Contrasting Ferromagnetism in Pyrite FeS2 Induced by Chemical Doping versus Electrostatic Gating

Ezra Day-Roberts, Turan Birol, Rafael M. Fernandes

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Recent advances in electrostatic gating provide a novel way to modify the carrier concentration in materials via electrostatic means instead of chemical doping, thus minimizing the impurity scattering. Here, we use first-principles Density Functional Theory combined with a tight-binding approach to compare and contrast the effects of electrostatic gating and Co chemical doping on the ferromagnetic transition of FeS$_2$, a transition metal disulfide with the pyrite structure. Using tight-binding parameters obtained from maximally-localized Wannier functions, we calculate the magnetic susceptibility across a wide doping range. We find that electrostatic gating requires a higher electron concentration than the equivalent in Co doping to induce ferromagnetism via a Stoner-like mechanism. We attribute this behavior to the formation of a narrow Co band near the bottom of the conduction band under chemical doping, which is absent in the electrostatic gating case. Our results reveal that the effects of electrostatic gating go beyond a simple rigid band shift, and highlight the importance of the changes in the crystal structure promoted by gating.
Original languageEnglish (US)
Article number054405
JournalPhysical Review Materials
Volume4
Issue number5
DOIs
StatePublished - May 2020

Bibliographical note

Funding Information:
We thank C. Leighton and J. Walter for useful discussions. This work was supported by the National Science Foundation through the UMN MRSEC under Grant No. DMR-1420013. The authors acknowledge the Minnesota Supercomputing Institute (MSI) at the University of Minnesota for providing resources that contributed to the research results reported within this paper.

Publisher Copyright:
© 2020 American Physical Society.

Keywords

  • cond-mat.mtrl-sci

How much support was provided by MRSEC?

  • Primary

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