title: The exchange coupling in Cr3On (n = 0-3) clusters.
abstract: The structures of neutral and cationic Cr3On0,+ (n = 0-3) clusters are calculated with density functional theory employing the BLYP and BP86 functionals. Gas-phase CrnOm clusters are produced by laser vaporization and characterized with time-of-flight mass spectrometry. The ionization energies of Cr3On (n = 0-2) are determined with threshold photoionization spectroscopy using tunable laser light in the 4.5-5.60 eV range. On the basis of a comparison between experimental and calculated ionization energies, ground-state structures were assigned. The influence of sequential addition of oxygen on the exchange coupling between the chromium atoms is investigated providing evidence for enhanced ferromagnetic coupling of chromium atoms in both the neutral and cationic Cr3On0,+ clusters. This evidence of superexchange interaction through oxygen extends earlier ideas to control the magnetic interactions in the chromium dimer via chemical reactions with oxygen toward larger chromium clusters.
authors.affiliation: Laboratory of Solid State Physics and Magnetism, and INPAC-Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium.
authors.forename: Ewald
authors.initials: E
authors.lastname: Janssens
authors.forename: Xin Juan
authors.initials: XJ
authors.lastname: Hou
authors.forename: Sven
authors.initials: S
authors.lastname: Neukermans
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Roger E
authors.initials: RE
authors.lastname: Silverans
authors.forename: Peter
authors.initials: P
authors.lastname: Lievens
authors.forename: Minh Tho
authors.initials: MT
authors.lastname: Nguyen