Theoretical studies of d– d magnetic interaction in organic superconductors

• Published in: Polyhedron 2007-06, Vol.26 (9), p.2304-2308
• Main Authors: Takenaka, Mao, Nishimura, Youhei, Kawakami, Takashi, Kitagawa, Yasutaka, Okumura, Mitsutaka, Yamaguchi, Kizashi
• Format: Article
• Language: English
• Subjects: Ab initio MO method; Density functional method; Effective exchange integral; Magnetic d– d interaction; Molecular magnetism; Organic superconductor; κ-(BETS) 2FeX 4 (X = Cl, Br)
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2006.11.027

To investigate all the magnetic interactions between neighboring two FeCl 4 - anions, various spatial conformation of dimers were assumed and studied. For variety of configurations of FeCl 4 - anion dimers, the values of effective exchange integral ( J) in the Heisenberg spin model were calculated by using ab initio MO methods. In the κ-(BETS) 2FeCl 4 crystal as one of organic magnetic-metal crystals, localized spins of d-orbitals in FeCl 4 - anions is expected to play an important role to magnetic properties. To investigate all the magnetic interactions between neighboring two FeCl 4 - anions, various spatial conformation of dimers were assumed and studied. For variety of configurations of FeCl 4 - anion dimers, the values of effective exchange integral ( J) in the Heisenberg spin model were calculated by using ab initio MO methods. It was found that very weak ferromagnetic interaction existed in a certain conformation, though antiferromagnetic interaction was reproduced in most of all conformations.