Annealing temperature effect on structural and optical investigations of Fe 2O 3 nanostructure

摘要

Ferric oxide (Fe2O3) was synthesized at different temperatures (TS) between 300 and 500°C by spray pyrolysis technique. Surface of annealed Fe2O3nanostructure was characterized by field emission scanning electron microscopic (FESEM). Annealed Fe2O3nanostructure has showed rhombohedral hexagonal structure with the preferred orientation along (104) plane in X-ray diffraction patterns (XRD). Crystallite size was increased from 43 to 63nm with increasing ofTSbetween 300 and 500°C. The maximum transmittance was found to be 72% for Fe2O3nanostructure atTS=300°C. The energy gap for direct band transitions was measured to be 2.05–2.09eV. Refractive index of Fe2O3nanostructure in the visible region was found in the range of 2.37–2.62. Fe2O3nanostructure has showed n-type electrical conductivity and electrical resistivity was found in the range of 1.02×103–6.23×103Ωm. Formation of transparent Fe2O3nanostructure with band gap and high refractive index suggests the suitability of Fe2O3nanostructure in gas sensors.