Fe2O3 nanostructures on SrTiO3(111) by chemical vapor deposition: growth and characterization

Fe2O3 nanostructures were grown on SrTiO3(111) substrates by chemical vapor deposition. The material morphology and crystal structure were significantly affected by the growth temperature. In fact, the metastable, scarcely investigated epsilon-Fe2O3 polymorph was obtained as a pure phase at 400 °C, whereas a transition to alpha-Fe2O3 took place at 500 °C. The synthesized systems, characterized by a high purity and homogeneity, underwent a remarkable morphological evolution as a function of the growth temperature, ranging from columnar nanoarrays to dense pyramidal-like nanodeposits. For the first time, the optical properties of CVD-derived epsilon-Fe2O3 nanomaterials have been characterized, revealing an efficient absorption in the Vis range. In addition, magnetic force microscopy suggested that spin domains were formed in the obtained systems.