Comparison of iron photoelectron spectra. Normalized high-resolution Fe 2p_3/2 photoelectron spectra of C0242 and A0226 particles. The Fe 2p_3/2 peak for A0226 is slightly shifted toward low BE compared to C0242. A decrease of about 10% in the Fe³⁺/ΣFe_tot ratio for the A0226 was estimated using the procedure of Biesinger et al. (2015), suggesting a more reduced environment on the A0226 surface.