Stability of the body-centered-tetragonal phase of Fe at high pressure: Ground-state energies, phonon spectra, and molecular dynamics simulations
2006 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 74, no 21Article in journal (Refereed) Published
It is well established that at a pressure of several megabars and low temperature Fe is stable in the hexagonal-close-packed (hcp) phase. However, there are indications that on heating a high-pressure hcp phase of Fe transforms to a less dense (open structure) phase. Two phases have been suggested as candidates for these high-temperature stable phases: namely, body-centered-cubic and body-centered-tetragonal (bct) phases. We performed first-principles molecular dynamics and phonon analysis of the bct Fe phase and demonstrated its dynamical instability. This allows us to dismiss the existence of the bct Fe phase under the high-pressure high-temperature conditions of the Earth's inner core.
Place, publisher, year, edition, pages
2006. Vol. 74, no 21
brillouin-zone integrations, augmented-wave method, x-ray-diffraction, earths core, in-situ, atomistic simulation, cubic phase, inner-core, iron, elasticity
IdentifiersURN: urn:nbn:se:kth:diva-16242DOI: 10.1103/PhysRevB.214102ISI: 000243195500024ScopusID: 2-s2.0-33845260540OAI: oai:DiVA.org:kth-16242DiVA: diva2:334284
QC 201005252010-08-052010-08-05Bibliographically approved