Characterization and gas-sensing properties of nanocrystalline iron(III) oxide films prepared by ultrasonic spray pyrolysis on silicon

Thin films of nanocrystalline hematite (alpha-Fe2O3) are deposited on silic on substrates by nebulization of a 0.01 M solution of iron acetylacetonate in an ethanol/water mixture, followed by pyrolysis and annealing in flowing air. The resulting films are characterized by X-ray diffraction, scanning electron microscopy, atomic force microscope, IR transmission spectrum and Raman Spectra, and the gas-sensing properties of as-deposited films are inv estigated as well. The resulting films consist of spherical particles and p orous, columnar order structure for Si(111) with several nm order of magnit ude of crystal grain size, and highly crystalline alpha-Fe2O3 films with (1 04) orientation are obtained. (C) 2000 Elsevier Science S.A. All rights res erved.