2004 年 112 巻 1303 号 p. 130-132
The absorption spectra of Cr-containing Li2O-SiO2 transparent glass-ceramics was investigated. The crystalline phases precipitated in glass-ceramics are mainly Li2O•2SiO2 with a small amount of α-SiO2. The percent crystallinity and crystal sizes are 40-77 and 20-42 nm, respectively. A strong absorption band ascribed to the charge transfer of Cr6+ ion and a weak d-d absorption band ascribed to Cr3+ ion were observed in the glass. However, the new absorption bands appeared at around 600-700 nm and the absorption intensity of these bands increased significantly (about 15 times) upon crystallization. It was suggested that the tetrahedrally coordinated Cr4+ ion might exist in Li2O-SiO2 transparent glass-ceramics.