title: A Three-Pronged Attack To Investigate the Electronic Structure of a Family of Ferromagnetic Fe4Ln2Cyclic Coordination Clusters: A Combined Magnetic Susceptibility, High-Field/High-Frequency Electron Paramagnetic Resonance, and57Fe Mössbauer Study.
abstract: We present the synthesis, structure, magnetic properties, as well as the Mössbauer and electron paramagnetic resonance studies of a ring-shaped [FeIII4LnIII2(Htea)4(μ-N3)4(N3)3(piv)3] (Ln = Y 1, Gd 2, Tb 3, Dy 4, Ho 5, Er, 6) coordination cluster. The Dy, Tb, and Ho analogues show blocking of the magnetization at low temperatures without applied fields. The anisotropy of the 3d ion and the exchange interaction between 3d and 4f ions in Fe4Ln2complexes are unambiguously determined by high-field/high-frequency electron paramagnetic resonance measurements at low temperature. Ferromagnetic exchange interaction JFe-Lnis found which decreases upon variation of the Ln ions to larger atomic numbers. This dependence is similar to the behavior shown in the effective barrier values of complexes 3-5. Further information about the anisotropy of the Ln3+ions was gathered with57Fe Mössbauer spectroscopy, and the combination of these methods provides detailed information regarding the electronic structure of these complexes.
authors.affiliation: Institut für Anorganische Chemie, Karlsruher Institut für Technologie , Engesserstrasse 15, 76131 Karlsruhe, Germany.
authors.forename: Sebastian F M
authors.initials: SFM
authors.lastname: Schmidt
authors.forename: Changhyun
authors.initials: C
authors.lastname: Koo
authors.affiliation: Institut für Anorganische Chemie, Karlsruher Institut für Technologie , Engesserstrasse 15, 76131 Karlsruhe, Germany.
authors.forename: Valeriu
authors.initials: V
authors.lastname: Mereacre
authors.forename: Jaena
authors.initials: J
authors.lastname: Park
authors.affiliation: Institute for Theoretical Physics, Philosophenweg 16, Heidelberg University , 69120 Heidelberg, Germany.
authors.forename: Dieter W
authors.initials: DW
authors.lastname: Heermann
authors.affiliation: Leibniz Institute for Solid State and Materials Research , Helmholtzstrasse 20, IFW Dresden, 01069 Dresden, Germany.
authors.forename: Vladislav
authors.initials: V
authors.lastname: Kataev
authors.affiliation: Institut für Anorganische Chemie, Karlsruher Institut für Technologie , Engesserstrasse 15, 76131 Karlsruhe, Germany.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Anson
authors.affiliation: Institute of Chemistry, Academy of Sciences of Moldova , Chisinau, Moldova.
authors.forename: Denis
authors.initials: D
authors.lastname: Prodius
authors.affiliation: Laboratoire National des Champs Magnétiques Intenses, UPR CNRS 3228, Grenoble, France.
authors.forename: Ghenadie
authors.initials: G
authors.lastname: Novitchi
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Klingeler
authors.affiliation: Institut für Anorganische Chemie, Karlsruher Institut für Technologie , Engesserstrasse 15, 76131 Karlsruhe, Germany.|Karlsruhe Institute of Technology, Institute of Nanotechnology , Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Annie K
authors.identifier: http://orcid.org/0000-0003-3944-7427
authors.initials: AK
authors.lastname: Powell