Fig. 3: CSRO and chemical mapping of the dual phase medium entropy alloy CuAuAg.

a HR-HAADF image of the Cu-rich region with the [110] zone axis and the corresponding FFT pattern (inset). b Inverse FFT image showing the CSRO regions, which exhibit a lattice spacing approximately twice that of the perfect FCC lattice. c Atomic mapping of L1₂ region in CuAuAg MEA Cu-rich phase. d Pair probabilities and CSRO parameters correspond to the first nearest neighbors calculated by CVM, percentages of Cu and Au and Ag are 0.73, 0.21 and 0.06, respectively. e–g Atomic resolution mapping of Cu-Au pair, Cu-Ag pair, and Au-Ag pair in L1₂ region of Cu-rich phase, the scale bars in (e–g) are identical. h 3DAP images of Cu, Au, Ag elements. i Element distribution of 3DAP near the phase boundary between Cu-rich and Ag-rich phases. j Component fluctuations in Cu-rich phase represents a signature of L1₂ strips, the specific iso-concentration surfaces are defined at 60 at%.