Magnetic Nanocrystals in Organisms

Ferrimagnetic nanocrystals are present in virtually every organism. They are used by bacteria, algae, mollusks, insects, and vertebrates either for navigating in the geomagnetic field or for hardening their tissues. Advanced transmission electron microscopy techniques, including electron holography, reveal the complex interplay between the physical and magnetic properties and biological functions of ferrimagnetic nanocrystals in bacteria. Although some information is now available about magnetic sensory systems in more complex organisms, much further research is required to understand fully the origin and function of biomagnetism.