MO K-EDGE XAFS IN NA2O-K2O-SIO2 GLASSES

The XAFS spectra of the Mo K-edge were investigated regarding molybden um ions in sodium potassium silicate glasses. In all the measured glas ses the molybdenum ions are considered to be in the 6+ oxidation state . We evaluated the Mo-O correlation and concluded that Mo6+ ion forms the MoO42- tetrahedron. Tile Mo-O distance is approximately 0.177 nm. This configuration is stable in the investigated composition range. Th e results indicate that the MoO42- tetrahedra are located outside the Si-O network anions. These MoO42- characteristics were discussed with the acid-base concept of the oxide glasses.