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

Deconvoluting interrelationships between low‐energy vibrational modes and elastic properties in CaO–Al2O3 glasses

“…The above finding indicates that the low‐frequency vibrations observed in the Raman spectra acquired from CA glasses originate from transversal phonon vibrations. The above link has also been shown to hold valid also in the case of fluorophosphate glasses 45 and in other systems both experimentally 48 and theoretically 49 . Indeed, as is shown in Figure 3, the BP frequency for both polarization geometries as a function of the transversal sound velocity for fluorophosphate (Figure 3A) and for CA glasses (Figure 3B) seem to be linearly correlated.…”

“…The compositional dependence of the Debye temperature resembles that of the compositional evolution of the corresponding longitudinal and transversal sound velocities as shown in Figure 2B. The latter can also be used as an indicator for the cross‐linking density in these glasses as Debye temperature is also strongly related to the heat capacity of glasses and thus reflecting their cross‐linking density 45 …”

“…Analogous results have been observed in other glassy systems, such as Sr-Mg fluorophosphates. 45 The significant noncoincidence between the polarized and depolarized values corresponding to the BP frequency is attributed to the different functions of C(ω) corresponding to the VV and VH geometries.…”

“…The latter can also be used as an indicator for the cross-linking density in these glasses as Debye temperature is also strongly related to the heat capacity of glasses and thus reflecting their cross-linking density. 45 The BP can also be correlated to another very important parameter in these glasses, namely, the mean atomic volume 𝑉 𝑚 , through the following equation 50 :…”

Structure and dynamics of aqueous norspermidine solutions: an in situ ultrasonic relaxation spectroscopic study

“…Local heating and cavitation effects in the system are negligible. The validity of the homemade acoustic cell has been verified by measuring the acoustic properties (sound absorption and sound speed) of pure solvents and other organic liquids, such as water, castor oil, glycerin, benzene and others, that are reported in the literature and are established as standards [20,21]. The comparison between our experimental values with the literature values reveals an adequate agreement in both velocity and sound absorption coefficient indicating that our setup is reliable for measuring velocity and absorption of liquids [20,21].…”