Nanostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Tb3+ particles: polyol-mediated synthesis and luminescent properties

J Nanosci Nanotechnol. 2007 Feb;7(2):602-9.

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+.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Compounds / chemical synthesis*
  • Calcium Compounds / chemistry
  • Calcium Compounds / radiation effects
  • Crystallization
  • Differential Thermal Analysis
  • Lead / chemistry*
  • Lead / radiation effects
  • Light
  • Luminescence
  • Luminescent Measurements / methods*
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Microspheres
  • Nanoparticles / chemistry*
  • Nanoparticles / radiation effects
  • Nanoparticles / ultrastructure
  • Particle Size
  • Phase Transition
  • Photochemistry / methods*
  • Polymers / pharmacology*
  • Powders
  • Spectrophotometry, Ultraviolet
  • Spectroscopy, Fourier Transform Infrared
  • Terbium / chemistry*
  • Terbium / radiation effects
  • Thermogravimetry
  • Tungsten Compounds / chemical synthesis*
  • Tungsten Compounds / chemistry
  • Tungsten Compounds / radiation effects
  • X-Ray Diffraction

Substances

  • Calcium Compounds
  • Polymers
  • Powders
  • Tungsten Compounds
  • polyol
  • Terbium
  • Lead
  • calcium tungstate