First-Order Polymorphic and Melting Phase Transitions Under Shock Loading

Abstract

Some materials at high pressure have structural arrangements of atoms and molecules that are at a lower energy state than that at (P = 0, vo, T-293 K) conditions. When this occurs a thermodynamic force on the material exists to change the configuration to the new one. This process is called a first-order phase transition that is characterized by the coexistence of several thermodynamic phases. It is well established that condensed matter can also undergo thermodynamic second order phase transitions in electric and magnetic properties that are not treated in this book. Readers interested in second order phase transitions seen in dynamic experiments consult the literature especially the articles by Keeler and Royce [1].