fig7

Figure 7. High-resolution XPS spectra of the corroded surface on Cr0 (A1-A4), Cr0.6 (B1-B5), Cr1 (C1-C5), and Cr1.5 (D1-D5) HEAs after polarization in a 0.5 M H2SO4 solution at room temperature. (A1-D1) Co 2p3/2; (A2-D2) Fe 2p3/2; (A3-D3) Mn 2p3/2; (A4-D4) Ni 2p3/2; and (B5-D5) Cr 2p3/2. XPS: X-ray photoelectron spectroscopy.