Fig. 6
From: Shape and Size-Dependent Magnetic Properties of Fe3O4 Nanoparticles Synthesized Using Piperidine
(1) The first step is the hydrolysis of FeCl2 by water in presence of piperidine which facilitates the hydrolysis by neutralizing HCl produced in the reaction and hence making the reaction move in forward direction. (2) The next step is dehydration of Fe(OH)2 to produce ferrous oxide. (3) The similar dehydration of two molecules of ferrous hydroxide produces H2Fe2O3 which on spontaneous aerial oxidation produces the Fe2O3. (4) The FeO and Fe2O3 combine to give Fe2O4