 100 Hz to 1 MHz were investigated. The normal behavior of dielectric dispersion was shown by the thin films, as evidenced by the reduction of the dielectric constant and dielectric loss with the increase in frequency due to Maxwell–Wagner interfacial polarization. Similarly, dielectric results showed that the increase in frequency enhanced the AC conductivity. It is used to evaluate the minimum distance of hopping, maximum height of the barrier and the localized density of states at the Fermi level. The induced spin polarization is found for Ce doping.