Thermodynamic and mechanical stabilities of alpha- and beta-Ta4AlC3 via first-principles investigations Academic Article uri icon

abstract

  • Recently, it has been predicted that Ta4AlC3 is likely to exhibit an () polymorphic transformation at temperatures above 1873K. However, recent X-ray diffraction and transmission electron microscopy experiments suggest on the other hand that the phase remains stable up to temperatures close to the limit of experimental capabilities and no transition has yet been observed. While the matter has already been settled experimentally, in this work, we re-investigate the phase stability problem in Ta4AlC3 by using first-principles methods. The study was carried out by considering both thermodynamic and mechanical stabilities of the Ta4AlC3 polymorphs. Particularly, finite-temperature Gibbs free energies and elastic properties of the polymorphs were calculated using density functional theory. Calculation results reveal that the phase continue to be stable even at temperatures exceeding 1875K, which is in agreement with experimental results reported in literature.

published proceedings

  • JOURNAL OF APPLIED PHYSICS

author list (cited authors)

  • Thawabi, H. S., Thien, D., & Arroyave, R.

citation count

  • 3

complete list of authors

  • Thawabi, Hassan S||Thien, Duong||Arroyave, Raymundo

publication date

  • December 2013