Self-assembled light lanthanide oxalate architecture with controlled morphology, characterization, growing mechanism and optical property

Flower-like Sm₂(C₂O₄)₃·10H₂O had been synthesized by a facile complex agent assisted precipitation method. The flower-like Sm₂(C₂O₄)₃·10H₂O was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, thermogravimetry-differential thermal analysis and photoluminescence. The possible growth mechanism of the flower-like Sm₂(C₂O₄)₃·10H₂O was proposed. To extend this method, other Ln₂(C₂O₄)₃·nH₂O (Ln = Gd, Dy, Lu, Y) with different morphologies also had been prepared by adjusting different rare earth precursors. Further studies revealed that besides the reaction conditions and the additive amount of complex agents, the morphologies of the as-synthesised lanthanide oxalates were also determined by the rare earth ions. The Sm₂(C₂O₄)₃·10H₂O and Sm₂O₃ samples exhibited different photoluminescence spectra, which was relevant to Sm³⁺ energy level structure of 4f electrons. The method may be applied in the synthesis of other lanthanide compounds, and the work could explore the potential optical materials.