Abstract
Using a combination of density functional theory calculations with an on-site Coulomb repulsion term () and Boltzmann transport theory within the constant relaxation time approximation, we explore the effect of oxygen vacancies on the electronic, magnetic, and thermoelectric properties in ultrathin superlattices (SLs). For the pristine SL (), an antiferromagnetic charge-disproportionated (AFM-CD) ( phase is stabilized, irrespective of strain. At and 0.25, the localization of electrons released from the oxygen defects in the plane triggers a charge-disproportionation, leading to a ferrimagnetic insulator both at (tensile strain) and (compressive strain). At , an insulating phase emerges with alternating stripes of (high-spin) and (low-spin) and oxygen vacancies ordered along the [110] direction (S-AFM), irrespective of strain. This results in a robust -type in-plane power factor of cm at and cm at at 300 K (assuming relaxation time fs). Additionally, the pristine and = 0.5 SLs are shown to be dynamically stable. This demonstrates the fine tunability of electronic, magnetic, and thermoelectric properties of ultrathin nickelate superlattices by oxygen vacancies.
9 More- Received 26 October 2022
- Revised 16 November 2023
- Accepted 4 December 2023
DOI:https://doi.org/10.1103/PhysRevResearch.6.013189
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Published by the American Physical Society