Electrical conductivity and dielectric properties of zinc substituted lithium ferrites prepared by sol–gel method

Polycrystalline zinc substituted lithium ferrites, Li 0.5− x /2Zn x Fe 2.5− x /2O 4 (where x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), were prepared by sol–gel method. The samples were characterized by X-ray diffraction (XRD), DC electrical conductivity and dielectric studies. X-ray diffraction patterns of all the samples showed the single phase structure. DC conductivity and dielectric properties were investigated as a function of temperature and frequency at room temperature, respectively. DC conductivity of the samples increases as the temperature increases indicating that the samples have semiconductor like behavior. It is also found that the DC resistivity and dielectric constant of the lithium–zinc ferrites changes considerably with zinc content and the sintering temperatures. The variations of DC resistivity ( ρ dc) and dielectric constant ( ε 1) with zinc content are found to be opposite to each other. The possible mechanism for the influence of zinc on the electrical transport properties of lithium ferrites is discussed in this paper.