Effect of Cu dopant on the structural, magnetic and electrical properties of Ni-Zn ferrites

Ni0.8-xCuxZn0.2Fe2O4 (x = 0.0, 0.2, 0.4, 0.6) ferrite was synthesized through auto-combustion method. (XRD) patterns confirmed the crystallization of the samples in spinel structure. FESEM showed that the size of ferrite particles are about few hundred nanometers and with increase in Cu concentration (x) in the structure there is increase in particle size. Fourier transform infrared (FUR) spectrometry indicates that octahedral and tetrahedral sites are formed. Vibrating sample magnetometer (VSM) results proved reduction of saturation magnetization (M-s) by increasing Cu content, which is explained according to the ferrimagnetic nature of these samples in which Ni is replaced by Cu at octahedral site. Real part of dielectric constant (epsilon) and loss tangent (tan delta) of samples were also studied in frequency range of 100-20000 Hz. Results showed an increase in a and tans of the sample with x = 0.6 which is considered to be the result of higher density of this sample.