Magnetite Nucleation and Growth

Magnetite is a ubiquitous iron oxide mineral found in Earth and planetary settings where its magnetic properties are, e.g., used to reconstruct past climates. Magnetite can also be biomineralized, i.e., formed by organisms such as magnetotactic bacteria or some mollusks (chitons), where the mineral is used either for its magnetic properties as compass or for its mechanical properties as reinforcement strategy. Finally, numerous synthetic routes have been established for the formation of magnetite nanoparticles, in particular because they possess numerous industrial, medical, and technological applications. In this chapter, we particularly focus on the description of the reaction pathways leading to biological, chemical, and biomimetic magnetite nanoparticles under ambient conditions and show that particulate intermediates are involved in some of the abovementioned processes.