Precisely tailoring dendritic α-Fe2O3 structures along [100] directions

Abstract

In the present work, a significant advance has been made in precisely tailoring dendritic α-Fe₂O₃ structures along [100] and/or its equivalent directions. We proposed that the benzoate anions adsorb on (100) and/or its equivalent facets, leading to the slow growth of these facets. By carefully controlling the experimental conditions, the dendritic structures can be gradually tailored to nanorods and finally to dodecahedral α-Fe₂O₃ nanoparticles with twelve exposed (012) planes. Interestingly, with the process proceeding, the coercivity (Hc) of these particles decreases successively due to the reduction in magnetic anisotropy by lessening intensity of hierarchical hyperbranched structure. The tailoring process gives us an in-depth understanding of the formation mechanism of dendritic α-Fe₂O₃ structures, which is not possibly achieved by the traditional time-dependent method.