Structural studies of nanoparticles doped with rare-earth ions in oxyfluoride lead-silicate glasses

Abstract

Formation of PbF₂ nanoparticles as up-conversion luminescent centers in oxyfluoride lead-silicate glass matrixes doped with rare-earth oxides has been studied by means of small-angle neutron scattering and neutron diffraction methods. During a two-stage heat treatment process, amorphous nanoparticles with sizes of ~ 5–7 nm were initially formed, then were aggregated into more complex clusters with average dimensions up to ~ 30 nm. The thermal treating at higher temperature led to crystallization of amorphous nanoparticles and, as a result, the formation of up-conversion luminescent centers in studied lead-silicate glasses. The sizes of amorphous and crystalline nanoparticles, fractional dimensions of density fluctuations in glass materials, as well as the lattice parameters of a phase of PbF₂ were calculated.

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