CoCrPtTa and Co/Pd perpendicular magnetic recording media with amorphous underlayers

• Published in: IEEE transactions on magnetics Vol. 37; no. 4; pp. 1592 - 1594
• Main Authors: Onoue, T., Asahi, T., Kuramochi, K., Kawaji, J., Homma, T., Osaka, T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.07.2001; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amorphous materials; Carbon; Chemistry; Chromium; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Density; Exact sciences and technology; Magnetic anisotropy; Magnetic films; Magnetic multilayers; Magnetic properties and materials; Magnetic recording; Magnetic recording materials; Magnetic separation; Magnetism; Media; Multilayers; Palladium; Perpendicular magnetic anisotropy; Perpendicular magnetic recording; Physics; Recording; Signal to noise ratio; Studies of specific magnetic materials; Quaternary alloys; Tantalum alloys; Platinum alloys; Palladium; Subshell; Chromium alloys; Experimental study; Cobalt; Magnetic thin films; Thin films; Multilayers; Perpendicular recording; Recording material; Coupling; Recording; Cobalt alloys; Exchange interactions; Magnetic recording
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/20.950910

The effect of amorphous carbon underlayers on magnetic properties and read-write characteristics of Co/sub 73/Cr/sub 18/Pt/sub 6/Ta/sub 3/ single layer and Co/Pd multilayer perpendicular magnetic recording media were investigated. The increase in H/sub c/ and decrease in /spl alpha/, defined as 4/spl pi/(dM/dH)/sub H=Hc/, were observed by increasing the underlayer thickness for both Co/sub 73/Cr/sub 18/Pt/sub 6/Ta/sub 3/ and Co/Pd media. The media with a low /spl alpha/ value, suggesting a decrease in the exchange coupling, exhibited the higher coercivity and the improvement of S/N ratio. In read-write experiments, the improvement of S/N ratio for the Co/Pd media was achieved up to 400 kFRPI or even higher in the recording density by increasing carbon underlayer thickness, while that for the Co/sub 73/Cr/sub 18/Pt/sub 6/Ta/sub 3/ media was obtained up to ca. 250 kFRPI.