Potential Fields of Parallel Edge Dislocation Arrays

The equipotential lines for a free test dislocation in the stress field of fixed parallel edge dislocation arrays are calculated from linear elasticity theory. The potential fields determine the path a free dislocation will take under ideal conditions. The well known fact is demonstrated that from an energetic point of view edge dislocations prefer to arrange in a wall rather than in a glide plane, namely by the positions of the calculated potential valleys which give the stable positions for the free test dislocation. Calculations are presented for characteristic arrays with a small number of dislocations. As the qualitative features of the results will hold also for arrays with a large number of dislocations some conclusions are drawn on the process of polygonization and a comparison with properties of edge dislocation arrays in silicon is made.