MAGNETIC PROPERTIES OF TTF-TYPE CHARGE TRANSFER SALTS IN THE MOTT INSULATOR REGIME
MAGNETIC PROPERTIES OF TTF-TYPE CHARGE TRANSFER SALTS IN THE MOTT INSULATOR REGIME
复制标题
MOT绝缘体体系中TTF型电荷转移盐的磁性
DOI：
10.1246/bcsj.72.639
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发表时间：
1999
影响因子：
4
通讯作者：
G. Saito
中科院分区：
文献类型：
--
作者：
N. Yoneyama;A. Miyazaki;T. Enoki;G. Saito
我们研究了几种由二聚体/三聚体供体单元组成的ttf基Mott绝缘体的磁性，这些绝缘体分为三个亚群：(1)β ' -(BEDT-TTF)2X （X = ICl2, AuCl2）和（BEDT-TTF）2GaCl4为强二聚体体系，(2)α ' -(BEDT-TTF)2IBr2盐为弱二聚体体系，(3)(BMDT-TTF)3ClO4（1,2-二氯乙烷）和（BMDT-TTF）3AsF6（1,1,2-三氯乙烷）为弱三聚体体系。基团(1)化合物具有定域自旋体系，每个二聚体单元的定域自旋为S = 1/2。在组(2)中，弱二聚化产生分数磁矩，反映了电子的离域，尽管磁性是用S = 1/2低维反铁磁体来描述的。基团(3)中的ClO4盐表明每个三聚体存在一个局域自旋，而三聚体的三聚化非常弱，因为三聚体间的库仑相互作用产生了电荷歧化，导致电子的局域化。没有指控…
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 dis...