Thermodynamics of dielectric systems depending upon three variables

In a previous paper, a thermodynamic examination of magnetic fluids was con ducted and the obtained relations were compared with the relations usually applied to fluids. Three independent variables were considered in the gener al formulation. The aim of this paper is to examine, in a similar way, diel ectric systems (gases, liquids and solids) considering three independent va riables in the general case. The independent variables can be assumed as on ly two, when the volume is practically constant. In some ranges of temperat ure, various dielectrics present a dependence of the electric field strengt h upon temperature, similar to that of magnetization (Curie's law); this ca se also is studied. Quasi-static irreversible processes with uniform intens ive properties are considered. (C) 2000 Elsevier Science Ltd. All rights re served.