Power-law statistics for avalanches in a martensitic transformation

We devise a two-dimensional model that mimics the recently observed power-l aw distributions for the amplitudes and durations of the acoustic emission signals observed during martensitic transformation [Vives et al., Phys. Rev . Lett. 72, 1694 (1994)]. We include a threshold mechanism, long-range inte raction between the transformed domains, inertial effects, and dissipation arising due to the motion of the interface. The model exhibits thermal hyst eresis and, more importantly, it shows that the energy is released in the f orm of avalanches with power-law distributions for their amplitudes and dur ations. Computer simulations also reveal morphological features similar to those observed in real systems.