[1] Univ Hassan 2, Lab Phys Mat Condensee, Casablanca, Morocco
[2] Univ Hassan II Casablanca, Fac Sci Ben MSik, Pb7955, Casablanca, Morocco
[3] Int Iberian Nanotechnol Lab, Ave Mestre Jose Veiga S-N, P-4715330 Braga, Portugal
[4] LMTF, Casablanca, Morocco
[5] Univ Maine, CNRS, UMR 6283, Dept Phys,Inst Mol & Mat Le Mans IMMM, Ave Olivier Messiaen, F-72085 Le Mans 9, France