Superconductivity in PrNiO<sub>2</sub> Infinite-Layer Nickelates.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40059509.
- Also identified by DOI 10.1002/adma.202416187 and PMC identifier 12016738.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Several reports about infinite-layer nickelate thin films suggest that the superconducting critical temperature versus chemical doping phase diagram has a dome-like shape, similar to cuprates. Here, a highly reproducible superconducting state in undoped PrNiO<sub>2</sub> thin films grown on SrTiO<sub>3</sub> are demonstrated. Scanning transmission electron microscopy measurements show coherent infinite-layer phase with no visible stacking-fault defects, an overall high structural quality where possible unintentional chemical doping or interstitial oxygen, if present, sum well below the measurable threshold of the technique. X-ray absorption measurements show very sharp features at the Ni L<sub>3,2</sub>-edges with a large linear dichroism, indicating the preferential hole occupation of Ni<sup>1+</sup>-3 <math xmlns="http://www.w3.org/1998/Math/MathML"> <semantics><msub><mi>d</mi> <mrow><msup><mi>x</mi> <mn>2</mn></msup> <mo>-</mo> <msup><mi>y</mi> <mn>2</mn></msup> </mrow> </msub> <annotation>${\rm d}_{x^2-y^2}$</annotation></semantics> </math> orbitals in a square planar geometry. Resonant inelastic X-ray scattering measurements reveal sharp magnon excitations of 200 meV energy at the magnetic Brillouin zone boundary, highly resonant at the Ni<sup>1 +</sup> absorption peak. The results indicate that, when properly stabilized, infinite-layer nickelate thin films are superconducting without chemical doping.