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

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

doi:10.1007/s40243-020-0165-9

Suppression of magnetism and Seebeck effect in Na_0.875CoO₂ induced by Sb_Co dopants

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

Research output: Contribution to journal › Article › peer-review

3 Citations (Scopus)

Abstract

We examined the electronic property of Sb-doped Na_0.785CoO₂ 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 Na_0.875CoO₂ lattice structure. We also showed that the Sb_Co dopants adopted the + 5 oxidation state introducing two electrons into the host Na_0.875CoO₂ 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 Na_0.875(Co_0.9375Sb_0.0625)O₂ non-magnetic and diminished the compound’s thermoelectric effect. Furthermore, the Sb_Co 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 Na_xCoO₂ that replace a Co.

Original language	English
Article number	5
Journal	Materials for Renewable and Sustainable Energy
Volume	9
Issue number	1
DOIs	https://doi.org/10.1007/s40243-020-0165-9
Publication status	Published - 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

Access to Document

10.1007/s40243-020-0165-9

Cite this

@article{6b47f19c5a3a4c58b0cdc3010f5b6bfc,

title = "Suppression of magnetism and Seebeck effect in Na0.875CoO2 induced by SbCo dopants",

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{\textquoteright}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.",

keywords = "Density functional theory, Magnetism, Sb dopant, Sodium cobaltate, Thermoelectric effect",

author = "Assadi, {M. H.N.} and Paolo Mele and Marco Fronzi",

note = "Funding Information: This work was supported by the Australian Research Council. The simulation facility was provided by Australian National Computational Infrastructure and Intersect Ltd. Publisher Copyright: {\textcopyright} 2020, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",

year = "2020",

month = mar,

day = "1",

doi = "10.1007/s40243-020-0165-9",

language = "English",

volume = "9",

journal = "Materials for Renewable and Sustainable Energy",

issn = "2194-1459",

publisher = "Springer International Publishing AG",

number = "1",

}

TY - JOUR

T1 - Suppression of magnetism and Seebeck effect in Na0.875CoO2 induced by SbCo dopants

AU - Assadi, M. H.N.

AU - Mele, Paolo

AU - Fronzi, Marco

N1 - Funding Information: This work was supported by the Australian Research Council. The simulation facility was provided by Australian National Computational Infrastructure and Intersect Ltd. Publisher Copyright: © 2020, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2020/3/1

Y1 - 2020/3/1

N2 - 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.

AB - 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.

KW - Density functional theory

KW - Magnetism

KW - Sb dopant

KW - Sodium cobaltate

KW - Thermoelectric effect

UR - http://www.scopus.com/inward/record.url?scp=85078238987&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85078238987&partnerID=8YFLogxK

U2 - 10.1007/s40243-020-0165-9

DO - 10.1007/s40243-020-0165-9

M3 - Article

AN - SCOPUS:85078238987

SN - 2194-1459

VL - 9

JO - Materials for Renewable and Sustainable Energy

JF - Materials for Renewable and Sustainable Energy

IS - 1

M1 - 5

ER -