Because of their long-range nature, the elastic stresses due to dislocations could provide a mechanism for the spatial organization of alloys having misfitting constituents. Here, the connection between dislocation patterning and correlations in the elastic stress fields associated with dislocations was explored. In particular, the effect of obstacles, such as impurities and grain boundaries, upon pattern formation in a collection of mutually interacting dislocations was examined. This was done by characterizing the order in terms of various dislocation structure-factors that reflected the tendency to form dislocation wall segments. It was found that random stationary impurities frustrated wall formation without altering the characteristic length-scale of the dislocation patterning. Meanwhile, grain boundaries promoted wall formation via dislocation incorporation, and frustrated polygonization away from the boundaries.

Impact of Obstacles on Dislocation Patterning and Stress Correlations. J.M.Rickman, M.Haataja, R.LeSar: Physical Review B, 2008, 77[17], 174105