  PbSe-doped silicate glasses were studied through wide-angle X-ray diffraction
(WXRD) and small-angle neutron scattering (SANS). PbSe nanoparticles in the
glasses were produced due to the secondary heat treatment at different
temperatures and their appearance was established by WXRD, SANS, and TEM
techniques with the results for particle sizes in accordance to our recent
optical studies of this material. The simulation of SANS measurements revealed
new structural features of the PbSe nanoparticles. They form fractal aggregates
as several overlapping spheres up to ~30 nm in full size.
