Relative energetics and structural properties of zirconia using a self-consistent tight-binding model

S. Fabris, Anthony Paxton, M.W. Finnis

Research output: Contribution to journalArticle

84 Citations (Scopus)

Abstract

We describe an empirical, self-consistent, orthogonal tight-binding model for zirconia, which allows for the polarizability of the anions at dipole and quadrupole levels and for crystal field splitting of the cation d orbitals, This is achieved by mixing the orbitals of different symmetry on a site with coupling coefficients driven by the Coulomb potentials up to octapole level. The additional forces on atoms due to the self-consistency and polarizabilities are exactly obtained by straightforward electrostatics, by analogy with the Hellmann-Feynman theorem as applied in first-principles calculations. The model correctly orders the zero temperature energies of all zirconia polymorphs. The Zr-O matrix elements of the Hamiltonian, which measure covalency, make a greater contribution than the polarizability to the energy differences between phases. Results for elastic constants of the cubic and tetragonal phases and phonon frequencies of the cubic phase are also presented and compared with some experimental data and first-principles calculations. We suggest that the model will be useful for studying finite temperature effects by means of molecular dynamics.
Original languageEnglish
Pages (from-to)6617-6630
Number of pages14
JournalPhysical Review B (Condensed Matter)
Volume61
Issue number10
DOIs
Publication statusPublished - 01 Mar 2000

ASJC Scopus subject areas

  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Relative energetics and structural properties of zirconia using a self-consistent tight-binding model'. Together they form a unique fingerprint.

  • Cite this