[SY-L4] Symposium L-4

[SY-L4] Effect of solute atoms and Peierls stress on the critical behaviour of discrete dislocations

^○Peter Dusan Ispanovity¹, Gabor Peterffy¹, Peter M. Derlet² (1.Eotvos Universty, Hungary, 2.Paul Scherrer Institut, Switzerland)

It is well-known from micropillar and acoustic emission experiments that plastic strain accumulates in sudden avalanche-like events. Based on the statistical analysis of these bursts it is now apparent that plastic deformation can be described as a critical phenomenon. A lot of subsequent attention has been paid to understand the fundamental nature of this criticality: whereas the analysis of experiments suggests that scale-free behavior is characteristic only to the onset of yield, discrete dislocation dynamic (DDD) simulations hint at a more involved picture. Namely, the dynamics of the system is of glassy nature, where power-law distributions arise irrespective of the distance to the yielding threshold. These DDD simulations represent pure systems where neither Peierls stress nor any kind of impurities impede dislocation motion. In the talk we will discuss how addition of these realistic ingredients affect the critical behavior in terms of relaxation properties, avalanche statistics, dynamic correlations and system size dependence.