Hydrogen solubility in amorphous Mg0.6SiO2.6 at high pressure

• Published in: Journal of experimental and theoretical physics Vol. 124; no. 6; pp. 914 - 919
• Main Authors: Efimchenko, V. S., Barkovskii, N. V., Fedotov, V. K., Meletov, K. P.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-06-2017; Springer Nature B.V
• Subjects: Classical and Quantum Gravitation; Elementary Particles; Hydrogen storage; Hydrogenation; Particle and Nuclear Physics; Phase transitions; Physics; Physics and Astronomy; Quantum Field Theory; Quenching; Raman spectroscopy; Relativity Theory; Solid State Physics; Solids and Liquids; Solubility; X-ray diffraction
• ISSN: 1063-7761; 1090-6509
• DOI: 10.1134/S1063776117050028

The solubility of hydrogen in amorphous Mg
0.6
SiO
2.6
at a temperature of 250°C and pressures up to 75 kbar is studied using a quenching technique. The molar ratio H
2
/formula unit is found to nonlinearly increase with pressure from
x
= 0.12 at
P
= 10 kbar to
x
= 0.303 at
P
= 75 kbar. An investigation of the quenched samples by Raman spectroscopy demonstrated that hydrogen dissolves in amorphous Mg
0.6
SiO
2.6
in the form of H
2
molecules. X-ray diffraction and Raman studies showed that the hydrogenation of the samples is likely to be accompanied by a phase transition in the amorphous lattice of Mg
0.6
SiO
2.6
at
P
≈ 52.5 kbar to a denser amorphous modification.