The pressure–temperature phase diagram of MgH2 and isotopic substitution

Moser, D, Baldissin, G, Bull, DJ ORCID: https://orcid.org/0000-0001-9406-2031, Riley, DJ, Morrison, I ORCID: https://orcid.org/0000-0002-6886-1398, Ross, DK, Oates, AW and Noreus, D 2011, 'The pressure–temperature phase diagram of MgH2 and isotopic substitution' , Journal of Physics Condensed Matter, 23 (30) , p. 305403.

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Abstract

Computational thermodynamics using density functional theory ab initio codes is a powerful tool for calculating phase diagrams. The method is usually applied at the standard pressure of p = 1 bar and where the Gibbs energy is assumed to be equal to the Helmholtz energy. In this work, we have calculated the Gibbs energy in order to study the release temperature and phase modifications of MgH2 at high pressures up to 10 GPa (100 kbar). The isotopic substitution of hydrogen with deuterium (or tritium) does not bring about any strong effects on the phase diagram. These considerations are of extreme importance for (i) the synthesis of novel substitutional magnesium based materials at high pressure and (ii) the determination of the correct reference states for the calculation of phase diagrams at high pressure. The calculated results are compared with experimental data obtained with an in situ neutron diffraction measurement.

Item Type:	Article
Themes:	Energy
Schools:	Schools > School of Computing, Science and Engineering Schools > School of Computing, Science and Engineering > Salford Innovation Research Centre
Journal or Publication Title:	Journal of Physics Condensed Matter
Publisher:	Institute of Physics
Refereed:	Yes
ISSN:	0953-8984
Funders:	European Commission
Depositing User:	D Moser
Date Deposited:	14 Jul 2011 11:59
Last Modified:	13 Mar 2023 15:02
URI:	https://usir.salford.ac.uk/id/eprint/16646

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