화학공학소재연구정보센터
Journal of Crystal Growth, Vol.519, 20-24, 2019
Interface structure and planar defects in the heterostructure of pyrochlore-type (Ca,Ti)(2)(Nb,Ti)(2)O-7 film on SrTiO3 (001) substrate
Pyrochlore-type (Ca,Ti)(2)(Nb,Ti)(2)O-7 thin film has been successfully prepared on (0 0 1)-oriented SrTiO3 substrate. The atomic-scale microstructure properties of the heterostructure have been investigated by advanced electron microscopy techniques. It is found that the (Ca,Ti)(2) (Nb,Ti)(2)O-7 thin film is polycrystalline and an intermediate layer of perovskite-type Ca(Nb,Ti)O-3 with a few unit cell thicknesses forms at the (Ca,Ti)(2)(Nb,Ti)(2)O-7/SrTiO3 interface. In the (Ca,Ti)(2) (Nb,Ti)(2)O-7 thin film, planar defects including {1 1 1}-type stacking faults, reflection twin and glide-reflection twin appear. The stacking faults have a projected displacement vector of (a/8)<112>. Cation segregation and boundary reconstruction occur at the twin boundaries and the stacking faults, which cause the change of the local stoichiometry and are believed to affect the electrical properties of the film.