Synthesis and Ferroelectric Properties of Sol-gel Derived Intergrowth-Superlattice-structured SrBi_4Ti_4O_(15)-Bi_4Ti_3O_(12) Thin Films

摘要

Intergrowth-superlattice-structured SrBi_4Ti_4O_(15_-Bi_4Ti_3O_(12) (SBT-BIT) films prepared on p-Si substrates by sol-gel processing. Synthesized SBT-BIT films exhibit good ferroelectric properties. As the annealing temperature increases from 600°Cto 700°C, the remanent polarization P_r of SBT-BIT films increases, while the coercive electric field E_c decreases. SBT-BIT films annealed at 700°Chave a Pr value of 18.9μC/cm~2 which is higher than that of SBT (16.8μC/cm~2) and BIT (14.6μC/cm~2), and have the lowest E_c of 142 kV/cm which is almost the same as that of SBT and BIT. The C-V curves of Ag/SBT-BIT/p-Si heterostructures show the clockwise hysteresis loops which reveal the memory effect due to the polarization. The memory window in C-V curve of Ag/SBT-BIT/p-Si is larger than that of Ag/SBT/p-Si heterostructure or Ag/BIT/p-Si heterostructure.