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arXiv · 2402.05326

Structural modifications of GeO$_2$ glass under high pressure and high temperature

Antoine Cornet·Remy Molherac·Bernard Champagnon·Christine Martinet
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Abstract

Vitreous GeO$_2$ 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$^\circ$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 (GeO$_4$) to octahedrally (GeO$_6$) coordinated GeO$_2$ are accelerated with the heating during the compression.

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Antoine Cornet, Remy Molherac, Bernard Champagnon, Christine Martinet. 2024-02-07. Structural modifications of GeO$_2$ glass under high pressure and high temperature. https://doi.org/10.1063/1.4962718

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