Correlation of bulk saturation magnetization with signal-to-media-noise ratio of Co–Cr–(Pt)–Ta alloy thin film disks

• Published in: Journal of magnetism and magnetic materials 1999-02, Vol.192 (2), p.253-257
• Main Authors: Gao, C, Malmhäll, R, Lin, Z.-H, Chen, J.-P, Chen, G.-L, Rauch, G.C
• Format: Article
• Language: English
• Subjects: Alloys; Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of monolayers and thin films; Magnetic properties of surface, thin films and multilayers; Magnetic recording; Magnetic recording materials; Metals. Metallurgy; Physics; Saturation magnetization; Signal-to-noise ratio; Studies of specific magnetic materials; Thin film media
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(98)00316-3

The effects of intrinsic saturation magnetization σ s on media magnetic properties and recording performance in Co–Cr–(Pt)–Ta alloy films were studied. Correlation between cobalt content and σ s and between σ s and media signal-to-noise ratio (SNR), has been revealed. Additions of Cr and Ta strongly reduce the film saturation magnetization; the addition of Pt makes the reduction of saturation magnetization less pronounced. It is found that higher σ s degrades media SNR. The mechanism for this decrease in SNR is believed to be an increase in the strength of magnetostatic interaction. It is concluded that for very low noise recording media low saturation magnetization alloys are preferred.