Structural and magnetic characterization of Fe0.3Ti0.7O2-?Ô films

CLAUDIA E. RODRÍGUEZ TORRES; STELLA DUHALDE; A. FABIANA CABRERA; M. FLORENCIA VIGNOLO; CLAUDIO CHILLIOTE; FRANCISCO H. SÁNCHEZ

PHYSICA B - CONDENSED MATTER

Año: 2006 vol. 384 p. 341 - 344

0921-4526

We present a study of crystalline structure, local environment around the magnetic atoms and magnetic behaviour of Fe0.3Ti0.7O2-d films, produced by Pulsed Laser Deposition, as a function of oxygen pressure and substrate temperature. Dark films were obtained by deposition at low O2 pressure (between 210
3 and 10
2 Pa). These films are ferromagnetic with coercivities around 0.03?0.04 T. Fe atoms are found to be predominantly metallic Fe. Transparent films were obtained when deposition was performed at high O2 pressure (between 4 and 20 Pa). Fe atoms are mainly in +3 valence state. These films have a component magnetically ordered probably corresponding to a-Fe(Ti)2O3 and a paramagnetic one attributed to Fe substituted anatase. After a thermal treatment Fe changes to +2 valence state and a-Fe(Ti)2O3 orders in the ilmenite phase increasing ten times the saturation magnetization of the magnetically ordered (hysteretic) component.