NEW TYPES OF PHASE TRANSITIONS: PHENOMENOLOGY, CONCEPTS AND TERMINOLOGY

摘要

The current state of study and basic ideas for describing phase transitions in topologically disordered condensed matter, such as liquids and amorphous solids, has been briefly outlined. In contrast to ordinary phase transitions in crystals, mechanisms of transformations in disordered condensed matter remain unclear in many respects, and the introduction of order parameters for such transitions is still conceptually problematic. The problems in the theoretical description of new phase transition types naturally pose a number of terminological problems. Comparing transitions in amorphous solids and in liquids, one should emphasize the metastable and non-ergodic nature of amorphous substances and the existence of static local atomic stresses in thermally frozen amorphous networks. For the development of theoretical description, it is most actual to find out a hidden symmetry in disordered systems, whereas precision measurements of thermodynamic characteristics in the vicinity of possible transitions are especially important from the experimental point of view.