1. Laboratory LaSCOM, Faculty of Sciences of Sfax, University of Sfax, BP1171, 3000, Sfax, Tunisia
2. Laboratoire Physico-chimie de l’Etat Solide, D'epartement de Chimie, Facult'e des Sciences de Sfax, Universit'e de Sfax, B.P. 1171, 3000 Sfax, Tunisia
3. Department of Physical Chemistry, Faculty of Chemical Sciences, University of Salamanca, E-37008 Salamanca, Spain
4. Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo-CINN(CSIC), 33006 Oviedo, Spain