title: Multimillimetre-large superlattices of air-stable iron-cobalt nanoparticles.
abstract: Self-organization of nanoparticles into two- and three-dimensional superlattices on a large scale is required for their implementation into nano- or microelectronic devices. This is achieved, generally after a size-selection process, through spontaneous self-organization on a surface, layer-by-layer deposition or the three-layer technique of oversaturation, but these techniques consider superlattices of limited size. An alternative method developed in our group involves the direct formation in solution of crystalline superlattices, for example of tin nanospheres, iron nanocubes or cobalt nanorods, but these are also of limited size. Here, we report the first direct preparation in solution of multimillimetre-sized three-dimensional compact superlattices of nanoparticles. The 15-nm monodisperse FeCo particles adopt an unusual short-range atomic order that transforms into body-centred-cubic on annealing at 500 degrees C. The latter process produces an air-stable material with magnetic properties suitable for radiofrequency applications.
authors.affiliation: Laboratoire de Chimie de Coordination du CNRS, 205, route de Narbonne, 31077 Toulouse Cedex 04, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Desvaux
authors.forename: Catherine
authors.initials: C
authors.lastname: Amiens
authors.forename: Peter
authors.initials: P
authors.lastname: Fejes
authors.forename: Philippe
authors.initials: P
authors.lastname: Renaud
authors.forename: Marc
authors.initials: M
authors.lastname: Respaud
authors.forename: Pierre
authors.initials: P
authors.lastname: Lecante
authors.forename: Etienne
authors.initials: E
authors.lastname: Snoeck
authors.forename: Bruno
authors.initials: B
authors.lastname: Chaudret
mesh_terms: D000388:Air; D001672:Biocompatible Materials / Q000737:chemistry / Q000528:radiation effects; D003035:Cobalt / Q000737:chemistry* / Q000528:radiation effects; D003460:Crystallization / Q000379:methods*; D004581:Electronics; D016247:Information Storage and Retrieval / Q000379:methods; D007501:Iron / Q000737:chemistry* / Q000528:radiation effects; D008280:Magnetics; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D010316:Particle Size
chemical_list: D001672:Biocompatible Materials; D003035:Cobalt; D007501:Iron