Pressure-induced monotonic enhancement of T(c) to over 30 K in superconducting Pr(0.82)Sr(0.18)NiO(2) thin films

The successful synthesis of superconducting infinite-layer nickelate thin films with the highest T(c) ≈ 15 K has ignited great enthusiasm for this material class as potential analogs of the high-T(c) cuprates. Pursuing a higher T(c) is always an imperative task in studying a new superconducting material system. Here we report high-quality Pr(0.82)Sr(0.18)NiO(2) thin films with T(c)(onset) ≈ 17 K synthesized by carefully tuning the amount of CaH(2) in the topotactic chemical reduction and the effect of pressure on its superconducting properties by measuring electrical resistivity under various pressures in a cubic anvil cell apparatus. We find that the onset temperature of the superconductivity, T(c)(onset), can be enhanced monotonically from ~17 K at ambient pressure to ~31 K at 12.1 GPa without showing signatures of saturation upon increasing pressure. This encouraging result indicates that the T(c) of infinite-layer nickelates superconductors still has room to go higher and it can be further boosted by applying higher pressures or strain engineering in the heterostructure films.