  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.
