title: Annealing effects on 5 nm iron oxide nanoparticles.
abstract: Morphological, structural and magnetic properties of 4.8 nm iron oxide nanoparticles have been investigated after annealing under inert atmosphere at different temperatures. The as-prepared iron oxide nanoparticles have been synthesized by chemical route from high temperature reaction of Fe(acac)3 solution in presence of oleic acid and oleylamine surfactant. Annealing the particles at low temperatures (Tann = 573 K) produces an increment of the mean size from 4.8 nm to 6.0 nm, preserving the same morphology. The coercive field of the annealed sample has a small increasing with respect to the as-prepared sample in agreement with the mean particle volume change. Annealing at higher temperature (Tann = 823 K) leads to a bimodal size distribution of the iron oxide nanoparticles with 6.0 nm and 17 nm mean sizes respectively, where the bigger particles dominate the observed magnetic properties.
authors.affiliation: Centro Atómico Bariloche and Comisión Nacional de Energía Atómica, 8400 San Carlos de Bariloche, Rio Negro, Argentina.
authors.forename: J M
authors.initials: JM
authors.lastname: Vargas
authors.forename: E
authors.initials: E
authors.lastname: Lima
authors.forename: L M
authors.initials: LM
authors.lastname: Socolovsky
authors.forename: M
authors.initials: M
authors.lastname: Knobel
authors.forename: D
authors.initials: D
authors.lastname: Zanchet
authors.forename: R D
authors.initials: RD
authors.lastname: Zysler
mesh_terms: D000588:Amines / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D052203:Ferrosoferric Oxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D019301:Oleic Acid / Q000737:chemistry; D010316:Particle Size; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D000588:Amines; D005290:Ferric Compounds; D013501:Surface-Active Agents; C000499:ferric oxide; D019301:Oleic Acid; D007501:Iron; D052203:Ferrosoferric Oxide; C008703:oleylamine