Photoemission Spectra and Electronic Properties of KxC60

Photoemission spectra of vacuum deposited layers of C60, before and after exposure to K vapor, show that the K donates its conduction electron into the band derived from the lowest unoccupied molecular orbital. A compound with composition of K3C60, corresponding to the maximum conductivity, has been prepared. In it the potassium atoms presumably occupy both the octahedral and the two tetrahedral interstitial sites of the face-centered-cubic (fcc) C60 structure.