16 research outputs found
X-ray absorption and photoemission electron spectroscopic investigation of crystalline and amorphous barium silicates
X-ray absorption near edge structure (XANES) measurements at
the Si K-edge, X-ray photoelectron spectroscopy of the Si 2p
and 0 1 s photoelectrons and X-ray excited Auger electron
spectroscopy of the Si KLL Auger electrons are applied in order
to investigate the degree of polymerisation (Q(n)) of the
SiO4)-Polyhedra in barium silicate glasses with different BaO-
contents. The spectra of the glasses with 33.3 and 37.0 mol%
BaO are compared to those of the crystalline reference
compounds: low quartz, BaSi2O5, BaSiO3 and Ba2SiO4. The
analysis reveals a high average polymerisation between Q(3) and
Q(4) in both glasses. The results are supported by calculations
of the bound state transitions in Si K-XANES using the multiple
scattering Xalpha method. (C) 2002 Published by Elsevier
Science B.V