Angle-dependent switching of granular and multilayer perpendicular media

• Published in: IEEE transactions on magnetics Vol. 39; no. 5; pp. 2314 - 2316
• Main Authors: Thomson, T., Coffey, K.R., Thiele, J.-U.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-09-2003; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Goniometers; Magnetic multilayers; Magnetic properties and materials; Magnetic recording; Magnetic recording materials; Magnetic switching; Magnetism; Magnetization reversal; Metals. Metallurgy; Nonhomogeneous media; Perpendicular magnetic recording; Physics; Remanence; Studies of specific magnetic materials; Temperature; Writing; Platinum alloys; Ternary alloys; Chromium alloys; Experimental study; magnetization processes; Switching; Magnetic thin films; Granular structure; Magnetic films; Cobalt base alloys; Perpendicular recording; Angular variation; Recording material; Magnetic recording
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2003.816282

Optimal writing of media where full remanent switching is achieved depends on the reversal mechanism and is of interest in designing ultrahigh density magnetic recording systems. Angle-dependent measurements of remanence curves provide a method of determining magnetization reversal mechanisms through comparison with well-known models, such as that due to Stoner and Wohlfarth. The commonly used switching models do not include magnetic viscosity effects and hence only approximate experimental data collected at laboratory times and temperatures. In order to achieve a more accurate comparison to the models and estimate the differences between finite temperature and time-independent data, we have determined the time-independent switching field H/sub swo/(/spl theta/) and thermal stability parameter KV/kT(/spl theta/) for representative samples from the two classes of media, granular CoCrPt and multilayer Co/Pd, currently under consideration for perpendicular recording. Generalizing the switching field to arbitrary values of magnetization allows the time-independent switching field distribution to be determined and correlated with the fields produced by recording heads.