Ultrahigh-pressure polyamorphism in GeO2 glass with coordination number >6

Ultrahigh-pressure polyamorphism in GeO2 glass with coordination number >6.

Knowledge of pressure-induced structural changes in glasses is important in various scientific fields as well as in engineering and industry. However, polyamorphism in glasses under high pressure remains poorly understood because of experimental challenges. Here we report new experimental findings of ultrahigh-pressure polyamorphism in GeO2 glass, investigated using a newly developed double-sta...

Simulation of pressure-induced polyamorphism in a chalcogenide glass GeSe2

The pressure-induced insulator-metal transition in amorphous GeSe2 (a-GeSe2) is studied using an ab initio constant pressure molecular-dynamic simulation. a-GeSe2 transforms gradually to an amorphous metallic state under the application of pressure. The transition is reversible, and is associated with a gradual change from fourfold to sixfold Ge coordination, and from twofold to fourfold Se coo...

Polyamorphism in Yb-based metallic glass induced by pressure

The Yb62.5Zn15Mg17.5Cu5 metallic glass is investigated using synchrotron x-ray total scattering method up to 38.4 GPa. The polyamorphic transformation from low density to high density with a transition region between 14.1 and 25.2 GPa is observed, accompanying with a volume collapse reflected by a discontinuousness of isothermal bulk modulus. This collapse is caused by that distortional icosahe...

First-order pressure-induced polyamorphism in germanium

We report on the pressure-induced phase transition in amorphous Germanium (a-Ge! using an ab initio constant pressure-relaxation simulation. a-Ge exhibits a first-order polyamorphic phase transition at 12.75 GPa with a discontinuous volume change of ;19%. The transition pressure is also calculated from the Gibbs free-energy curves, and it is found that the transition occurs at 5.2 GPa in agreem...

Polyamorphism of a Ce-based bulk metallic glass by high-pressure and high-temperature density measurements