Pressure-induced linear enhancement of the superconducting transition in Nd0.8Sr0.2NiO2 thin films.

We report the pressure (P) effect on the superconducting transition temperature Tc and the upper critical field μ0Hc2 of infinite-layer Nd0.8Sr0.2NiO2 thin films by measuring the electrical transport properties under various hydrostatic pressures to 4.6 GPa. At ambient pressure, it shows the clear superconducting transition with Tc ~ 10 K. Based on the evolution of resistance R(T), we found that the Tc is monotonically enhanced to ~ 14 K upon increasing pressure to 2.9 GPa. The constructed temperature-pressure phase diagram indicates that the calculated slope dTc/dP is about 1.14 K/GPa and the superconducting Tc shows no signatures of saturation with pressure. It thus gives the possibility to further enhance Tc by employing higher pressures or heterostructure engineering. In addition, the normalized slope of upper critical field μ0Hc2(0) implies that the electron correlations are gradually decreasing with pressure, which exhibits an opposite evolution with superconducting Tc. Our work further confirms the positive pressure effects in nickelate superconductors and gives more insight to further enhance its superconducting transition temperature.&#xD.