Growth Mechanisms of Iron Oxide Particles of Differing Morphologies from the Forced Hydrolysis of Ferric Chloride Solutions

A closer look at the synthesis and formation mechanism of hematite nanocubes

“…The growth of the individual cubes is enhanced by the presence of non-aggregated single spindle and small starshaped aggregates, which act as reservoirs that enhance the growth of hematite crystals by Ostwald ripening. This formation scenario for large hematite pseudocubes is in line with the proposed growth model by Bailey et al [12]. They suggested that for the formation of large pseudocubical particles, akaganeite rods of similar length have first to aggregate into stacks.…”

“…They described in particular the formation of polycrystalline pseudocubical hematite particles (i.e. cubes with round edges) at high FeCl 3 concentration through a three-step process: first, akaganeite rods are formed, which then arrange into stacks, finally leading to pseudocubes [12]. An important observation made was that these particles were found to be polycrystalline.…”

“…The formation mechanisms of differently shaped hematite particles from akaganeite precursors were studied in the past by Bailey and Mercartney as a function of the FeCl 3 concentration (0.018-0.45 M) [12]. They described in particular the formation of polycrystalline pseudocubical hematite particles (i.e.…”

“…Hematite (␣-Fe 2 O 3 ) shows very interesting magnetic properties, which change with particle size and shape. Nanosized hematite has been synthesized in various shapes such as cubes [7][8][9], rods [10], spheres [11,12], pseudocubes [12], platelets [13], ellipsoids [14,15], nanobelts and dendrite micro pines [16,17]. The final hematite particle size and shape can be tuned by adjusting synthesis parameters such as the concentration of the reactants [7], duration of the reaction [18], ionic strength [19,20], reaction temperature, surfactants [10], presence of hematite seed [21] and pH of the solution [19].…”

The Synthesis and Magnetic Properties of Nanosized Hematite (α-Fe2O3) Particles

“…These deviations from the results of Matijevic and Scheiner (6) are probably caused by small differences in the hydrolysis rate. Bailey et al (11) reported for the same hydrolysis reaction that only after 7 days spherical particles with an average size of 250 nm were formed. Figures 3 and 4 and the XRD results show that before hematite was formed in the solution, akaganéite was formed as was reported before (6,11).…”