1. Graz Centre for Electron Microscopy 8010 Graz Austria
2. Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
3. Department of Materials Science and Engineering University of Tennessee Knoxville TN 37996 USA
4. Institute of Electron Microscopy and Nanoanalysis Graz University of Technology 8010 Graz Austria
5. Physikalisches Institut Goethe University Frankfurt 60438 Frankfurt Germany