Structural and magnetic behaviour of Fe0.1Ti0.9O2 films obtained by pulsed laser deposition

C.E. RODRÍGUEZ TORRES

Reñaca, Chile

Workshop; VII Latin American Workshop on Magnetism Materials and Their Applications; 2005

Diluted magnetic semiconductors (DMS) consist of nonmagnetic semiconducting materials doped with a few atomic percent of impurity magnetic cations. DMS have attracted much attention because the combination of magnetic and semiconducting properties makes them good candidates for spintronic device applications. Magnetic properties differed considerably for the different preparation methods, indicating that the local environment of the impurity could have a drastic effect on the magnetic structure. Fe0.1Ti0.9O2-ä films produced by Pulsed Laser Deposition (PLD) as a function of oxygen pressure and substrate temperature conditions are investigated. Crystal structure, local environment of Fe atoms and magnetic behaviour of the samples were studied by x ray diffraction, x-ray absorption (XAS) and magnetometry measurements. Room temperature magnetic dark films were obtained when deposition was performed at low O2 pressure (between 10-5 and 10-4 mBar). In these films Fe atoms are predominantly in metallic Fe then, the observed magnetism is due to á-Fe. Transparent films were obtained when deposition was performed at high O2 pressures (between 4x10-2 and 10-1 mbar). In these films atoms Fe are in +3 valence state, probably in a mixture of hematite and anatase, where Fe substituting Ti. Ferromagnetic – like behaviour at RT was observed when the iron atoms are into the octahedral distorted oxygen environment with oxygen vacancies.