Abstract
The microstructure of BaM thin films, sputter-deposited using on alternate layer deposition technique on both a c-axis oriented ZnO underlayer and a (111) oriented ZnFe2O4 underlayer, was investigated using a high-resolution transmission electron microscope (HRTEM). When the films were deposited on the ZnO underlayer, the film had a layered structure of BaM (c-axis orientation) / Ba-Zn-Fe-O / ZnFe2O4 ((111) orientation) / Ba-Zn-Fe-O / Zn-Si-O/SiO2 / Si. This suggests that the BaM layer was formed after the formation of the layered structure of Ba-Zn-Fe-O / ZnFe2O4 ((111) orientation) / Ba-Zn-Fe-O / Zn-Si-O / SiO2 / Si. On the other hand, when films were deposited on the (111) oriented ZnFe2O4 underlayer, the BaM layer grew epitaxially on the (111) plane of the ZnFe2O4 underlayer, and the formation of transition layers was not observed. These results suggest that the diffusions of Ba, Fe, and Zn ions between the BaM layer and ZnO or Ba-Zn-Fe-O layer occurred easily but was completely suppressed in the ZnFe2O4 layer, which resulted in formation of a ZnFe2O4 layer that was sandwiched between the Ba-Zn-Fe-O layers when BaM films were deposited on a ZnO underlayer.
