Recently precise positioning devices with low outgassing rates have been required for production systems of very large scale integrated circuits, surface analysis systems, and scanning tunneling microscopes in ultrahigh vacuum. A bakable XYθ three-axis positioning table using a unique positioning mechanism utilizing friction and inertial forces caused by rapid deformations of piezoelectric elements was developed. The table has a hexagonal shape of 120 mm in diameter and is mainly made of aluminum alloys with an EX-process. The table has three feet with an Si3N4 ball on each bottom side and set on a plate made of Pyrex glass. The table was able to operate in an ultrahigh vacuum environment of the order of 10−12 Torr.

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We report a simple and facile procedure to control molecular orientation in a single-molecule junction and relevant rectification properties. Rectification properties of single-molecule junctions consisting of tripodal triptycene and C 60 moieties at the termini that couple to the Au electrodes were determined using the break junction method. Because of the strong affinity of the tripodal triptycene moiety to the Au electrode, the molecular orientation and the related rectification direction are uniquely determined. Statistical analysis of the I-V curves of the single-molecule diode reveals the robustness of the rectification behavior with a statistically significant rectification ratio of 1.7.