The Phenomenology of Modulated Phases: from Magnetism to Organic Films and Polymers
Tel Aviv University
Tue, Oct. 28th 2008, 11:00
Salle Claude Itzykson, Bât. 774, Orme des Merisiers
Patterning of spatially modulated structures at thermodynamical equilibrium will be discussed in a wide range of physical systems having interacting combinations of magnetic, electric, entropic and interfacial energies. We will review unifying principles resulting from the competition between short and long-range interactions, such as surface tension and dipolar interactions. Materials of interest range from garnet magnetic films and ferrofluids to organic monolayers and heterogeneous polymer films. We will discuss, in particular, several recent advances in thin films of block copolymers inclusing how patterned and structured surfaces induce complex polymer film morphology and orientation. Finally, perhaps more striking is the film response to external electric fields in the range of 1-100V/micron. Such fields can re-orient phases of block copolymers, and even cause morphological phase transitions.