Options
2014
Conference Paper
Titel
Transparent nano-glass-ceramic for photonic applications - distribution of RE-doping elements in the fluoride nano-crystals analysed by XAS and HR-TEM
Abstract
Rare-earth (RE) ions-doped oxyfluoride transparent glass-ceramics containing nano-crystalline phases with very low phonon energies like LaF3, NaLaF4 and KLaF4 combine the superior optical performance of low phonon energy phases with the high mechanical, chemical and thermal stability of oxide silicates. The insertion of the doping RE ions in the fluoride nanocrystals enhances the radiative optical emission processes currently focused on up- and down-conversion emissions. Thus, a key point is to identify and quantify the RE ions in the fluoride nano-crystals. In this contribution an oxyfluoride glass and the corresponding glass-ceramics of composition 55 SiO2. 20 Al2O3.15 Na2O.10 LaF3 mol % doped with 1 mol % Tm2O3 is presented. The Tm3+ incorporation in the precipitated LaF3 nano-crystals has been analysed by two different techniques. Firstly, TEM and Energy Dispersive X-Ray Spectroscopy (EDXS) were used to perform elemental distribution mappings of RE elements that allow to directly localising RE ions in the glass and glass-ceramics. Additionally, X-ray absorption spectroscopy (XAS) measurements were performed to analyse the distribution and first coordination sphere of Tm3+ ions in the glass and glass-ceramics by using X-ray absorption near edge structure spectroscopy (XANES) and extended absorption X-ray fine structure spectroscopy (EXAFS), which have allow to quantify the Tm3+ incorporation in the LaF3 nano-crystals.