A superconducting praseodymium nickelate with infinite layer structure

TL;DR

This paper reports the synthesis of PrNiO₂ thin films and demonstrates superconductivity with transition temperatures of 7-12 K, expanding the family of infinite layer nickelates and providing insights into their superconducting properties.

Contribution

It introduces PrNiO₂ as a new superconducting infinite layer nickelate and shows its properties are similar to other rare-earth variants, broadening the scope of nickelate superconductors.

Findings

Superconductivity observed in PrNiO₂ with Tc of 7-12 K

High critical current density of 334 kA/cm² at 2 K

Superconductivity relatively insensitive to rare earth 4f configuration

Abstract

A variety of nickel oxide compounds have long been studied for their manifestation of various correlated electron phenomena. Recently, superconductivity was observed in nanoscale infinite layer nickelate thin films of Nd$_{0.8}$Sr$_{0.2}$NiO$_2$, epitaxially stabilized on SrTiO$_3$ substrates via topotactic reduction from the perovskite precursor phase. Here we present the synthesis and properties of PrNiO$_2$ thin films on SrTiO$_3$. Upon doping in Pr$_{0.8}$Sr$_{0.2}$NiO$_2$, we observe superconductivity with a transition temperature of 7-12 K, and robust critical current density at 2 K of 334 kA/cm$^2$. These findings indicate that superconductivity in the infinite layer nickelates is relatively insensitive to the details of the rare earth 4$f$ configuration. Furthermore, they motivate the exploration of a broader family of compounds based on two-dimensional NiO$_2$ planes, which will enable systematic investigation of the superconducting and normal state properties and their underlying mechanisms.