The crystalline orientation and ferroelectric properties of Bi_(3.25)La_(0.75)Ti_3O_(12) thin films mediated by the intermediate layer of LaNiO_3

摘要

c-Axis-oriented and (11 7)-oriented Bi_(3.25)La_(0.75)Ti_3O_(12) (BLT) thin films are successfully controlled by the intermediate layer of LaNiO_3 (LNO) with chemical solution deposition (CSD), respectively. X-ray diffraction (XRD) demonstrates that the structure and orientation of LNO thin films have a strong effect on the orientation of BLT thin films. Scanning electron microscopy suggests that BLT thin films on LNO electrode exhibit crack-free, uniform size grains and dense microstructure. A crystalline orientation dependent remanent polarization is observed in BLT thin films, and it is found that the remanent polarization (2Pr) of (11 7)-oriented films is larger than that of c-axis-oriented films. Our research directly demonstrates that the vector of the main spontaneous polarization in these layered perovskite materials (BLT) is along a-axis.