Eu Self-Doping Induced Superconductivity in NENO Thin Films Using In-Situ Synthesis

First observed in 2019, the superconducting infinite-layer-nickelates represent a novel class of unconventional superconductors that are spurring intense research interest due to their electronic and structural similarities to cuprate superconductors. One well known challenge to studying these materials is the ability to synthesize these materials. The common approach is to synthesize alkaline-earth-doped high-valance perovskite nickelate and conduct a topotactical reduction, a testament to the remarkable achievements to date.<br/>In this talk, we apply an all-<i>in-situ</i> synthesis thin film processing technique to induce superconductivity in a new nickelate composition. This technique relies on the unique properties of Eu and its 4<i>f</i> electrons as a dopant and uses metallic Al deposited on top of thin film Nd_1-xEu_xNiO₃ to reduce the samples to the superconducting phase. The resulting Nd_1-xEu_xNiO₂ has an onset superconducting temperature as high as 21K and an unusually large upper critical magnetic field.<br/>Work at Yale University was supported by the US DOE, Office of Science, Office of Basic Energy Sciences under award no. DE-SC0019211.