Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 33: Bio- Molecular Magnetism

MA 33.7: Vortrag

Donnerstag, 26. März 2009, 11:45–12:00, HSZ 103

SMM-like magnetic properties of Cobalt(II) Cubane [Co₄(HL)₄(Cl)₄] — •Klaus Gieb¹, Konstantin Petukhov¹, Andreas Scheurer², Ayuk M. Ako², Rolf W. Saalfrank², and Paul Müller¹ — ¹Department für Physik, Universität Erlangen-Nürnberg, Germany — ²Department für Chemie und Pharmazie, Universität Erlangen-Nürnberg, Germany

We report on magnetic properties of the novel tetranuclear cobalt compound [Co₄(HL)₄(Cl)₄]. We have found that this Co(II) cubane system shows evident single-molecule magnet (SMM)-like behavior. In particular, we have found that the nominal ground spin state of this complex is S = 6. The uniaxial anisotropy parameter D has a negative value of around -1.6 Kelvin. Relaxation studies have evidenced a single relaxation process following an Arrhenius law. The anisotropy barrier is Δ≈55.8 K and the relaxation time is τ₀≈10⁻⁸s. The measurements were performed by means of SQUID magnetometry, AC susceptibility measurements, and micro-Hall-probe hysteretic characterization.