Synthesis of lanthanide doped CeF3:Gd3+, Sm3+ nanoparticles, exhibiting altered luminescence after hydrothermal post-treatment

The series of nanocrystalline (approximate to 5-10 nm), lanthanide doped fluorides - CeF3:Gd3+, Sm3+ were prepared by a simple coprecipitation method. The as-prepared nanoparticles were hydrothermally treated, which resulted in increased crystallinity and size of the nanocrystals formed (approximate to 50-100 nm). The precipitated products (before the hydrothermal treatment) exhibited pink luminescence. The hydrothermal post-treatment of the colloidal nanomaterials caused alteration of their luminescence, namely the emission was tuned from pink to orange. This was because of the increased energy transfer from Ce3+ and Gd3+ ions to the Sm3+ ion (luminescence activator), in larger and better crystallized nanoparticles. The products obtained in the presence of EDTA and citric acid revealed altered morphology, being more homogeneous and monodisperse, as well. The structural and morphological properties of the nanomaterials synthesized were determined by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and infrared spectroscopy (FT-IR). Elemental analysis, thermogravimetric-differential thermal analysis (TG-DTA) and energy dispersive X-ray analysis (EDX) confirmed the nanomaterials composition. The luminescence properties of the products were studied based on the recorded excitation/emission spectra and emission-decay curves. Radiative lifetimes and luminescence quantum yields were also determined. (C) 2015 Elsevier B.V. All rights reserved.