Grain boundary motion of binary alloys was investigated experimentally using an organic alloy model system (succinonitrile–coumarin). In a temperature gradient, the grain boundaries drift toward the high temperature region in addition to grain boundary migration due to grain coarsening. It was found that the grain boundary drift speed V depends on temperature gradient G and temperature T as V = DG/{(1−k)(T0−T)}, where D was the diffusion coefficient, k was the segregation coefficient, and T0 was the melting point of the pure succinonitrile. It was shown that the grain boundary orientation could be controlled by applying a local temperature gradient through UV or laser heating. In bulk samples, local heating of the interior was generated using two-photon absorption and imaged with a laser scanning microscope.

Controlled Dynamics of Grain Boundaries in Binary Alloys. K.Lee, W.Losert: Acta Materialia, 2005, 53[12], 3503-10