Ferroelectric and Pyroelectric Properties of Nano Graded Ferroelectric Films

In order to improve the properties of nano graded ferroelectric films (NGFF), the generalized Ginzburg-Landau-Denvonshire (OLD) theory is used to investigate the ferroelectric and pyroelectric properties of NGFF. A function is introduced to describe the local structure of this graded film. The numerical results show that parameter a and film thickness are two very important factors that influence the ferroelectric and pyroelectric properties of films, larger a values lead to smaller spontaneous polarization and lower pyroelectric peak Local structure in NGFF leads to flatten the polarization distribution, which raises the spontaneous polarization of components with lower transition temperature, but reduces spontaneous polarization of components with higher transition temperature.