The formation of quasi-crystalline structures in a dislocation cluster

The formation of inhomogeneous dislocation structures is investigated within a model taking into account correlation interaction between screw dislocations. This interaction is found to give rise to an instability of the homogeneous state of the system. It is shown that when the critical nonequilibrium conditions for this instability are attained in a local volume, an inhomogeneous dislocation structure is formed spontaneously. As the degree of instability of the system increases further, this structure is transformed into a cellular quasi-crystalline structure.