The recent discovery of superconductivity in infinite-layer (IL, ABO2) nickelates has opened a new avenue to deepen the understanding of high-temperature superconductivity. However, progress in this field is slowed by significant challenges in material synthesis and the scarcity of research groups capable of producing high quality superconducting samples. IL nickelates are obtained from a reduction of the perovskite ABO3 phase, typically achieved by annealing using CaH2 as a reducing agent. Here, we present a new method to synthesize superconducting infinite-layer nickelate Pr0.8Sr0.2NiO2 thin films using an aluminum overlayer deposited by sputtering as a reducing agent. We systematically optimized the aluminum deposition parameters and obtained superconducting samples reduced either in situ or ex situ (after air exposure of the precursor ABO3 films). A comparison of their crystalline quality and transport properties shows that in situ Al reduction enhances the quality of the superconducting Pr0.8Sr0.2NiO2 thin films, achieving a maximum superconducting transition temperature Tconset of 17 K, in agreement with the optimum value reported for this compound. This simple synthesis route, much more accessible than existing methods, offers better control and reproducibility over the topotactic transformation, opening new opportunities to gain insights into the physics of superconductivity in nickelates.
@article{arxiv.2411.04896,
title = {Achieving superconductivity in infinite-layer nickelate thin films by aluminum sputtering deposition},
author = {Dongxin Zhang and Aravind Raji and Luis M. Vicente-Arche and Alexandre Gloter and Manuel Bibes and Lucía Iglesias},
journal= {arXiv preprint arXiv:2411.04896},
year = {2026}
}