Suppression of magnetism and Seebeck effect in Na0.875CoO2 induced by SbCo dopants

M. H.N. Assadi, Paolo Mele, Marco Fronzi

Research output: Contribution to journalArticle

Abstract

We examined the electronic property of Sb-doped Na0.785CoO2 using density functional calculations based on GGA+U formalism. We demonstrated that Sb dopants were the most stable when replacing Co ions within the complex Na0.875CoO2 lattice structure. We also showed that the SbCo dopants adopted the + 5 oxidation state introducing two electrons into the host Na0.875CoO2 compound. The newly introduced electrons recombined with holes that were borne on Co4+ sites that had been created by sodium vacancies. The elimination of Co4+ species, in turn, rendered Na0.875(Co0.9375Sb0.0625)O2 non-magnetic and diminished the compound’s thermoelectric effect. Furthermore, the SbCo dopants tended to aggregate with the Na vacancies keeping a minimum distance. The conclusions drawn here can be generalised to other highly oxidised dopants in NaxCoO2 that replace a Co.

Original languageEnglish
Article number5
JournalMaterials for Renewable and Sustainable Energy
Volume9
Issue number1
DOIs
Publication statusPublished - 2020 Mar 1

Keywords

  • Density functional theory
  • Magnetism
  • Sb dopant
  • Sodium cobaltate
  • Thermoelectric effect

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Suppression of magnetism and Seebeck effect in Na<sub>0.875</sub>CoO<sub>2</sub> induced by Sb<sub>Co</sub> dopants'. Together they form a unique fingerprint.

  • Cite this