1. a Joint Research Center for Atom Technology — Angstrom Technology Partnership (JRCAT-ATP) , Higashi 1-1-4, Tsukuba, Ibaraki, 305, Japan
2. d E-mail:
3. b Argonne National Laboratory, Materials Science Division , 9700 South Cass Av., Argonne, IL, 60439-4838
4. c JRCAT, National Institute for Advanced Interdisciplinary Research , Higashi 1-1-4, Tsukuba, Ibaraki, 305, Japan