Revealing atomic-scale vacancy-solute interaction in nickel

Imaging individual vacancies in solids and revealing their interactions with solute atoms remains one of the frontiers microscopy microanalysis. Here we study a creep-deformed binary Ni-2 at.% Ta alloy. Atom probe tomography reveals random distribution Ta. Field ion microscopy, contrast interpretation supported by density-functional theory time-of-flight mass spectrometry, evidences positive correlation tantalum vacancies. Our results support solute-vacancy binding, which explains improvement creep resistance Ta-containing Ni-based superalloys helps guide future material design strategies.