Infinite-layer nickelates
The recent discovery of superconductivity in nickel-oxide systems has been the result of a decades-long search and has sparked great excitement, as well as numerous experimental and theoretical studies that aim to understand these systems further [1]. So far, superconducting nickel-oxides have been stabilised in thin-film form. This is done by depositing a perovskite rare-earth nickelate RNiO3 (R = Nd, Pr, La) hole-doped with Sr or Ca, and reducing it to the infinite-layer phase using a soft chemistry process called topotactic reduction [2,3].
In Geneva, we synthesise rare-earth nickelate thin films and heterostructures using off-axis RF magnetron sputtering and we research novel ways to dope these systems. Benefiting from fruitful international collaborations, we use topotactic reduction to reach the infinite-layer phase and study the electronic properties of this phase.
[1] D. Li et al, Nature 572, 624-627 (2019)
[2] M. A. Hayward et al, J. Am. Chem. Soc. 121, 8843-8854 (1999)
[3] M. Kawai et al, Appl. Phys. Lett. 94, 082102 (2009)
Main researchers
Lucia Varbaro, Lukas Korosec