Noncontact Atomic Force Microscopy and synchrotron x-ray scattering measurements on dotriacontane (n-C32H66 or C32) films adsorbed on SiO2-coated Si(100) wafers reveal a narrow temperature range near the bulk C32 melting point Tb in which a monolayer phase of C32 molecules oriented perpendicular to surface is stable. This monolayer phase undergoes a delayering transition to a three-dimensional (3D) fluid phase on heating to just above Tb and to a solid 3D phase on cooling below Tb. An equilibrium phase diagram provides a useful framework for interpreting the unusual spreading and receding of the monolayer observed in transitions to and from the respective 3D phases.
@article{arxiv.cond-mat/0611497,
title = {Nanoscale Observation of Alkane Delayering},
author = {M. Bai and K. Knorr and M. J. Simpson and S. Trogisch and H. Taub and S. N. Ehrlich and H. Mo and U. G. Volkmann and F. Y. Hansen},
journal= {arXiv preprint arXiv:cond-mat/0611497},
year = {2007}
}