Role of dipolar and exchange interactions in the positions and widths of EPR transitions for the single-molecule magnets Fe8 and Mn12

Role of dipolar and exchange interactions in the positions and widths of EPR transitions for the single-molecule magnets Fe8 and Mn12 Kyungwha Park,* M. A. Novotny, N. S. Dalal, S. Hill, and P. A. Rikvold1,5,i School of Computational Science and Information Technology, Florida State University, Tallahassee, Florida 32306 Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306 Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762 Department of Physics, University of Florida, Gainesville, Florida 32611 Center for Materials Research and Technology and Department of Physics, Florida State University, Tallahassee, Florida 32306 ~Received 22 April 2002; published 16 October 2002!