A rational design by hydrothermal methods of a tetrazolate-bridged bimetallic spin-canted antiferromagnet. Synthesis, X-ray structure and magnetic properties of [CoNi(pmtz)4] (Hpmtz− = 5-(pyrimidyl)tetrazole)
Articolo
Data di Pubblicazione:
2008
Citazione:
A rational design by hydrothermal methods of a tetrazolate-bridged bimetallic spin-canted antiferromagnet. Synthesis, X-ray structure and magnetic properties of [CoNi(pmtz)4] (Hpmtz− = 5-(pyrimidyl)tetrazole) / A. Rodriguez-Dieguez, M. A. Palacios, A. Sironi, E. Colacio. - In: DALTON TRANSACTIONS. - ISSN 1477-9226. - 2008:21(2008), pp. 2887-2893.
Abstract:
The bimetallic complex [CoNi(pmzt)4] (pmtz− = 5-(pyrimidyl)tetrazolate ligand) has been prepared by
hydrothermal treatment of an equimolecular mixture of the mononuclear complexes[Co(pmtz)2(H2O)2]
and [Ni(pmtz)2(H2O)2]. The structure of [CoNi(pmzt)4] consists of (4,4) square-grid-like sheets, in
which Co(II) and Ni(II) metal ions are connected by pmtz− bridging ligands. This compound is a
spin-canted antiferromagnet (weak ferromagnet) with Tc = 18 K. Although Co(II) and Ni(II) ions have
different spin values, the spin-canted structure can be formed because of the accidental compensation
of their magnetic moments. Both magnetic anisotropy and antisymmetric exchange interaction
promote the spin canting of the compensated magnetic moments in the 3D antiferromagnetic phase. On
passing from the homometallic complex, [Co2(pmzt)4], which is also a spin-canted antiferromagnet with
Tc = 15 K, to the bimetallic complex, [CoNi(pmzt)4], Tc increases and the hysteresis parameters,
remnant magnetization (Mr) and critical field (Hc), decrease. The increase in Tc may be a consequence
of the increase of the JCoNi, whereas the decrease in Mr and Hc is probably due to the presence in
[CoNi(pmzt)4] of a lower content of the highly anisotropic Co(II) ion
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
A. Rodriguez-Dieguez, M. A. Palacios, A. Sironi, E. Colacio
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