Preparation and dielectric properties of Co-based Nano-ferrites

Abstract

The effects of copper on the cobalt based spinel ferrites nanoparticles have been investigated. Five samples of spinel Co-ferrites with nominal compositions Co1-xCuxFe2O4 x=0.0,Co1-xCuxFe2O4 x =0.25, Co1-xCuxFe2O4 x = 0.50, Co1-xCuxFe2O4 x = 0.75 and Co1-xCuxFe2O4 x =1.0 respectively, were prepared by the chemical co-precipitation method. The samples were characterized by Therogravimetric analysis (TGA), Fourier Transformed Infra-red spectroscopy (FTIR), Scanning electron microscopy (SEM),Energy dispersive X-rays spectroscopy (EDS), X-ray diffraction and DC electrical resistivity. The average crystallite sizes were calculated from the indexed XRD diffraction peaks using the Scherer formula. The average crystallite sizes of precipitated particles lie within the range 28.64nm,40.2 nm,63.25nm,26 nm and 20.02nm respectively.DC electrical resistivity measurements were carried out by two-probe method from 370±3 K to 580±3 K.Temperature dependent DC electrical resistivity decreases with increase in temperature ensuring the semiconductor nature of the samples. DC electrical resistivity results are discussed in terms of cations distribution between tetrahedral (A) and octahedral (B)sites. Activation energy calculated from the DC electrical resistivity versus temperature for all the samples. The drift mobility increases by increasing temperature due to decrease in DC electrical resistivity in all the samples.