Mn substituted Ni-Zn mixed ferrites doped with Gd3+ ions belonging to the series Mn0.2Ni0.6 Zn0.2 Gdx Fe2-xO4 (x=0, 0.02, 0.04, 0.06) have been synthesized by sol-gel method. The effect of Gd3+ substitution on the structural, cationic distribution, magnetic and dielectric properties has been investigated in detail. X-Ray analysis reveals formation of single phase spinel cubic ferrite nanoparticles

A modification of the Lichtenecker–Rother model is proposed for the dielectric permittivity of polymer composites that takes into account aggregation of filler particles into clusters. The governing equations for the real and imaginary parts of the complex permittivity of a composite involve three adjustable parameters with transparent physical meaning. These quantities are determined by fitting experimental