2003/03/27 by Marco Evangelisti, M. Evangelisti, M. L. Kahn +11 · 1 citation
Materials Science · Physics and Astronomy · #Lanthanide and Transition Metal Complexes #Magnetism in coordination complexes #Organic and Molecular Conductors Research #cond-mat
paper · pdf · doi:10.1103/physrevb.68.184405
published as Phys. Rev. B 68, 184405 (2003) · 13 pages, 15 figures, submitted to Phys. Rev. B
arxiv created 2003/03/27 · openalex publication_date 2003/11/06 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report on the low-temperature magnetic susceptibilities and specific heats of the isostructural spin-ladder molecular complexes L2[M(opba)]3\ensuremath⋅xDMSO\ensuremath⋅yH2O, hereafter abbreviated by L2M3 (where L=La, Gd, Tb, Dy, Ho and M=Cu, Zn). The results show that the Cu containing complexes (with the exception of La2Cu3) undergo long-range magnetic order at temperatures below 2 K, and that for Gd2Cu3 this ordering is ferromagnetic, whereas for Tb2Cu3 and Dy2Cu3 it is probably antiferromagnetic. The susceptibilities and specific heats of Tb2Cu3 and Dy2Cu3 above TC have been explained by means of a model taking into account nearest-as well as next-nearest-neighbor magnetic interactions. We show that the intraladder L-Cu interaction is the predominant one and that it is ferromagnetic for L=Gd, Tb, and Dy. For the cases of Tb, Dy, and Ho containing complexes, strong crystal field effects on the magnetic and thermal properties have to be taken into account. The magnetic coupling between the (ferromagnetic) ladders is found to be very weak and is probably of dipolar origin.