Research results on cathodo-and photoluminescence with time-resolution of Al2O3 nanostructural powders at excitation with strong electron beams as well as synchrotron radiation pulses have been presented. Nanopowders Al2O3 before and after irradiation by Fe + ions have been found to be characterized by an identical phase composition (γ-phase/δ-phase ratio equals 1), an average grain size ∼ 17 nm. Nanopowders Al2O3 have been determined to have fast photoluminescence (PL) (band at 3.2 eV), whose decay kinetics is described by two exponential stages (τ1,=0.5 ns and τ2=5.5 ns). In the fast photoluminescence excitation spectrum three bands 5.24, 6.13, 7.44 eV were distinguished. Two alternative models of centres according to which luminescence 3.2 eV is related to the radiative relaxation of P- centres or is due to the formation of the surface Fs+-type centers have been proposed. On the basis of analysis of spectral-luminescence properties of nanostructural Al 2O3 a slow luminescence of nanopowders at 3.5 eV is assumed to be due to a radiative annihilation of excitons localized near structural defects.
ASJC Scopus subject areas
- Condensed Matter Physics