Title :
The effect of oxygen gas pressure on Ba-ferrite sputtered films for perpendicular magnetic recording media
Author :
Morisako, A. ; Matsumoto, Morio ; Naoe, M.
Author_Institution :
Fac. of Eng., Shinshu Univ., Nagano, Japan
fDate :
11/1/1988 12:00:00 AM
Abstract :
Barium ferrite (BaM) sputtered films with a small c-axis dispersion angle, Δθ50, and smooth surface are needed for ultra-high-density perpendicular recording. These properties, which depend strongly on oxygen partial pressure, PO2, during sputtering, were studied experimentally. In the low-PO2 region (below 0.003 mTorr at total P (PAr+PO2) of 3.7 mTorr), a spinel phase was formed and exhibited a rough surface with large grain. In the mid-PO2 (0.003-0.2 mTorr) and high-PO2 (0.3-3.7 mTorr) regions, a mixed spinel and a BaM single phase were formed, respectively. The films deposited at high PO2 exhibited large perpendicular anisotropy and consisted of needle-like particles, while those deposited at medium PO2 exhibited perpendicular anisotropy of about 1.0 kOe. The Hk⊥ of these films was about 10 kOe, and they had a very smooth surface and small Δθ50
Keywords :
barium compounds; coercive force; ferrites; magnetic anisotropy; magnetic recording; magnetic thin films; sputtered coatings; surface topography; 0.003 to 3.7 mtorr; BaFe12O19 sputtered films; O2 partial pressure; c-axis dispersion angle; coercivity; ferrite; needle-like particles; perpendicular anisotropy; perpendicular magnetic recording media; spinel phase; surface roughness; Ferrite films; Magnetic films; Magnetic properties; Oxygen; Perpendicular magnetic recording; Rough surfaces; Sputtering; Substrates; Surface morphology; Surface roughness;
Journal_Title :
Magnetics, IEEE Transactions on
