The relaxation mechanism of diblock copolymers above the order-to-disorder transition has been identified. We present the first experimental evidence of the existence of both a local internal breathing relaxation process and a diffusive pattern relaxation mode measured on the same sample for a series of diblock copolymers by applying photon correlation spectroscopy in the polarized geometry. The relaxation characteristics of both modes are modeled in terms of recent theories, with the necessity for a complete theory becoming evident.

• Received 7 December 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.2415