Structure and humidity sensitive electrical properties of the Sn4+ and/or Mo6+ substituted Mg ferrite

Pure and Sn4+ and/or Mo6+ substituted Mg ferrites with compositions Mg1−xSnxFe2−yMoyO4 (x = 0.00, 0.10 and y = 0.00, 0.02) have been prepared by sol–gel autocombustion method. The ceramic samples were sintered at 1100 °C for 4 h. The phase composition and lattice parameters were determined by XRD, while effect of Sn and Mo substitutions on the granular structure was studied by SEM. Experimental results revealed that some physical properties are in close relation with the structural changes induced by the presence of Sn and Mo ions. We have found that the humidity sensitivity of the electrical resistivity largely depends on composition, crystallite size, surface area and porosity. The best results concerning humidity sensitivity were obtained for Mg0.9Sn0.1Fe2O4 ferrite. The Sn ions enhance the humidity sensitivity of the Mg ferrite and assure a nanocrystalline structure of this ferrite.