Structural and Dielectric Properties of Rare Earth Doped Lithium Nanoferrites for Sensing Applications

Nowadays it is the hot topic to analyze the behavior of different materials towards gasses so that they can be used for sensing purpose. Ferrites specifically lithium ferrites show very good response to gasses present in the environment. Lithium ferrite doped with Gd (Li0.5Fe2.475Gd0.025 O (4)) was selected for this purpose. Sample was synthesized by simplified sol-gel technique. After that, pellets were formed and sintered at different temperatures. Spinel cubic phase was observed in x-ray diffraction (XRD). It is noted that by increasing sintering temperature, results slightly decrease in lattice constant. Scanning electron microscopy (SEM) was used to study the surface morphology of the samples. It was observed that particles were spherical in shape. AC electrical properties were studied at room temperature in the frequency range of 20 Hz to 3 MHz. AC electrical conductivity and dielectric constant decreased with the increase in sintering temperature. The maximum conductivity was observed in the sample that was sintered at temperature of 700 C-ay. Significant variation in electrical response with frequency made these samples suitable for sensing applications.