OSCILLOGRAPHIC STUDY OF THE DIELECTRIC POLARIZATION OF CU-DOPED NIZN FERRITE

A series of samples of the system Ni0.65Zn0.35CuxFe2-xO4 (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5) were prepared using the usual ceramic technique. X-ray analyses showed that the samples have cubic spinel structure (single phase). The oscillographic study of the dielectric hysteresis loops showed an increase in the induced polarization of the samples with Cu additions x and have maximum value at x = 0.3. For x less-than-or-equal-to 0.3, the local displacement of electrons in the direction of the applied electric field due to the electronic exchange Cu2+ + Fe4+ half arrow left over half arrow right Cu3+ + Fe3+ gives rise to the dielectric polarization. Mainly, the reduction of Cu2+ to Cu 3+ during the sintering process causes a decrease in the hopping electrons between Fe4+ and Fe3+ ions, resulting in a decrease in the dielectric polarization with Cu additions more than 0.3. A good agreement between the calculated dielectric constant and the dissipation factor, based on the oscillographic dielectric hysteresis loops, and their experimental values was obtained.