β Fe2O3: Preparation of Thin Films by Chemical Vapor Deposition from Organometallic Chelates and Their Characterization

Thin films of a new iron oxide phase, β-Fe2O3, were prepared by chemical vapor deposition (CVD) from tris(trifiuoroacetylacetonato) iron (III) at 30O~ in the presence of oxygen onto a variety of substrates. The films were characterized by x-ray dittraction analysis, scanning electron microscopy, and Mossbauer spectroscopy. For the latter measurements the films were prepared from enriched 57Fe2O3. The ultraviolet, visible, and infrared spectra of the films were also recorded. The iron (III) oxide phase prepared was bcc having the bixbyite structure, Ia3 space group and the lattice constant ao = 9.393Å. There are 16 formula molecules to the unit cell and the two iron atoms occupy two nonequivalent distorted octahedral lattice sites: 3 (8b); 2(24d).