Unusual 90°domain structure in (2/3)Bi(Zn1/2Ti 1/2)O3-(1/3)BiFeO3 epitaxial films with giant 22% tetragonal distortion

Abstract

Epitaxial films of tetragonal (001)/(100)-oriented (2/3)Bi(Zn 1/2Ti1/2)O3-(1/3)BiFeO3 were grown on (100)cSrRuO3//(100)SrTiO3 substrates by metalorganic chemical vapor deposition. 93% of the film is occupied by c-domain [(001) orientation], and the out-of-plane (c-axis) and in-plane (a-axis) lattice parameters are 0.465 nm and 0.381 nm, respectively. The tetragonal distortion, (c/a)-1, is 22% which is 3.5 times larger than that of PbTiO3 (6.3%). High-angle annular dark-field-scanning transmission electron microscopy images show clear c-/a-domain structures with unusual boundary angles of 51°/39°due to the large c/a ratio of tetragonal phase. High temperature X-ray diffraction measurements reveal that the Curie temperature of this film is above 800°C. © 2013 AIP Publishing LLC.