Dielectric and Magnetic Study of NiCuZn Spinel Ferrites

Abstract

The ferrite system having spinel structure with composition Ni 1-x-y Cu x Zn y Fe 2 O 4; [(x = 0.3, 0.2), (y = 0.2, 0.3, 0.5)] has been amalgamated through solid-state reaction method and structural, dielectric and magnetic studies have been carried out. The Presence of tetrahedral and octahedral bands in FTIR spectra confirmed the proper phase formation of spinel ferrites. In lowfrequency region dispersive behaviour has been shown by both dielectric constant (ε′) and tangent loss (tanδ) and they show nearly constant value at higher frequencies. This follows Maxwell-Wagner double layer model in which low conductive grain boundaries separate higher conductivity grains and in good agreement with Koop's Model. The Nyquist plot shows depressed semi-circular arcs. The ac conductivity (σ ac ) shows increasing trend with temperature and frequency both. The S parameter has been calculated from the fitted ac conductivity plot and used to explain conductivity mechanism. The samples show good magnetic behaviour. Maximum value of saturation magnetization has been observed for the sample having the highest Zn content. Magnetization versusTemperature plot implies towards non equilibrium magnetization below its reversibility temperature.

Dielectric Characterization and Modeling of Composite Materials Based on Epoxy Resin/Black Iron Oxide/Titanates in Several Frequency Ranges

“…By combining two or more components, it becomes possible to obtain very different properties depending on the properties of the constituent phases in order to meet the required combinations of properties. 1 Composites based on ferroelectric polymer-ceramic with high dielectric permittivity 2,3 have been widely used as structural materials due to their perfect dielectric proprieties over a wide range of frequencies, including microwaves. 4 These materials have many uses in many fields such as mobile and satellite communication systems, antennas, oscillators, filters, capacitors, wireless communications, and sensors.…”