The formation ofa–Fe₂O₃monodispersed particles in solution

Uniform α–Fe₂O₃particles of varying axial ratios have been prepared from hydrolyzed ferric chloride solutions at 100 °C. In the absence of phosphate anions, spherical particles were obtained by a mechanism that follows the classical LaMer and Dinegar scheme. However, in the presence of phosphates ellipsoidal particles were observed, with their formation taking place through an aggregation process from smaller primary particles of α–Fe₂O₃. It is also shown that all particles are monocrystalline irrespective of their formation mechanism.