Thermodynamics of non-linear polarizable systems in the presence of electromagnetic fields

Abstract

Thermodynamics of non-linear materials in the presence of fields is considered. It is shown that appropriate transformation of field variables facilitates the use of detailed results that are available for linear materials, also for non-linear materials, and in this sense the theory is unified. This transformation simulates a linear material at the same energy level of the non-linear one, under the given field. The use and role of field dependent temperature, pressure and chemical potential remains unchanged, irrespective of their being dependent on transformed or untransformed field variables. This applies to setting conditions of equilibrium of non-linear systems in non-uniform fields, where the required uniformity of T̂, P̂and [small zeta, Greek, circumflex] can involve non-uniformity of T, P and ζ across the system and viceversa.