Titanium phosphate glasses: Beyond tetrahedral network structures.

Area of Science:

• Materials Science
• Solid-State Chemistry
• Glass Science

Background:

• Titanium phosphate glasses are an atypical glass-forming system.
• Understanding their structure is crucial for developing new materials.
• Previous studies lack detailed structural insights into these glasses.

Purpose of the Study:

• To elucidate the structure of titanium phosphate glasses (TiO2)x(P2O5)1-x.
• To determine the composition dependence of structural motifs.
• To provide a benchmark for future glass structure investigations.

Main Methods:

• Combined neutron and high-energy X-ray diffraction.
• Solid-state 31P nuclear magnetic resonance (NMR) spectroscopy.
• Raman spectroscopy and ab initio molecular dynamics simulations.

Main Results:

• Decreasing P-O-P bonds from 23% to 11% with increasing TiO2 content.
• Increasing Ti-O coordination number from 5.32(7) to 5.49(7).
• Prevalence of five- and six-coordinated titanium and coexistence of O(II) and O(III) oxygen atoms.

Conclusions:

• Structural variability, including Ti coordination and oxygen environments, drives vitrification.
• Phosphate groups form P-O(II)-Ti and P-O(III)-2Ti connections.
• These findings offer insights into glass formation in systems with higher-coordinated polyhedra.