[1] Tech Univ Ilmenau, Ctr Micro & Nanotechnol, D-98684 Ilmenau, Germany
[2] Russian Acad Sci, Inst Res & Educ, St Petersburg Physicotech Ctr Res & Educ, Moscow 117901, Russia
[3] Russian Acad Sci, AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia
[4] St Petersburg State Tech Univ, St Petersburg 195251, Russia
[5] Univ Cadiz, Fac Ciencias, Dept Ciencia Mat & Ingn Met & Quim Inorgan, Puerto Real 11510, Cadiz, Spain