Occurrence of Antiferromagnetic Transitionin Iodine Doped AlPcF Film

Magnetism of iodine doped fluoro-aluminum phthalocyanine (AlPcF) film is studied by electron spin resonance (ESR) in two stable doping states: In State I, a doped AlPcF film is always in contact with saturated I 2 gas (AlPcF·I 4.0 ); In State II, a doped film is in no contact with I 2 gas (AlPcF·I 0.10 ). An antiferromagnetic transition is observed in both states. In State I in vacuum, the transition temperature depends on samples and the highest transition temperature observed is 160 K. In State II, it does not depend on samples and is 150 K in vacuum and 220 K at 1 atm. The occurrence of the magnetic transition indicates an existence of three dimensional magnetic coupling, i.e. interchain and intrachain couplings. An information about back charge transfer probability from I 3 - to AlPcF· + in State II is obtained from a degree of g anisotropy. With a help of this information, possible mechanisms of the interchain coupling are discussed.