Radio-frequency (RF) studies of the magneto-dielectric composites: Cr_0.75Fe_1.25O₃ (CRFO)-Fe_0.5Cu_0.75Ti_0.75O₃ (FCTO)

This paper concerns a study about the electrical properties of Cr_0.75Fe_1.25O₃ (CRFO)/Fe_0.5Cu_0.75Ti_0.75O₃ (FCTO) magneto-dielectric composites. These compounds were prepared by the conventional solid-state reaction synthesis. The samples synthesized, as well their two-phase composites [Cr_0.75Fe_1.25O₃]_Z-[Fe_0.5Cu_0.75Ti_0.75O₃]_100-Z (Z=17, 34, 50, 66, 83), were characterized by X-ray powder diffraction technique (XRD). Rietveld's method was employed to verify the quantitative phase abundances in the composites' and their theoretical densities, which were compared with the experimental densities (pycnometer method). To predict the effect of the phases in the composites effective dielectric function (κ), traditional dielectric mixing models such as parallel, series, and Lichtenecker's model were observed. An alternative approach, a sigmoidal fitting function based on the Boltzmann equation, was proposed to fit the experimental data