Superconducting Praseodymium Nickelate Thin Films via a Soft Chemistry Approach*

A variety of nickel oxide compounds have long been studied for their manifestation of various correlated electron phenomena due to their analogous electronic or atomic structure to cuprates. Recently, superconductivity was observed in nanoscale infinite layer nickelate thin films of Nd_0.8Sr_0.2NiO₂, epitaxially stabilized on SrTiO₃ substrates via topotactic reduction from the perovskite precursor phase [1-4]. Here we present the synthesis and properties of PrNiO₂ thin films on SrTiO₃. Upon doping in Pr_0.8Sr_0.2NiO₂, we observe superconductivity with a transition temperature of 7-12 K, and robust critical current density at 2 K of 334 kA/cm² [5]. These findings indicate that superconductivity in the infinite layer nickelates is relatively insensitive to the details of the rare earth 4f configuration. Furthermore, they motivate the exploration of a broader family of compounds based on two-dimensional NiO₂ planes.

[1] D. Li et al., Nature 572, 624 (2019).
[2] K. Lee et al., APL Mater. 8, 041107 (2020).
[3] D. Li et al., Phys. Rev. Lett. 125, 027001 (2020).
[4] S. Zeng et al., Phys. Rev. Lett. 125, 147003 (2020).
[5] M. Osada et al., Nano Lett. 20, 5735 (2020).