Structural changes at the Verwey transition in Fe3O4

Investigations of the dynamic process of the appearance of the Verwey transition in magnetite are performed by simultaneous measurements of magnetic susceptibility χAC and the intensity of the (111/2 2) superstructure peak, using the coherent X-ray diffraction (CXD) technique. The results suggest that while the volume of a new low-temperature monoclinic phase increases gradually across the transition, it is initially in the form of grains too small to form the well-developed superlattice reflection. Finally, at the end of the transition, those small grains coalesce into micrometer size structural domains, reflected in (111/2 2) superlattice peak.