Relationship between the elastic properties and structure of BaO-TiO2-GeO2-SiO2 glasses

The macroscopic elastic modulus of a solid-state matter is generally affected by the packing density and average bond strength of the constituent atoms. However, because of the diversity of network connections in oxide glasses, an understanding based on the network structure is also required for precise structural categorisation. Here, we examine the relationship between the elastic modulus and structural parameters, viz., the correlation length of the Boson peak and cavity size calculated from the positron annihilation measurement, of BaO-TiO2- GeO2-SiO2 glasses. The Poisson's ratio correlates with the ratio of the longitudinal and transversal sound velocities, and thermal stability parameter Delta T. The Boson peak frequencies of these glasses at the GeO2-rich region exhibit an apparent plateau behavior, indicating that the rate of change in the sound velocity is similar to that in the correlation length. Although the numerical calculation of the cavity in this glass by positron annihilation spectroscopy is unavailable because of the D-electron of Ti cations, the tau 1 value shows a similar compositional dependence as the correlation length of the Boson peak. It is expected that a combination of elastic modulus and inelastic light scattering of glasses will be helpful in understanding glass-forming melts.

Automated summary

This study examines the relationship between the elastic modulus of glasses and structural parameters, including the correlation length of the Boson peak and cavity size, as well as the correlation with the longitudinal and transversal sound velocities and thermal stability parameters. The results show that the glasses in the GeO2-rich region exhibit a plateau behavior in the Boson peak frequencies, indicating a similarity in the rate of change in sound velocity and correlation length.