Examining Growth Rates of Iron Oxide Heterogeneous Phase Transformations

Materials and Methods 6-line ferrihydrite, goethite, and hematite were synthesized and adjusted to pH 5. Samples of ferrihydrite and were spiked with goethite and hematite to make the ratios: 0% goethite/0% hematite (Fh), 4% goethite/0% hematite (4Gt), 4% goethite/3.5% hematite (4Gt/3.5Ht), and 0% goethite/3.5% hematite (3.5Ht) Samples were aged in a 90°C oven and taken out at various timepoints over a course of 6 days. After aging, the samples were dried and ground with pestle and mortar for analysis via Xray diffraction (XRD). Determining Phase Transformations Using XRD