Raman spectra and structural peculiarities of TeO₂-TeO₃ mixed oxides.

Area of Science:

• Materials Science
• Solid-State Chemistry
• Spectroscopy

Background:

• Mixed crystalline oxides of the (1-x)TeO2 + xTeO3 series were synthesized.
• Understanding the structure-property relationships in these materials is crucial for their application.

Purpose of the Study:

• To investigate the structural properties and vibrational dynamics of mixed TeO2-TeO3 crystals.
• To establish a correlation between structural features and observed Raman spectral characteristics.

Main Methods:

• Synthesis of mixed TeO2-TeO3 crystals via solid-state chemistry.
• Recording Raman spectra of the synthesized crystalline oxides.
• Simulating Raman spectra using Density Functional Theory (DFT) calculations.

Main Results:

• A good agreement was found between experimental and calculated Raman spectra.
• All prominent Raman lines were unambiguously assigned.
• Raman bands were successfully correlated to internal vibrations of TeO4 and TeO6 polyhedrons.
• Observed Raman bands serve as fingerprints for different structural units.

Conclusions:

• DFT calculations accurately describe the structures and phonon spectra of TeO2-TeO3 oxides.
• The study provides insights into the relationship between structural peculiarities and spectral features.
• These findings are valuable for the development of crystals with nonlinear optical properties.