A constitutive theory for ferroelectric ceramics

A constitutive theory is proposed in this paper to depict the ferroelectric / ferroelastic response of ferroelectric ceramics subjected to external electric fields and stresses. In the theory, a body of ceramic is regarded as an aggregation of domains with different orientations. Each domain has a spontaneous polarization and a spontaneous strain. Domain switching results in the nonlinear behavior of ferroelectric ceramics. The process is investigated by means of thermodynamic approaches, which leads to the attainment of the constitutive relation for ferroelectric ceramics. Theoretic predictions are carried out and compared with experimental results.