Anisotropic giant magnetoresistance originating from the π–d interaction in a molecule

• Published in: The Journal of physics and chemistry of solids 2004-04, Vol.65 (4), p.749-752
• Main Authors: Matsuda, M., Hanasaki, N., Tajima, H., Naito, T., Inabe, T.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Giant magnetoresistance; Magnetic properties and materials; Magnetotransport phenomena, materials for magnetotransport; Physics
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2003.11.011

We synthesized TPP[Fe III(Pc)(CN) 2] 2, PTMA x [Fe III(Pc)(CN) 2]· y(MeCN), and PXX [Fe III(Pc)(CN) 2], a new series of charge-transfer salts containing the axially-substituted phthalocyanine (Pc), [Fe III(Pc)(CN) 2] −. In this molecular unit, the π conduction electron derived from the Pc-ring coexists with the d electron which is a potential source of a local magnetic moment. Therefore various phenomena associated with the interplay between local magnetic moments and conduction electrons are expected. We observed the giant negative magnetoresistance (GNMR) in all the three salts. The GNMR is highly anisotropic for the magnetic-field direction, and reflects the g-tensor anisotropy of the local magnetic moment in the [Fe III(Pc)(CN) 2] − unit. This indicates that the GNMR in these salts originates from the strong π–d interaction in the [Fe III(Pc)(CN) 2] − unit.