Phase composition of KxC60 (x ≤ 1) samples as probed by 13C and 39K NMR

Samples of K x C 6 0 (x < 1) have been studied by 1 3 C and 3 9 K NMR. The following phases are identified in this system at room temperature: K 3 C 6 0 , a solid solution of potassium in fullerite, and a potassium-containing polymer. In the K 1 C 6 0 sample, the content of the polymeric phase is estimated to be as large as 90%. In all these phases, the distribution of potassium over tetrahedral and octahedral interstices remain unaltered, their ratio being 2:1.