Heavy metal glasses and transparent glass-ceramics: preparation, local structure and optical properties.

Heavy metal oxide and oxyfluoride lead silicate glasses doped with rare-earth ions were prepared. Next, they were heat treated in order to obtain transparent glass-ceramics. The rare-earths as optically active ions were limited to trivalent Eu³⁺ and Dy³⁺. Correlation between the local structure and the luminescence properties of Eu³⁺ and Dy³⁺ ions in the studied glass and glass-ceramic systems was examined using X-ray diffraction, FT-IR and optical measurements. Especially, the ratio of integrated emission intensity of the ⁵D₀--⁷F₂ transition to that of the ⁵D₀--⁷F₁ transition of Eu³⁺, defined as the luminescence intensity ratio R (Eu³⁺) as well as the ratio of integrated emission intensity of the ⁴F_9/2--⁶H_13/2 transition to that of the ⁴F_9/2--⁶H_15/2 transition of Dy³⁺, defined as the luminescence intensity ratio Y/B (Dy³⁺), have been analyzed in details. Their values are reduced due to part incorporation of rare-earth ions into cubic β-PbF₂ crystalline phase. The excitation and luminescence spectra of rare-earth ions in glass samples before and after heat treatment are presented and discussed in relation to potential application in optoelectronics. [ABSTRACT FROM AUTHOR]