Delhi iron pillar rust characterization by mossbauer spectroscopy analysis

Rust samples from the region just below the decorative bell capital of the Delhi iron pillar have been analysed by Mossbauer spectroscopy. The analysis indicates that they contain -FeO-OH, superparamagnetic -FeO-OH and magnetite, all in the amorphous form. The Mossbauer spectrum also confirmed that the iron in the crystalline iron hydrogen phosphate hydrate (whose presence was confirmed by XRD analysis) is in the ferric state indicating that it is a stable end corrosion product