Epr Study Of Mn2+ Doped Silica Glasses Prepared By The Sol-Gel Process

Manganese (II) ions have been used as paramagnetic probes for EPR investigation of the local structural changes taking place during the sol-gel-xerogel transformation of silica. The probe was introduced during the initial phases of preparation of the sol. The bredth of hyperfine lines is sensitive to both the treatment temperature and ageing of the xerogels. The most important modifications are due to changes in water pressure. The results are indicitive of interactions between the probe and the surface of the pores. There is no evidence of structural substitution of Mn in the glass network.