Formation of two-dimensional crystal-like structures from inclusions in smectic C films
P. Cluzeau, G. Joly, H. T. Nguyen+, V. K. Dolganov*
Laboratoire de Dynamique et de Structure des Matériaux Moleculaires, ESA CNRS 8024, Universite de Lille I
59655 Villeneuve d'Ascq Cedex, France
+Centre de Recherche Paul Pascal, CNRS, Universite de Bordeaux I, F-33600 Pessac, France
*Institute of Solid State Physics RAS, 142432 Chernogolovka, Moscow distr., Russia
PACS: 61.30.-v, 82.70.Dd
Abstract
The structures formed by inclusions in smectic C (SmC) free-standing
films are investigated using polarized light microscopy. The domains
confined in these two-dimensional (2D) systems induce distortion of the
in-plane orientational order which governs the elastic interaction between
the inclusions. The balance between long range quadrupolar attraction
and short range repulsion gives rise to a non-trivial collective behaviour
of domains. Various 2D structures are created as a function of the
concentration and size of the inclusions. We observe the formation of
chains and then 2D square lattice when the concentration of domains
increases. Further increase of the domain size leads to the transition from
square to hexagonal close packed structure.