Superstructures in insulating and metallic lanthanum-doped sodium cobaltate

DOI

The thermoelectric properties of NaxCoO2 can be substantially improved by replacing Na ions by cations of higher valence. Our neutron diffraction studies on SXD for doping with divalent ions, NaxCayCoO2, directly link the superstructures to the thermoelectric properties. We now propose to study two very different systems doped with trivalent ions, NaxLayCoO2. For Na0.57La0.14CoO2, the combination of Na vacancies and trivalent La ions leads to a cancelation of the Coulomb potential in the CoO2 layers, and the sample adopts the insulating alpha-NaCoO2 structure. For Na0.7La0.1CoO2, the superstructure is believed to lead to a much larger modulation of the Coulomb potential in the CoO2 layers than for the pure compound, and the sample is metallic with the gamma-NaxCoO2 structure. We shall determine the superstructures in each case using neutron Laue diffraction on SXD.

Identifier
DOI https://doi.org/10.5286/ISIS.E.24089663
Metadata Access https://icatisis.esc.rl.ac.uk/oaipmh/request?verb=GetRecord&metadataPrefix=oai_datacite&identifier=oai:icatisis.esc.rl.ac.uk:inv/24089663
Provenance
Creator Professor Jon Goff; Dr Dan Porter; Dr Uthayakumar Sivaperumal; Dr David Voneshen; Dr Michel Roger; Mr Eron Cemal; Mr Toby Willis; Mr Manoj Soundhira Pandiyan
Publisher ISIS Neutron and Muon Source
Publication Year 2016
Rights CC-BY Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Contact isisdata(at)stfc.ac.uk
Representation
Resource Type Dataset
Discipline Photon- and Neutron Geosciences
Temporal Coverage Begin 2012-10-04T10:15:04Z
Temporal Coverage End 2013-03-06T06:57:19Z