N. Abidi, B. Deroide, J. V. Zanchetta
Lab. de Physicochimie de la Matiere Condensee, UMR 5617 CNRS Univ. Montpellier II, Pl. E. Bataillon 34095, Montpellier Cedex 5, France
Mn2+ ions have been incorporated in silica gel in order to follow the evolution of the ESR spectra during the formation of xerogels and to study the nature of their interaction with the glassy network. The breadth of hyperfine lines is sensitive both to the heat treatment and the ageing of the xerogels. Important modifications are due to changes in the water pressure. The results are indicative of the interactions between the probe and the surface of the pores. A simple ESR method for evaluating the dimension of the pores is proposed.