Fig. 3.

Real- and reciprocal-space analyses. (A) Experimental PDFs for samples with aging times t = 0 h (Lower) to 14 h (Upper). (B) Individual PDFs for fh, ferrifh, and hm obtained by the MCR method for the three phases (Circles). Calculated fits for ferrihydrite or hematite overlain (Red) with difference plots below (Gray). (C) Comparison of the reciprocal-space scattering data at t = 8 h (Circles) with calculated diffraction profiles (Lines) based on fits of the PDF for ferrifh with models for (i) ferrihydrite, (ii) maghemite, and (iii) magnetite (∗= hematite).