Dielectric relaxation behavior of AxCo1−xFe2O4 (A = Zn, Mg) mixed ferrites

► Effect of cation distribution on structural and dielectric properties. ► The dielectric dispersion behavior is due to Maxwell-Wagner polarization. ► Minimum loss (∼0.04) makes present system useful in microwave applications. ► Impedance spectra reveal grain interior contribution in the conduction process. ► Modulus study reveals the presence of non-Debye type of dielectric relaxation.