Revealing atomic-scale vacancy-solute interaction in nickel

• DOI: 10.1016/j.scriptamat.2021.114036
• Publication Date: 2021-06-11T09:37:28Z
• Authors: Felipe F. Morgado; Shyam Katnagallu; Christoph Freysoldt; Benjamin Klaes; François Vurpillot; Jörg Neugebauer; Dierk Raabe; Steffen Neumeier; Baptiste Gault; Leigh T. Stephenson
• Keywords: Atom probe; Field ion microscope; Microanalysis; Atomic units

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