Numéro
J. Phys. I France
Volume 7, Numéro 12, December 1997
Page(s) 1645 - 1664
DOI https://doi.org/10.1051/jp1:1997160
DOI: 10.1051/jp1:1997160
J. Phys. I France 7 (1997) 1645-1664

A Model for the Structure of Cryslalline Adsorbed Organic Monolayers with Application to nCB

E. Lacaze1, P. Barois2 and R. Lacaze3, 4

1  Groupe de Physique des Solides URA CNRS 17, Universités Paris 6 & 7, Tour 23, 4 place Jussieu, 75251 Paris Cedex 05, France
2  Centre de Recherche Paul Pascal UPR CNRS 8641, Domaine Universitaire, avenue Schweitzer, 33600 Pessac, France
3  Service de Physique Théorique, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
4  Application Scientifique du Calcul Intensif UPR CNRS 9029, Bâtiment 506, Université Paris-Sud, 91405 Orsay Cedex, France



(Received 14 June 1997, revised 17 July 1997, accepted 27 August 1997)

Abstract
In order to understand the structure of nCB monolayers adsorbed on MoS 2 as observed by STM, we have built a 2D phenomenological model through which the observed structures can be interpreted in term of a commensurate-incommensurate transition monitored by the molecular length. This model is derived from the theory of frustrated smectics; it demonstrates that the two main parameters governing the structure of such monolayers are the frustration of the adsorbed monolayers and the strength of the substrate-molecule interaction, similarly to the case of physisorbed rare gas monolayers. More generally, various STM results on monolayers of elongated molecules physisorbed on a substrate can be reinterpreted which emphasizes the role of molecule-substrate interactions.

Résumé
Nous avons construit un modèle bidimensionnel des monocouches de nCB adsorbées sur MoS 2. Ce modèle permet de comprendre les structures observées par STM et de les interpréter en terme d'une transition commensurable-incommensurable régie par la longueur des molécules. Ce modèle est dérivé de la théorie des smectiques frustrés; il montre que les deux paramètres qui gouvernent la structure de ces monocouches sont la frustration des monocouches adsorbées et la force de l'interaction substrat-molécule, comme dans le cas des monocouches de gaz rare physisorbées. Plus généralement, on peut réinterpréter divers résultats STM sur les monocouches de molécules allongées physisorbées sur un substrat ce qui met en évidence le rôle des interactions molécule-substrat.



© Les Editions de Physique 1997

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.