Alladi Ramakrishnan Hall

Avalanche dynamics in First-Order Phase Transitions

Eduard Vives

University of Barcelona

Many materials, when slowly driven with en external force or an applied field, respond by a metastable trajectory that, is constituted by a sequence of discontinuous jumps. In many cases, also these jumps show an absence of characteristic scales which suggest the existence of an underlying out-of-equilibrium critical point. In the first part of this colloquium I will introduce a basic thermodynamic framework that allows explaining the existence of avalanche response associated with first order phase transitions. The phenomenon has been found in ferromagnetism structural phase transition in solids, superconductivity, ferroelectricity, etc. In the second part I will present the Acoustic Emission experimental technique that is very appropriate for monitoring avalanche processes in solids. I will show different examples of applications for the study of structural phase transitions in solids.