Introduction to Phase Transition Kinetics

Phase transition kinetics is a classical area of thermodynamics and statistical mechanics dealing with the transient dynamical evolution of a system that relaxes towards equilibrium from an initial metastable or unstable state. These non-equilibrium processes involve competition between different thermodynamic phases and give rise to late-times emerging mesostructures which determine the macroscopic properties (mechanical, electric, magnetic, ...) of these systems to a large extent. In this lecture some of the most fundamental topics in the theory of phase transition kinetics will be introduced. Taking a binary alloy a prototypical example, phenomena such as nucleation, spinodal decomposition and domain growth will be discussed. For systems undergoing magnetic and structural transitions the relevance of disorder and long-range interactions arising from compatibility effects will also be considered. These effects are responsible for the existence of a complex energy landscape, which is at the origin of avalanche behaviour and athermal kinetics found experimentally. These concepts will be discussed and simple statistical models aimed at accounting for the observed phenomenology will be introduced.