The Effect of Grain Size on Magnetoelectric Effect in Ferroelectric-Ferromagnetic Composite

摘要

A real-space phase field model based on the Landau-Ginzburg theory is employed to investigate the effect of grain size on magnetoelectric (ME) coupling effect in ferroelectric-ferromagnetic (FE-FM) composite. The ME coupling in FE-FM composite is achieved by transferring the magnetostrictive strain caused by external magnetic field from FM phase to FE phase. The simulation results show that ME coefficient increases first and then decreases as grain size increases within a specific range. The emergence of 90° domain in FE phase leads to the increase of ME coefficient. However, the affected range of FM phase becomes stable as the grain size further increases, which contributes to the decline of ME coefficient. The results suggest an optimized range of grain size to obtain higher ME coupling effect.