Alkali-Metal Doping of Langmuir-Blodgett Films of C60 Studied by ESR

Abstract
Various doping methods were used in order to realize the charge transfer between C60 molecules and alkali-metal atoms in the Langmuir-Blodgett structure. ESR measurements have clearly indicated the charge transfer in the samples heated with RbN3 powder. The development of the metallic region in these films, possibly in the form of o-Rb1C60, has been indicated, for the first time, by the obtained Pauli-like spin susceptibility and the Elliott-like ESR linewidth. Furthermore, hysteresis was observed in the low-magnetic-field microwave absorption signal (LFS) for a sample, showing the appearance of the superconducting phase with T c≈23 K in the sample tube.