... [40]. In the present study, the value of n varies between 0.073 and 0.086, which suggests that the conduction phenomenon in the studied samples is ac conduction and is due to the hopping of charges. ... composition. The composition-dependent behavior of the investigated samples can be explained on the basis that Ni as well as Cu ferrites are inverse spinel in structure, and the degree of inversion ... remains almost constant. Thus, according to Equation 10, the increase of the total porosity P (in percent) is mainly due to the increase of Pintra with Zn2+ doping [28, 29]. The FETEM and...