Theoretical study of protactinium at high pressure
2006 (English)In: Mater Res Soc Symp Proc, 2006, 255-269 p.Conference paper (Refereed)
We have studied the crystal structure of Pa metal under high pressure by means of first-principles calculations based on the density functional theory (DFT) using the generalized gradient approximation (GGA). The body centered tetragonal (bct) to orthorhombic (α-U) phase transition was calculated to take place at 29 GPa and with a volume change of 1.3%. The calculated c/a for the bet phase reaches the ideal c/a value (0.816) at around 50 GPa. A bulk modulus of 113 GPa was derived from a Murnaghan equation of state (EOS) fitting procedure. Our results are in general good agreement with recent experiment performed by Haire et al, [Phys. Rev. B 67, 134101 (2003)]. We have also calculated phonon spectra for fcc, bct and bcc Pa. The bcc spectrum gives imaginary frequencies showing the low temperature instability of this crystallographic phase for Pa.
Place, publisher, year, edition, pages
2006. 255-269 p.
, Materials Research Society Symposium Proceedings, ISSN 0272-9172 ; 893
Crystal structure, Materials science, Phase transitions, Phonons, Probability density function, Crystallographic phase, Equation of state (EOS), Generalized gradient approximation (GGA), Imaginary frequencies, Protactinium
IdentifiersURN: urn:nbn:se:kth:diva-156340ISI: 000237224800031ScopusID: 2-s2.0-33646433722ISBN: 1558998470ISBN: 9781558998476OAI: oai:DiVA.org:kth-156340DiVA: diva2:766672
2005 Materials Research Society Fall Meeting, 28 November-1 December 2005, Boston, MA, USA
QC 201411282014-11-282014-11-262014-11-28Bibliographically approved