Dielectric properties of Chromium substituted Nickel nano ferrites

Background The powders of Ni-Cr Nano ferrites were synthesized with the chemical formula, NiCrXFe2−XO4 (Where X = 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) by using citrate-gel auto combustion technique. The structural characterization was investigated by X-Ray Diffractomerter (XRD). X-ray analysis shows that the samples are cubic spinel structure (single phase) without any impurity peak and average crystallite size was in the range of 8.5-10.5nm. The dielectric measurements were carried out as a function of frequency and composition (X) at room temperature in the range of 20Hz-2MHz. The real part of dielectric constant (ε') and dielectric loss factor (tan δ) showed a decreasing trend with increasing field frequency. The ac conductivity (σac) is calculated from the dielectric measurements and it is increased with the increase of frequency. The composition dependent dielectric parameters are reported.