Investigation of Paramagnetic Centers in Fullerides A2MC60 and AM2C60 (A = K, Rb, M = Mg, Be)

Paramagnetic centers in heterofullerides with the composition A₂MC₆₀ and AM₂C₆₀ (A = K, Rb, M = Mg, Be) were investigated by the electron spin resonance (ESR) method. It was found that the ESR signal can be interpreted as a composition of two lines with different temperature dependence of ESR absorption magnitude. This gives an evidence of the presence of at least two different types of paramagnetic centers. Centers of the first type behave as localized spins, while the rest can be interpreted as conduction electrons. Authors' address: Vladimir A. Kulbachinskii, Physics Faculty, M. V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russian Federation