Landau-Khalatnikov Theory for the Hysteresis Loops of a Ferroelectric Thin Film

We use the Landau-Khalatnikov equation of motion to illuminate the hysteresis behavior of a ferroelectric thin film with surface transition layers. Our model can reflect a more realistic situation compared to the previous treatments of the same problem using the so-called extrapolation length. The influence of the surface transition layer on the hysteresis loops under a driving electric field is discussed in detail. The results show that the surface transition layer can induce a transfiguration of the hysteresis loops in a ferroelectric thin film.