Effects of Ce3+ doping on magnetic and dielectric properties of cobalt zinc manganese ferrites for high frequency applications

Abstract

In this paper, a constant quantity of Co2+ ions and a series of Ce3+ ions were used to substitute Fe3+ ions to control the magnetic and electrical properties of the pristine Zn–Mn nanoferrites with the formula Co0.5Zn0.25Mn0.25CexFe2-xO4 (CZMC). The addition of a suitable content of Ce3+ ions (x = 0.1) enhanced the magnetization (with an enhancing ratio of 9.43 %), initial permeability (with an enhancing ratio of 31.06 %), and coercivity (with a decreasing ratio of 12.86 %). The CZMC nanoferrites can operate from 13.5 GHz to 16.5 GHz, which can be utilized in high frequency-based technical purposes such as magnetic memories, filters, and transformer cores. The AC conductivity results of the CZMC nanoferrites are in correspondence with Jonscher's single-power law, and the conduction mechanism is established to be attributed to the overlapping large-polaron tunneling model. Nyquist plots of the samples revealed that the diameters of the semicircles decrease as the temperature increases, confirming the semiconducting behavior with one semicircle due to the electrode and grain boundary contributions to the conduction process. The high-frequency response of the CZMC nanoferrites revealed that they could operate in the frequency range of 13.5 GHz–16.5 GHz, which is suitable for electronic and microwave devices. The dielectric loss value reduces with Ce replacement (with a decreasing ratio of 66 %), suggesting it might be a candidate for planar inductor and transformer cores at high-frequency applications.