[1] Inst Chem Technol, Dept Inorgan Chem, CR-16628 Prague 6, Czech Republic
[2] Acad Sci Czech Republ, Inst Phys, CR-16200 Prague 6, Czech Republic
[3] Forschungszentrum Julich, Inst Bio & Nanosyst IBN 1, D-52425 Julich, Germany
[4] JARA, Fundamentals Future Informat Technol, Julich, Germany