Ab initio free energy calculations on the polymorphs of iron at core conditions

Details Ab initio free energy calculations on the polymorphs of iron at core conditions Ab initio free energy calculations on the polymorphs of iron at core conditions

Jan 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000pepi..117..123v&link_type=abstract

Physics of the Earth and Planetary Interiors, Volume 117, Issue 1-4, p. 123-137.

Physics

43

Scientific paper

In order to predict the stable polymorph of iron under core conditions, calculations have been performed on all the candidate phases proposed for inner core conditions, namely, body-centred cubic (bcc), body-centred tetragonal (bct), hexagonal close-packed (hcp), double-hexagonal close-packed (dhcp) and an orthorhombically distorted hcp polymorph. Our simulations are ab initio free energy electronic structure calculations, based upon density functional theory, within the generalised gradient approximation; we use Vanderbilt ultrasoft non-normconserving pseudopotentials to describe the core interactions, and the frozen phonon technique to obtain the vibrational characteristics of the candidate structures. Our results show that under conditions of hydrostatic stress, the orthorhombic, bcc and bct structures are mechanically unstable. The relative free energies of the remaining phases indicate that dhcp and fcc Fe are thermodynamically less stable than hcp Fe, therefore, we predict that the stable phase of iron at core conditions is hcp-Fe.

Affiliated with

Also associated with

No associations

Rating

Ab initio free energy calculations on the polymorphs of iron at core conditions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Ab initio free energy calculations on the polymorphs of iron at core conditions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ab initio free energy calculations on the polymorphs of iron at core conditions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-810654