Correlation between boson peak and anomalous elastic behavior in GeO2 glass: an in situ Raman scattering study under high-pressure.

We present low-frequency Raman scattering of pure GeO(2) glass under pressure up to 4 GPa, corresponding to an elastic transformation. Intensity variation and frequency shift of the boson peak are analysed and compared to the Debye model. The decrease of the boson peak intensity scaled by the Debye energy is correlated to the elastic anomalous properties under pressure up to 1.5 GPa, and interpreted as an elastic homogenisation process at the local scale. We emphasize similarities between a-GeO(2) and a-SiO(2) behavior under pressure, and compare our results to other experiments, numerical studies, and predictions of several models concerning amorphous systems.