A Non-Linear Model for Elastic Dielectric Crystals with Mobile Vacancies

摘要: Abstract A framework is developed for electromechanical behavior of dielectric crystalline solids subjected to finite deformations. The theory formulated in the context electrostatics; however, vacancies lattice may carry an electric charge, and their concentrations be large. material treated as a continuous body with distribution point vacancies, but volumes charges individual defects enter description. deformation gradient decomposed multiplicatively into terms accounting recoverable thermoelasticity irreversible volume changes associated vacancies. Thermodynamic arguments lead constitutive relations among quantities framed elastically unloaded intermediate configuration, Cauchy stress tensor consistently non-symmetric result electrostatic effects. requirement non-negative dissipation imposes constraints on vacancy migration. Following postulation quadratic form free energy potential, kinetic equation flux derived diffusion driven by gradients concentration, hydrostatic pressure, crystal structure. Effects geometric non-linearity (i.e. elastic strains large concentrations) are found affect biaxial strain, example film device mismatch at its interfaces.