A model for large electrostrictive actuation in ferroelectric single crystals

A new mode of large electrostrictive actuation, based on 90° domain switching in ferroelectric crystals subjected to combined electromechanical loading, has recently been experimentally demonstrated. In this paper, we develop a model for this phenomenon by assuming a reasonable arrangement of domain walls and formulating equations of motion for these walls. The model captures most of the features observed in the experiments, reveals the significant role of friction at the interfaces between the loading frame and the crystal surfaces, and predicts that a reduction of friction will allow larger strains at lower mechanical loads.