Study of the high-pressure helium phase diagram using molecular dynamics
2007 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 19, no 1Article in journal (Refereed) Published
The rich occurrence of helium and hydrogen in space makes their properties highly interesting. By means of molecular dynamics ( MD), we have examined two interatomic potentials for He-4. Both potentials are demonstrated to reproduce high-pressure solid and liquid equation of state (EOS) data. The EOS, solid - solid transitions and melting at high pressures ( P) were studied using a two-phase method. The Buckingham potential shows a good agreement with theoretical and experimental EOS, but does not reproduce experimental melting data. The Aziz potential shows a perfect match with theoretical melting data. We conclude that there is a stable body-centred-cubic (bcc) phase for He-4 at temperatures ( T) above 340 K and pressures above 22 GPa for the Buckingham potential, whereas no bcc phase is found for the Aziz potential in the applied PT range.
Place, publisher, year, edition, pages
2007. Vol. 19, no 1
generalized-gradient approximation, x-ray-diffraction, equation-of-state, melting curve, solid he-4, density, quasi, iron
IdentifiersURN: urn:nbn:se:kth:diva-16301DOI: 10.1088/0953-8984/19/1/016206ISI: 000243136300018ScopusID: 2-s2.0-33847187754OAI: oai:DiVA.org:kth-16301DiVA: diva2:334343
QC 201005252010-08-052010-08-05Bibliographically approved