Stress relaxation in icosahedral small particles via generation of circular prismatic dislocation loops

A theoretical model is developed that describes stress relaxation in icosahedral small particles through generation of circular prismatic dislocation loops. It is shown that loop generation is energetically favorable in the equatorial section of the particle, the radius of which is larger than the critical one. The dislocation loop then extends until it reaches its optimal radius which increases with particle size. Both the critical particle radius and optimal loop radius strongly depend on dislocation core energy.