Reversible and irreversible magnetization behavior in SmCo films

Recent studies of demagnetization processes in permanent magnets have used two different methods for determining the reversible magnetization, often arriving at conflicting results. In the present work, enhanced-remanence SmCo films have been prepared by DC magnetron sputtering. The evolution of the reversible (M-rev) and irreversible (M-irr) magnetization along the initial magnetization curve and the demagnetization curve of the films was determined using the two methods. In one case, the DCD definition of the reversible magnetization was used to measure the quantity from a set of recoil curves. Alternatively, the moving Preisach model was used to separate the magnetization into its components M-rev and M-irr. We discuss the different behaviors encountered for the reversible magnetization and the inter-relation function eta = (delta/M-rev/delta M-irr)(Hi) and interpret the differences. (C) 2000 Elsevier Science B.V. All rights reserved.