Skip to main content

The net charge at interfaces between insulators

Bristowe, N. C., Littlewood, P. B., Artacho, Emilio (2011) The net charge at interfaces between insulators. Journal of Physics: Condensed Matter, 23 (8). 081001 -081006. ISSN 0953-8984. (doi:10.1088/0953-8984/23/8/081001)

PDF - Author's Accepted Manuscript
Download (435kB) Preview
[img]
Preview
Official URL
http://dx.doi.org/10.1088/0953-8984/23/8/081001

Abstract

The issue of the net charge at insulating oxide interfaces is briefly reviewed with the ambition of dispelling myths of such charges being affected by covalency and related charge density effects. For electrostatic analysis purposes, the net charge at such interfaces is defined by the counting of discrete electrons and core ion charges, and by the definition of the reference polarization of the separate, unperturbed bulk materials. The arguments are illustrated for the case of a thin film of LaAlO3 over SrTiO3 in the absence of free carriers, for which the net charge is exactly 0.5e per interface formula unit, if the polarization response in both materials is referred to zero bulk values. Further consequences of the argument are extracted for structural and chemical alterations of such interfaces, in which internal rearrangements are distinguished from extrinsic alterations (changes of stoichiometry, redox processes), only the latter affecting the interfacial net charge. The arguments are reviewed alongside the proposal of Stengel and Vanderbilt (2009 Phys. Rev. B 80 241103) of using formal polarization values instead of net interfacial charges, based on the interface theorem of Vanderbilt and King-Smith (1993 Phys. Rev. B 48 4442-55). Implications for non-centrosymmetric materials are discussed, as well as for interfaces for which the charge mismatch is an integer number of polarization quanta.

Item Type: Article
DOI/Identification number: 10.1088/0953-8984/23/8/081001
Subjects: Q Science > QC Physics > QC173.45 Condensed Matter
Q Science > QC Physics > QC176 Solid state physics
Q Science > QD Chemistry > QD478 Solid State Chemistry
Q Science > QD Chemistry > QD473 Physical properties in relation to structure
Divisions: Faculties > Sciences > School of Physical Sciences
Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Nicholas Bristowe
Date Deposited: 21 Feb 2017 15:37 UTC
Last Modified: 29 May 2019 18:39 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/60264 (The current URI for this page, for reference purposes)
Bristowe, N. C.: https://orcid.org/0000-0003-1286-8440
  • Depositors only (login required):

Downloads

Downloads per month over past year