title: Ultrafast dynamics of a ferromagnetic nanocomposite.
abstract: Ensembles of iron nanocrystals up to 25 nm in diameter embedded in SiO(2) were found to exhibit an ultrafast magnetic response to a transient out-of-plane magnetic field. The response time varies as a function of in-plane bias magnetic field with the fastest rise times, as short as 26 ps, observed for both zero and high bias fields (140 kA/m). Analytical modeling and micromagnetic simulations confirm that magnetostatic interactions between nanoparticles play an important role in the dynamic response.
authors.affiliation: Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, USA. buchanan@anl.gov
authors.forename: Kristen S
authors.initials: KS
authors.lastname: Buchanan
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Zhu
authors.forename: Alkiviathes
authors.initials: A
authors.lastname: Meldrum
authors.forename: Mark R
authors.initials: MR
authors.lastname: Freeman
mesh_terms: D003198:Computer Simulation; D004574:Electromagnetic Fields; D007501:Iron / Q000737:chemistry* / Q000528:radiation effects*; D007700:Kinetics; D008422:Materials Testing; D020527:Microscopy, Scanning Probe / Q000379:methods; D008956:Models, Chemical; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D012822:Silicon Dioxide; D007501:Iron