Origin of peculiar STM molecular contrast in C60/Ag(100)
Journal
Surface Science
Journal Volume
519
Journal Issue
3
Pages
L605-L610
Date Issued
2002
Author(s)
Abstract
In the c(6 × 4) C60 layer on Ag(100), a strong "bright" and "dim" molecular contrast has recently been observed in scanning tunneling microscopy. While the nature of such contrast is still under debate, substrate reconstruction is considered unlikely due to the rather complicated local ordering in the C60 layer. Here we use variable temperature STM to study the temperature evolution of C60 contrast. We clearly show that the bright C60 turns into the dim C60, starting at approximately ∼280 K. This phenomenon, along with the simulated contrast evolution of multi-layer C60 film and the molecular resolved non-contact AFM (NCAFM) measurements, are consistent with a topographic interpretation of the bright-dim contrast, in contrary to what is previously believed. © 2002 Elsevier Science B.V. All rights reserved.
Type
journal article