STRESS INDUCED POLARIZATION SWITCHING AND COUPLED HYSTERETIC DYNAMICS IN FERROELECTRIC MATERIALS

摘要

The dynamic responses of ferroelectric materials with external mechanical and electrical stimulations are inherently nonlinear and coupled. In the paper, a macroscopic differential model is constructed for their coupled hysteretic dynamics via modeling the orientation switching induced in the materials. A nonconvex potential energy is constructed with both mechanic and electric field contributions. The governing equations are formulated as nonlinear ordinary differential equations by employing the Euler-Lagrange equation, and can be easily recast into a state space form. Hysteresis loops associated with stress induced polarization switching and butterfly-shaped behavior in ferroelectric materials are also successfully captured. The effects of the mechanical loadings on the electrically induced switching are numerically investigated, as well as the mechanically-induced switching with various bias electric fields.