[1] CSIC, Inst Ciencia Mat Madrid, E-28049 Madrid, Spain
[2] CSIC, Inst Ceram & Vidrio, E-28049 Madrid, Spain
[3] Univ Politecn Madrid, Dept Ciencia Mat, E-28040 Madrid, Spain
[4] ETS Ingn Caminos, IMDEA Mat, Madrid 28040, Spain
[5] CSIC, Inst Nacl Carbon, Oviedo 33011, Spain
[6] Univ Manchester, Ctr Mat Sci, Manchester M1 7HS, Lancs, England