Role of diffused Co atoms in improving effective exchange coupling in Sm-Co/Fe spring magnets

Y. Choi,1,2 J. S. Jiang,1 Y. Ding,3 R. A. Rosenberg,4 J. E. Pearson,1 S. D. Bader,1 A. Zambano,5 M. Murakami,5 I. Takeuchi,5 Z. L. Wang,3 and J. P. Liu2 1Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA 2Department of Physics, University of Texas at Arlington, Arlington, Texas 76019, USA 3School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA 4Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA 5Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA Received 6 November 2006; revised manuscript received 25 January 2007; published 30 March 2007