Electrochemical Annealing and Friction Anisotropy of Domains in Epitaxial Molecular Films.
Abstract
Electrochemical annealing of domain boundary defects in an epitaxial monolayer whose structure mimics the (001) layers of the organic superconductor Beta-bis(ethylenedithio)tetrathiafulvalene trioxide, (ET)2I3, has been visualized in situ using real-time atomic force microscopy. These defects are observed readily by lateral force imaging and high resolution contact mode imaging reveals that the domains are oriented at angles of +/-n6O because of epitaxy with the HOPG substrate. The frictional contrast between domains is due to the anisotropy molecular field encountered by the tip and is a direct consequence of the crystalline order of the rigid monolayer. Potential cycling about the deposition potential resulted in a reduction in the number of domains, with the smaller domains eventually adopting the orientation of surrounding larger ones, ultimately forming large (>15 micrometer(s) squared) defect free monolayers. This demonstrates that the defect density of redox-active molecular films can be reduced by relatively simple means.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 08, 1996
- Accession Number
- ADA306862
Entities
People
- Julie A. Last
- Michael D. Ward
Organizations
- University of Minnesota