title: Size selectable nanoparticle assemblies with magnetic anisotropy tunable across the superparamagnetic to ferromagnetic range.
abstract: We present a novel approach for the preparation of magnetic nanoparticle clusters of controlled size and selectable magnetic anisotropy, which provides materials with properties selectable for biomedical applications and as components in magnetically responsive nanocomposites. The assembly process is based on a ligand desorption strategy and allows selection of nanoparticle size and temporal control over final cluster size. Detailed NMR analysis of the suspensions pinpoints the role of particle size in controlling the interparticle interactions, within the clusters, which effectively determine the anisotropy. Colloidal interaction modelling confirms this interpretation and provides a means to predict both colloidal stability and magnetic anisotropy.
authors.affiliation: Photonics and Optoelectronics Group, Department of Physics and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany and Nanosystems Initiative Munich (NIM), Schellingstr. 4, 80799 Munich, Germany.
authors.forename: Jacek K
authors.initials: JK
authors.lastname: Stolarczyk
authors.affiliation: Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, Dunedin, New Zealand.
authors.forename: Carla J
authors.initials: CJ
authors.lastname: Meledandri
authors.affiliation: National Institute for Cellular Biotechnology, School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.
authors.forename: Sarah P
authors.initials: SP
authors.lastname: Clarke
authors.affiliation: School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland. dermot.brougham@ucd.ie.
authors.forename: Dermot F
authors.initials: DF
authors.lastname: Brougham