[1] Ctr Res Microelect & Nanotechnol Sousse, Technopk Sousse,BP 334, Tunis, Tunisia
[2] Natl Ctr Res Sci Mat, Lab Phys Chem Mineral Mat & Their Applicat, BP 95, Hammam Lif 2050, Tunisia
[3] Univ South Toulon Var, Inst Mat Microelect Nanosci Prov, F-83957 La Garde, France