By taking both stress and surface effects into account, the effect of thickness on ferroelectric films was investigated by using the time-dependent Ginzburg-Landau equation. Polarization hysteresis and butterfly hysteresis of various film thicknesses under different stresses were numerically simulated. The results show that under different stresses, the coercive field decreases with film thickness, while the remnant polarization and field-induced strain increase with film thickness. These trends are consistent with experimental results and verify that the effect of film thickness on remnant polarization strength and the coercive field should not be neglected.%为研究薄膜厚度对外延铁电薄膜铁电性能的影响,应用与时间有关的Ginzburg-Landau方程,在同时考虑应力和表面效应的条件下,获得了不同应力情况下,不同厚度铁电薄膜的电滞回线及蝶形应变迟滞回线.计算结果显示,处于不同应力值下的铁电薄膜,剩余极化强度和场致应变随着薄膜厚度的增加而增加.而矫顽场随着薄膜厚度的增加而减小.证明了不同应力情况下,薄膜厚度对剩余极化强度和矫顽场的影响是不能忽略的.这种变化趋势与实验结果的情况是一致的.
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