Fig. 3: Three-dimensional compositional distributions of the dual-phase fcc/D0₁₉ UFG architecture in the CR750 alloy.

a Three-dimensional reconstruction map of a typical atom probe tomography tip showing the distribution of each element. The fcc/D0₁₉ interface is highlighted using iso-composition surfaces containing 18 at.% V and 18 at.% Cr. b one-dimensional compositional profiles computed along the white arrow in (a), showing the compositional changes across the interface. Error bars refer to the standard deviations of the counting statistics in each bin of the profiles. Standard error s is calculated as: \({{\mbox{s}}}=\sqrt{\frac{{{c}}_{{i}}\left(1\,- \, {{c}}_{{i}}\right)}{{{n}}_{{t}}}}\) in which n_t is the total number of ions in the sample, and c_i is the concentration in atomic fraction of solute i in the sample, which is calculated as: \({{\mbox{c}}}_{i}=\frac{{{\mbox{n}}}_{{\mbox{i}}}}{{{\mbox{n}}}_{{\mbox{t}}}}\) in which n_i is the number of ions of solute i in the sample. c Ordered crystallographic structure and site occupancies of the D0₁₉ phase viewed along the c-axis direction by density functional theory calculations. d Atomic arrangement in the (0001) planes of the D0₁₉ phase with a (Ni, Co, Cr)₃V stoichiometry. Large circles represent atoms in the A-layer, the plane of the paper, and small circles represent atoms in the B-layer, immediately below the A-layer. Source data for (b) are provided as a Source data file.