Electromechanical coupling in nonpiezoelectric materials due to nanoscale nonlocal size effects: Green’s function solutions and embedded inclusions

摘要: In a piezoelectric material, an applied uniform strain can induce electric polarization (or vice versa). Crystallographic considerations restrict this technologically important property to noncentrosymmetric systems. It has been shown both mathematically and physically that nonuniform potentially break the inversion symmetry in nonpiezoelectric materials. The coupling between gradients polarization, conversely gradients, is investigated work. While conventional nonzero only for certain select materials, nonlocal of field (in principle) all dielectrics, albeit manifesting noticeably at nanoscale, around interfaces or general vicinity high gradients. Based on theoretic framework accounting phenomena, we (i) develop fundamental solutions (Green's functions) governing equations, (ii) motivated by eventual applications quantum dots, solve embedded mismatched inclusion problem with explicit results spherical cylindrical shape. Expectedly, our aforementioned problems are size dependent indicate generation fields reaching values approximately hundreds kV/m selected sizes locations---even isotropic centrosymmetric