Controlled synthesis of NdF3 and NaNdF4 micro- or nanocrystals by one-pot microwave-assisted hydrothermal reaction

NdF 3 nanoflakes and hexagonal NaNdF 4 nanorods were successfully prepared in a facile manner by the one-pot microwave-assisted hydrothermal reaction of Nd(NO 3 ) 3 ·6H 2 O and NaF within 3   h at pH   =   1 and pH   =   3–10, respectively. Ethylenediaminetetraacetic acid disodium salt (C 10 H 14 N 2 O 8 Na 2 ·2H 2 O, EDTA–2Na) was used as the morphology-controlling agent. The size, morphology, and crystallinity of the resulting nanocrystals can be easily tuned by adjusting the reaction temperature and time. The as-prepared NdF 3 nanoflakes and NaNdF 4 hexagonal prisms were characterized by X-ray diffraction and scanning electron microscope. All nanocrystals exhibited a typical hexagonal phase, and their crystallization improved with increasing reaction temperature and reaction time. A strong emission spectrum was observed at approximately 850–900, 1060, and 1330   nm for both NdF 3 nanoflakes and NaNdF 4 nanorods under a laser excitation of 354   nm, indicating that Nd 3+ exhibits high luminescence in these two nanocrystals.