Twin-coupled domain structures in epitaxial relaxor ferroelectric Ba(Zr,Ti)O_3 thin films on (001) MgO substrate

摘要

We report the twin-coupled multi-oriented domain structures in the epitaxial BZT20 (20 percent Zr) films grown on the (001) MgO substrate using pulsed-laser deposition. Transmission electron microscopy shows that the film consists of an epitaxial layer of pseudo-cubic perovskite structure and a nanopillar layer of multi-oriented twin domain structures near the surface. Four types of the twin domains were formed in the nanopillar layers by coherently joining their {111} with the epilayer and aligning their (110) directions parallel to the (110) axes of the epilayer. A non-uniform polarization switching behavior was observed due to the formation of such complex structure in the BZT20 films.