Uncovering the Thermo-Kinetic Origins of Phase Ordering in Mixed-Valence Antimony Tetroxide by First-Principles Modeling

Chang Eun Kim, Su Hyun Yoo, David F. Bahr, Catherine Stampfl, Aloysius Soon

Research output: Contribution to journalArticle

Abstract

Phase ordering in the mixed-valence oxide Sb2O4 has been examined by density functional theory (DFT) calculations. We find that the ground-state total energies of the two phases (α and β) are almost degenerate and are highly sensitive to the choice of the approximation to the exchange correlation (xc) functional used in our calculations. Interestingly, with the inclusion of the zero-point energy corrections, the α phase is predicted to be the ground state polymorph for most xc functionals used. We also illustrate the pronounced stereochemical activity of Sb in these polymorphs of Sb2O4, setting an exception to the Keve and Skapski rule. Here, we find that the actual bonding in the α phase is more asymmetric, while the anomalous stability of the β phase could be rationalized from kinetic considerations. We find a non-negligible activation barrier for this α-β phase transition, and the presence of a saddle point (β phase) supports the separation of Sb(III) over a continuous phase transition, as observed in experiments.

Original languageEnglish
Pages (from-to)6545-6550
Number of pages6
JournalInorganic Chemistry
Volume56
Issue number11
DOIs
Publication statusPublished - 2017 Jun 5

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this