Anisotropic phase field solution for morphological evolution and migration of inclusions in piezoelectric films

摘要

Based on an anisotropic phase field model, the morphological evolution and migration of inclusions in piezoelectric films under mechanical and electric loads are investigated. An order parameter field is introduced to characterize the evolution of inclusion in piezoelectric film, where the zero contour evolution of order parameter in the phase interface layer between inclusion and matrix film tracks the morphological change and migration of the inclusion driven by coupled mechanical and electric loads. Results show that morphological evolution and migration of inclusion in piezoelectric film is mainly caused by normal stress gradient in the phase interface layer between inclusions and piezoelectric film, and when piezoelectric film appears in a lower resistivity, an additional drive force induced by electron field (electron wind) exerted the piezoelectric film promotes the migration of an inclusion toward the higher electric potential direction. Anisotropic diffusion behavior of interface layer causes asymmetrically morphological evolution of inclusion in piezoelectric film under different loads.