Variety of scaling behaviors in nanocrystalline plasticity

Intermittent elasto-plastic deformation of sub-micron crystals features size-sensitivity of scaling exponents. We use a minimal integer-valued automaton model of crystal plasticity to show that with growing variance of quenched disorder, which can serve in this case as a proxy for increasing size, sub-micron crystals undergo a crossover from spin-glass-type marginality to criticality characterizing extended second order phase transition. We argue that this crossover is behind the non-universality of scaling exponents observed in physical and numerical experiments.