Deposition of Ba Ferrite Films for Perpendicular Magnetic Recording Media Using Mixed Sputtering Gas of Xe, Ar and O₂

Nobuhiro MATSUSHITA, Kenji NOMA, Shigeki NAKAGAWA, Masahiko NAOE

Summary :

Ba ferrite films were deposited epitaxially on ZnO underlayer from targets with composition of BaO-6.5Fe₂O₃ at substrate temperature of 600 using the facing targets sputtering apparatus. The gas mixture of Ar and Xe of 0.18 Pa and O₂ of 0.02 Pa was used as the sputtering gas and the dependences of crystallographic and magnetic characteristics on the partial Xe pressure P_Xe(0.0-0.18 Pa) were investigated. Films deposited at various P_Xe were composed of BaM ferrite and spinel crystallites, and the minimum centerline average roughness R_a of 8.3 nm was obtained at P_Xe of 0.10 Pa. Since saturation 4πM_s of 5.1 kG and perpendicular anisotropy constant K_u1 of 4.2310⁵ J・m^-3 were larger than those of bulk BaM ferrite of 4.8 kG and 3.3010⁵ J・m^-3, respectively, these films appeared promising for use as perpendicular recording media.

• Publication: IEICE TRANSACTIONS on Electronics Vol.E78-C No.11 pp.1562-1566
• Publication Date: 1995/11/25
• Type of Manuscript: Special Section PAPER (Special Issue on Ultra High Density Information Storage Technologies)

Authors

Nobuhiro MATSUSHITA
Kenji NOMA
Shigeki NAKAGAWA
Masahiko NAOE

Keyword

Ba ferrite films,  Xe mixed sputtering gas,  facing targets sputtering apparatus,  ZnO underlayer,  spinel intergrown BaM ferrite