Abstract
Thin-film multilayer structures with up to 20 repeat layers have been grown in a high-vacuum chamber by sequential deposition of aluminum (Al) and fullerene () onto room-temperature substrates. The periodicity of the layers is confirmed by x-ray-diffraction and in situ resistance measurements. The presence of underlying layers of reduces the critical thickness at which Al becomes conducting from ∼35 to ∼20 Å. In addition, there is a sudden increase in resistance that occurs when each Al layer is covered by a monolayer of . These observations, together with the measurement of a downward shift in frequency of a considerably broadened Raman-active (2) pentagonal-pinch mode, imply that up to six electrons per are transferred from the Al to the layer. This demonstration of charge transfer across planar metal- interfaces suggests that multilayers may be a useful vehicle for forming fullerene interface compounds in two-dimensional structures.
- Received 30 August 1994
DOI:https://doi.org/10.1103/PhysRevB.50.17740
©1994 American Physical Society