Seeding effect of SrBi2Ta2xO9 thin buffer layer on crystallization and electric properties of SrBi2Ta2O9 thin films

Abstract

The seeding effects of the precrystallized (RTP 750 degrees C 30s) thin buffer layer, SrBi2Ta2xO9 (SBT, x=0.9, 1.0, and 1.1), regarding the structure, the morphology and the ferroelectric properties of the SrBi2Ta2O9 ferroelectric thin films on top of buffer layer, have been investigated. X-ray diffraction patterns revealed that the crystallinity of SrBi2Ta2O9 thin films were significant influenced by the buffer layers with various Ta contents. By adding a Ta deficient buffer layer, the preferred polar a-axis orientation and the uniformity of grain size within the SBT thin films were promoted. Meanwhile, the optimized ferroelectric properties were achieved from the SrBi2Ta1.8O9 buffered SrBi2Ta2O9 thin film, with maximum 2Pr values about 19.7 mu C/cm(2), which was almost 93% greater than that of specimen with the stoichiometric buffered one.