Models of electromagnetic materials

A thermodynamic framework is provided for the modelling of smart materials acted upon by electromagnetic fields. The description is based on the notion of state and process which, jointly, determine the response of the material. The view is taken that only the balance equations which are compatible with thermodynamics represent physically-admissible behaviours. Concerning simple materials, linear, anisotropic materials with memory are considered in detail by disregarding the effects of motion. Necessary and sufficient conditions are determined for the relaxation functions to be compatible with the second law. Next, ferromagnetic and ferroelectric materials are considered. Liquid crystals are described both as materials with microstructure of a micropolar form and as materials within a generalized form of the director model. The modelling of nonsimple materials requires that the second law is considered in a global form. This is exemplified by considering dielectrics with quadruples and spatially-dispersive crystals.