Group theoretical statistical mechanics of the Evans effects: Phase changes produced by inhomogeneous electric and magnetic fields

Abstract

The effects first observed by G.J. Evans are explored in terms of the symmetry of ensemble averages, using the principles of group theoretical statistical mechanics (GTSM). The effects include phase changes brought about by inhomogeneous electric and/or magnetic fields, all of whose gradients are included in the treatment in a multipole expansion of the force differential across the interface between a molecular crystal and a molecular liquid. It is shown by GTSM that the force differential is generated by extra vector components which are sustained in the laboratory frame by the symmetry of the molecular crystal but which vanish in the liquid. In this way the symmetry of the former is continuously imparted to the latter.