Co-Cd nanoferrite for high frequency application with phenomenal rise in DC resistivity

Abstract

The communication concentrates on the possibility of developing a composition suitable for high-frequency operation as a magnetic core through an extensive understanding of the cation distribution of cobalt ferrite containing cadmium. The samples having a composition, Co1-xCdxFe2O4, were processed by the sol–gel method using polyvinyl alcohol (PVA) as a chelating agent and characterized by standard techniques. Substantial growth in specific saturation magnetization from 82.2 emu/g to 99 emu/g and DC resistivity from 1.54 × 106 Ω-cm to 1.34 × 1011 Ω-cm, requisite characteristics for high-frequency application were provided with increasing concentration of cadmium. The average crystallite size ranging from 5.7 nm to 17 nm has been estimated by X-ray diffraction patterns using Williamson-Hall analysis. The proposed cation distribution based on saturation magnetization data established the amount of cadmium occupying the tetrahedral sites of spinel lattice, which was well supported by the variation of DC resistivity with cadmium. The unparalleled matching between the experimentally observed lattice constant and that provided by the proposed cation distribution as well as Rietveld refinement confirms the amounts of cadmium entering tetrahedral and octahedral sites of the spinel lattice. All the samples of cadmium substituted cobalt ferrite assure their suitability for high frequency application with the pertinent properties.