Studies on the influence of structure units on the state of ytterbium ions in TeO₂-based glasses

Abstract

Abstract

Efficient green upconversion emission in transparent Teo2-Geo2 glass-ceramic obtained by billet extrusion

“…The results show a promising use in different optical applications. One of them is the optical thermometry as we observed, since the sensitivity of this material is 6.30 × 10 −3 364 K. [28,30] ν a (Ge-O-Ge) 823 877 894 [28,30]…”

“…The FTIR spectra between 400 and 1100 cm −1 have mainly two bands centered around 500 and 770 cm −1 . These bands correspond to the vibrational modes of tellurite, germanate, and gallate structural units [27][28][29], and their deconvoluted components are presented in Table S1 [27][28][29][30]. The deconvolution of the spectra exhibits slight changes in the vibrations ascribed to symmetric and asymmetric stretching vibrations of Ge-O-Ge, located in the 400 -600 cm −1 range [27].…”

“…3b and S3). The most evident increment occurred at 745 cm −1 suggesting that[TeO 3 ]tps units grew, triggering changes in the RE 3+ ions arrangement that could influence the optical properties [28,29]. On the other hand, the band between 750 and 950 cm −1 decreases and shifts to higher wavenumbers, which could be associated with the reduction of the bridging Ge-O-Ge of GeO 4 tetrahedra in glass-ceramic and ceramic samples, because the thermal treatment favors other vibrations (Fig.…”

“…However, their low thermal stability limits their use. For that reason, the use of other dopants such as GeO 2 that increase its thermal stability and maintain its high RE solubility results very attractive [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. Also, it was observed that its presence diminishes the phonon density of the glass, causing a slight enhancement in the UC emission intensity [12][13][14][15].…”