Size Distribution of Cobalt Nanocrystals: A Key Parameter in Formation of Columns and Labyrinths in Mesoscopic Structures.

Columnar or labyrinthine mesostructures of magnetic nanocrystals are obtained by applying a perpendicular magnetic field during evaporation of the nanocrystal solution. The effect of the polydispersity of the nanocrystals is investigated, and the size distribution of the nanocrystals appears to be a key factor in the formation of one particular structure.