title: Uranium and manganese assembled in a wheel-shaped nanoscale single-molecule magnet with high spin-reversal barrier.
abstract: Discrete molecular compounds that exhibit both magnetization hysteresis and slow magnetic relaxation below a characteristic 'blocking' temperature are known as single-molecule magnets. These are promising for applications including memory devices and quantum computing, but require higher spin-inversion barriers and hysteresis temperatures than currently achieved. After twenty years of research confined to the d-block transition metals, scientists are moving to the f-block to generate these properties. We have now prepared, by cation-promoted self-assembly, a large 5f-3d U(12)Mn(6) cluster that adopts a wheel topology and exhibits single-molecule magnet behaviour. This uranium-based molecular wheel shows an open magnetic hysteresis loop at low temperature, with a non-zero coercive field (below 4 K) and quantum tunnelling steps (below 2.5 K), which suggests that uranium might indeed provide a route to magnetic storage devices. This molecule also represents an interesting model for actinide nanoparticles occurring in the environment and in spent fuel separation cycles.
authors.affiliation: Laboratoire de Reconnaissance Ionique et Chimie de Coordination, SCIB, UMR-E 3 CEA-UJF, INAC, CEA-Grenoble, 17 rue des Martyrs, F-38054                 Grenoble Cedex 09, France.
authors.forename: Victor
authors.initials: V
authors.lastname: Mougel
authors.forename: Lucile
authors.initials: L
authors.lastname: Chatelain
authors.forename: Jacques
authors.initials: J
authors.lastname: Pécaut
authors.forename: Roberto
authors.initials: R
authors.lastname: Caciuffo
authors.forename: Eric
authors.initials: E
authors.lastname: Colineau
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Griveau
authors.forename: Marinella
authors.initials: M
authors.lastname: Mazzanti
mesh_terms: D008671:Actinoid Series Elements / Q000737:chemistry; D059346:Magnets; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D053758:Nanoparticles; D009942:Organometallic Compounds / Q000737:chemistry; D014501:Uranium / Q000737:chemistry*
chemical_list: D008671:Actinoid Series Elements; D009942:Organometallic Compounds; D008345:Manganese; D014501:Uranium