Heat capacity data near the smectic-A-hexatic-B transition in thin free-standing liquid-crystal films has been obtained. Films greater than two molecular layers in thickness display multiple anomalies associated with the smectic-A-hexatic-B transition. The anomalies are sharply peaked and are therefore inconsistent with recent defect mediated melting theory. Moreover, the separate surface and interior transition data can be successfully fit to a simple power law. The fitting results indicate that these films exhibit similar, continuous transitions at significantly different temperatures localized to regions only 30Å apart.
|Original language||English (US)|
|Number of pages||11|
|Journal||Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals|
|State||Published - 1997|
Bibliographical noteFunding Information:
This work was supported by the Donors of the Petroleum Research Fund, administered by the American Chemical Society and by the National Science Foundation, Solid State Chemistry, Grant Nos. DMR-89-19334 and 93-00781.