Mössbauer analysis of iron compounds in the Earth’s soils and some soil from mars

Water Vapor Diffusion into a Nanostructured Iron Oxyhydroxide

“…Akaganéite (β-FeOOH·(HCl) 0.11–0.19 ) − is an iron oxyhydroxide mineral with a hollandite-type structure that consists of 0.4 nm × 0.4 nm wide tunnels that are capable of exchanging with various ions and water molecules ,− from surrounding media (Figure ). This mineral occurs naturally in chloride-rich environments, such as oceans, saline lakes, hot brines, mines, and soils ,− and can form from the oxidation of pyrrhotite (Fe 1 – x S x ), as, for example, in lunar samples brought back to earth from the Apollo mission. , Previous studies have speculated on its possible presence on Mars, where it might serve as a suitable sink for chloride and water. − A common corrosion product of steels, , it has also been used as an efficient and low-cost contaminant sorbent. − It also has potential uses in lithium iron cells , as well as in the fabrication of magnetic nanocapsules for pharmaceutical drug delivery . Although many of these various applications take advantage of akaganéite’s nanostructured tunnels and large specific surface area, its exchange mechanisms with water-bearing environments have not been sufficiently well-resolved.…”