Effect of Zn+2 doping on Structural, dielectric and electrical properties of Cobalt Ferrite prepared by Auto Combustion method

Abstract

Zinc doped cobalt ferrite nanoparticles having the basic composition Co1-xZnxFe2O4(x=0, 0.1, 0.2, 0.3, 0.4, 0.5) were prepared using auto combustion method. The structural, dielectric and a.c conductivity of these samples, which are sintered at 900°C were studied. XRD patterns were recorded using X-ray diffractometer. XRD patterns confirm the nanocrystalline nature for the sintered samples. The peaks observed in the XRD spectrum indicated single phase spinel cubic structure for the samples. Surface morphology of the samples has been investigated using Field Emission Scanning Electron Microscope (FESEM). The dielectric constant (ε') and dielectric loss tangent (tan δ) of nanocrystalline cobalt ferrites were investigated as a function of frequency and Zn+2 concentration at room temperature over the frequency range 100 Hz to 1 MHz using Hioki make LCR Hi-Tester 3250. The dependence of ε' and tan δ with the frequency of the alternating applied electric field is in accordance with the Maxwell-Wagner type interfacial polarization. The electrical conductivity (σac) deduced from the measured dielectric data has been thoroughly analyzed and found that the conduction mechanism in the present Co1-xZnxFe2O4 nanoferrites are in conformity with the electron hopping model.