The local structure of europium–lead-borate glass ceramics

Glass ceramics in the xEu2O3(100 − x)[3B2O3·PbO] system with 0 ⩽ x ⩽ 50 mol% have been prepared using the melt quenching method, succeeded by heat treatment applied at 625 °C and 675 °C, respectively, for 48 h. The influence of europium ions on structural behavior of the lead-borate glass ceramics has been investigated using infrared spectroscopy and DFT calculations. The addition of europium ions into the host glass ceramics matrix leads to an increase of the glass network polymerization due to the replacement of BOB bonds by the more resistant BOPb bonds.The structural evolution of the studied glass ceramics with the gradual increase of the europium oxide content up to 50 mol% could be explained by considering that the excess of oxygen may be accommodated by the formation of [PbO4] structural units. Then, the formation of different ionic complexes of the lead ions will decrease the rate of crystal growth and the conversion of the glass into crystalline material becomes more difficult, in agreement to the X-ray data.