Transverse phonons and intermediate-range order in Sr-Mg fluorophosphate glasses

Area of Science:

• Materials Science
• Condensed Matter Physics
• Glass Science

Background:

• Understanding the structure-property relationships in glass materials is crucial for developing new functional materials.
• Mixed fluoride-phosphate glasses offer a tunable platform to study network connectivity and its impact on physical properties.

Purpose of the Study:

• To investigate the vibrational and elastic properties of xSr(PO3)2-(1-x)(0.62MgF2-0.38AlF3) glasses.
• To elucidate the effect of varying connectivity between fluoride and phosphate sub-networks on the Boson peak.
• To establish a potential link between the Boson peak and transverse phonons.

Main Methods:

• Vibrational spectroscopy (Raman and IR) to analyze composition and short-range order.
• Ultrasonic spectroscopy to determine elastic properties.
• Systematic variation of the Sr(PO3)2 content (x) to tune glass composition.

Main Results:

• Phosphate group incorporation leads to a less interconnected and less rigid glass network.
• The Boson peak's nature is influenced by the connectivity between fluoride and phosphate sub-networks.
• A correlation between the Boson peak and transverse phonons was identified.

Conclusions:

• The study provides quantitative insights into how composition affects the structure and properties of mixed fluoride-phosphate glasses.
• The findings contribute to understanding the origin of the Boson peak in amorphous materials.
• This work highlights the potential for tailoring glass properties through controlled network engineering.