Dielectric loss in a C_(60) film observed by coupling with the external electromagnetic field of a surface acoustic wave

摘要

The dielectric loss in C_(60) films was studied by a noncontacting technique utilizing the external electric fields associated with surface acoustic waves (SAW) on a piezoelectric crystal. A sharp increase in loss was observed at temperatures below 220 K together with other structure not found with standard SAW measurements. We believe that these features are due to induced current in C_(60), causing joule loss, and to the formation of localized dipole moments by charge transfer between adsorbed O_(2) and C_(60) molecules, giving rise to thermally activated relaxation.