Comparative study of the short-range structure of α-V₂O₅, α-TeO₂ and xV₂O₅-(100 - x)TeO₂ glasses using X-ray...

Area of Science:

• Materials Science
• Solid State Chemistry
• Glass Science

Background:

• Vanadium-tellurite glasses are technologically relevant materials.
• Understanding their atomic structure is crucial for property prediction.

Purpose of the Study:

• To characterize the atomic structure of vanadium-tellurite glasses and compare them with crystalline V2O5 and TeO2.
• To determine coordination numbers and interatomic distances using advanced analytical techniques.

Main Methods:

• Synchrotron X-ray diffraction
• Pair distribution function (PDF) analysis
• Reverse Monte Carlo (RMC) simulations
• Rietveld analysis

Main Results:

• The pair correlation function (G(r)) of crystalline V2O5 shows a first peak at 1.61 Å (V-O).
• Crystalline TeO2 exhibits G(r) peaks at 1.57, 2.13, and 2.88 Å (Te-O) and 3.85 Å (Te-Te).
• Vanadium tellurite glass shows an initial G(r) peak at 1.90 Å (overlapping V-O and Te-O).
• Average coordination numbers: V-O in V2O5 (4.39), Te-O in TeO2 (3.71).
• RMC analysis indicates V-O coordination (5.27-5.59) and Te-O coordination (5.39-5.67) in glasses.
• Short-range disorder complicates precise coordination number definition in glasses.

Conclusions:

• Atomic structure and coordination numbers differ significantly between crystalline and glassy states.
• Short-range disorder is a key feature influencing coordination in vanadium-tellurite glasses.
• The study provides fundamental insights into the structure-property relationships of these materials.