title: Fe1-yO nanoparticles: organometallic synthesis and magnetic properties.
abstract: Non-stoichiometric wüstite particles (Fe(1-y)O) are synthesized using the controlled room-temperature hydrolysis of the organometallic precursor {Fe[N(SiMe3)2]2}. Particles stabilized by hexadecylamine with a diameter of approximately 5 nm are obtained. For such small nanoparticles, a distorted crystallographic structure is evidenced by wide-angle X-ray scattering at room temperature and reported for the first time. The study of the magnetic properties indicates that these particles are composed of an antiferromagnetic core surrounded by a ferromagnetic shell. According to the Néel theory, we demonstrate that this shell consists of 1.5 % of Fe3+ ions ferromagnetically coupled with Fe2+ ions.
authors.affiliation: Laboratoire de Chimie de Coordination, UPR8241 CNRS, 205 route de Narbonne, 31077 Toulouse Cedex, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Glaria
authors.forename: Myrtil L
authors.initials: ML
authors.lastname: Kahn
authors.forename: Pierre
authors.initials: P
authors.lastname: Lecante
authors.forename: Bernard
authors.initials: B
authors.lastname: Barbara
authors.forename: Bruno
authors.initials: B
authors.lastname: Chaudret