Vitreous GeO2 has been compressed at high temperature, to investigate the effect of thermal activation on the structural reorganization during compression. The measurements were performed in-situ using micro Raman spectroscopy under pressure up to 6 GPa and temperature up to 400∘C. The evolution of the Raman shift of the main band (400-500 cm−1) with temperature during compression evidences a pressure window around 3 GPa within which temperature has a remarkable influence on the structure, in particular the intermediate range order. We find that this change is well correlated with previous ex-situ density measurements from high pressure-high temperature densifications. Moreover, coordination changes from tetrahedrally (GeO4) to octahedrally (GeO6) coordinated GeO2 are accelerated with the heating during the compression.
@article{arxiv.2402.05326,
title = {Structural modifications of GeO$_2$ glass under high pressure and high temperature},
author = {Antoine Cornet and Remy Molherac and Bernard Champagnon and Christine Martinet},
journal= {arXiv preprint arXiv:2402.05326},
year = {2024}
}