Immobile defects in ferroelastic walls: Wall nucleation at defect sites

摘要

Randomly distributed, static defects are enriched in ferroelastic domain walls. The relative concentration of defects in walls, N-d, follows a power law distribution as a function of the total defect concentration C: N-d similar to C-alpha with alpha = 0.4. The enrichment N-d/C ranges from similar to 50 times when C = 10 ppm to similar to 3 times when C = 1000 ppm. The resulting enrichment is due to nucleation at defect sites as observed in large scale MD simulations. The dynamics of domain nucleation and switching is dependent on the defect concentration. Their energy distribution follows the power law with exponents during yield between epsilon similar to 1.82 and 2.0 when the defect concentration increases. The power law exponent is epsilon approximate to 2.7 in the plastic regime, independent of the defect concentration. Published by AIP Publishing.