Transparent Glass Ceramics Research Articles

Optical properties and energy transfer of Tm3+ single-doped and Tm3+-Tb3+ co-doped transparent glass-ceramics containing NaGd(MoO4)2 single phase

Tm3+ single-doped and Tm3+-Tb3+ co-doped SiO2–B2O3–Na2O–ZnO–MoO3-Gd2O3 glasses were successfully prepared by the melt-quenching process. X-ray diffraction and transmittance measurements were used to determine that the optimal heat treatment regime consisted of crystallization at 620 °C for 5 h and transparent glass-ceramics containing the NaGd(MoO4)2 single phase were obtained. The characterization results by SEM confirmed that the size of the crystals precipitated in the glass matrix was on the nanometer level. The effects of different contents of Tm2O3 on the luminescent properties of glass-ceramics in this system were explored. The results showed that the emission peak at 453 nm (1D2→3F4) had the highest intensity when Tm2O3 was doped with 0.5 mol% under the wavelength at 359 nm excitation. In addition, with the gradual increase of Tb2O3 contents, the luminescence colour of the Tm2O3–Tb2O3 co-doped glass-ceramics gradually shifted from blue to green. This indicates its potential application in blue-green light display technologies and various other areas. The experimental results of the water resistance stability of the samples show that the co-doped glass-ceramic still has good luminescence stability after being immersed in water, which provides further favourable support for its application.

Ultrabroadband mid-infrared emission and gas sensing of cobalt-doped chalcogenide glass ceramics.

Mid-infrared (MIR) gain materials are of great significance for the development of MIR tunable fiber lasers. Herein, for the first time, to the best of our knowledge, it is found that Ga2Se3 nanocrystals distributed in chalcogenide glass ceramics can provide new tetrahedral-coordinated sites that can be used to activate ultrabroadband MIR emissions of divalent transition metal ions, such as Co2+. Under the excitation of a 1550 nm diode laser, the transparent Ge-Ga-Se glass ceramic embedded with Co2+: Ga2Se3 nanocrystals shows an intense 2.5-5.5 µm ultrabroadband emission. The peak wavelength is located at ∼4.2 µm and the full width at half maximum exceeds 2 µm. Such emission properties, originating from the dual lattice sites of Ga3+ ions, are superior to those of transparent chalcogenide glass ceramics embedded with Co2+: ZnSe nanocrystals. Moreover, the gas detection system built based on the glass ceramic shows a sensitivity of 45.9 ppm for butane gas. Therefore, the chalcogenide glass ceramics embedded with active Co2+: Ga2Se3 nanocrystals have great potential in MIR tunable fiber lasers and gas sensing.

Enhanced mechanical properties in transparent mullite glass-ceramics synthesized from EMT-type zeolites via spark plasma sintering

Transparent glass-ceramics offer a unique combination of optical clarity and the mechanical strength of ceramics, making them ideal for various advanced applications such as cell phone screens and telescope mirrors. However, traditional fabrication methods involve high temperatures and long processing times, which result in high energy consumption and limitations in material integration. In this study, we explore the fabrication of transparent mullite glass-ceramics from EMT-type zeolites using the spark plasma sintering (SPS) technique to address these challenges. By varying the concentrations of ammonium salts to replace Na+ in the zeolite, we modified the SiO2+Al2O3 content and successfully synthesized the mullite glass-ceramics at 950 °C. The resulting glass-ceramics exhibited high transmittance (>65 % in the visible region), improved mechanical properties with a Young's modulus up to 103 GPa, a Vickers hardness of 8.0 GPa, and an indentation fracture toughness of 1.8 MPa m1/2. X-ray diffraction and Raman spectroscopy confirmed the formation of mullite phases, with increased crystallinity and a strengthened glass structure, correlating with higher SiO2+Al2O3 content. The study demonstrates the potential of using high Al/Si ratio molecular sieves as precursors for high-performance glass-ceramics, offering significant advancements in both optical and mechanical properties.

Influence of the synthesis route on optical and luminescence properties of glass-ceramic doped with europium ions

The production of transparent glass-ceramic materials often faces challenges, such as inhomogeneities, inclusions, uncontrolled crystallization and other defects that make glass ceramics unsuitable for fiber optics, for example. At the same time, the chosen chemical composition is valuable for its unique properties. The present study investigated the effect of different methods of synthesizing glass-ceramic silica-germanium-antimony matrices on their transmittance optimization and luminescence properties where the conventional melt-quenching route is insufficient in terms of the transparency and homogeneity of the material obtained. The effect of heat treatment on the studied properties was also considered. Full Text: PDF References G.A. Khater, E.M. Safwat, J. Kang, Y. Yue, A.G.A. Khater, "Some Types of Glass-Ceramic Materials and their Applications", Int. J. Res. Stud. Sci. 7(3), 1 (2020). DirectLink J. Deubener, M. Allix, M.J. Davis, A. Duran, T. Höche, T. Honma, et al., "Updated definition of glass-ceramics", J. Non-Crystalline Solids 501, 3 (2018). CrossRef W. Blanc, Y. Gyu Choi, X. Zhang, M. Nalin, K.A. Richardson, G.C. Righini, et al., "The past, present and future of photonic glasses: A review in homage to the United Nations International Year of glass 2022", Progr. Mat. Sci. 134, 101084 (2023). CrossRef P. Golonko, M. Kochanowicz, P. Miluski, M. Kuwik, J. Pisarska, W. Pisarski, J. Dorosz, M. Leśniak, D. Dorosz, A. Basa, J. Żmojda, "Glass-ceramic optical fibers with controlled crystallization of core doped with europium ions", Ceram. Int. S0272884224002955 (2024). CrossRef J. Zmojda, M. Kochanowicz, P. Miluski, A. Baranowska, A. Basa, R. Jadach, M. Sitarz, D. Dorosz, "The influence of Ag content and annealing time on structural and optical properties of SGS antimony-germanate glass doped with Er3+ ions", J. Mol. Struct. 1160, 428 (2018). CrossRef X. Liu, J. Zhou, S. Zhou, Y. Yue, J. Qiu, "Transparent glass-ceramics functionalized by dispersed crystals", Progr. Mat. Sci. 97, 38 (2018). CrossRef T.N.L. Tran, A. Chiasera, A. Lukowiak, M. Ferrari, "Eu3+ as a Powerful Structural and Spectroscopic Tool for Glass Photonics", Materials 15, 1847 (2022). CrossRef Z. Li, L. Tan, C. Chen, D. Zhou, L.R. Jensen, J. Ren, Y. Zhang, J. Qiu, Y. Yue, "The effect of melt-homogenization and heat-treatment on the optical properties of the rare earth doped oxyfluoride glass-ceramics", J. Non-Cryst. Solids 593, 121773 (2022). CrossRef D. Dorosz, M. Kochanowicz, R. Valiente, A. Diego-Rucabado, F. Rodríguez, N. Siñeriz-Niembro, et al., "Pr3+-doped YPO4 nanocrystal embedded into an optical fiber", Sci Rep. 14, 7404 (2024). CrossRef

Ni2+ concentration-dependent and temperature-dependent NIR photoluminescence properties in novel transparent glass-ceramics containing cubic CaTa2O6: Ni2+ nanocrystals

Novel transparent glass-ceramics (TGCs) containing cubic α-CaTa2O6: Ni2+ nanocrystals and their Ni2+ concentration-dependent and temperature-dependent spectroscopic properties were reported. They were obtained from precursor glasses (PGs) with a subsequent heat treatment, in which the PGs of 31CaO-31Ta2O5-38Al2O3-xNiO (x = 0.02–1.5 in mol%) were prepared by the aerodynamic levitation technique. A broadband near-infrared (NIR) emission with a full width at half maximum (FWHM) of ∼250 nm was observed at ∼1220 nm under excitation at 980 nm, attributing to the spin-allowed transition of 3T2g (3F) → 3A2g (3F) of Ni2+ in octahedral Ta5+ sites in α-CaTa2O6. With the increasing of NiO content, the emission intensity increases at first reaching a maximum at x = 0.3 mol%, and then declines. A red-shifting emission from 1189 to 1258 nm is observed with a broadening FWHM from 218 to 292 nm and a significantly reducing average lifetime from 594.4 to 56.0 μs. When the temperature increased from 298 to 473 K, the emission shows an apparent thermal quenching with a blue shift of 15 nm, where the intensity remained 51 % at 373 K of that at 298 K. Furthermore, it supposes that there are two types of Ni2+ active centers according to the deconvolution of the photoluminescence (PL) spectra, double-exponential fitting of the decay curves and temperature-dependent PL spectra. One shows a stronger concentration quenching, while the other exhibits a more serious thermal quenching. The possible thermal quenching mechanism was also discussed.

Gamma attenuation and buildup factors of GeO2-Ga2O3–Gd2O3 transparent glass ceramics for shielding applications

While gamma radiation presents significant hazards, the development of reliable shielding materials is demanded. This research study aims to investigate the gamma attenuation and buildup factors of transparent glass ceramics with the composition described by the formula of 99 [60GeO2 + (40-y)Ga2O3 + yGd2O3] +1Nd2O3, with y = 13,15,17, and 19 mol%. The basic gamma attenuation factor, namely mass attenuation coefficient (MAC), is calculated theoretically by using WinXCOM. By using MAC values, obtained by WinXCOM, we estimated the other gamma attenuation factors such as effective atomic number (Zeff) and electron density (Neff). Moreover, the absorption parameters, such as mass energy-absorption coefficient (MEAC), and buildup factors are also evaluated. It is found that the highest Zeff values are observed at 0.015 MeV with the values of 37.648, 38.618, 39.577, and 40.528 for GN1, GN2, GN3, and GN4 respectively. Moreover, the Gd2O3 content has a significant effect to improve the attenuation capacity of the studied samples.

Energy transfer and color tunability in high-thermal-stability Dy3+/Tb3+ co-doped K3YF6 transparent oxyfluoride glass ceramics

The production process and comprehensive analysis of the co-doping of Dy3+ and Tb3+ in K3YF6 oxyfluoride glass-ceramics (GCs) are delved. The primary focus is on investigating the luminescent properties and energy transfer (ET) mechanisms within these systems. The embedding of well-formed K3YF6 nanocrystals within the matrix was verified through detailed analyses using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Fine-tuning the Tb3+ concentration facilitated the achievement of tunable emission, ranging from a subtle yellow to a yellowish green hue, demonstrating the remarkable flexibility in color manipulation. Fluorescence analysis unmistakably demonstrates the occurrence of energy transfer occurring between Dy3+ and Tb3+ ions, attaining a peak energy transfer efficiency of 51.33 %. Additional analysis applying Dexter's energy transfer formula affirms that the fundamental mechanism of energy transfer between Dy3+ and Tb3+ ions is dipole-dipole interaction. The K3YF6 glass ceramics (GCs) incorporating Dy3+/Tb3+ nanocrystals exhibit a remarkable thermal stability, retaining 89.07 % of their original relative emission intensity at 423 K when stimulated by 350 nm light. These findings indicate that Dy3+/Tb3+ co-doped K3YF6 GCs hold significant potential in solid state lighting, positioning them as a candidate for future lighting.

Preparation, structure, and property evolution of transparent germanate glass-ceramics based on a new strategy: One-step heat treatment around Tg

In this work, Cr3+ ion introduced germanate transparent glass-ceramics with one-step heat treatment around the glass transition temperature were prepared. By using TEM and other structural characterizations, it was demonstrated that the microstructure of glass-ceramics had uniform distribution and excellent grain development. Through XPS, FTIR, Raman and JMA model calculation, it was found that the substitution of Cr2O3 for Ga2O3 led to the decrease of [TO4] ratio in the glass network, and the crystallization behavior changed to the whole crystallization. The results of optical performance tests indicated that the transmittance of the transparent glass-ceramics with one-step heat treatment was 46 % higher than that of glass-ceramics prepared by the two-step heat treatment, and the broadband emission intensity at 980 nm was 1.69 times higher than that of the basic glass. There is some guiding relevance to the innovative preparation approach suggested in this work for the creation of transparent glass-ceramics.

Preparation of low thermal expansion, transparent LAS glass-ceramics via simplified heat-treatment method

Li2O–Al2O3–SiO2 (LAS) glass-ceramics are commercially significant due to their unique microstructure and exceptional properties, including near-zero thermal expansion coefficient, making them suitable for a wide range of applications. However, the content of SiO2 and Al2O3 in the composition of LAS glass is very high, which leads to high viscosity and very difficult melting of this type of glasses. In order to reduce the melting temperature of the glass, use of relatively high Na2O in the basic glass composition allows high-quality glass to melt. Employing a simplified heat-treatment method, LAS glass-ceramics are prepared with Australian spodumene as the primary material. By exploring the effect of crystallization temperature on the structures and properties of the resulting LAS glass-ceramics, samples with excellent comprehensive properties are achieved. The prepared glass-ceramics are thoroughly characterized using DSC, XRD, FTIR, SEM, and TEM, along with assessments of their viscosity, thermal, optical, and mechanical properties. Relatively more Na2O is introduced into the glass compositions, which can lower the melting temperature of the glass to below 1600 °C. The basic glass is annealed at 700 °C for 2 h, nucleation phenomenon Nucleation phenomenon can be generated in the LAS glasses. When the microcrystalline temperature of glasses increases from 835 °C to 910 °C, the main crystalline phase of glass-ceramics changes from β-quartz solid solution to β-spodumene solid solution. The change in the main crystal phase has significantly affected the properties of glass-ceramics. When the crystallization temperature is below 860 °C, the glass-ceramics exhibit a low negative expansion coefficient (<-0.5 × 10−6 K−1), high visible light transmittance (>85 %), and excellent average flexural strength (173.3 MPa).

Transparent magnesium aluminosilicate glass-ceramics with high content of ZrO2

Magnesium aluminosilicate glass-ceramics are one of the important glass-ceramics with good mechanical performance. However, most of these magnesium aluminosilicate glass-ceramics are colored and non-transparent. In this work, transparent magnesium aluminosilicate glass-ceramics containing ZrO2 are investigated. Devitrification of these magnesium aluminosilicate glass-ceramics is investigated using thermal analysis, X-ray diffraction, Raman spectroscopy, transmission electron microscope, transmission spectra, and Vickers hardness. It is found that crystals precipitated in these glasses and transparency of the glass-ceramics are strongly affected by the concentration of ZrO2. Magnesium aluminosilicate glass-ceramics are found to be nontransparent when the ZrO2 concentration is lower than 6.45 mol.%. With the increase in heat-treatment temperature ZrO2 nanocrystals, MgAl2O4 nanocrystals, and Al6Si2O13 nanocrystals are sequentially precipitated, and Vickers hardness as high as 9.2 GPa are realized in glass-ceramics containing 7.19 mol.% ZrO2.

Effect of nucleating agents on structure and crystallization behavior of high-aluminum glass-ceramics system

In this work, a transparent and high strength spinel glass-ceramics containing excess Al2O3 (26.5 mol%) were prepared successfully. The influence of the substitution amount of TiO2 by ZrO2 on the structure, nucleation process, crystallization behavior and properties of glasses and glass-ceramics were investigated respectively. The results showed that ZrO2 would play different roles under different concentrations and the existence form of Al in glass network would also be influenced. Moreover, the nucleation process and crystallization behavior of glasses were studied and the mechanism of TiO2/ZrO2 induced crystallization was proposed. It is concluded that TiO2/ZrO2 as nucleating agents can induce glass to form Ti-rich phase droplets or Zr-rich inhomogeneous regions. Finally, the properties of the glasses and glass-ceramics with different nucleating agents were compared and analyzed. It is found that high Al2O3 content contributes to the improvement of microhardness, and could strengthen the role of ZrO2 in refining grains.

Effect of temperature and excitation power on down-conversion process in Tb3+/Yb3+-activated silica-hafnia glass-ceramic films

Transparent glass ceramics, when activated by rare earth ions, are excellent photonic materials. Regarding photonic glass-ceramics based on silicates, hafnia and silica in a binary system has proved to be an excellent matrix to incorporate rare earth ions in the hafnia nanocrystals, resulting in important luminescence enhancement and, consequently, allowing a large spectrum of critical applications. Here we will focus on the down-conversion mechanism driven by the couple Tb3+/Yb3+, largely exploited in photovoltaic systems. The research presented here has been performed on 70SiO2–30HfO2 silica-hafnia glass-ceramic films activated with 19 % rare earth ions: [Tb + Yb]/[Si + Hf] = 19 %. Two main results will be discussed: (a) the intensity and the broadening of the Yb3+ emission band at 975 nm were found to be temperature-dependent, as shown in the figure; (b) the energy transfer mechanism Tb3+→Yb3+ will be discussed, referring to the mechanisms that have been proposed in the literature. In relation to the latter topic, the power dependence spectra for the luminescence of Yb3+:2F5∕2 → 2F7∕2 will be discussed.

Preparation of Eu ions doped Sr5(PO4)3F transparent glass ceramics and their luminescence properties

The lack of red light components in solid-state lighting technology urgently requires the development of new efficient red-emitting bulk phosphors. Herein, we successfully prepared a kind of red-emitting glass ceramics (GCs) (λex = 392 nm, λem = 613 nm) containing Eu-doped strontium fluorophosphates (Sr5(PO4)3F:Eu) nanocrystals via a melt-quenching method in SrF2–K2CO3–P2O5–H3BO3 glass. The heat treatment temperature was found to significantly affect the grain size of the Sr5(PO4)3F:Eu nanocrystals as well as the transmittance of the prepared GCs. After heat treatment at 600 °C for 2 h, the Sr5(PO4)3F:Eu nanocrystals with grain size of about 18 nm were precipitated inside the GCs (GC600), which exhibited a high transmittance of 58–70 % in the range of 500–800 nm, with a stronger luminescence intensity than that of PG. Under excitation of 392 and 464 nm wavelengths, the CIE 1931 color coordinates of GC600 were around (0.626, 0.373) and (0.638, 0.362), respectively, both falling in red region. The present Sr5(PO4)3F:Eu GCs are promising as red phosphors for UV-pumped white-light LEDs.

Properties of Ultra-low Thermal Expansion LAS Transparent Glass-ceramics Prepared by Spodumene

Properties of Ultra-low Thermal Expansion LAS Transparent Glass-ceramics Prepared by Spodumene

Transparent aluminoborosilicate glass-ceramics containing Al4B2O9 nanorods

Transparent glass-ceramics containing nanorods are attractive for many applications. In this work, transparent aluminoborosilicate glass-ceramics containing aluminum borate nanorods are reported. Effects of Al2O3 and SiO2 concentrations on the thermal properties and crystallization of aluminoborosilicate glasses are studied. It is found that lithium aluminosilicate nanocrystals and Al4B2O9 nanorods are co-precipitated in glasses with Al2O3/SiO2 molar ratios of 0.29 and 0.33, and only Al4B2O9 nanorods are precipitated in glasses with Al2O3/SiO2 molar ratios of 0.375 and 0.42. Precipitation of these nanocrystalline phases leads to the enhancement in Vickers hardness. Glass-ceramics with Al2O3/SiO2 molar ratios of 0.375 and 0.42 are highly transparent in the visible region due to the small size of the Al4B2O9 nanorods precipitated inside.

Photoluminescence Study of Undoped and Eu-Doped Alkali-Niobate Aluminosilicate Glasses and Glass-Ceramics.

In this study, the photoluminescence (PL) behavior of two aluminosilicate glass series containing alkali-niobates ranging from 0.4 to 20 mol% was investigated. The glasses exhibit an intense visible emission centered at ~18,400 cm-1 for the peralkaline series and at higher energies (~19,300 cm-1) for the metaluminous glasses. However, the photoluminescence emission intensity varies significantly with the niobate content and the bulk chemistry. PL and fluorescence lifetime measurements indicate that the broad emission bands result from the overlap of different niobate populations, whose distribution changes with niobate content. The distinct PL behavior in the two glass series was related to the structural evolution of the niobate units upon niobium addition. An enhancement of the visible emission was observed for a higher fraction of distorted [NbO6] units. Eu-doping was carried out as a structural probe of the glass network, and also to determine if these glasses could be used as potential rare earth element (REE) activators. The crystal field strength around Eu ions is strongly dependent on the bulk chemistry and the niobate content. Furthermore, the peralkaline series showed energy transfer from the host [NbO6] to Eu3+, confirming the feasibility of exploring niobate glasses and glass-ceramics as lanthanide ion-activated luminescent materials. In addition, glass-ceramics (GCs) containing alkali-niobate phases with a perovskite-like structure were developed and studied to verify the optical performance of these materials. It was verified that the bulk chemistry influences crystallization behavior, and also the photoluminescence response. The transparent GC from the metaluminous series exhibits a quenching of the Eu3+ emission, whereas an enhanced emission intensity is observed for the peralkaline GC. The latter shows a strong excitation-dependent PL emission, suggesting energy transfer and migration of electronic excitation from one Eu population to another. Additionally, Eu3+ emissions arising from the D15 and D25 excited states were observed, highlighting the low phonon energy achievable in niobo-aluminosilicate hosts.

Color tunability and temperature sensing capabilities in Dy3+/Sm3+ co-doped transparent oxyfluoride glass ceramics containing K3YF6 nanocrystals

This paper presents the preparation and characterization of transparent oxyfluoride glass ceramics (GCs) that contain nanocrystals of K3YF6 co-doped with Dy3+ and Sm3+. The study investigates the luminescence characteristics, the process of energy transfer (ET) and the behavior of the ratio-metric temperature sensing. The formation of well-defined nanocrystals of K3YF6 in the glass substrate was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). By varying Sm3+ concentration, a tunable emission ranging from pale yellow to orange-red was observed. Energy transfer from Dy3+ to Sm3+ ions was confirmed through fluorescence spectra and decay curves. Sample K3YF6, containing 0.5 mol%Dy3+/1.2 mol%Sm3+, showed an absolute sensitivity (Sa) of 0.635 % K−1 and relative sensitivity (Sr) of 0.401 % K−1. These findings underscore the promising applications of K3YF6: Dy3+, Sm3+ GCs in multicolor displays and high-performance temperature sensing devices.

Synthesis and upconversion luminescence properties of Ho3+-Yb3+ co-doped glass ceramics containing LiGd(WO4)2

Ho3+-Yb3+ co-doped glass ceramics containing LiGd(WO4)2 were prepared by melt crystallization method. By using the methods of differential scanning calorimetry (DSC), X-ray diffraction (XRD), transmittance, and scanning electron microscopy (SEM), the optimal heat treatment condition for the samples was identified to be 580 °C/140 min. In these conditions, the transmittance of glass ceramic is about 75 % in the 380–780 nm range. In the upconversion emission spectra, strong green emission (543 nm) and red emission (650 nm) due to 5F4/5S2, 5F5→5I8 transitions are observed at 980 nm excitation. Additionally, the optimum doping concentrations of Ho3+ and Yb3+ were 0.12 % and 0.4 %. The crystal field changes around dopant ions were analyzed using J-O theory and Eu3+ probe to explain the up-conversion luminescence enhancement of glass ceramics containing LiGd(WO4)2. The chrominance coordinates of 0.12 % Ho3+-0.4 % Yb3+ co-doped glass ceramics are located in the green light region, and the color purity is 95.6 %. In summary, Ho3+-Yb3+ co-doped transparent glass ceramics containing LiGd(WO4)2 have potential applications in infrared detection and green solid-state lasers.

PROSPECTIVE LITHIUM ALUMINOSILICATE GLASS-CERAMIC MATERIALS FOR PULSE RANGEFINDERS

The relevance of creating multi-functional nanosecond pulsed laser devices with a generation wavelength that lies in the conditionally eye-safe region of the spectrum of 1.5÷1.6 μm has been established. The prospects of using the mode of passive Q-switching when receiving powerful nanosecond laser pulses with a radiation divergence close to the diffraction one have been determined. Materials for shutters that function in the mode of passive Q-switching were analyzed: solid-state nonlinear optical materials based on single crystals of yttrium-aluminum garnet doped with cations of neodymium, chromium, vanadium and other Nd- or Yb-doped crystals in the wavelength range of 0.8–1.2 μm. The promising use of oxide single crystals activated by Co2+ ions in four-coordinated oxygen positions for MgAl2O4, LiGa5O8, LaMgAl11O19 has been confirmed. The feasibility of developing transparent glass-ceramics based on aluminomagnesium and lithium gallium spinel for pulsed ranging was determined, taking into account its commercial availability, the simplicity of the production technology, as well as the homogeneity of the distribution of the activator in the volume. The feasibility of creating a new type of nonlinear optical materials based on nanostructured heat-resistant lithium aluminosilicate glass ceramics with spinel nanocrystals activated by Co2+ ions under low-temperature heat treatment conditions, has been determined. The purpose and tasks of the work are formulated, which consist in justifying the choice of the system and compositions of glasses for obtaining glass-ceramic materials as a passive laser shutter for powerful lasers that operate at a wavelength of 1.54 μm and are characterized by high heat resistance. The choice of the lithium aluminosilicate system R2O – RO – RO2 – P2O5 – R2O3 – SiO2 based on phase-forming SiO2, Al2O3, Li2O, modifying K2O is substantiated; RO – MgO, ZnO, CaO, SrO, BaO components and a complex crystallization catalyst of P2O5, CeO2, TiO2, SnO2, ZrO2 and ZnO. The structural criteria for the glass matrix were formulated. Compositions of model glasses were designed taking into account the calculated parameters fSi &gt; 0.22, Kсr ≥ 3.5, Ktr ≥ 2.1, and the probability of obtaining transparent glass-ceramic materials with a sitallized structure for pulse rangefinders was established on their basis.

The effect of Al3+ ions on the self-reduction process of Yb3+ to Yb2+ ions and optical properties of Nd3+/Ybn+ (n = 3, 2) co-doped transparent silicate glass-ceramics containing Ba2LaF7 nanocrystals and Ag nanoparticles

The effect of Al3+ ions in the AlF3 compound on the reduction process of Yb3+ to Yb2+ ions in SiO2–AlF3–BaF2–TiO2–LaF3 (SABTL) transparent silicate glass-ceramics was investigated. The valence states of the elements in the raw materials mixture existing in the transparent silicate glass-ceramics were determined using X-ray photoelectron spectroscopy (XPS) spectrum analysis. The transparent silicate glass-ceramics SABTL containing Ba2LaF7 nanocrystals and Silver (Ag) nanoparticles (AgNPs) were identified through X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) image. With the increase of Al3+ ions molar concentration, the self-reduction process of Yb3+ to Yb2+ ions was enhanced and thus significantly affected the optical bandgaps and upconversion (UC)-, near-infrared (NIR)- emissions of Nd3+/Yb3+ co-doped in SABTL containing Ba2LaF7 nanocrystals and AgNPs under excitation of 980 nm laser diode (LD). The optimal molar concentration ratio between SiO2 and AlF3 compound was determined such that the NIR bandwidth flatness of Nd3+/Yb3+ co-doped in SABTL containing Ba2LaF7 nanocrystals in the wavelength range of 1000–1200 nm was the flattest. In addition, the CIE 1931 (x, y) color coordinates for UC- and visible (VIS)- emissions of Nd3+/Yb3+ co-doped SABTL-0.5Nd2Yb-xAg (x = 0, 2, 3, 4, and 5) glass-ceramics samples are also calculated and determined the color region for light-emitting diode (LED) application.