Phase-Field Simulation of Energy Storage Properties of NaNbO3 Thin Films

The phase field model of NaNbO3 thin films is constructed on the basis of the phase field model, and the influence of mismatch strain on the domain structure of NaNbO3 thin films is simulated. The results show that compressive strain can make the in-plane domains flip to out-plane domains, while tensile strain can promote the formation of in-plane domains. At the same time, the P-E loops of NaNbO3 thin films under different misfit strains are simulated to explore the relationship between misfit strain and storage properties of thin films. When the type of strain within the film changes from compressive strain to tensile strain, the residual polarization and coercive electric field of thin films decrease, which is beneficial to obtain higher storage density. However, excessive tensile strain will lead to the decrease of saturation polarization and storage density. The present study complements previous studies using XRD as well as RSM method on the mismatch strain of NaNbO3 ferroelectric thin films in terms of theory, showing excellent theoretical research value in the field of energy storage.