Author(s)

S. L. Mammah, F. E. Opara, F. B. Sigalo, S. C. Ezugwu, F. I. Ezema

Department of Physics and Astronomy, University of Nigeria, Nsukka, Nigeria.
Department of Physics and Astronomy, Western University, London, Canada.
Department of Physics, Faculty of Science, Rivers State University of Science and Technology, Nkpolu, Nigeria.
Department of Science Laboratory Technology, School of Applied Sciences, Rivers State Polytechnic Bori, Bori, Nigeria.

Thin films of hematite (α-Fe₂O₃) were deposited by heteronucleation through the process of hydrolysis and condensation of an aqueous solution of 0.1 M Fe (NO₃)₃.9H₂O, 1 M NaNO₃, 50 ml H₂O in addition with five drops of HCl at 90℃. One of the samples was kept as prepared while the others were annealed at different temperatures in order to determine the effect of annealing on their solid state and optical properties. The films were characterized using Rutherford Back Scattering (RBS), spectroscopy for chemical composition and thickness, X-Ray Diffraction (XRD) for structural analysis, UV-VIS Spectrophotometer for the analysis of other solid state and optical properties and a photomicroscope for photomicrographs. The results indicate that while the absorbance and absorption coefficient decreases with increasing annealing temperature, the direct band gap and refractive index increases with increasing annealing temperature in the direction of increasing photon energy in the visible range. Also, there is a high infrared transmittance which increases with increasing annealing temperature and a shift/decrease in peak value of all the optical properties except transmittance in the direction of increasing photon energy as annealing temperature increases. The results further indicate that ACG hematite thin film annealed at 632K is a suitable metal oxide semiconductor material for photocatalytic applications. It is also suitable for use in the construction of poultry houses for the rearing of chicks because of its high infrared transmittance including other opto-electronic applications.

Aqueous Chemical Growth; αFe₂O₃; RBS; XRD; Optical Properties

S. Mammah, F. Opara, F. Sigalo, S. Ezugwu and F. Ezema, "Annealing Effect on the Solid State and Optical Properties of αFe₂O₃ Thin Films Deposited Using the Aqueous Chemical Growth (ACG) Method," Materials Sciences and Applications, Vol. 3 No. 11, 2012, pp. 793-801. doi: 10.4236/msa.2012.311115.