Ab-initio modelling of Mg:H interstitial solid solutions

M. Messina, F. Cleri, M. Volpe

Research output: Contribution to conferencePaper

Abstract

We studied the thermodynamics of interstitial Mg:H solid solutions by means of ab-initio electronic structure calculations. Soft pseudopotentials (Troullier-Martins) with non linear core correction and Perdew-Burke-Ernzerhof GGA exchange-correlation functional were employed, in the framework of a DFT plane-wave scheme. We inserted increasing concentrations of interstitial H atoms in the hep Mg lattice, in both tetrahedral and octahedral positions. We calculated the heat of solution and the volume variation as a function of H concentration. Although the difference in Gibbs free energy is positive at any H concentration above 10-6 at.%, our results show that the enthalpic contribution is negative at any H concentration, therefore locally favouring H clustering. This reflects the existence of a driving force for the subsequent formation of the hydride. The volume deformation was characterized, finding that octahedreal interstitials have a minor effect, while tetrahedral interstitial can induce very large local expansion.
Original languageEnglish
Publication statusPublished - 2003
EventMaterials and Technology for Hydrogen Economy - , United States
Duration: 1 Jan 2003 → …

Conference

ConferenceMaterials and Technology for Hydrogen Economy
CountryUnited States
Period1/1/03 → …

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Messina, M., Cleri, F., & Volpe, M. (2003). Ab-initio modelling of Mg:H interstitial solid solutions. Paper presented at Materials and Technology for Hydrogen Economy, United States.