A novel class of ferromagnetic materials

Abstract

We have prepared a class of stable ferromagnetic materials with high Curie temperatures by thermal treatment of transition metal phthalocyanines, MnPc, FePc, CoPc or NiPc, for several hours at 500–700°C in inert ambient. Part of the phthalocyanine ring is pyrolyzed with corresponding loss in mass. Mössbauer studies of FePc and Co( 57Co)Pc indicate that the MeN 4 moiety and the aromatic character of the ring are retained, and that there is fairly strong interaction between the central atom and axially situated aromatic rings or nitrogens of neighboring coplanar rings. The axial interactions provide a pathway for ferromagnetism.