Synthesis and ferroelectric properties of SrBi2Ta2O9/Bi4Ti3O12/P-Si ultilayer thin films by Sol-Gel

摘要

SrBi2Ta2O9 (SBT)/Bi4Ti3O12 (BIT) multilayer thin films were prepared on p-Si substrates by Sol-Gel method, the effect of thickness of SBT and annealing temperature oil structure, morphology, ferroelectric and fatigue properties of SBT/BIT ferroelectric films were investigated. The SBT/BIT multilayer films annealed at above 600 degrees C were uniform and crack free as well as exhibited no pyrochlore phase. The remanent polarization and the coercive field of SBT/BIT multilayer films both increases with the increase of annealing temperature due to better crystallization and larger grain size. The SBT/BIT multilayer thin films consisting of 1 layer of SBT and 3 layers of BIT annealed above 650 degrees C obtained its best ferroelectric properties with a P-r of 8.1 mu C/cm(2) and a E-c of 130 kV/cm which is comparable to that of pure BIT films and had a fatigue-free property up to 10(11) switching cycles, but P-nv appeared under the cycle field of 175 kV/cm and increased with the decrease of cycle field.