Morphology-controlled synthesis of orthorhombic LuFeO3 particles via a hydrothermal route

LuFeO3 particles were synthesized via a hydrothermal route, where the influence of various experimental parameters on the products was systematically investigated. XRD analysis reveals that single o-LuFeO3 samples can be synthesized at reaction temperatures of 160-260 degrees C, reaction times of 24-60 h, NaOH concentrations of 0.625-6.25 M, and Lu3+/Fe3+ ion concentrations of 0.025-0.075 M. SEM observation shows that LuFeO3 particles prepared at relatively low temperatures (160-220 degrees C) and low NaOH concentrations (0.625-3.75 M) exhibit bar-like shape, and the aspect ratio of the bars decreases with increasing the temperature and NaOH concentration. At relatively high temperatures (240-260 degrees C) and high NaOH concentrations (5-6.25 M), the resulted LuFeO3 particles are shaped like spheres, polyhedrons or cubes. The samples prepared at the temperature of 220 degrees C and the NaOH concentration of 2.5-3.75 M have a relatively large particle size. All the particles exhibit a layered structure, indicating that they are mainly constructed from irregular sheets. Compared to the reaction temperature and NaOH concentration, the reaction time and Lu3+/Fe3+ concentration has a relatively small effect on the morphology and size of LuFeO3 particles. The as-prepared LuFeO3 samples have a similar bandgap energy of 2.14 eV and exhibit a week ferromagnetic behavior at room temperature. (C) 2014 Elsevier B.V. All rights reserved.