ATOMIC PACKING AND LOW ENERGY VIBRATIONS IN B2O3 GLASSES, COMPACTED UNDER GPa PRESSURES

Vibrational properties of crystals are well described by Debye’s theory. This doesn’t hold for vitreous systems, where an excess density of low frequency vibrational states, called Boson peak, appears. In this work we study glassy boron trioxide (B2O3), a prototype system widely used as basic element of multi-component glasses. Our aim is to get some insight into the dependence of mechanical and vibrational properties on the structure of glasses, i.e., on the atomic packing. For this reason, samples were compacted byusing a multi anvil press up to pressures of 10 GPa. A comparative analysis of light Raman scattering and mechanical characteristics have been performed on densified samples. The results show that either Raman spectra and elastic constants are affected by the densification process owing to the hardening of the elastic continuum.