Estimation of πd-Interactions in Organic Conductors Including Magnetic Anions

Abstract

Magnetic interactions in organic conductors including magnetic anions, such as λ-(BETS) 2 FeCl 4 and κ-(BETS) 2 FeX 4 [X = Cl and Br], are estimated from intermolecular overlap integrals; the overlaps between anions afford J dd , and those between anions and donors give J πd . From this, the most stable spin alignments are decided, and such quantities as the Néel and Weiss temperatures, as well as the magnitude of spin polarization on the π-molecules are evaluated on the basis of the mean-field theory of πd-systems. The calculation is extended to several other πd-conductors, which are classified depending on the relative magnitudes of the direct dd- and indirect πd-interactions.