Quantitative three-dimensional imaging of chemical short-range order via machine learning enhanced atom probe tomography.

Li, Yue; Wei, Ye; Wang, Zhangwei; Liu, Xiaochun; Colnaghi, Timoteo; Han, Liuliu; Rao, Ziyuan; Zhou, Xuyang et al. · Nat Commun · 2023

basic_science · Level V

Where this comes from

Abstract

Chemical short-range order (CSRO) refers to atoms of specific elements self-organising within a disordered crystalline matrix to form particular atomic neighbourhoods. CSRO is typically characterized indirectly, using volume-averaged or through projection microscopy techniques that fail to capture the three-dimensional atomistic architectures. Here, we present a machine-learning enhanced approach to break the inherent resolution limits of atom probe tomography enabling three-dimensional imaging of multiple CSROs. We showcase our approach by addressing a long-standing question encountered in body-centred-cubic Fe-Al alloys that see anomalous property changes upon heat treatment. We use it to evidence non-statistical B<sub>2</sub>-CSRO instead of the generally-expected D0<sub>3</sub>-CSRO. We introduce quantitative correlations among annealing temperature, CSRO, and nano-hardness and electrical resistivity. Our approach is further validated on modified D0<sub>3</sub>-CSRO detected in Fe-Ga. The proposed strategy can be generally employed to investigate short/medium/long-range ordering phenomena in different materials and help design future high-performance materials.