Modeling charge-imbalanced NaNbO3/SrTiO3 superlattices: Lattice relaxation and metallicity
Loading...
Access rights
© 2009 American Physical Society (APS). This is the accepted version of the following article: Oja, Riku & Nieminen, Risto M. 2009. Modeling charge-imbalanced NaNbO3/SrTiO3 superlattices: Lattice relaxation and metallicity. Physical Review B. Volume 80, Issue 20. 205420/1-12. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.80.205420, which has been published in final form at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.80.205420.
URL
Journal Title
Journal ISSN
Volume Title
School of Science |
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Unless otherwise stated, all rights belong to the author. You may download, display and print this publication for Your own personal use. Commercial use is prohibited.
Authors
Date
2009
Major/Subject
Mcode
Degree programme
Language
en
Pages
205420/1-12
Series
Physical Review B, Volume 80, Issue 20
Abstract
The electronic and structural properties of different charge-imbalanced perovskite oxide NaNbO3/SrTiO3 superlattices are investigated with density-functional theory (local density approximation and local spin density approximation+U) methods. Metallic or insulating behavior of such a superlattice depends on the types of interfaces present: nonstoichiometric composition of a superlattice introduces holes to O p orbitals or extra electrons to Nb/Ti d orbitals. Lattice parameters, superlattice volume, and the extent of conduction electron or hole states are found to depend on interface type. The extent of the metallic state may also depend on the NaNbO3/SrTiO3 ratio. Octahedral rotations and other low-symmetry phases increase the gap between p and d orbitals but do not affect metallicity. Adding a Hubbard U to account for possible electronic correlations does not affect electron localization. Within LSDA+U, the delocalized holes align ferromagnetically.Description
Keywords
conduction bands, density functional theory, lattice constants, sodium compounds, stoichiometry, strontium compounds, superlattices
Other note
Citation
Oja, Riku & Nieminen, Risto M. 2009. Modeling charge-imbalanced NaNbO3/SrTiO3 superlattices: Lattice relaxation and metallicity. Physical Review B. Volume 80, Issue 20. 205420/1-12. ISSN 1550-235X (electronic). DOI: 10.1103/physrevb.80.205420.