Nano-Structured C_(60)-SAM Formed on Ultrathin Au Films/MgO Single Crystal

摘要

Exotic electric conducting properties have been expected in organic molecules/metals interfaces with low-dimensional nano-structures. A self-assembly monolayer of a C_(60) derivative, C_(60)-O-C_8SH, (C_(60)-SAM) was synthesized on ultrathin Au films which were deposited on MgO (100) single crystal substrates. Since the surfaces of annealed MgO were atomically flat and revealed step-terrace structures, the ultrathin Au films were deposited along the edges of the steps with the length of a few micrometer. As the result of the characteristic nano-structure of the Au films, the C_(60)-SAM adsorbed on them showed also one-dimensional alignments with the width of few tens nm. The surface morphology of the C_(60)-SAM/Au was observed and analyzed by AFM. In particular samples the resistivity deviated from a normal linear dependence on temperature and revealed an anomalous decrease in the temperature rangeof 150-250K.