Article

Luminescence and phonon properties of nanocrystalline Bi2WO6:Eu3+ photocatalyst prepared from amorphous precursor.

Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław 2, Poland.
Journal of Nanoscience and Nanotechnology (Impact Factor: 1.15). 09/2010; 10(9):5746-54. DOI: 10.1166/jnn.2010.2465
Source: PubMed

ABSTRACT Bi2WO6:Eu3+ samples were prepared by mechanically activated metathesis reaction and subsequent annealing at different temperatures of the as-prepared precursor. X-ray, TEM, Raman, IR, diffuse reflectance and luminescence studies of the prepared samples are presented. It was found that variation of the particle size have significant impact on phonon and emission properties of this material. It was observed that intensity of some Raman and IR bands significantly decreases and the bandwidth of Raman, IR and Eu3+ emission lines significantly increases with decreasing particles size. Moreover, it was observed that intensity ratios I((5)D0-(7)F2)/I((5)D0-(7)F1) and I(5D0_(7)F0)/I((5)D0-(7)F1) increase with decreasing particle size. The observed changes were attributed to phonon confinement effect, decrease in the orthorhombic distortion of the unit cell and concentration increase of surface defects.

1 Bookmark
 · 
107 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The microscopic origin of ferroelectric instabilities in Aurivillius compounds is investigated from first principles using the full-potential linearized augmented plane-wave method. A comparative study of the ferroelectric instabilities in archetype materials like Bi2WO6, SrBi2Ta2O9, and Bi4Ti3O12 is investigated by a lattice-dynamics study of the paraelectric phase using the frozen-phonon approach. An analysis of the different displacement patterns displayed by the resulting unstable phonon modes gives insight into the microscopic origin of the ferroelectric transition and the different polarization behavior of the materials.
    Physical Review B 12/2004; 70(21). · 3.77 Impact Factor

Full-text (2 Sources)

View
7 Downloads
Available from
May 21, 2014