Glass Matrix Research Articles

Robust efficiency stability and excellent aging resistance broadband NIR all-inorganic LEDs based on Tellurium-doped germanate glasses for multifunctional applications

Broadband near-infrared (NIR) spectroscopy based on glass-converted light-emitting diodes (gc-LEDs) has been of great interest to multifunctional applications ranging from night vision to chemical industry, stimulating the demand for exploring broadband NIR gc-LEDs with sufficient efficiency stability and aging resistance. Herein, an all-inorganic broadband NIR LEDs based on Te cluster-doped germanate glass is developed. Via adjustment of melting atmosphere and network topology of the glass matrix, active NIR Te cluster centers can be generated and stabilized in germanate glass and show a broad emission at 770 nm with a full width at half maximum (FWHM) of 260 nm under blue light excitation. By combining the Te-doped glass with a commercial blue LED chip, a high-performance NIR gc-LEDs is fabricated with an NIR output power of 14.21 mW@10.1% under a driving current of 400 mA. Particularly, the fabricated NIR-LED device exhibits high efficient stability with a relatively low-efficiency drop of 0.0023 %mA−1, and excellent aging resistance while retaining an electroluminescence intensity up 90 % of their initial value after aging for 480 h under harsh conditions, which is comparable to the commercial phosphors. Finally, its multifunctional application of gc-LEDs is also demonstrated.

Structural elucidation by Raman spectroscopy and analysis of luminescence quenching by the Inokuti-Hirayama model in the Pr3+ doped multi-component silicate photonic films

Thin films of multi-component silica glasses doped with Ca2+ and Pr3+ modifiers were fabricated by the spin coating technique. Surface micrographic images extracted by the Field Emission Scanning Electron Microscope revealed a homogeneous texture of the films. Detailed structural analysis by Fourier Transform Raman spectroscopy confirmed the existence of Si-O-Si and polyphosphate groups in the glass matrix. The Burstein-Moss shift was evidenced with doping, by an increase in the band gap of the glass films, evaluated by Tauc’s plots. The films exhibit red and near infra-red emissions (NIR), corresponding to the transitions: 3P0→3F2 and 3P0→3F4 respectively. The decay analysis by the Inokuti-Hirayama (I-H) model validated the contributions of multi-polar interactions particularly that of dipole-quadrupole mechanisms, leading to significant quenching in the highly doped film. The energy transfer efficiency between the sensitizer and activator ions, determined by the formulations of the model was 51.8 %. The decreasing lifetime of the metastable state observed in the glass films could be considered to be prospective for NIR waveguide lasers and red laser sources for optical display screens.

General Strategies for Preparing Hybrid Polymer/Quantum Dot Nanocomposites for Color Conversion

Quantum dots (QDs), with their exceptional optical properties, have emerged as promising candidates to replace traditional phosphors in lighting and display technologies. This study delves into the integration strategies of QDs within glass and polymer matrices to engineer advanced quantum dot color converters (QDCCs) at the industrial scale for practical applications. To achieve enhancements in the photostability and thermal stability of QDCCs, we explore two distinct approaches: the dispersion of QDs in a hydrophilic glass matrix via a sol–gel process and the incorporation of QDs into a non-polar acrylate monomer to formulate QD/polymer nanocomposites. This research further investigates the optical behaviors of these composites, focusing on their light-scattering and propagation mechanisms, which are critical for optimizing light extraction efficiency in QDCCs. Additional optical film and light-scattering particles can improve color conversion efficiency by ~140%. These advancements present a significant step forward in the development of high-performance, energy-efficient, QD-based lighting and display systems.

Robust high-efficiency LuAG: Ce phosphor-in-silica glass (PiSG) for high-brightness laser lighting

Blue laser diodes (LDs), owing to their high electro-optical conversion efficiency, strong directivity, and small size under high power, have paved new paths in the semiconductor lighting and display industry. Blue LDs are expected to replace LED lighting in laser displays, automotive headlights, and other advanced lighting fields. In this study, the Lu3Al5O12: Ce3+ phosphor-in-silica glass (LuAG: Ce-PiSG) is fabricated using spark plasma sintering at 1060 °C. This method enables rapid sintering while maintaining the stability of the silica glass matrix, resulting in high transparency and minimal destruction of the crystal structure of the LuAG: Ce phosphor. The phosphor-converted LDs made from LuAG: Ce-PiSG exhibit high luminous efficacy (298 lm·W−1) and luminous flux (1069 lm). The results show that LuAG: Ce-PiSG has significant potential for application as a robust, high-efficiency phosphor conversion material for high-brightness laser lighting applications.

Thermal performance of glass-based seals for reversible solid oxide cell: Effect of Al2O3 ceramic addition on the crystallization behavior

Al2O3 ceramic addition in glass significantly influenced thermal performance during sealing process in RSOC stack. The effect of Al2O3 ceramic on crystallization behavior, phase compositions, microstructure, and viscosity of glass were discussed. With increasing Al2O3 ceramic content, the crystallization activation energy of glass gradually increased. The crystallization behavior of glass was effectively suppressed with Al2O3 ceramic addition. The glass with 20 wt% Al2O3 ceramic exhibited that the content of BaAl2Si2O8 crystallization phase remained at around 45 wt% after heat-treated at 750 °C for 300 h. The controlled hexagonal BaAl2Si2O8 crystallization content combining with Al2O3 ceramic in seals effectively adjusted viscosity at about 105.1 Pa s and 107.2 Pa s during 700 °C–900 °C. During sealing process, the moderate Al2O3 ceramic and BaAl2Si2O8 were embedded in glass matrix acting as frame to enhance structural stability. Simultaneously, the glass phase owned proper fluidity, which could infiltrate components and ceramic without wide flow and release thermal stress during sealing.

Effects of Fe2O3-[BOx] reaction on sodium borosilicate glass structure doping with nano to macro sized α-Fe2O3 particles

Fe3+ is readily reacted with structural units to modify various properties of the borosilicate glasses and glass ceramics. However, there exists some controversies on Fe2O3 containing borosilicate glasses: (1) whether the Fe2O3 turned into the nanometer-sized polycrystalline structure or reacted with the glass matrix to form a new substance and (2) whether the role of Fe2O3 was depended on its concentration in the network of glass. Theoretical extinction spectra of α-Fe2O3 particles ranging from 1 to 180 nm in borosilicate glass align with UV–vis absorption spectra. Based on the Na2O-B2O3-Fe2O3 phase diagram, xFe2O3·(100-x) [41.6B2O3–20.7Na2O-19.2CaO-9.7Al2O3–7.0SiO2–0.6ZnO] (x=1.20∼1.95 mol%) were prepared for this study, analyzing from exterior characteristics to interior structure. Molecular vibrational spectroscopy and component structure measurement were applied to study the effect of doping α-Fe2O3 powders (particle sizes of 30 nm, 1 μm, 75 μm) on the sodium borosilicate glasses. Combination of experimental characterization and numerical simulation were also utilized to investigate the effects of iron oxide particle size on the color of dispersion systems. We discovered that (i) doping with either nanometer-sized or micron-sized particles of α-Fe2O3 can result in both the substitution for B3+ in tetra-coordination [BO4] and the bonding with [BO3] units within the amorphous network of sodium borosilicate glasses; (ii) Even at lower concentrations, α-Fe2O3 can still act as a network intermediate, combining both its former role and modifying properties. Based on these outcomes, for the reactive process, we formulated a constitutive model which offers valuable insights into understanding the behavior of iron oxide in sodium borosilicate glass. These findings are crucial for comprehending the processes involved in matrix preparation and are pivotal for progressing to the subsequent stage where designing and fabricating nanocomposite materials based on these matrices with spatial separation.

Antimicrobial effects of a borate-based bioactive glass wound matrix on wound-relevant pathogens

Objective: The antimicrobial effects of a borate-based bioactive glass matrix (BBBGM) on clinically relevant microorganisms was investigated for up to seven days in vitro. Method: A total of 19 wound-relevant pathogens were studied using the in vitro AATCC 100 test method. Results: The reduction of viable Gram-negative and Gram-positive bacteria and yeasts at days 4 and 7 post-culture on the BBBGM was significant (> 4log10) in most cases. Mould counts were reduced (<2log10) during the seven-day assessment, indicating that mould viability and reproduction was inhibited. The cell count of each organism was reduced at seven days indicating that the BBBGM not only reduced the viable cell count, but that the cell count did not recover during the seven-day period, indicating a sustained reduction in pathogenic activity. Conclusion: Based on the present results, the use of a BBBGM as a pathogenic barrier should be considered as a tool for combating pathogenic colonisation and infection in acute and hard-to-heal (chronic) wounds.

Generation of Reflected Second Harmonic at Semiconductor Quantum Dots

Generation of the reflected second harmonic has been observed for the first time in a composite material: a glass matrix containing microscopic CdSe crystals, ranging in size from 500 to 50 Å. The violation of polarization selection rules in the second-harmonic generation indicates that the nonlinear sources are of a fluctuational nature. A size effect has also been observed: The intensity of the second harmonic increases by a factor of 102 as the size of the microscopic crystals is reduced. A possible mechanism for this size effect is analyzed.

Concentration dependence of visible luminescence from Pr3+-doped niobium zinc barium boro-tellurite glasses

This study explored the luminescence properties of a glass with the compositions defined in the formula (30-x)TeO2-30B2O3-10ZnO-20BaO-10Nb2O5, doped with varying concentrations of praseodymium (Pr3+) ions (x = 0.00 to 1.50 mol%). The investigation covers multiple aspects, including the physical, structural, optical, and luminescence properties, to explain the material’s behaviour with respect to its physical attributes. The measured density, molar volume, and refractive index span a range of 3.76-3.86 g/cm3, 35-36 cm3/mol, and 1.71-1.79, respectively. Structural analysis through FTIR spectroscopy demonstrates characteristic stretching vibrations of Te-O (677 cm−1) and B-O (892 cm−1) bonds, providing insight into the molecular arrangement within the glass composition. The optical investigation on transitions from the ground state 3H4 to higher-energy states: 1D2 (590 nm), 1G4 (1008 nm), 3F3 (1529 nm), and 3F2 (1932 nm). These emission peaks furnish crucial information on the material’s electron transitions, which are suitable for curtain potential applications in optical devices. Significantly, our study reveals a quenching effect at a Pr3+ doping concentration of 0.10 mol%, indicating interactions between Pr3+ ions and the glass matrix, affecting luminescence behaviour. This work contributes to an enhanced understanding of material properties and lays the groundwork for potential applications in luminescence and optical technologies.

Impact of modifiers on structural and optical properties of Dy3+doped different lithium tetraborate glasses for W-LED applications

The melt quenching technique achieved the synthesis of multiple samples of glasses were prepared, each containing Dy3+ ions as dopants and containing alkali and alkaline earth metals. Subsequently, several physical properties of these samples were assessed. The current investigation covers the characterization of Dy3+ doped lithium tetraborate glasses with varying compositions using powder X-Ray Diffraction (PXRD), FTIR, FT-Raman spectroscopy, optical absorption, and photoluminescence spectroscopy. The X-ray powder diffraction (PXRD) analysis indicates that the glass specimens exhibit an amorphous structure. The elemental composition of these materials has been determined using EDS. The utilization of FTIR and FT-RAMAN spectra is employed for the purpose of identifying distinct structural groups. J-O theory is employed to obtain J-O Intensity parameters and radiative parameters based on the absorption spectra. The photoluminescence spectra were utilized to determine the experimental branching ratios (βexp), effective bandwidths (Δʋeff), and stimulated emission cross-sections (σP) for all of the glass matrices that were prepared. The bi-exponential decay profiles of the 4F9/2 state were obtained and analyzed for all glass specimens containing Dy3+ ions. The lifetimes (τ) and quantum efficiencies (η) were determined by measuring decay profiles. Emission spectra are used to calculate correlated color temperatures (CCTs), CIE chromaticity coordinates and yellow-to-blue intensity ratios (Y/B).

Thermal consequences of sintering the borosilicate matrix blue-green color release properties

Color transformation glass ceramics were produced of borosilicate matrix co-doped (SrBaSm)Si2O2N2:(Eu3+Ce3+) blue–green (B-G) (abbreviated as (SBS)SON:(EuCe) B-G) phosphors using a two-step co-sintering technique. The shift in illumination characteristics and drift of chromaticity coordinates (CIE) of (SBS)SON:(EuCe) (B-G) phosphors and hue transformation glass ceramics were investigated over a 600–800 ºC sintering thermal range. With rising sintering heat, the illuminated strength and inner quantum yield (QY) of (abbreviated as B-G) phosphors and glass ceramics reduced. Once the sintering heat was raised above 750 ºC, the phosphors and hue transformation glass ceramics showed nearly no high point among their luminescence photoluminescence (PL) and photoluminescence excitation (PLE) bands of color. B-G phosphors have low heating steadiness at more elevated temperatures, according to the findings. The glass matrix destructed the phosphors lattice layout and the Ce3+ in the phosphors was oxidized to Ce4+, resulting in a reduction in the luminous characteristics of the color transformation glass ceramics.

Analysis of Clay Mineral Transformation in Plambik Village, Central Lombok Using X-Ray Diffraction and Scanning Electron Microscope Methods

Analysis of minerals and microfabric changes during the burning process of clay in Plambik village, Central Lombok has been carried out using 2 methods: X-Ray Diffraction and Scanning Electron Microscope. A brick of dimension (10 x 20 x 5) mm was prepared which was formed through a gypsum mould. After drying it is burned using an electric furnace with temperatures: 800oC, 1000oC and 1100oC. The results show that using the X-ray diffraction method when burned at 800oC there are quartz minerals with several illite peaks, at 1000oC there is only quartz, the illite peaks disappear while at 1100oC the quartz mineral peaks remain accompanied by the appearance of mullit peaks. Then the effect of the firing temperature on the clay microfabric was analyzed by observing the sample with a Scanning Electron Microscope. This test aims to obtain information about the changes in structure and texture that develop during the combustion process and more specifically on the morphology of the particles and their interaction with the development of the vitrification process and the distribution of the shape and size of the pores. The results showed that before burning, the kaolinite and illite particles were randomly distributed with porous aggregates and the grain size was between 1 – 5 microns. During firing at 800oC some parts have undergone melting and welding phases with the development of secondary porosity. Meanwhile, when burning with a temperature of 1100oC, it appears that the welding and smelting processes that occur are wider and the emergence of mullite crystals from the glass matrix.

Nanocrystallization of Bi2O3 based system from the glassy state under high compression

This report presents the pressure-temperature (p-T) plane of Bi2O3-Al2O3-SiO2 ternary system in the context of nanocrystallite formation from its amorphous state. The diagram was constructed through differential thermal analysis (DTA) performed in situ under high-pressure-high-temperature (HP-HT) conditions, with nitrogen serving as the pressurizing medium. Above the glass transition temperature Tg, a wide ultraviscous, supercooled liquid state spanning approximately 150 K is observed. Later heating transforms this state into nanocrystallites embedded within an amorphous matrix, thereby keeping distinctive structural characteristics even after the decompression process. The p-T plane serves as a fundamental prerequisite for the design of nanocrystallites within a glass matrix, a well-established technique known as glass-ceramics. Various paths within the p-T plane, followed by annealing just below Tg, can be explored, potentially leading to the development of Bi2O3-based materials with enhanced electrical, dielectric, photonic, and mechanical properties, predicated on nanocrystallites formed by high-pressure treatment.

Remobilization and eruption of an upper crustal cumulate mush at the Singkut caldera (North Sumatra, Indonesia)

Understanding the conditions and timescales of storage and remobilization of magma bodies in the upper crust is key to interpreting the signals of potential reawakening at active volcanoes. In this paper, we provide the first volcanological and petrochronological characterization of the Singkut caldera, a young volcanic system located in northern Sumatra (Indonesia), in close proximity to Medan, one of the country's most popoluous cities. Singkut formed at ∼44 ka during a VEI 6 explosive eruption that deposited at least ∼26 km3 of tephra (dense rock equivalent, DRE). The cataclysmic eruption was preceded by >200 ky of mostly effusive pre-caldera activity and followed by effusive to mildly explosive post-caldera activity. The lavas and pumices have high crystallinity (up to 62% crystals) with andesitic to dacitic bulk-rock composition and rhyolitic glass. Mineral textures and matrix glass compositions indicate resorption of quartz, plagioclase and zircon. Zircon crystallization ages show a complete overlap with the eruption ages in pre-caldera lavas, while a time gap in zircon crystallization (>50 ky) is identified in the caldera-forming tuff and post-caldera lavas. Ti-in-zircon thermometry shows that the Singkut magma body experienced a temperature increase starting approximately upon eruption of the pre-caldera lavas (∼254 ka). Such thermal perturbation determined progressive melting of mineral phases in the cumulate crystal mush, caused the resorption of the youngest zircon domains before the caldera-forming eruption, and hampered zircon crystallization between the caldera-forming eruption and the effusion of the post-caldera lavas (∼16 ka). Our data demonstrate how cumulate melting processes played a key role in leading the volcanic system towards a caldera-forming eruption and controlled the transitions in eruptive style between the effusive phases and the explosive climactic eruption.

Analysis of surface roughness, temperature, short aging, and residual notched and bearing strengths in supported drilling of thin GFRP composites

This study aimed to analysis open‐hole tensile strength, pin-bearing strength, cutting temperature, and surface roughness of drilled thin glass fiber reinforced polymer composites. The specimens were clamped from both sides during drilling operations. The cutting temperature was measured using high resolution infrared camera. Surface roughness was evaluated by seven parameters to identify the most suitable ones. Multiple regression models were developed to predict critical thrust force (CTF), critical feed, and cutting temperature in drilling operations. The measurements indicate that the cutting temperature is higher than the matrix's glass transition temperature and hence, the surface roughness paramaters Ra, Rq and Ry are increased at the maximum cutting conditions by 57%, 51%, and 36% respectively. In contrast, the bearing strength improved by 13%. This peculiar phenomenon was deeply analyzed with the aid of short ageing effects on the post curing, which increase the crosslinking density within the composites and improve the matrix's capacity to efficiently transmit the loads to the reinforcing fibers. For the first time, the optimum cutting conditions were determined based on the optimum short ageing parameters (temperature and time). Supported drilling increases CTF by 23%, which can reduce machining time and manufacturing costs with fewer delamination concerns.

Trace element partitioning in strongly peraluminous rare-metal silicic magmas – Implications for fractionation processes and for the origin of the Macusani Volcanics (SE Peru)

The Macusani Volcanics and related rocks (SE Peru) are well known examples of erupted strongly peraluminous rare-metal rich silicic magmas. We used the phenocryst/matrix glass method to determine relevant mineral/melt partition coefficients to facilitate modeling of such systems. Concentrations of trace (Li, Be, B, Al, P, Ti, Mn, Zn, Ge, Rb, Sr, Zr, Nb, Sn, Cs, Ba, La, Sm, Eu, Gd, Yb, Ta, W, Pb and U) and major elements were measured in obsidians, matrix glasses, glass inclusions, phenocrysts and phases from biotite reaction zones by Laser-Ablation ICP-MS and Electron Microprobe Analysis. The derived phenocryst/melt partition coefficients for quartz, plagioclase, sanidine, biotite, muscovite, andalusite and ilmenite are compared with values from reference silicic magmas and literature. Mineral/biotite partition coefficients are calculated for tourmaline and hercynite. The database is then applied to model chemical fractionation in Macusani magmas. Fractional crystallization and partial melting trends (with the B concentration used as a proxy for the fraction of residual liquid) generate progressively more evolved (higher Rb, Nb, Sn, Cs and Ta and lower Sr, Ba and Pb) residual liquids. The trace element concentrations in obsidians are reproduced for 50–70% crystallization of matrix glasses from ash-flow tuffs. This demonstrates that differentiation of magmas parental to the ash-flow tuffs can generate the highly evolved obsidian-forming liquids. Based on this, we present an updated model for crustal melting and the generation of the Macusani magmas. A metapelitic component dominates the source region but calcic plagioclase cores enriched in Sr, Ba and La suggest an affiliation with mafic magmas, which were likely potassic to ultrapotassic. The presence of a mafic component is consistent with the high heat fluxes in the source region and accounts for specific magmatic variables (i.e., middle crustal anatectic zone, very reducing fO2, high F). Petrogenetic processes differ significantly between Macusani Volcanics suites and two-mica leucogranites despite both having nearly identical source rocks, mineral assemblages and compositions.

Down-conversion emission of Er3+ doped sulfophosphate glass: The role of TiO2 and Ag nanoparticles co-embedment

In this study, Er3+-doped sulfophosphate glasses containing titanium nanoparticles (TiO2 NPs) with 0.0, 0.01, 0.02, 0.03, 0.04, and 0.05 mol% of silver (Ag) nanoparticles (AgNPs) were synthesized using the melt-quenching technique. The impact of AgNPs on the physical and structural characteristics, optical absorption and emission features, and photocatalytic activity of the glasses were investigated. The density and molar volume of the glasses were determined. Transmission electron microscopy (TEM) was used to study the existence of both AgNPs and TiO2 NPs in the glass matrix. The absorption spectra of the glasses revealed several bands of absorption in the UV–Vis–NIR region, with peaks at 1534, 977, 795, 650, 544, 520, 487, 450, 406, 378, and 364 nm. The SPR peaks of silver were observed at 553 and 588 nm, while those of TiO2 NPs were located around 409 and 849 nm. The intensity of emission was found to be enhanced by increasing the concentration of AgNPs. According to the findings of Judd-Ofelt theory, the system containing of 0.04 mol% of AgNPs has also the optimal performance which can be applied to the function of a broadband amplifier by having a high emission cross section of 70.18 × 10−22 cm2. Finally, the photocatalytic performance of the glasses was evaluated by conducting a degradation experiment with methylene blue (MB). The results validated their light-activated self-cleaning properties in the presence of Ag/TiO2 NPs.

Optical and luminescent characteristics of thermally stable new Eu3+ doped potassium tungstate tellurite glasses for epoxy-free luminescent devices

Transparent, Eu3+ doped potassium tungstate tellurite (TKWZBiEu) glass matrices were successfully synthesized via employing the traditional melt quenching method and their thermal, structural and photoluminescent characteristics were thoroughly investigated. To estimate the aggregate weight loss, glass transition temperature (Tg) and thermal stability factor (ΔT) of the prepared host glass matrix, thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) were utilized. The non-crystalline character of the prepared TKWZBiEu glass was studied via XRD profile. Various vibrational functional groups were revealed via employing Fourier transform infrared (FT-IR) spectroscopy. The optical bandgap (Eopt) values for all prepared TKWZBiEu glasses have been evaluated by employing the absorption spectra. Under n-UV and blue excitations, all the prepared TKWZBiEu glasses are demonstrating reddish emission at 614 nm ascribed to the 5D0 → 7F2 transition, in which the intensity is increasing continuously with Eu3+ ion content up to 5.0 mol%. The experimental lifetime (τ) profiles demonstrate the single-exponential nature of prepared TKWZBiEu glasses under n-UV excitation. Furthermore, temperature dependent photoluminescence (TDPL) spectra indicate excellent thermal stability of the TKWZBiEu glass matrix with the highest value of activation energy (ΔE). The prototype organic epoxy resin/binder-free device has been developed using the 5.0 mol% Eu3+ doped with TKWZBi glass matrix and n-UV LED chip. All the aforementioned findings validate that the optimized TKWZBiEu glass is an auspicious candidate for the red component to fabricate organic epoxy-free w-LEDs.

Potentially toxic elements speciation in bottom ashes from a municipal solid waste incinerator: A combined SEM-EDS, µ-XRF and µ-XANES study

Bottom Ashes from Municipal Solid Waste Incinerators and Waste to Energy plants represent an interesting source of secondary raw materials for many applications, like urban mining and inclusion in concrete, and road pavement. However, Bottom Ashes may contain potentially toxic elements, whose actual toxicity depends essentially on their oxidation state and mineralogical environment. For this reason, a representative sample of bottom ashes from Parma Waste to Energy plant has been selected to investigate the chemical speciation of Cr, Ni, Pb, Co, Zn and Cu by means of complementary techniques: Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM-EDS), micro X-Ray Fluorescence (µ-XRF) mapping and X-Ray Absorption Near Edge Structure (XANES) measurements by synchrotron radiation. This multi-technique approach allowed to obtain a general image of the mineralogical and chemical environment in which these elements are found. SEM-EDS analyses show the presence of Zn and Pb both in minerals and in glass matrix. Cr has been detected in the form of oxide and in spinel structure (chromite) whereas Co and Cu are found as alloy or metal inclusions. µ-XRF mapping reveals that Cu, Ni and Cr are generally associated to Na, K and Si suggesting their presence in glass matrix. XANES investigations exhibit that Cu has a variable oxidation state that suggesting its presence in the form of oxide, hydroxide, acetate and metal. Zn is mainly found as +II and in a number of different phases (including Zn-carbonates, in agreement with SEM-EDS data). Cr has been found only as +III, with XANES features resembling those of chromite, whereas as +VI was never identified. Ni and Co were found either as metal form and oxides. Pb spectra show a good match with oxides.

Facile Fabrication of Silica Glass Embedded with NiO Nanoparticles by 3D Printing Technology and its Optical Nonlinearity

Metal and metal oxide nanoparticles (NPs) embedded in glass matrixes exhibit special optical, electrical, or magnetic properties. Despite various approaches of encapsulating NPs in different kinds of glasses to prepare functional composite materials, there still exist challenges in fabricating efficiency and performance for silica glass made by traditional methods, such as sol–gel or melt quenching. Herein, the authors report a facile way to fabricate metal oxide NP‐doped silica glass by digital light processing (DLP) 3D printing technology for the first time. Different from common ion doping in silica glass, metal acetylacetonates that can be thermally decomposed to corresponding metal oxides innocuously, are chosen as a general precursor. Then, the representative nickel(II) acetylacetonate is introduced during the 3D printing process. The subsequent heat treatment generates a homogeneous distribution of NiO NPs in silica glass and it also exhibits optical nonlinear effect. The results provide a facile method for developing functional metal oxide‐doped glasses as well as the freeform fabrication of optoelectronic devices based on them.