The state of Fe3+ in the C–F–A–S–H system with varying Fe/Si and Ca/Si ratios

Synthetic CaO–Fe 2 O 3 –Al 2 O 3 –SiO 2 –H 2 O (C–F–A–S–H) gels with Fe/Si and Ca/Si ratios in the ranges 1/8–1/4 and 1.0–2.0, respectively, are investigated to reveal the coordination, location, and doping configuration of Fe 3+ .