Quantification of the disorder in network-modified silicate glasses.

Area of Science:

• Materials Science
• Solid-State Chemistry
• Spectroscopy

Background:

• Local atomic order in silicate glasses resembles crystalline materials.
• Understanding intermediate-range order is crucial for explaining glass properties and composition effects.
• Previous studies lacked detailed insights into intermediate-range structural arrangements.

Purpose of the Study:

• To investigate intermediate-range order in silicate glasses.
• To elucidate the distribution of inter-tetrahedral bond angles.
• To determine the ordering of oxygen atoms around network-modifying cations.

Main Methods:

• Utilized two-dimensional 17O dynamic-angle-spinning nuclear magnetic resonance (2D 17O DAS NMR) spectroscopy.
• Analyzed spectral data to probe atomic arrangements at intermediate ranges.
• Focused on silicate glass systems with varying compositions.

Main Results:

• Identified significant intermediate-range order in the distribution of Si-O-Si bond angles.
• Observed a high degree of order in oxygen atom placement around network-modifying cations.
• NMR data provided detailed structural information beyond local ordering.

Conclusions:

• Silicate glasses exhibit distinct intermediate-range structural order.
• 2D 17O DAS NMR is a powerful technique for characterizing glass structure.
• Findings advance the understanding of how composition influences glass network topology.