title: Size-dependent magnetic properties of CoFe2O4 nanoparticles prepared in polyol.
abstract: Highly crystalline CoFe(2)O(4) nanoparticles with different diameters ranging from 2.4 to 6.1 nm have been synthesized by forced hydrolysis in polyol. The size can be controlled through adjusting the nominal water/metal molar ratio. X-ray diffraction, transmission electron microscopy, x-ray absorption spectroscopy and (57)Fe Mössbauer spectrometry were employed to investigate the structure and the microstructure of the particles produced. Magnetic measurements performed on these particles show that they are superparamagnetic with a size-dependent blocking temperature. At 5 K, high saturation magnetization (~85 emu g(-1)) approaching that of the bulk was found for the larger particles, whereas a very large coercivity (14.5 kOe) is observed for the 3.5 nm sized particles.
authors: ITODYS, Université Paris Diderot, CNRS UMR-7086, F-75205, Paris, France.
authors: Mathieu
authors: M
authors: Artus
authors: Lotfi Ben
authors: LB
authors: Tahar
authors: Frédéric
authors: F
authors: Herbst
authors: Leila
authors: L
authors: Smiri
authors: Françoise
authors: F
authors: Villain
authors: Nader
authors: N
authors: Yaacoub
authors: Jean-Marc
authors: JM
authors: Grenèche
authors: Souad
authors: S
authors: Ammar
authors: Fernand
authors: F
authors: Fiévet