[1] IFW Dresden, D-01171 Dresden, Germany
[2] Tech Univ Dresden, Dept Phys, D-01062 Dresden, Germany
[3] Tech Univ Dresden, Inst Mat Sci, D-01062 Dresden, Germany
[4] Tech Univ Dresden, Max Bergmann Ctr Biomat, D-01062 Dresden, Germany
[5] Univ Oxford, Dept Mat, Oxford OX1 3PH, England
[6] Natl Univ Tainan, Dept Mat Sci, Tainan 700, Taiwan