Nanocomposite Fe1xO=Fe3O4, Fe=Fe1xO thin films prepared by RF sputtering and revealed by magnetic coupling effects

Bruno Mauvernay (1) , Lionel Presmanes (1) , Corine Bonningue (1) , Philippe Tailhades (1)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

Magnetic and semi-conducting nanocomposite iron oxide thin films have been prepared under bias polarization, by radio-frequency sputtering of a magnetite target. The nature of the phases obtained in the thin films depends on the bias power density. The increase in power density, from 0 to 110mW=cm2, allows the preparation of magnetite, magnetite/wustite and wustite/a-iron nanocomposites successively. Magnetic measurements at low temperature show exchange bias for two-phases films even though the minor phase is not detected by grazing angle X-ray diffraction. The exchange bias can reach very high values of about 4300 Oe. Electrical properties at room temperature are interpreted taking into account both the modifications of the film compactness, and the nature of the phases from which they are made.

Mots clés: Iron oxides; Magnetic coupling; Exchange bias; Sputtering; Nanocomposite; Magnetite; Wustite; Iron oxides

Domaines: Matériaux

Bruno Mauvernay, Lionel Presmanes, Corine Bonningue, Philippe Tailhades. Nanocomposite Fe1xO=Fe3O4, Fe=Fe1xO thin films prepared by RF sputtering and revealed by magnetic coupling effects. Journal of Magnetism and Magnetic Materials, 2008, vol. 320, pp. 58-62. ⟨10.1016/j.jmmm.2007.05.042⟩. ⟨hal-00801706⟩