Investigating cerium redox changes between aluminosilicate glass and melt: A multispectroscopic approach

Area of Science:

• Materials Science, Glass Chemistry, Solid State Chemistry

Background:

• The redox state of multivalent elements like cerium in glass is critical for glass properties and processing.
• A clear understanding of how melting parameters influence the final redox state of cerium in glasses is lacking.

Purpose of the Study:

• To establish a predictive model for cerium redox state in sodium aluminosilicate glasses across a broad temperature range.
• To correlate high-temperature redox behavior with room-temperature characterization techniques.

Main Methods:

• In situ X-ray Absorption Near-Edge Structure (XANES) spectroscopy at the Ce L3-edge at high temperatures (900-1500 °C).
• Raman spectroscopy on quenched samples.
• Wet chemical analysis and optical absorption spectroscopy for redox state determination.

Main Results:

• Thermodynamic constants were determined to predict cerium redox state as a function of temperature.
• Quenching rates were sufficient to "freeze" the high-temperature cerium oxidation state.
• Room-temperature Raman spectra correlated with melting conditions, validating the quenched state.

Conclusions:

• The study successfully determined the redox state of cerium in aluminosilicate glasses using multiple techniques.
• High-temperature in situ XANES combined with room-temperature Raman spectroscopy provides a robust method for characterizing glass redox states.
• The findings enable better control over glass properties by predicting and managing cerium redox states during processing.