1999/04/01 by N. Yoneyama, Naoki Yoneyama, Akira Miyazaki +2
Materials Science · Physics and Astronomy · #Magnetism in coordination complexes #Organic and Molecular Conductors Research #Rare-earth and actinide compounds
paper · doi:10.1246/bcsj.72.639
crossref issued 1999/04/01 · crossref published 1999/04/01 · crossref published-print 1999/04/01 · openalex publication_date 1999/04/01 · crossref published-online 2003/12/24 · crossref created 2003/12/24 · crossref deposited 2024/01/19 · openalex created_date 2025/10/10 · crossref indexed 2026/07/29 · openalex updated_date 2026/07/30
Abstract We have investigated the magnetic properties of several TTF-based Mott insulators consisting of dimerized/trimerized-donor units, which are classified into three subgroups: (1) β′-(BEDT-TTF)2X (X = ICl2, AuCl2) and (BEDT-TTF)2GaCl4 as strong dimer systems, (2) α′-(BEDT-TTF)2IBr2 salt as a weak dimer system, and (3) (BMDT-TTF)3ClO4(1,2-dichloroethane) and (BMDT-TTF)3AsF6(1,1,2-trichloroethane) as weak trimer systems. The group (1) compounds have localized spin systems with an S = 1/2 localized spin per dimer unit. In group (2), weak dimerization produces a fractional magnetic moment, which reflects the delocalization of the electrons, although the magnetism is described in terms of an S = 1/2 low-dimensional antiferromagnet. The ClO4 salt in the group (3) indicates the existence of a localized spin per trimer, whereas the trimerization is quite weak, because the inter-trimer Coulomb interactions generate the charge disproportionation resulting in the localization of electrons. The absence of the charge disproportionation brings about the feature of fractional magnetic moments in the AsF6 salts.