Existence of a liquid-liquid phase transition in CH3Cl adsorbed on graphite
Institut für Experimentalphysik der
Christian-Albrechts-Universität, 24118 Kiel, Leibnizstr. 19, Germany
Accepted: 6 December 1995
A compressed monolayer of adsorbed on graphite has been examined by X-ray diffraction, EXAFS and molecular-dynamics calculations (MD). A two-stage melting process with continuous melting in one spatial direction ( K), followed by a second process, which ultimately is discontinuous, has been found. The intermediate liquid state at 147 K<T<156 K, recently suggested on the basis of a specific-heat measurement, has been identified as a liquid-crystal–like phase. It has a high degree of orientational order of the dipolar molecules.
PACS: 61.10.My – Crystal structure solution and refinement techniques / 61.30.Gd – Orientational order of liquid crystals; electric and magnetic field effects on order / 64.70.Ja – Liquid-liquid transitions
© EDP Sciences, 1996