Superconducting Nd1-xEuxNiO2 thin films using in situ synthesis

Abstract

We report on superconductivity in Nd1-xEuxNiO2 using Eu as a 4f dopant of the parent NdNiO2 infinite-layer compound. We use an all-in situ molecular beam epitaxy reduction process to achieve the superconducting phase, providing an alternate method to the ex situ CaH2 reduction process to induce superconductivity in the infinite-layer nickelates. The Nd1-xEuxNiO2 samples exhibit a step-terrace structure on their surfaces, have a Tc onset of 21 K at x = 0.25, and have a large upper critical field that may be related to Eu 4f doping.