Disentangling types of lattice disorder impacting superconductivity in Sr₂RuO₄ by quantitative local probes

The unconventional superconductivity in Sr 2 RuO 4 is infamously susceptible to suppression by small levels of disorder such that it has been most commonly studied extremely high-purity bulk crystals. Here, we harness local structural and spectroscopic scanning transmission electron microscopy measurements epitaxial thin films disentangle the impact different types crystalline on superconductivity. We find cation off-stoichiometry during growth gives rise two distinct disorder: mixed-phase inclusions accommodate excess ruthenium vacancies when ruthenium-deficient. Several superconducting host intergrowths, suggesting this microstructural relatively little In a non-superconducting film, other hand, measure high density ruthenium-vacancies [Formula: see text] with no significant reduction crystallinity film. results suggest vacancy disorder, which hidden many probes, plays an important role suppressing discuss broader implications our findings guide future synthesis layered systems.