Magnetic and Magnetization Properties of Iron Aluminum Oxide Thin Films Prepared by Sol-Gel

Amongst various spinels of the form MAl₂O₄ (where M=Fe, Co, Mg and so on), FeAl₂O₄ exhibits exceptional chemical and physical properties including high flexibility and ductility. Reports on magnetic properties of these spinels are limited especially in the form of thin films. Structural and magnetic properties of iron aluminium oxide thin films prepared by Sol-Gel and spin coating method have been reported in this work. The ratio of Fe/Al is varied as 0.4, 0.45, 0.5, 0.55, and 0.6. Films are annealed in the presence of vacuum at 300°C under 500 Oe applied magnetic field. Peaks of FeAl₂O₄ are observed for Fe/Al of 0.4. However, Fe₂O₃ peaks appear along with iron aluminium oxide peaks for rest of the ratios. M-H curves show enhanced magnetic properties of films having 42.325 emu/cm³ saturation magnetization (M_s), 10 emu/cm³ remnant magnetization (M_r), and 430.19 Oe coercivity (H_c). Conductivity measurements show transition in electrical properties at a temperature of 127 K. Room temperature magnetoresistance ~10% is observed for iron aluminum oxide thin films with Fe/Al of 0.4.