Ferromagnetic Properties of Al-doped Fe2O3 Thin Films by Sol-gel

We here report synthesis and characterization of aluminum (Al) doped Fe2O3 thin films using sol-gel method. Effect of aluminum doping on Fe2O3 thin films has been given very little consideration in the past especially the reports on magnetic properties are limited. Fe3+ has an ionic radii of 0.69 Å whereas Al3+ has ionic radii extremely close to that of Fe3+ i.e. 0.675 Å. XRD results indicate that aluminum is well incorporated in the host Fe2O3 lattice. Intensity of the diffraction peaks decreases as the concentration of aluminum is increased. In case of undoped Fe2O3 thin films net magnetization arises due to difference in magnetization of two sublattices. However, as the dopant concentration is increased the imbalance between the magnetic moments of the sublattices enhances the total magnetic moment thus leading to increase in saturation magnetization.