2003/01/21 by R. Koch, Robert J. Koch, O. Waldmann +5 · 1 citation
Materials Science · Physics and Astronomy · #Lanthanide and Transition Metal Complexes #Magnetism in coordination complexes #Organic and Molecular Conductors Research #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.67.094407
7 pages, 7 figures
arxiv created 2003/01/21 · openalex publication_date 2003/03/13 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We investigated the magnetic properties of two isostructural Ni(II) metal complexes [Ni4L8b] and [Ni4L8c]. In each molecule the four Ni(II) centers form almost perfect regular squares. Magnetic coupling and anisotropy of single crystals were examined by magnetization measurements and in particular by high-field torque magnetometry at low temperatures. The data were analyzed in terms of an effective spin Hamiltonian appropriate for Ni(II) centers. For both compounds, we found a weak intramolecular ferromagnetic coupling of the four Ni(II) spins and sizable single-ion anisotropies of the easy-axis type. The coupling strengths are roughly identical for both compounds, whereas the zero-field-splitting parameters are significantly different. Possible reasons for this observation are discussed.