Fluorescence and absorption probe of metal ion center in organically modified silicates

摘要

An optical probe of structure of metal ion center in sol-gel systems based on the Eu$+3$PLU$/ and Pr$+3$PLU$/ emission and absorption measurements have been developed. It was tested how far the substrates affect the structure of metal centers in the glasses obtained by two different methods. Splitting of the levels, as well as their electronic transition probabilities at room and liquid nitrogen temperatures were used for considerations of the structure and symmetry of metal center. It was shown that the structure of metal centers was partially preserved up to 450 K. Correlation of the thermogravimetric measurements of substrates with the gels dried and heated up to 1100 K enables to control spectroscopically possible clustering processes occurring in sol-gel silicas. The effect of organic modification of water retention and dopant aggregation was investigated too.