Synthesis of Superconducting Bilayer Nickelate Thin Films

Recently, several Ruddlesden-Popper-type nickelates have been discovered to exhibit superconductivity in their bulk crystal form under high-pressure conditions^1-3. This naturally raises the question of whether superconductivity can be achieved in thin films subjected to compressive epitaxial strain, mimicking the effects of high pressure. However, two major challenges arise in the synthetic process. First, the growth window for bilayer nickelate is very narrow. Second, epitaxial strain may introduce structural disorder into the films. In this talk, I will focus on our efforts to explore this possibility by growing bilayer nickelate thin films using pulsed laser deposition and present various strategies we employed to overcome these obstacles.