Preparation and dielectric properties of cadmium substituted lithium ferrite using microwave-induced combustion

Li–Cd ferrite powders with general formula Li 0.5−x/2 Cdx Fe2.5−x/2O4 (where x = 0.45, 0.5, 0.55, 0.6, 0.65, 0.7) were synthesized using microwave-induced combustion process in a suitably modified microwave oven. The powders were palletized and sintered in microwave oven. The XRD and IR analysis confirm the single phase spinel structure. The dielectric properties like dielectric constant ɛ′, quality factor as a function of frequency and temperature in the frequency range 50 Hz to 1 MHz and from room temperature to 450 °C have been measured. The dielectric constant is found to decrease with frequency for all the samples. The samples with x = 0.5 and 0.55 show higher values of dielectric constant. The quality factor, which is the reciprocal of dissipation factor, shows cusps in the frequency range 80–400 KHz. The behavior has been explained on the basis of Maxwell–Wangler interstitial polarization model.