Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 3: Quantum Magnets and Molecular Magnets (joint session TT/MA)

MA 3.4: Vortrag

Montag, 12. März 2018, 10:15–10:30, H 3010

Magnetic susceptibility and high frequency EPR studies on three isostructural Fe₂^IIILn₂^III complexes — •Silvia Menghi¹, Changhyun Koo¹, Yan Peng², Christopher Anson², Annie Powell², and Rüdiger Klingeler¹ — ¹Kirchhoff-Institut für Physik, Universität Heidelberg, Heidelberg, Germany — ²Institute of Inorganic Chemistry, Karlsruhe Institut of Technology, Karlsruhe, Germany

Magnetic interactions and anisotropy of three 3d/4f heteronuclear metal-organic complexes are studied by means of high-frequency electron paramagnetic resonance (HF-EPR) and magnetic susceptibility measurements. All complexes under study exhibit isostructural tetranuclear core motifs [(Fe₂^IIILn₂^III(µ₃-OH)₂(teaH)₂(O₂CCPh)₆]·3MeCN (L=Y,Gd,Dy). The HF-EPR data show various resonance branches, each of which with finite zero field splitting. The static magnetic susceptibility data imply strong antiferromagnetic coupling of J_FeFe=−6.71(4) cm⁻¹ between the two Fe^III centers. The coupling between Fe and Ln was found to be weak and ferromagnetic. In order to gain quantitative insight into the anisotropy and the Fe-Dy exchange interaction, simulations have been performed using a proper hamiltonian which applies a Ising concept for the lanthanide ions.