Effects of the oxygen partial pressure during deposition on the material characteristics and magnetic properties of BaM thin films

Barium hexaferrite thin films were deposited on Si (1 0 0) substrates using a radio frequency magnetron sputtering system. The effects of oxygen partial pressure during deposition process on the material characteristics and magnetic properties of BaM thin films were investigated. X-ray diffraction data indicated that with the oxygen partial pressure ratio increasing from 0% to 8%, the diffraction peaks shift slightly towards the larger angles and the corresponding lattice parameters (a and c) decrease. The saturation magnetization (Ms) ranges from 200 to 358 kA/m as the oxygen partial pressure ratio is varied from 0% to 8%. These changes are attributed to the different oxidation states of Fe ions in the films with oxygen excess or vacancies. When deposited with 1% oxygen partial pressure, the film possesses the highest saturation magnetization (358 kA/m) and exhibits better perpendicular c-axis orientation in comparison with those deposited without oxygen partial pressure or with higher oxygen partial pressure.

► BaM thin films were deposited on Si (1 0 0) substrates by RF magnetron sputtering.
► Effects of oxygen partial pressure on the properties of BaM thin films were studied.
► Lattice parameters (a and c) decreased with the increase of oxygen partial pressure.
► Ms ranged from 200 to 358 kA/m as the oxygen partial pressure varied from 0% to 8%.
► The changes are attributed to the different oxidation states of Fe ions.