High pressure behaviour of liquid GeO2: a molecular dynamics study

TL;DR

This study uses molecular dynamics simulations to explore how liquid GeO2's structure and density change under high pressure, revealing a reversible LDL to HDL transition with temperature-dependent characteristics.

Contribution

It provides new insights into the pressure-induced structural transitions of liquid GeO2 through detailed molecular dynamics simulations.

Findings

Ge-O coordination increases under compression.

Discontinuous density change at ~11.5 GPa at 1650 K.

Reversible LDL to HDL transition with temperature dependence.

Abstract

High pressure behaviour of liquid GeO2 is investigated by means of molecular dynamics simulations in the pressure range 0-20 GPa and at various temperatures. In agreement with the recent experiments (PRL, 92, 155506, 2004), Ge-O coordination increases under compression. For 1650 K, at ~11.5 GPa the structure becomes 6 coordinated with a discontinuous change in the density. The transition from the low density liquid (LDL) to high density liquid (HDL) is found to be reversible and the transition pressure increases with the temperature. At lower temperatures, the low density to high density transition is found to be continuous, but with the coexistence of two structures.