Materials Research Science and Engineering Center


Date of this Version



Published in IEEE TRANSACTIONS ON MAGNETICS, VOL. 40, NO. 4, JULY 2004. Digital Object Identifier 10.1109/TMAG.2004.829829
Used by permission.
"©2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE."


Highly coercive granular SmCo/CuTi films were produced by thermal processing of sputtered SmCo5 (CuTi) multilayers and investigated experimentally and theoretically. Electron microscopy shows that the processed films consist of spherical grains that have diameters of 5–10 nm and are embedded in a matrix. Both the grains and the matrix phase exhibit the CaCu5 structure, but the matrix is probably Cu-rich. The films have high coercivities of up to 50.4 kOe at 300 K. Analytical calculations and micromagnetic simulations yield a transition from a nucleation-type weak-interaction regime to a discrete-pinning-type strong-interaction regime. The transition occurs at packing fractions similar to those encountered in the investigated films and is accompanied by a coercivity maximum.