Antiferroelectric Thin Films for Decoupling Capacitor and Microactuator Applications

ABSTRACTLanthanum-doped or niobium-doped lead zirconate titanate stannate antiferroelectric thin films with the thickness of about 0.4 μm have been prepared from acetic acid-based or 2-methoxyethanol-based sol-gel method. All the films have the maximum polarization larger than 30 μC/cm2 and show zero remanent polarization. By choosing appropriate compositions, we can make the films have “square” hysteresis loops with very sharp phase transition or “slanted” hysteresis loops with very small hysteresis. The properties that are important for decoupling capacitor and microactuator applications are characterized. For decoupling capacitor applications, films having square hysteresis loops with energy storage density of up to 7 J/cm3 can be made, which release more than half of their stored charge in 10 ns with a maximum current density of more than 9400 A/cm2. For microactuator applications, the films can either have a strain level of 0.32% with very small hysteresis or have a strain level of 0.42% with moderate hysteresis.