Solutions of the equations for piezoelectromagnetism in polarized ceramics: Infinite medium and slab

"A method is proposed to calculate both acoustic and electromagnetic modes in piezoelectric hexagonal ceramics. In the infinite system, the five characteristic modes ( three acoustic and two electromagnetic ) are divided into two classes: the first one includes two modes ( one acoustic and one electromagnetic ) that are slightly interacting through the piezoelectric coupling; the second class comprises three modes ( two acoustic and one electromagnetic ) that show relevant effects due to piezoelectricity in their dispersion relations. Finally, acoustic and electromagnetic modes are analyzed in a slab surrounded by vacuum taking fully into account the effects of piezoelectric coupling."