Using surface X-ray diffraction, 20nm-thick α-Fe2O3(00•1) thin films deposited on α-Al2O3(00•1) and Pt(111) single crystals were investigated. The films were grown in identical conditions by atomic O assisted molecular beam epitaxy techniques. Both substrates offer close lattice parameter misfits. On sapphire an isostructural epitaxial relationship was observed and a 30° in plane rotation of the lattice for Pt(111). The crystalline quality of the film deposited on Pt(111) was much better and contained less parasitic contributions. The improved crystalline quality of α-Fe2O3(00•1) layers on Pt(111) was attributed to the presence of a very well ordered interfacial dislocation network which was missing when α-Al2O3 was used as substrate.

Dislocation Network Driven Structural Relaxation in Hematite Thin Films. A.Barbier, O.Bezencenet, C.Mocuta, J.B.Moussy, H.Magnan, N.Jedrecy, M.J.Guittet, M.Gautier-Soyer: Materials Science and Engineering B, 2007, 144[1-3], 19-22