研究目的
Investigating the structure and properties of gallium-rich sodium germano-gallate glasses as a function of the Na/Ga cationic ratio for a fixed GeO2 content.
研究成果
The gallium-rich region of the ternary GaO3/2-GeO2-NaO1/2 vitreous system was explored through glass compositions varying as a function of the Na/Ga ratio for a fixed GeO2 content. The thermal, physical, and optical properties of the obtained glasses were characterized. Vibrational and 71Ga MAS-NMR spectroscopic techniques were used to propose a structural model of these Ga-rich glasses for different Na/Ga ratios. The glass network is formed of mixed GeO4 and GaO4 units in which the charge is balanced by sodium ions. For Na/Ga below unity, high-coordinate gallium (5- or 6-fold) is formed. For Na/Ga above unity, all gallium is in 4-fold coordination, with short-range order consisting of [GeO4], [Ge?3O-] and [GaO4]- units, and sodium ions charge balancing the anionic tetrahedral species.
研究不足
The study is limited to gallium-rich compositions in the ternary GaO3/2-GeO2-NaO1/2 vitreous system with a fixed GeO2 content. The experimental conditions and quenching techniques may affect the glass properties and structure.
