[Na and Mg K-edge XANES study in silicate glasses]

Area of Science:

• Materials Science
• Solid-State Chemistry
• Spectroscopy

Context:

• Investigating the structural roles of sodium (Na) and magnesium (Mg) in silicate and phosphate glasses.
• Utilizing advanced spectroscopic techniques like X-ray near edge structure (XANES) for elemental analysis.
• Examining the impact of compositional variations on glass structures.

Purpose:

• To elucidate the structural function of Na in sodium silicate and sodium phosphate glasses.
• To determine the coordination and bonding environment of Mg in diopside-albite (Di-Ab) glasses.
• To understand how phosphorus (P) incorporation influences Na's structural role.

Summary:

• Na K-edge XANES spectra revealed minimal structural changes with increasing Na2O in Na2O-SiO2 glasses, but significant alterations upon P2O5 addition.
• Mg K-edge XANES in CaMgSi2O6--NaAlSi3O8 glasses indicated Mg-O bond distances suggesting potential five-coordination or mixed coordination states (MgIV, MgV, MgVI).
• The study suggests that Di-Ab glasses may exhibit medium-range ordering.

Impact:

• Provides fundamental insights into glass structure and bonding.
• Highlights the significant influence of phosphorus on sodium's structural behavior in glasses.
• Offers evidence for complex coordination environments of magnesium in mixed silicate systems.
• Contributes to the understanding of medium-range order in geological glasses.