Growth of [00/] preferentially oriented Pb1-xLax(ZryTiz) O3 (PLZT) thin films was carried out by using targets of either tetragonal or rhombohedral structure. The tetragonal films grew in a similar manner to the rhombohedral films. Both the substrate temperature (500 or 550°C) and oxygen pressure (0.1 mbar, 10 Pa) required stringent control in order to deposit [00/]-textured PLZT thin films. The ferroelectric and fatigue properties were examined. The films deposited on YBa2Cu3O7-x and CeO2 coated silicon (YBCO/CeO2/Si) substrates possessed substantially lower remanent polarization than those grown on YBCO coated SrTiO3 (YBCO/STO) substrates; this is ascribed to inferior crystallinity of the PLZT/YBCO/CeO2/Si films. The remanent polarization of tetragonal PLZT films was degraded insignificantly up to 108 polarization switching cycles, whereas that of rhombohedral PLZT films was already reduced to 80% of the initial value after 108 cycles. Low endurance of rhombohedral films was ascribed to the periodic stress induced when the inclined spontaneous polarization vector (P=) switched. On the other hand, high endurance of tetragonal films was explained by the fact that the spontaneous polarization vector (P=) lies along the film's normal such that switch cycles cause no lateral stress.
|Number of pages||9|
|Journal||Journal of Materials Science: Materials in Electronics|
|State||Published - Dec 1996|