COLL 496 |
| Thomas F. Magnera and Josef Michl. Department of Chemistry, University of Colorado, Boulder, CO 80309 |
| The polarity of the strong electric field between an STM tip and a gold substrate is expected to dictate the orientation of a permanent dipole associated with the nearly free rotator installed in the center of an altitudinal molecular rotor adsorbed on a gold surface (axle parallel to the surface), such as those we have prepared recently. The orientation of the dipole will be reflected in the local work function and should be detectable by barrier height imaging (BHI). We report an adaptation of BHI in which a difference image is recorded by interleaved scanning with alternating polarity. The images differentiate between two classes of surface-mounted altitudinal rotors: (i) rotors in which the rotator carries a permanent dipole moment and is free to turn with the polarity of the electric field, and (ii) rotors in which either the rotator carrying a permanent dipole moment is blocked from turning, or the rotator is non-polar. |
|
Nanoscience and Nanotechnology
8:30 AM-11:45 AM, Thursday, April 1, 2004 Marriott -- Orange County 5, Oral
Division of Colloid and Surface Chemistry |