Nanocrystalline MgFe2O4 ferrite sample was synthesized by sol–gel auto-combustion method. Analysis of X-ray diffraction patterns reveals the formation of single phase cubic spinel structure. The crystalline size was calculated from XRD data using Debye Scherrer equation, which reveals the formation of nanocrystalline ferrites. The dielectric constant ( Î ') and loss tangent (tan d ) were determined in a frequency range 100 Hz to 120 MHz. The dielectric constant decreases rapidly with increasing frequency, and then reaches a constant value. This shows the usual dielectric dispersion which is due to the Maxwell–Wagner type interfacial polarization and explained by Verway-de-Boer hopping mechanism. The loss tangent tanδ exhibits a peak which is explained by resonance phenomena.
Nanocrystalline, loss tangent, Dielectric constant