Direct and Alternate Current Conductivity and Magnetoconductivity of Nanocrystalline Cadmium-Zinc Ferrite below Room Temperature

Abstract

Nanocrystalline cadmium-zinc ferrite samples were prepared by ball milling method and its electrical transport property were investigated within a temperature range 77 K ≤ T ≤ 300 K in presence of a magnetic field up to 1T and in a frequency range 20 Hz to 1 MHz. The investigated samples follow a simple hopping type charge transport. The dc magnetoconductivity has been explained in terms of orbital magnetoconductivity theory. The alternating current conductivity follows the universal dielectric response σ'/(f) ∝ Tnfs. The values of ‘s’ have a decreasing trend with temperature. The temperature exponent ‘n’ depends on frequency. The dielectric permittivity of the samples depends on the grain resistance and interfacial grain boundary resistance. The ac magnetoconductivity is positive which can be explained in terms of impedance of the sample.