Effect of surface treatment of substrates on epitaxial alpha-Fe2O3 films by coating-pyrolysis process

Using a coating-pyrolysis process, an alpha -Fe2O3 film, which consists of densely packed epitaxial alpha -Fe2O3 particles with a rectangular shape, w as obtained when an iron 2-ethylhexanoate solution was spin-coated onto an alpha -Al2O3 (012) substrate rinsed with methanol, and subsequently anneale d in air. When the alpha -Al2O3 substrate was rinsed with other conventiona l solvents, such as toluene, etc., round-shaped particles were formed on th e substrate. Since densely packed rectangular crystals of alpha -Fe2O3 were formed only on the substrate rinsed with methanol, methanol molecules adso rbed on the alpha -Al2O3 substrate are considered to promote alpha -Fe2O3 t o form a densely packed layer of rectangular crystals. The ordered adsorpti on of iron 2-ethylhexanoate molecules through methanol molecules is discuss ed. (C) 2001 Elsevier Science B.V. All rights reserved.