Quantitative analysis of the magnetism of the meta-(methoxy)phenyl nitronyl nitroxide crystal: A bottom–up analysis of a crystal presenting competing ferro and antiferromagnetic interactions
2005; Elsevier BV; Volume: 24; Issue: 16-17 Linguagem: Inglês
10.1016/j.poly.2005.03.110
ISSN1873-3719
AutoresMercé Deumal, Michael A. Robb, Juan J. Novoa,
Tópico(s)Lanthanide and Transition Metal Complexes
ResumoCrystals of the meta isomer of the (methoxy)phenyl nitronyl nitroxide radical, m-(OMe)PhNN, present the characteristics of an antiferromagnet (paramagnetic θ = −0.97 K, |J| = 1.6 cm−1, [L. Angeloni, A. Caneschi, L. David, A. Fabretti, F. Ferraro, D. Gatteschi, A. le Lirzin, R. Sessoli, J. Mater. Chem. 4 (1994) 1047]). Using our quantitative bottom–up approach, we analyze here the magnetism of this crystal by first computing its magnetic topology and, then, using this information, the macroscopic magnetic susceptibility χ(T) of the crystal. The crystal presents one ferro and two antiferromagnetic exchange interactions, JAB, of similar strength (+0.20, −0.20 and −0.11 cm−1) that create a complex three-dimensional magnetic topology of interacting planes. This complex network of competing ferro and antiferromagnetic pathways does not allow a sounding prediction of the macroscopic magnetic susceptibility using qualitative considerations. Our approach computes the χT versus T curve that fully reproduces the experimental shape.
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