1. Department of Physics, Chemistry, and Biology (IFM), Linköping University, SE 58183 Linköping, Sweden
2. School of Science and Technology, Örebro University, SE-70182 Örebro, Sweden
3. ICAMS, Ruhr-Universität Bochum, 44780 Bochum, Germany
4. Sandvik Coromant AB, SE-126 80 Stockholm, Sweden
5. Frederick Seitz Materials Research Laboratory and the Materials Science Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
6. Materials Science Department, National Taiwan University of Science and Technology, Taipei 10607, Taiwan