Magnetic susceptibility of Co2+ pairs in [Co-2(ox)tpmc](ClO4)(2)center dot 3H(2)O cluster complex

Abstract

Calculation of the magnetic susceptibility of Co2+ pairs in the recently synthesized cobaltous cluster complex [Co-2(ox)tpmc](ClO4)(2). 3H(2)O has been conducted by the use of two different theoretical models. The calculated results were compared to the experimental data collected in a wide temperature region. Conclusions on both the magnetic properties of Co2+ dimers and the validity of the proposed models have been drawn. In the temperature region above chi(T) maximum, the best results are obtained with the Heisenberg model that includes spin-orbit coupling and excited single-ion levels. In the low-temperature region anisotropy of the magnetic properties dominates and Ising dimer ground-stare model gives a more appropriate description. Obtained g-values (g(parallel to a) = 5.67, g(parallel to b) = 5.73, and g(perpendicular to) = 1.54) confirm strong Co2+ anisotropy. Each model gives the same value of the intracluster exchange integral J/k(B) approximate to - 14.6 K, within the fitting error. (C) 2000 Elsevier Science B.V. All rights reserved.