High-frequency dielectric behaviour of Li-Mg ferrites

摘要

Dielectric properties such as dielectric constant (ε′) and dielectric loss tangent (tanδ) of mixed Li-Mg ferrites have been measured at room temperature in the frequency range 1 to 13 MHz using an HP 4192A impedance analyser. Plots of dielectric constant (ε′) vs. frequency show a normal dielectric behaviour of spinel ferrites. The frequency dependence of dielectric loss tangent (tanδ) is found to be abnormal, giving a peak at certain frequency for all mixed Li-Mg ferrites. A qualitative explanation is given for the composition and frequency dependence of the dielectric constant and dielectric loss tangent.