Structure and magnetic properties of hexagonal barium ferrite films deposited by alternate layer deposition method

Abstract

Deposition of c-axis perpendicularly oriented hexagonal barium ferrite thin films were formed by an alternate periodic deposition of S (Fe6O8) and R(BaFe6O11) layers. BaM film with excellent c-axis orientation and good crystallinity was obtained when S layers 4.7 A thick and Rlayers 6.9 A thick was deposited on a ZnO underlayer. To reduce the amount of the Zn ions diffusing from the ZnO underlayer to the BaM film, the thickness of the ZnO underlayer was reduced. An underlayer less than 10 nm thick, however, significantly degraded the c-axis orientation of the BaM films. We also tried to deposit BaM films on various kinds of underlayers such as α-Fe2O3 and amorphous barium ferrite (a-BaM). A BaM film with c-axis orientation was obtained only on a ZnO underlayer and an a-BaM/ZnO underlayer, although the c-axis of the BaM crystallites in the film deposited on a ZnO underlayer inclined about 2 degrees from the normal to the film surface.