Mössbauer, Raman, and magnetoresistance study of aluminum-based iron oxide thin films

Thin films of Al-based hematite iron oxide were synthesized by spray pyrolysis in aqueous medium onto the glass microslides. The compact and homogeneous distribution of grains (spindle-shaped hematite nanostructures) with varying sizes has been observed in surface morphological studies. The room temperature Mössbauer study has been carried out to monitor the local environment around Fe cations and valence state of Fe ions. Mössbauer and micro-Raman (low temperature) results suggest that oxygen vacancies cause cation redistribution between the interstitial sites resulting in magnetic ordering. The variation of magnetoresistance in low magnetic field (>3 kOe) is also reported