An in-depth study was made of the magnetotransport properties of epitaxial Fe3O4 films as a function of film thickness. The films, grown onto α-Al2O3(00▪1) single crystals by atomic-O assisted molecular beam epitaxy, exhibited high structural order and sharp interfaces. The films contained antiphase boundaries, the density of which was strongly dependent upon film thickness. Resistivity and magnetoresistance measurements revealed a systematic evolution of these properties, with decreasing film thickness, revealing the impact of antiphase boundaries upon the transport properties. A model was presented which was based upon spin-polarized transport across an antiferromagnetically coupled antiphase boundaries in order to reproduce successfully the experimental data over a large range of applied magnetic fields. A comparison of this model with experimental results further clarified the mechanism of anomalous magnetotransport behavior in Fe3O4.

Magnetotransport Properties of Fe3O4 Epitaxial Thin Films - Thickness Effects Driven by Antiphase Boundaries. A.V.Ramos, J.B.Moussy, M.J.Guittet, A.M.Bataille, M.Gautier-Soyer, M.Viret, C.Gatel, P.Bayle-Guillemaud, E.Snoeck: Journal of Applied Physics, 2006, 100[10], 103902 (8pp)