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Magnetic behavior of a spin-1 Heisenberg dimer is analysed in dependence on both uniaxial single-ion anisotropy and XXZ exchange anisotropy in a zero-as well as non-zero longitudinal magnetic field. A complete set of eigenfunctions and eigenvalues of the total Hamiltonian is presented together with an exact analytical expression for the Gibbs free energy, longitudinal magnetization, longitudinal and transverse susceptibility. The obtained theoretical results are compared with the relevant experimental data of [Ni 2 (Medpt) 2 (µ-ox)(H 2 O) 2 ](ClO 4 ) 2 .2H 2 O (Medpt = methyl-bis(3-aminopropyl)amine).

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The magnetization process of the spin-1 Heisenberg dimer model with the uniaxial or biaxial single-ion anisotropy is particularly investigated in connection with recent experimental high-field measurements performed on the single-crystal sample of the homodinuclear nickel(The results obtained from the exact numerical diagonalization indicate a striking magnetization process with a marked spatial dependence on the applied magnetic field for arbitrary but finite single-ion anisotropy. It is demonstrated that the field range, which corresponds to an intermediate magnetization plateau emerging at a half of the saturation magnetization, basically depends on a single-ion anisotropy strength as well as a spatial orientation of the applied field. The breakdown of the intermediate magnetization plateau is discussed at length in relation to the single-ion anisotropy strength.

The mononuclear tetracoordinate [Co(dmphen)X2] (dmphen = 2,9‐dimethyl‐1,10‐phenanthroline = neocuproine; X = Cl, Br, I) complexes were prepared by a solvothermal method. X‐ray diffraction experiments showed that they possess analogous molecular structures, even though the chlorido complex crystallizes in a different crystal system and space group. The crystal structures of the complexes are stabilized by π–π interactions. Alternating‐current (AC) susceptibility measurements show that the bromido and iodido complexes behave as field‐induced single‐molecule magnets with several slow relaxation channels, whereas the chlorido complex exhibits antiferromagnetic interactions and does not display slow relaxation of magnetization.

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Preparation, spectroscopic and magnetic characterization of Cu(cyclam)M(CN) 4 complexes exhibiting one-dimensional crystal structures (cyclam 5 1,4,8, M 5 Ni, Pd, Pt) Abstract From the systems Cu(II)-cyclam-[M(CN) 4 ] 2-(cyclam = 1,4,8,11-tetraazacyclotetradecane; M = Ni, Pd, Pt), three cyanidocomplexes Cu(cyclam)M(CN) 4 [M = Ni (1), Pd (2), Pt (3)] were isolated and characterized by chemical analysis, IR and UV-VIS spectroscopy. The three compounds are isostructural, and their crystal structures are formed by quasi-linear chains exhibiting [-Cu(cyclam)-l-NC-M(CN) 2 -l-CN-] n composition. The Cu(II) atoms reside on centres of symmetry and are coordinated in the form of an elongated octahedron with mean equatorial Cu-N bonds of 2.015(12), 2.017(13) and 2.011(11) Å in (1), (2) and (3), respectively, and weakly N-bonded bridging cyanido ligands in the axial positions [2.5321(9) Å in (1), 2.518(2) Å in (2) and 2.549(3) Å in (3)]. Hydrogen bonds of the N-HÁÁÁN cyanido ÁÁÁH-N type link neighbouring chains, and a topologically square network of paramagnetic Cu(II) atoms is formed. The magnetic susceptibilities of all three complexes follow the Curie-Weiss law with a weak antiferromagnetic exchange coupling below 5 K.