X-ray diffraction and dielectric study of Co1-xCdFe2-xCrxO4 ferrite system

The samples of the Cd-Cr co-substituted cobalt ferrite (Co1-xCdFe2-xCrxO4) with x=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 were prepared by the usual double sintering ceramic technique and were characterized by means of X-ray diffraction (XRD) and dielectric measurements. X-ray analysis shows that the samples are cubic spinels (single phase). The lattice parameter a is determined from XRD data with an accuracy of +/-0.002 Angstrom for x=0.0 to 0.5 and their variation with Cd and Cr addition is studied. The lattice parameter a increases with the compositional parameter x. the dielectric constant (epsilon), dielectric loss (tandelta) and dielectric loss tangent (tandelta) of Co1-xCdFe2-xCrxO4 were measured at room temperature as a function of frequency. The measurements were carried out with the help of HP 4192 LF impedance analyzer in the range 100 Hz-1 MHz. It is observed that epsilon', epsilon decrease with increasing frequency. The dielectric loss (epsilon) decreases with increasing frequency at a faster rate that the dielectric constant (epsilon'). The parameter (tandelta) decreases with increasing frequency. (C) 2002 Elsevier Science B.V. All rights reserved.