Edith Simmen^1*, Nicola A. Spaldin^1*

1 Materials Theory, ETH Zurich, 8093 Zurich, Switzerland

* Corresponding authors emails: edith.simmen@mat.ethz.ch, nicola.spaldin@mat.ethz.ch

DOI10.24435/materialscloud:gy-nd [version v1]

Publication date: Apr 07, 2025

How to cite this record

Edith Simmen, Nicola A. Spaldin, Interplay of metallicity, ferroelectricity and layer charges in SmNiO₃/BaTiO₃ superlattices, Materials Cloud Archive 2025.54 (2025), https://doi.org/10.24435/materialscloud:gy-nd

Description

Using density-functional theory, we demonstrate that the formal layer charges of the metallic samarium nickelate electrode influence the spontaneous ferroelectric polarization of the barium titanate in SmNiO₃/BaTiO₃ capacitors. We find that, despite the metallic screening of SmNiO₃, the spontaneous polarization of BaTiO₃ always aligns with the layer polarization of the SmNiO₃ formal charges. We also find zero critical thickness for the ferroelectricity in BaTiO₃ in this orientation. The opposite polarization direction is highly disfavored for thin BaTiO₃ slabs but becomes less unstable with increasing slab thickness. We construct a simple electrostatic model that allows us both to study the behavior for thicker BaTiO₃ and SmNiO₃ slabs and to extract the influence of various material parameters on the behavior. We mimic a metal-insulator transition in the SmNiO₃ by varying the metallic screening length, which we find influences the stability of the ferroelectric polarization. Our results show that layer charges in the metal electrodes strongly influence the properties of ferroelectric capacitors and can even provide new ways to control them.

Materials Cloud sections using this data

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File name	Size	Description
met-sno_bto_data.zip MD5md5:ba813be09299a7803f07b5d973251e5e	723.0 MiB	Compressed archive with necessary input and output files for publication
README.txt MD5md5:7d8cbc6ff62f2c2db4d93707784bac02	4.3 KiB	README file with description of the data

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External references

Keywords

SNSF DFT ferroelectricity polar discontinuity