Modeling charge-imbalanced NaNbO3/SrTiO3 superlattices: Lattice relaxation and metallicity

Thumbnail Image

Files

PhysRevB.80.205420.pdf (6.3 MB)

Access rights

openAccess
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
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

Department

Department of Applied Physics

Major/Subject

Mcode

Degree programme

Language

en

Pages

Series

Physical Review B, Volume 80, issue 20, pp. 1-12

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

DOI

10.1103/PhysRevB.80.205420

Citation

Oja, R & Nieminen, R M 2009, 'Modeling charge-imbalanced NaNbO3/SrTiO3 superlattices: Lattice relaxation and metallicity', Physical Review B, vol. 80, no. 20, 205420, pp. 1-12. https://doi.org/10.1103/PhysRevB.80.205420

Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-202510087682

Collections

[article-cris] Perustieteiden korkeakoulu / SCI