Study on Preparation and Physical Properties of Fe2O3 Nanopowders

Fe
₂
O
₃
nanopowders were prepared by solid phase reaction method. The phase structure, microstructure, magnetic properties and gas sensor properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), vibration sample magnetometer (VSM) and gas sensor measuring system. It was found that the precursor sintered at 300 °C was spinel structure and transformed into α-Fe
₂
O
₃
above 400 °C. The results of the room temperature hysteresis loops showed that the results obtained from the magnetic hystersis loop at room temperature were in agreement with those from the XRD spectra. Moreover, it was shown that γ-Fe
₂
O
₃
can be used as gas sensor of the alcohol. The α-Fe
₂
O
₃
nanopowders can be obtained at a lower sintering temperature. In addition, the gas sensor of γ-Fe
₂
O
₃
was more sensitive to the alcohol.