Effect of compositional variation on optical and structure properties of europium-doped SiO(2)-HfO(2) glasses.

Glasses with compositions (100-x)SiO(2)-xHfO(2):0.3Eu(3+) (molar ratio, x=0,10,20,30) for optical applications were prepared using the sol-gel route. The introduction of hafnium into the glass matrix induced the energy splitting of the F27 state of Eu(3+) ions.

Local order around rare earth ions during the devitrification of oxyfluoride glasses.

Erbium L(3)-edge extended x-ray absorption fine structure (EXAFS) measurements were performed on rare earth doped fluorosilicate and fluoroborate glasses and glass ceramics. The well known nucleating effects of erbium ions for the crystallization of cubic lead fluoride (based on x-ray diffraction measurements) and the fact that the rare earth ions are present in the crystalline phase (as indicated by Er(3+) emission spectra) seem in contradiction with the present EXAFS analysis, which indicates a lack of medium range structural ordering around the Er(3+) ions and suggests that the lead fluoride crystallization does not occur in the nearest neighbor distance of the rare earth ion. Molecular dynamics simulations of the devitrification process of a lead fluoride glass doped with Er(3+) ions were performed, and results indicate that Er(3+) ions lower the devitrification temperature of PbF(2), in good agreement with the experimental results.

Molecular dynamics simulation study of erbium induced devitrification in vitreous PbF2.

Molecular dynamics simulations of the devitrification process of a lead fluoride glass doped with Er(3+) ions were carried out. This technique appears to be a relevant way to perform systematic analysis of the system structure and to study the influence of defects on PbF2 crystallization. We modeled the total enthalpy, the radial distribution functions, and the diffracted intensities of systems containing different amounts of Er(3+) ions.

Molecular dynamics simulation on devitrification: isothermal devitrification and thermodynamics of PbF2 glasses.

The vitrification and devitrification features of lead fluoride are investigated by means of molecular dynamic simulations. The influence of heating rate on the devitrification temperature as well as the dependence of the glass properties on its thermal history, i.e.