Unveiling the low–temperature crystalline structure of magnetite nanoparticles using model bacterial magnetosomes

Résumé

Magnetotactic bacteria synthesize magnetosomes, which are highly crystalline, reproducible, chemically stable magnetite nanoparticles (40–45 nm). Taking advantage of these model nanoparticles, we aim to unveil the temperature–driven structural modifications undergone by magnetite at the nanoscale, a matter that has been under debate in the last decades, but still remains unclear. For this purpose, we will measure the X–ray diffraction patterns in a wide range of temperature values above, close to, and below the Verwey transition (TV ≈ 120 K), which will allow us to correlate the modifications of the crystalline structure with the changes observed in the magnetic behaviour.