INVESTIGADORES
VILLAR Marcelo Armando
congresos y reuniones científicas
Título:
Non-equilibrium dynamics of symmetry breaking phase transitions in copolymer thin films
Autor/es:
D.A. VEGA; L.R. GÓMEZ; A.D. PEZZUTTI; M.A. VILLAR; E.M. VALLÉS; A.E. CIOLINO
Lugar:
Buzios, Brasil
Reunión:
Workshop; XI Latin American Workshop on Nonlinear Phenomena; 2009
Resumen:
Amphiphilic organic molecules will, under appropriate conditions, self-assemble into well ordered crystalline structures. Using these molecules as a model system, a great variety of problems of interest to statistical physics, material science and condensed matter physics have been investigated during the past decade [Ruzette and Leibler, Nat. Mat., 4, 31 (2005); Kramer, Nature, 437, 824 (2005)]. Particularly, these molecules are attractive templates for making ordered nanostructures, as they spontaneously form supramolecular aggregates with a tunable interaction. One prominent feature of these systems is the spontaneous formation of topological defects during a quench through the critical point. Since any addressable nanoscale device, such as an ultrahigh-density hard drive, requires well ordered structures, different strategies have been proposed to control the density of topological defects [Register, Nature, 424, 378, (2003)]. Although important advances have been made to obtain well ordered patterns, it has been found that the slow kinetics of defect annihilation prevents the use of thermal treatments to obtain systems with long range order [Gomez et al., Phys. Rev. Lett. 97, 188302 (2006)]. On the other hand, recently there has been an increasing interest in the study of 2D ordered phases on curved surfaces [D. R. Nelson, Nano Lett. 2, 1125 (2002); Santangelo et al., Phys Rev Lett. 99, 017801, 2007]. One of the main differences with planar systems is the nature of topological defects because the curvature of the substrates can impose a topological requirement that includes defects in the ground state [Gomez and Vega, Phys Rev. E, 79, 51607, 2009]. In this talk we will discuss the process of defect formation during a continuous symmetry breaking phase transition in thin films of block copolymers and additional features, such as the role of the curvature on the mechanism of self-organization and the coupling between defects and intrinsic curvature.