Influence of plasma treatment conditions on structural-phase composition and magnetic properties of barium hexaferrite ($M$-type) films on $c$-sapphire

In the work investigated the influence of plasma treatment conditions on the structural-phase composition and magnetic properties of barium hexaferrite films (0001) BaFe$_{12}$O$_{19}$ on $c$-sapphire. Two treatment modes were used: with a weight average plasma temperature of 4–5 kK and 8–10 kK. It has been shown that the films obtained at the low treatment temperature have a pronounced magnetic anisotropy and saturation magnetization of 42 emu/g. The films obtained at high temperature have weak magnetic anisotropy, but have a higher saturation magnetization value of 62 emu/g. All films have low coercive fields of less than 500 Oe, which indicates the low magnetic hardness of barium hexaferrite samples and the possibility of their use as magnetic conductors of transformers, electromagnets, in measuring devices. The presented results demonstrate the promise of the plasma treatment technique in the formation of coatings with high anisotropy.