Radio-frequency (RF) studies of the magneto-dielectric composites: Cr0.75Fe1.25O3 (CRFO)-Fe0.5Cu0.75Ti0.75O3 (FCTO)

• Published in: Physica. B, Condensed matter Vol. 403; no. 17; pp. 2902 - 2909
• Main Authors: ROCHA, H. H. B, FREIRE, F. N. A, SANTOS, M. R. P, SASAKI, J. M, CORDARO, T, SOMBRA, A. S. B
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 01.08.2008
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Physics; Boltzmann equation; Dielectric materials; Magneto-dielectric composites; Titanates; 77.84.-s; XRD; 77.22.Ch; Dielectrics; Radiofrequency; Ferrites; Dielectric function; Composite materials; Solid state reaction; Magnetic materials; 72.80.Tm
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2008.02.033

This paper concerns a study about the electrical properties of Cr0.75Fe1.25O3 (CRFO)/Fe0.5Cu0.75Ti0.75O3 (FCTO) magneto-dielectric composites. These compounds were prepared by the conventional solid-state reaction synthesis. The samples synthesized, as well their two-phase composites [Cr0.75Fe1.25O3]Z-[Fe0.5Cu0.75Ti0.75O3]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 (kappa), 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.