Highly Transparent Fluorotellurite Glass-Ceramics: Structural Investigations and Luminescence Properties

Abstract

Crystallization from glass can lead to the stabilization of metastable crystalline phases, which offers an interesting way to unveil novel binary or ternary compounds and control the optical properties of obtained glass-ceramics. Here, we report on a crystallization study of the ZrF 4 -TeO 2 glass system and show that under specific synthesis conditions, a previously unreported Zr 10 Te 9 O x F y zirconium oxyfluorotellurite anti-glass phase can be selectively crystallized at the nanometric scale within the 65TeO 2 -35ZrF 4 amorphous matrix. This leads to highly transparent glass-ceramics in both the visible and near infrared ranges. Under longer heattreatment, the stable cubic ZrTe 3 O 8 phase crystallizes in addition to the previous unreported anti-glass phase. The structure, microstructure and optical properties of different 65TeO 2 -35ZrF 4 Tm 3+ -doped glass-ceramics, were investigated in detail by means of X-ray diffraction, 2 scanning and transmission electron microscopies, 19 F, 91 Zr and 125 Te NMR, Raman and photoluminescence spectroscopies.Single crystals of this novel phase could be successfully synthesized from the liquid state and their basic structure has been determined. The crystal chemistry study of several samples evidences various superstructures along a, b and c axes and likely twinning of crystals, suggesting that the novel phase corresponds to a complex series of micro-phases rather than a stoichiometric compound. These results highlight the peculiar disorder-order phenomenon occurring in tellurite materials.

Transparent glass‐ceramics in the TeO2–InF3 system

“…Finally, the absorption of hydroxyl groups (absorption band located around 3000 nm) commonly observed in tellurite glasses is reduced here, clearly proving the efficiency of fluorine addition even if some losses are observed during the synthesis and in particular, during the quenching of the glass 16,19 …”

“…Finally, the absorption of hydroxyl groups (absorption band located around 3000 nm) commonly observed in tellurite glasses is reduced here, clearly proving the efficiency of fluorine addition even if some losses are observed during the synthesis and in particular, during the quenching of the glass. 16,19 PL properties have been measured at room temperature for the glass and glass-ceramics. The emission spectra corresponding to the 2 F 5/2 → 2 F 7/2 electronic transition of Yb 3+ ions for all the analyzed samples are depicted in Figure 7C.…”

“…Due to the disorder, anti‐glass materials are also called “glass of anions.” Anti‐glass structures have been mostly reported in tellurite materials. We can cite SrTe 5 O 11 , Ln 2 Te 6 O 15 , Bi 2 Te 4 O 11 , Bi 0.5 Nb 0.5 Te 3 O 8 , Te 0.47 Zr 0.53 O x F y and Bi 0.8 Nb 0.8 Te 2.4 O 8 materials 11–16 …”

“…Anti-glass structures have been mostly reported in tellurite materials. We can cite SrTe [11][12][13][14][15][16] The 75TeO 2 -25InF 3 glass-ceramics are transparent to opaque for longer thermal treatment while maintaining very low hydroxyl groups content due to the presence of fluorine in the composition. The structural and microstructural properties of the glass-ceramics have been investigated by means of XRD, Raman spectroscopy, scanning and transmission electron microscopy (TEM).…”

Physicochemical Properties and Fiber-Drawing Ability of Tellurite Glasses in the TeO2-ZnO-Y2O3 Ternary System

“…During the past twenty years, tellurite glasses have been the focus of highly motivated research activities related to material engineering for photonic applications. Thanks to their large vitrification domain, tellurites offer a wide variety of compositions with practical advantages in different fields, ranging from the elaboration of transparent glass-ceramics [ 1 , 2 ], to the development of rare-earth doped amplifiers [ 3 , 4 ], or even for infrared (IR) transmitting optics [ 5 ]. One of the main topics where TeO 2 -based glasses have long remained interesting oxide-based materials is the development of highly nonlinear optical fiber systems [ 6 , 7 , 8 , 9 ] operating in the mid-infrared (MIR).…”