Ce Ions Research Articles

A Multi-Functional Cascade Nanoreactor for Remodeling Tumor Microenvironment to Realize Mitochondria Dysfunction via ROS/Zn2+ Ions Overload.

Combining chemo/photodynamic therapy (CDT/PDT) to generate highly harmful reactive oxygen species and cause mitochondria dysfunction is considered a potential strategy to improve the efficiency of anticancer treatment. However, within tumor, the relatively deficient concentration of H2O2, hypoxic microenvironment, and overexpressed reduced glutathione (GSH)seriously suppress the efficacy of dynamic therapy. Herein, a multi-functional cascade nanoreactor, bovine serum albumin modified ZnO2@CeO2-ICG, is reported for remodeling tumor microenvironment (TME) to boost dynamic therapy and realize mitochondria dysfunction via reactive oxygen species (ROS) storm/Zn2+ ions overload. Within TME, ZnO2 decomposed into exogenous H2O2 and Zn2+ ion. The dual enzyme-like CeO2 catalyzes the increased H2O2 into ·OH and oxygen molecules respectively, and then the oxygen molecules are translated into 1O2 by indocyanine green (ICG) under 808 nm light irradiation to boost PDT. The effective consumption of GSH through the reduction of Ce(IV) ions not only regenerates Ce(III) ions to enhance the efficiency of CDT but also efficaciously alleviates the elimination of ROS generated by dynamic therapy to further improve dynamic therapeutic efficiency. So the improved ROS level under remodeling TME and Zn2+ ions acutely lead to mitochondria dysfunction to boost the efficiency of antitumor treatment. Thus, developing functional nanoreactors that enable remodeling TME provides a potential strategy to enhance the efficiency of dynamic therapy.

Growth and spectroscopy characteristics of Er, Ce:BGSO crystal: A promising material for eye-safe laser applications

Er, Ce co-doped BGSO single crystals were successfully grown by the Bridgman method. The growth parameters, including temperature gradient and growth rate, were optimized to achieve high-quality crystals. The crystal structure and morphology were characterized using X-ray diffraction and scanning electron microscopy. The optical absorption properties of Er, Ce co-doped BGSO single crystals were studied using UV–Vis absorption spectroscopy. The absorption spectrum revealed the absorption edge and the presence of absorption bands related to the presence of Ce dopant, providing valuable insights into the energy transfer processes occurring within the crystal lattice. Furthermore, the luminescence mechanism of BGSO crystals was analyzed using the Judd-Ofelt (J-O) theory, with detailed investigation into the role of ligands in spectral parameters. The photoluminescence spectra and emission decay time of Er, Ce co-doped BGSO single crystals were characterized. A comparative analysis with Er, Ce:BGSO crystals was conducted to investigate the sensitization mechanism of Ce ions on Er emission at 1.5 μm, demonstrating their potential for use as eye-safe laser materials in various applications.

Cerium-infused tungstate nanocrystals: Illuminating the future of solid-state lighting

Rare earth based luminescent materials have emerged as a focal point of the scientific investigation owing to their remarkable optical behaviour and potential applications. An effort has been made to develop a series of Ce3+ doped CaWO4 nano-phosphors using an ethylene-glycol assisted reflux route. The detailed structural and morphological properties have been examined through various analytical techniques. The +3-oxidation state of the activator ion Ce has been verified through the XPS study. The change in optical band gap due to the substitution is well discussed using diffuse reflectance spectroscopy. In Photoluminescence study, a broad emission centred at 465 nm is observed due to the 5D3/2→2FJ transitions (J = 7/2 and 5/2) and a significant enhancement in the emission peak is obtained for the optimized phosphor. Concentration quenching phenomenon, observed after 3 mol% of Ce3+ is mainly mediated by the electric multipole-multipole type interaction. The CIE diagram indicates the tuning of emission colour from blue to white region and the emission near white region for the optimized phosphor is further authenticated by its low colour purity value (43 %). The effective tunability of photo-physical properties and colorimetric parameters suggest the applicability of the optimized nano-phosphor in solid state lighting especially for outdoor illumination.

The influence of CeO2 on the oxidation resistance of TaC/Ni composites

The in-situ TaC/Ni composites with different CeO2 content (0 wt%, 1 wt%, 2 wt%) were prepared by reactive sintering method, and their oxidation behavior in air at 1073 K was analyzed by static cyclic oxidation method to investigate the influence mechanism of CeO2 on the oxidation resistance of composites. The results show that the CeO2 particles are distributed around the TaC particles in the Ni matrix, and the oxidation behavior of composites with different CeO2 content conforms to the linear kinetic law. The oxide film is mainly composed of NiTa2O6 and a small amount of NiO. The generation reactions of Ta2O5 and NiTa2O6 induce a high expansion and compressive stress in oxide scale, leading to the formation of nonprotective oxide film with pores and cracks on the surface. As the addition of CeO2 increases from 0 wt% to 2 wt%, the thickness of oxide scale on composites obviously reduces from 505 μm to 122 μm, and the Ni and Ta oxides content decreases, leading to the reduction of pores and cracks in oxide scale. The Ce ion generated from the dissolution of CeO2 particles mainly distributes in the Ta oxides during the oxidation process, which hinders the outward diffusion of Ni and Ta ions, resulted in the improved oxidation resistance of TaC/Ni composites.

Mechanistic insights on stabilization and destabilization effect of ionic liquids on type I collagen fibrils

Tuned assembly of collagen has tremendous applications in the field of biomedical and tissue engineering owing to its targeted biological functionalities. In this study, ionic liquids choline dihydrogen citrate (CDHC) and diethyl methyl ammonium methane sulfonate (AMS) have been used to regulate the self-assembly of collagen at its physiological pH by probing the assembled systems at certain concentration ratios of ionic liquids and the systems were studied using various characterization methods. Due to interaction with collagen, choline dihydrogen citrate causes delay in the collagen fibrillisation process showing no binding interactions with collagen. In contrast, diethyl methyl ammonium methane sulfonate shows crosslinking effect on collagen fibrillisation due to the electrostatic interaction with the tetrahedral hydration shell of collagen moieties. From rheological studies it was observed that the AMS treated collagen fibril at 1:1 % (w/v) has highest linear viscoelastic range, this can bear the stress under high strain compare to native collagen fibril as well as all CDHC composites. For a sustainable biomaterial or bio-scaffold, mechanical property plays pivotal role on it and from our experimental analysis we found certain composites of ionic liquid treated collagen fibrillar assembly which may act as a sustainable biomaterial or bio-scaffold. It was also evolved that, how the structure-function relationship of ionic force modulated fibrillar assembly controlling the mechanical properties of the tuned system. This self-assembled, ionic-liquid treated collagen-fibrillar system would accelerate various force modulated fibrillar network study, for mimicking the ECM and tissue engineering application.

N-Halosuccinimide-CeCl3 Transient Charge-Transfer Complexes as Semi Heterogeneous Photocatalyst in Cyclization of N-Propargylamides.

In this work, we used photoinert anhydrous cerium(III) chloride, to form a transient charge-transfer (CT) complex with NXS (N-bromosuccinimide or NBS and N-iodosuccinimide or NIS) in acetonitrile. These transient CT complexes acted as a semi-heterogeneous photocatalyst. These complexes allowed the Ce(III) ions to absorb light, turning them into strong electron donors that transferred electrons to NXS. This created halide radicals from NXS radical anions, helping to turn N-propargylamides into oxazole aldehydes. Experiments with DMPO and spin-trapping showed that a radical-based mechanism followed a single electron transfer (SET) pathway. Notably, CeCl3 was reused after the reaction without much decomposition, as it was regenerated and separated through simple filtration.

Stationary and Dynamic Sorption of 141Ce(III) and 152+154Eu(III) Using Alginate–Gypsum Bio-composite Beads

AbstractThis study introduces a novel Alginate–Gypsum bio-composite, synthesized at a 2:1 weight ratio, as an effective sorbent for Eu(III) and Ce(III) ions in aqueous solutions. Optimal conditions (pH 3, 5-h contact time) yielded 98% sorption efficiency for both ions in single batch systems (50 mg L−1, 20 °C). In binary systems, the composite adsorbed 33.04% of Ce(III) and 47.26% of Eu(III) (mg L−1, 20 °C). Dynamic column system showed 80.297% Ce(III) and 77.5% Eu(III) sorption. The process was endothermic, spontaneous, and best described by a quasi-nth order kinetic model. The sorption process was best described by the quasi-nth order kinetic model, with Eu(III) sorption aligning with the Langmuir and Sips models, and Ce(III) sorption following the Redlich–Peterson and Sips models. Desorption was highly efficient, with up to 99% for Eu(III) and 97% for Ce(III) using 0.1 M EDTA.

Synergistic impact of lanthanum and cerium co-doping ZnO for improved photocatalytic rhodamine B degradation efficiency under UV light

In this study, the influence of different La and Ce co-doping amounts on the structural, morphological, optical, and photodegradation properties of ZnO nanostructures was evaluated. Zn1-2xLaxCexO nanoparticles (NPs) were prepared using sol-gel auto-ignition process, where x = 0.00 (pure ZnO), 0.01 (LC1), 0.03 (LC3), and 0.05 (LC5). The X-ray diffraction (XRD) and Raman results revealed that the prepared ZnO NPs crystallize in the hexagonal wurtzite structure. The size of crystallites is affected by the increment of La and Ce and it decreased from 24.29 nm to 10.40 nm with the increase in the concentration of La and Ce. Transmission electron microscopy (TEM) showed that the samples exhibit an irregular distribution of NPs with a dominant spherical shape morphology. The simultaneous incorporation of La and Ce in ZnO NPs led to a slight variation in the absorption edge and a slight shift in the values of the band gap energy from 3.20 to 3.24 eV. Furthermore, a reduction in the recombination rate of photogenerated charge carriers and the creation of fewer additional defects upon the appropriate insertion of Ce and La ions are highlighted by the analysis of photoluminescence spectra, Nyquist plots, and transient photocurrent measurements. The photocatalytic activity of samples was evaluated against rhodamine B organic dye under UV light irradiation. The analysis showed that LC1 sample exhibited superior photocatalytic performance with 99.1% degradation efficiency and a degradation rate constant of 0.0762 min-1. This enhancement has been ascribed to the surface defects and the optimized crystallite size achieved, which help to generate reactive entities such as •OH and O2•− in addition to the great role of holes (h+) and impede the recombination of charge carriers e-/h+.

Hydrogen-based mineral phase transformation of bastnaesite: Detailed assessment of physicochemical properties and flotation behavior

Iron-bearing rare earth ores are valuable mineral resources, and the hydrogen-based mineral phase transformation (HMPT) process has significant development potential. In this study, the changes in physicochemical properties and flotation behavior of bastnaesites subjected to HMPT were investigated. The results show that bastnaesite decomposed slowly below 600 °C, but increased roasting temperature and time enhanced the decomposition, resulting in a roasted product with over 85 % rare earth oxide (REO) grade. HMPT also increased the initial pH of the flotation pulp from about 7.5 to 11.0 and increased La and Ce ion concentrations. By increasing the dosage of SHA, flotation recoveries comparable to the raw ore can be achieved. The HMPT process converted bastnaesite to REOF, which formed complex phases such as Ce7O12 and REF3 when exposed to air. This process resulted in significant damage to the particle structure, increased porosity, reduced geometric particle size, and improved wettability. After HMPT, Ce on the particle surface existed predominantly as Ce4+, which formed Ce(OH)4 precipitation during flotation, inhibiting SHA adsorption. The increased particle porosity facilitated deeper SHA penetration and greater adsorption, resulting in higher SHA dosage compared to the raw ore.

Advanced Free Radical Scavenger for Proton Exchange Membrane Fuel Cells

Yttrium doped cerium oxide (CeO2·Y2O3) was studied as a free radical scavenger for proton exchange membrane fuel cells (PEMFCs). The CeO2·Y2O3 was compared with pure CeO2 in MEAs with and without the free radical scavenger. Membrane Electrode assembly (MEA) after open circuit voltage (OCV) hold accelerated stress test (AST) show better performance retention with CeO2·Y2O3 than CeO2. CeO2·Y2O3 and CeO2 show slightly improved performance than pristine MEA without free radical scavenger. X-ray fluorescence (XRF) confirmed the improved Ce ions retention with CeO2·Y2O3 than pure CeO2, indicating improved stability of CeO2 after doping with Yttrium. Furthermore, ex-situ Fenton study with inductively coupled plasma mass spectrometry (ICP-MS) analysis shows better stability of Ce in CeO2·Y2O3. This study shows that yttrium-doped cerium oxide has better stability against dissolution and enhances the stability of polymer components against free radicals than CeO2.

Cerium(III)-induced structural transformation of hexagonal birnessite: Effect of mineral phase transition on arsenite transport and valence changes

The widespread mining and application of rare earth elements (REEs) have led to their continuous accumulation in the environment, with increasing concentrations in soil. The interaction between the most abundant REEs, cerium (Ce), and the prevalent hexagonal birnessite (HB) in the environment is worth attention. HB is one of the most effective metal oxides for the oxidation of arsenite [As(III)] and subsequent adsorption, and thus for arsenic (As) immobilization. Therefore, in this study, we investigated the effect of the presence of Ce(III) ion on the HB formation process and the influence of generating minerals on the oxidation and removal of As(III). Research has found that the interfacial reactions of REEs in manganese (Mn) minerals not only affect their cycling but also alter the properties of the Mn minerals, thereby affecting the environmental fate of As. The results indicated that the presence of Ce ions affected the structure of HB during mineral synthesis and reduced the crystallinity of the conversion products. Their substitution for Mn(IV) in the lattice increased the specific surface area of minerals, reduced particle size, and produced more hydroxyl groups that were conducive to the immobilization of As(III). Meanwhile, Ce(III) was oxidized to Ce(IV) during the formation of Ce-bearing hexagonal birnessite (Ce-HB), and CeO2 nanoparticles were formed on the mineral surface and the removal rate of As(III) by Ce-HB was greatly improved. When the As concentration was lower than 6 mg·L−1, the removal effect of Ce-HB could reach the drinking water standard. However, the oxidation rate decreased due to the decrease in the proportion of Mn(IV). This study fundamentally reveals the behavior of HB coexisting with Ce in the migration and transformation of As(III) in the environment.

A Meso Butterfly-Like Ce(III)-Containing Antimonotungstate with Catalytic Activity for Synthesizing Isoindolinones.

A unique meso Ce(III)-containing antimonotungstate, {Na(OAc)(H2O)2[Ce4(tar)(Htar)2(Sb2W21O72)2(H2O)7]}244- (Ce4tar3; H4tar = tartaric acid), consisting of two enantiomeric parts with a butterfly-like configuration, was successfully synthesized by a one-pot in situ method and characterized. The coordination of d- or l-tar ligands induced the formation of Dawson-like {Ce2Sb2W21} with right or left configurations, thereby determining the d/l configurations of {Na(OAc)(H2O)2[Ce4(tar)(Htar)2(Sb2W21O72)2(H2O)7]}22-. Carboxyl groups link these two enantiomeric parts with Ce(III) ions from each other around the symmetric center of the P1̅ space group. The three types of tar ligands exhibit distinct coordination modes, and all coordinate with at least one W(VI) atom using one carboxylate oxygen atom and one α-OH. Ce4tar3 represents the largest case among those meso-dl-tar-functionalized polyoxometalates. Furthermore, Ce4tar3 exhibits excellent catalytic activity for synthesizing isoindolinones via the three-component reaction of 2-acetylbenzoic acids, amines, and phosphine oxides.

Ce-doped ZnO nanonails synthesized by a simple thermal evaporation method for photocatalytic degradation

One-dimensional (1D) nanomaterials have garnered significant scientific and technological attention due to their potential applications in electronics devices, gas sensing, energy conversion, and photocatalysis. However, the development of a simple and low-cost technique for 1D nanostructure synthesis remains a challenge. The doping of ZnO nanostructures has proven to be an effective way to improve their internal properties. In this work, one-dimensional ZnO and Ce-doped ZnO nanorods and nanonails were synthesized by a simple thermal evaporation method using different weight ratios of ZnS and CeO2 precursor powders in a catalyst-free process. The effects of cerium doping concentration on the structural, morphological, and optical properties of the as-prepared samples were investigated. XRD analysis confirmed that the crystal structure was converted from the cubic ZnS phase to the hexagonal ZnO phase with increasing annealing temperatures. The UV–Vis spectra showed that the optical absorption edge of Ce-doped ZnO samples was slightly red-shifted. Additionally, the band gap energy decreases with increasing cerium concentration. SEM images showed that the morphology of the structures obtained changed from nanorods to nanonails as the Ce content increased. The incorporation of Ce ions into the ZnO matrix has been successfully confirmed by HRTEM, Raman, and EDX analysis. Photocatalytic activity studies showed that Ce-doped ZnO samples exhibited significantly enhanced photocatalytic performance compared to pure ZnO for the degradation of rhodamine B under UV radiation. These results may suggest the use of heterogeneous photocatalysis as an efficient, cheap, and environment-friendly alternative for the removal of pollutants from water and the use of Ce-doped ZnO as a promising candidate.

Enhancing Efficiency of Dye-Sensitized Solar Cell using Mn or Ce Doped and Co-doped ZnO Photoanodes with Lawsonia Inermis Natural Dye

Abstract In the present research paper, Mn (transition metal) and Ce (rare earth metal) doped and co-doped ZnO nanoparticles were synthesized using a cost-effective sol-gel technique. As synthesized samples were characterized using X-ray diffraction and field emission scanning electron microscope to examine the structure and morphology respectively. The optical properties were examined by UV-Visible and photoluminescence spectroscopic techniques. The synthesized samples were used as photoanode for the fabrication of dye-sensitized solar cell (DSSC). The utilization of a photoanode, containing Mn and Ce doped and co-doped in ZnO, in DSSC leads to a significant enhancement in photovoltaic conversion efficiency with natural dye lawsonia inermis. Different combinations of Mn or Ce doped and co-doped ZnO nanoparticles were used for testing their effectiveness as photoanode in DSSC. It was observed that the efficiency for Mn and Ce co-doped ZnO photoanode-based DSSC was found to be 0.2118%, which is approximately a 750% increase as compared to bare ZnO photoanode based DSSC. The enhancement in the efficiency of DSSCs was due to the formation of a blocking layer by Mn ions which helps to stop the flow of electrons backward and the broadening of the spectrum region with the help of Ce ions using up/down conversion process also helps to achieve higher efficiency. This enhancement in the efficiency of DSSC may be attributed to the synergic effect of Mn and Ce.

Theoretical study of adsorption of gas (CO, CO2, NH3) by metal (Au, Ag, Cu)-doped single-layer WS2.

The adsorptions of gas (CO, CO2, NH3) by metal (Au, Ag, Cu)-doped single layer WS2 are studied by density functional theory. The doping of metal atoms makes WS2 behave as n-type semiconductors. The final adsorption sites for CO, CO2, and NH3 are close to the atomic sites of the doped metal. The adsorptions of CO and NH3 gases on Cu/WS2, Ag/WS2, and Au/WS2 are dominated by chemisorption. The doped metal atoms enhance the hybridization of the substrate with the gas molecular orbitals, which contributes to the charge transfer and enhances the adsorption of the gas with the material surface. The adsorptions of CO and NH3 on Cu/WS2 and Ag/WS2 allow favorable desorption in a short time after heating. The single-layer Cu/WS2 is proved to have the potential to be used as a reliable recyclable sensor for CO. This work provides a theoretical basis for developing high-performance WS2-based gas sensors. In this paper, the adsorption energy, electronic structure, charge transfer, and recovery time of CO, CO2, and NH3 in the doped system have been investigated based on the CASTEP code of density functional theory. The exchange correlation function used is the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA). The TS (Tkatchenko-Scheffler) dispersion correction method was used to involve the effects of van der Waals interaction on the adsorption energies for all adsorption system. The ultrasoft pseudopotentials are chosen and the plane-wave cut-off energies are set to 500eV. The k-point mesh generated by the Monkhorst package scheme is used to perform the numerical integration of the Brillouin zone and 5 × 5 × 1k-point grid is used. The tolerances of total energy convergence, maximum ionic force, ionic displacement, and stress component are 1.0 × 10-5eV/atom, 0.03eV/Å, 0.001Å, and 0.05 GPa, respectively.

Significantly enhanced piezoelectric response in Aurivillius Bi3TiNbO9 ceramics simply by Ce doping

Bi3-xCexTiNbO9 (BTN-100xCe, x = 0, 0.01, 0.03, 0.05, 0.07, 0.09, 0.11) piezoelectric ceramics with ultra-high Curie temperature were fabricated by a solid-state sintering method, and the effect of Ce doping on the structure, dielectric and piezoelectric properties of the ceramics was investigated. All ceramic samples possess a single Aurivillius phase and Ce ions enter both A- and B-sites. Dense microscopic morphology with a remarkable decrease of grain size can be observed due to Ce doping. The resistivity markedly increases after Ce modification, and a significantly enhanced piezoelectric constant d33 of 17.1 pC/N can be achieved in the optimized BTN-7Ce ceramics, which is nearly 6 times that of pure Bi3TiNbO9 (d33 ≈ 3 pC/N). In addition to ultra-high Curie temperature (TC = 886.5 °C) and relatively high resistivity (ρ = 1.2 × 106 Ω cm @ 500 °C), the BTN-7Ce ceramics should be very promising for piezoelectric sensor under the application in high temperature conditions.

Electromagnetic Plasma Reactor: Fermionic Derivation Tools

From the developed theories around of an electromagnetic plasma reactor designed and controlled through geometrical invariants has been demonstrated the existence of derived products from electromagnetic plasma as are phonons, fermions, ions, free electrons and protons, magnetic and electric drifts, which can be used as complement or development part of the electromagnetic propulsion system where the fermion flow can produce a ionic force that could be used as propulsion force considering shock waves produced with an electric field on these ions. Likewise, experimentally and considering direct current and voltage in a constant regime, has been detected as ionic wind which carries fermion products to be used too in the possible electromagnetic propulsion. These are other products proposes of previous works. Likewise, through of a caption and detection camera, is measured the electromagnetic properties of the ionic flow of the space derived from the electromagnetic plasma, and is proposed a curvature energy signal of magnetic nature to measure the force and control the electromagnetic plasma and its ionic flow.

Theoretical Study of Co-Doping Effects with Different Ions on the Multiferroic Properties of BiFeO3 Nanoparticles.

Using a microscopic model and the Green's function theory, the size and co-doping effects on the multiferroic and optical (band gap) properties of BiFeO3 (BFO) nanoparticles are investigated. The magnetization increases, whereas the band gap energy decreases with decreasing nanoparticle size. The substitution with Co/Mn, Nd/Sm, Ce/Ni, and Cd/Ni is discussed and explained on a microscopic level. By the ion co-doping appear different strains due to the difference between the doping and host ionic radii, which leads to changes in the exchange interaction constants for tuning all properties. It is observed that by co-doping with Nd/Sm at the Bi site or with Co/Mn at the Fe site, the multiferroic properties are larger than those by doping with one ion. Moreover, by doping with Ni, the multiferroic properties are reduced. But by adding another ion (for example Ce or Cd), an increase in these properties is obtained. This shows the advantages of the co-doping, its flexibility, and its greater possibility of tuning the multiferroic properties compared to single ion substitution. The band gap energy decreases for all co-dopants. The polarization increases with increasing magnetic field. This is evidence of magnetoelectric coupling, which is enhanced by co-doping with Co/Mn. The observed theoretical results are in good qualitative agreement with the existing experimental data.

Hard X-ray nanoprobe to study the emission properties of Ce-doped YAG wafer by using XEOL and TR-XEOL

In this study, the valent state, emission properties, and decay lifetime of Ce-doped yttrium aluminum garnet (Y3Al5O12, YAG) wafer have been probed using X-ray absorption (XAS), X-ray excited optical luminescence (XEOL), and time-resolved XEOL (TR-XEOL). The XAS spectrum demonstrates that Ce ions are in the trivalent state, and the XEOL spectrum exhibits typical 5 d1-4f1(2F5/2) and 5 d1-4f1(2F7/2) transitions of Ce3+ ions, with emission peaks at ∼528 nm and 582 nm, respectively. From the TR-XEOL measurements, the decay lifetimes of 5 d1-4f1(2F5/2) and 5 d1-4f1(2F7/2) transitions are about ∼90 ns and ∼100 ns, respectively. We found that the reabsorption effects will not only make the 5 d1-4f1(2F7/2) transitions have longer decay lifetime, but also the higher emission intensity. By comparison with photoluminescence (PL) and time-resolved PL using a pulsed laser at 375 nm, we found that the emission spectra and decay lifetime of Ce-doped YAG (111) wafer are different when using X-ray irradiation. The longer decay lifetime measured by TR-XEOL compared TR-PL are caused by high X-ray dose irradiation. In addition, high X-ray doses provided by the nano-focus X-ray beam will be influenced the emission behaviors of Ce-doped YAG (111) wafer. Which phenomena have been demonstrated by using time-dependent XEOL with irradiation for 10 h. These peculiar emission behaviors observed with a hard X-ray nanoprobe may be able to provide important information on quantum technologies and scintillators used in hard X-ray detectors.

Influence of cerium addition and redox state on silicate structure and viscosity

AbstractThe viscosities of Ce‐free and Ce‐bearing (∼1.3 mol%, ∼6.5 wt.% Ce2O3) soda lime silicate (window glass) melts were measured with respect to oxidation state. Experiments were performed isothermally using a concentric‐cylinder viscometer on melts equilibrated with successively reducing CO–CO2 gas mixtures within a gas tight vertical tube furnace at 1 atm. Viscosity measurement and sampling were performed at the end of each melt reduction step. Further, viscosities in the glass transition temperature range were estimated using the shift factor method applied to glass transition temperature values determined using differential scanning calorimetry (DSC) measurements on quenched glasses. The Ce speciation at each stepwise melt reduction was probed using Ce L3‐edge X‐ray absorption near‐edge structure (XANES) spectroscopy, while structural information upon Ce addition and reduction was provided by Raman spectroscopy. The viscosities of these materials remain constant at this level of Ce addition and do not vary significantly with redox state at high temperature. Conversely, viscosity values in the glass transition temperature range increase upon both Ce addition and reduction. Our analysis, based on the glass composition analyses obtained via electron probe microanalyzer (EPMA), viscosity calculations, and observations of silicate structural changes, leads to the conclusion that the observed viscosity increase around the glass transition temperature is explained by the high ionic field strength of Ce ions as well as the polymerization behavior of the silicate matrix occurring during reduction of Ce. Because of its low concentration, resulting from its low solubility, Ce redox changes exert only minimal effects on the viscosity of this melt.