Si/NiFe/FeCoB Crystalline SUL to Reduce Ru Intermediate Layer Thickness for CoPtCr-SiO 2 Granular Perpendicular Magnetic Recording Media

• Published in: IEEE transactions on magnetics 2009-10, Vol.45 (10), p.3572-3575
• Main Authors: Matsuu, T, Hirata, K, Gomi, S, Hashimoto, A, Matsunuma, S, Inoue, T, Doi, T, Nakagawa, S
• Format: Article
• Language: English
• Subjects: Crystal structure; Intermetallics; Iron compounds; Nickel base alloys; Nickel compounds; Orientation; Surface layer; Texture
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2009.2022498

Bcc-FeCo (110) textured Ru/FeCoB films with high in-plane anisotropy field Hk were prepared as crystalline soft magnetic underlayers (SULs). The differences in crystallographic texture of the Ru intermediate layer (IML) and magnetic properties of Ru/CoPtCr-SiO sub(2) films with or without a FeCoB crystalline SUL were investigated. Ru/CoPtCr-SiO sub(2) films without Ru/FeCoB SULs exhibited a random orientation of Ru crystallites and in-plane magnetic anisotropy. On the other hand, Ru/CoPtCr-SiO sub(2) films deposited on the Ru/FeCoB SULs exhibited (001) preferential orientations of the CoPtCr as well as the Ru IMLs and possessed perpendicular magnetic anisotropy. The reduction of the thickness of the Ru IML from 30 nm to 1 nm did not cause the degradation of integrated intensity of the CoPtCr (002) diffraction peak. The application of the Si/NiFe/FeCoB SUL improved the FeCo (110) crystalline orientation, compared to the Ru/FeCoB SUL, and promoted (001) crystalline orientation of the CoPtCr-SiO sub(2) granular recording layer. The correlative relationship between Deltathetas sub(50) of FeCo (110) texture and that of CoPtCr (002) texture was confirmed.