Langmuir, Vol.26, No.22, 16986-16990, 2010
Imaging Ice-Like Structures Formed on HOPG at Room Temperature
In this work, ice was viewed at the nanoscale by scanning in atomic force microscopy tip over a highly oriented pyrolytic graphite (HOPG) surface in air. At low scan velocities, the tip exhibited stick slip motion with a period of 0.13 nm corresponding to the scanner step; at higher velocities, the HOPG lattice and the periodicity of the ice were visible. A hexagonal structure with a 0.45 +/- 0.04 run periodicity was observed in which the distance between the second neighbors of the HOPG coincided with the distance of the first neighbors for the ice-like arrangement. Small water clusters were also nucleated with an ice-lc structure (0.34 +/- 0.03 nm), and thus, the ice layers consisted of extensive sets composed of arrangements of hexamers and tetramers.