Free Radicals in K and Rb Admixtured Fullerene C$\text{}_{60}$

Molecules of C$\text{}_{60}$ form Van der Waals type crystals. The observations reported here concern EPR investigations of such C$\text{}_{60}$ samples with only a slight amount of Rb or K. Detected defects are (C$\text{}_{60}$)$\text{}^{+}$ or (C$\text{}_{60}$)$\text{}^{y-}$ ion-radicals. A hole (h) or trapped electron (t) are localized on one fullerene ball. In the case of potassium fullerites C$\text{}_{60}$:K the line shape of EPR signal was of the Dysonian form which is characteristic of conducting electrons in metal. The EPR lines of holes (C$\text{}_{60}$)$\text{}^{+}$ are characterized by g$\text{}_{h}$ ≥ g$\text{}_{0}$ whereas for electrons g$\text{}_{t}$ is below the value g$\text{}_{0}$ = 2.0023 characteristic of a free electron (g$\text{}_{t}$ ≤ g$\text{}_{0}$). The EPR linewidth 2ΔB$\text{}_{1s}^{h}$ of the (C$\text{}_{60}$)$\text{}^{+}$ weakly increased with decreasing temperature whereas the EPR linewidth attributed to the electron 2ΔB$\text{}^{t}$$\text{}_{1s}$ significantly decreases with decreasing temperature. The C$\text{}_{60}$:K sample reached superconducting phase below T$\text{}_{c}$ = 11 K which is significantly less than T$\text{}_{c}$ = 16.5 K observed for K$\text{}_{x}$C$\text{}_{60}$ where 2 ≤ x ≤ 4