Epitaxial strain and structural engineering of superconductivity in square-planar nickelate thin films

20.06.2024 11:00 – 12:30

The discovery of superconductivity in Sr-doped NdNiO2 thin films reignited interest in the nickelates as cuprate analogues [1]. The infinite-layer nickelates, RNiO2 (R = rare-earth cation), are the n = ∞ member of a homologous series of ‘layered square-planar’, or T’-type, nickelates, Rn+1NinO2n+2. In this structural series, the layering n tunes the nominal nickel 3d electron count, 9-1/n, as well as the electronic dimensionality. While higher-order nickelates (n > 3) are inaccessible by bulk synthetic methods, our group leverages the atomic precision offered by molecular beam epitaxy to synthesize Ndn+1NinO2n+2 films from n = 2 to n = 10. Indeed, we observed superconductivity in five-layer Nd6Ni5O12 thin films in the absence of chemical doping [2]. In this talk, I will discuss our efforts to tune superconductivity in T’ nickelates via epitaxial strain [3] and structural dimensionality, n.


[1] Li, D. et al. Superconductivity in an infinite-layer nickelate. Nature 572, 624–627 (2019).

[2] Grace Pan, Dan Ferenc Segedin, et al. Superconductivity in a quintuple-layer square-planar nickelate. Nat Mater 1–5 (2021).

[3] Dan Ferenc Segedin*, Berit H. Goodge*, et al. Limits to the strain engineering of layered square-planar nickelate thin films. Nat. Commun. 14, 1468 (2023).

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Bâtiment: Ecole de Physique

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