MAGNETIC-PROPERTIES OF FULLERENE C-60 DOP ED WITH THE PYROLYSIS PRODUCTS OF POLYTETRAFLUORETHYLENE - TRIPLET-STATES CONTRIBUTION

A study has been made of magnetic properties of fullerene C-60 doped w ith the pyrolysis products of polytetrafluorethylene. The temperature dependence of the magnetic susceptibility chi(T) of doped C-60 is show n to be satisfactorily described under the assumption that chi(T) is a total contribution of two types OF one-dimensional finite-length spin chains. The chains consisting of electron spins which are localized a t the separate (individual) atoms of cumulene-type polymer fragments m ay be identified as a first type and those consisting of spins caused by a thermal population of the low-lyin, triplet states of the polyene -type polymer chains as a second type. The non-linear dependence of th e total susceptibility on H observed at high temperatures Is found to be mainly defined by the magnetic-field dependence of susceptibility o f the second-type chains.