title: Nanostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Tb3+ particles: polyol-mediated synthesis and luminescent properties.
abstract: Nano-submicrostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Tb3+ particles were prepared by polyol method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR), thermogravimetry-differential thermal analysis (TG-DTA), photoluminescence (PL), cathodo-luminescence (CL) spectra and PL lifetimes. The results of XRD indicate that the as-prepared samples are well crystallized with the scheelite structure of CaWO4. The FE-SEM images illustrate that CaWO4 and CaWO4 : Pb2+ and CaWO4 : Tb3+ powders are composed of spherical particles with sizes around 260, 290, and 190 nm respectively, which are the aggregates of smaller nanoparticles around 10-20 nm. Under the UV light or electron beam excitation, the CaWO4 powders exhibits a blue emission band with a maximum at about 440 nm. When the CaWO4 particles are doped with Pb2+, the intensity of luminescence is enhanced to some extent and the luminescence band maximum is red shifted to 460 nm. Tb(3+)-doped CaWO4 particles show the characteristic emission of Tb3+ 5D4-7FJ (J = 6 - 3) transitions due to an energy transfer from WO4(2-) groups to Tb3+.
authors: Key Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022.
authors: Zhenling
authors: Z
authors: Wang
authors: Guangzhi
authors: G
authors: Lil
authors: Zewei
authors: Z
authors: Quan
authors: Deyan
authors: D
authors: Kong
authors: Xiaoming
authors: X
authors: Liu
authors: Min
authors: M
authors: Yu
authors: Jun
authors: J
authors: Lin
mesh_terms: D017610:Calcium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D003460:Crystallization; D004055:Differential Thermal Analysis; D007854:Lead / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D049449:Luminescence; D008163:Luminescent Measurements / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010316:Particle Size; D044367:Phase Transition; D010777:Photochemistry / Q000379:methods*; D011108:Polymers / Q000494:pharmacology*; D011208:Powders; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013725:Terbium / Q000737:chemistry* / Q000528:radiation effects; D013818:Thermogravimetry; D017973:Tungsten Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D014961:X-Ray Diffraction
chemical_list: D017610:Calcium Compounds; D011108:Polymers; D011208:Powders; D017973:Tungsten Compounds; C024617:polyol; D013725:Terbium; D007854:Lead; C018858:calcium tungstate