Magneto-optical study of magnetite nanoparticles prepared by chemical and biomineralization process

This paper deals with a magneto-optical study of suspensions of magnetosomes. These magnetosomes are synthesized by biomineralization process of magnetotactic bacteria, followed by steps of isolation and purification in order to obtain stable suspensions. The structural analysis evidences the good crystallinity of the magnetite particles with a diameter of 34 nm. Magneto-induced linear and circular anisotropy confirms the important role played by the chains in the orientation mechanism of such magnetic dipoles. Numerical adjustments of the linear anisotropy curves using a classical Langevin orientation model give the average number of magnetosomes per chain, about 12.