Structure, Humidity Sensitivity and Magnetic Properties of Ce Substituted Magnesium Ferrite

The effect of Ce ions substitution at Fe ions site on the microstructure, humidity sensing and magnetic properties of magnesium ferrite was investigated. MgCexFe2-xO4 ceramics with x = 0.00, 0.02 and 0.04 were prepared using sol-gel auto combustion technique. X-ray diffraction analysis confirms the formation of cubic spinel structure of magnesium ferrite for all samples. However a second phase of CeO was also present in samples with Ce substitution. Scanning electron images show porous structures with irregularly shaped grain. Sample with composition x = 0.04 has the highest percentage of porosity and smallest grain size. This sample also has the highest sensitivity towards humidity. Magnetic hysteresis loops show a soft magnetic material behavior with low coercive force for all samples. The magnetization decreases while the coercive field increases with Ce substitution.