SPINODAL-DECOMPOSITION-LIKE PATTERNS VIA METASTABLE STATE RELAXATION

The slow demixing of block copolymer thin films in relief domains is interpreted as a two-dimensional phase transition kinetics following a quench into a biphasic region of a phase diagram. The associated scalar parameter PSI is a linear function of the local thickness of film. Two samples with critical PSI's have been experimentally studied by atomic force microscopy. At long times, the two stable phases draw spinodal-decomposition-like patterns. At shorter times, the existence of an additional metastable phase is demonstrated and explained.