Mild fluctuations in ferroelastic domain switching

Abstract

We study the avalanche dynamics of shear-induced ferroelasticity by molecular dynamics simulations and statistical analysis. The dynamics of ferroelastic domain switching proceeds by avalanches which are power-law distributed. These avalanches can therefore be classified as wild with an energy exponent near 3. Wildness originates from the interaction between domain boundaries and defects, and jamming between domain boundaries. Concomitantly, mild events also arise but their distributions do not follow power-laws so that these mild energy releases are not scale invariant and exhibit a characteristic energy. We identify several mild domain switching events, namely the motion of single kinks and highly nonlinear relaxations of solitonic waves. The solitonic waves are reflected by domain boundaries, kinks, junctions, and free surfaces. Relaxations during domain switching have different characteristic energies from those created during creep. We observe the coexistence of mild and wild events depending on the external forces acting on the ferroelastic material.