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Incorporation of a dopant, an impurity, and a non-superconducting second phase in superconducting films is an important approach to control the superconducting property. In spite of extensive studies on the oxide superconducting nanocomposite films, the influence of additive materials on the phase formation and nanostructure is unclear in the iron based superconducting chalcogenide, Fe(Te,Se). Here, the incorporation of oxide or chalcogenide in Fe(Te,Se) films using pulsed laser deposition was investigated. When TiO2, Fe2O3, Yb2O3, CeO2, Nb2O5, SnSe, or SnTe was added, c axis oriented Fe(Te,Se) films were not formed. On the other hand, c axis oriented Fe(Te,Se) films were obtained when SrTiO3 was added at the content of 3–10 areal% and the deposition temperature of 400–550 °C. While a characteristic nanostructure originating from SrTiO3 was not observed for the small SrTiO3 content (3%), the nanocomposite structure comprising of nanocolumns was formed for the large SrTiO3 content (10%). The critical temperature was 8.2–8.6 K in the Fe(Te,Se) + SrTiO3(3%) thin films deposited at 500 °C, while the critical temperature was ∼10 K in the Fe(Te,Se) films. The irreversibility curve behavior was varied by the structural change in the natural pinning centers, which resulted from the SrTiO3 addition, while the pinning effect by the nanocomposite structure was concealed by the Tc degradation in the case of the large amount of SrTiO3 addition. Considering the dependence of the film structure on the additive material and the incorporation content, the superconducting properties of Fe(Te,Se) films should be designed. [ABSTRACT FROM AUTHOR]

The isotopic shifts of 149Sm–150Sm and 157Gd–158Gd have often been observed in meteorites and lunar surface materials, because they result from the neutron-capture reactions associated with secondary neutrons produced by cosmic-ray irradiation. While the Sm and Gd isotopic shifts can mainly be used for the estimation of thermal neutron fluences that of 167Er–168Er has recently been applied in the estimation of epithermal neutron fluences. The systematic isotopic dataset of Sm, Gd and Er helps us to consider the details of planetary materials' cosmic-ray exposure conditions using the balance of the fluences between thermal and epithermal neutrons. This paper reviews a series of isotopic variations of Sm, Gd, and Er in association with neutron-capture reactions for the application of planetary sciences. As a new attempt and possibility for better understanding the neutron fluence and its energy distribution, the use of Yb isotopic variation is then discussed using two different data sources, namely lunar regolith and the Oklo natural reactors. Finally, the preliminary result for the precise isotopic measurement of Yb is presented from the viewpoint of chemical separation and instrumental improvement. [ABSTRACT FROM AUTHOR]

Two new ytterbium coordination compounds Yb(HPTC)(H2O)2 (Yb1) and Yb(HPTC)(Phen) (Yb2) were obtained using 10-carboxyperylene-3,4,9-tricarboxylate ion (HPTC3−) as a sensitizer. Both coordination compounds exhibited intense NIR-II luminescence upon excitation in the visible range and formed stable suspensions with nanoparticles of 50–70 nm in size in an aqueous solution of sodium alginate. Both complexes demonstrated non-toxicity up to at least 25 mg L−1 in two cell cultures: cancer cells MCF7 and embryonic cells HEK293T – making them suitable for bioimaging. For both complexes, the accumulation in cells was directly measured and it was shown that the accumulation of Yb2 was the same for both cell types (0.51–0.52 πg per cell), while Yb1 demonstrated selective accumulation in cancer cells (0.04 πg per cell for HEK293T and 7.00 πg per cell for MCF7). Thus, Yb1 can also be proposed as a selective vis-excited NIR emitting bioprobe. [ABSTRACT FROM AUTHOR]

Silver and lanthanide (Tm3+, Yb3+) doped oxyfluoride glasses have been prepared by melt-quenching method. The absorption of the glasses was measured in the range from 350 to 550 nm revealing the absorption edges of Ag nanoclusters and Tm3+ transition. The photoluminescence spectra of the glasses were detected in the range from 400 to 1100 nm under excitation in the range from 300 to 500 nm. The photoluminescence excitation spectra showed that Ag nanoclusters and Tm3+ ions can effectively harvest energy in UV-range and convert to visible and infrared (through emission by Yb3+ ions) ranges making the glasses perspective as white light emitters and solar spectrum downconverters. [ABSTRACT FROM AUTHOR]

In this work, 5at.% Yb:Lu2O3 transparent ceramics were air‐annealed at different temperatures to eliminate oxygen vacancies for laser performance improvement. The influence of annealing temperature on microstructures, optical quality, and laser performance was investigated comprehensively. The ceramics HIP (Hot isostatic pressing) post‐treated at 1750°C and annealed above 1100°C show a significant optical quality decrease due to residual pore expansion, and the ceramic sample annealed at 900°C shows better laser performance than others. The maximum output of 2.88 W was obtained at 1033.3 nm with a slope efficiency of 37.4% under a quasi‐continuous wave (QCW) mode. Note that 5at.% Yb:Lu2O3 transparent ceramics HIP post‐treated at 1550°C still keep good transparency even when being annealed at 1300°C due to less residual compressed pores. The highest slope efficiency is about 73.8% with a maximum output power of 2.84 W under QCW. Fine‐grained and dense Yb:Lu2O3 transparent ceramics could be annealed at higher temperatures to eliminate oxygen vacancies more thoroughly to improve laser performance. [ABSTRACT FROM AUTHOR]

The Sanjiang Tethyan Orogen plays a pivotal role in elucidating the geodynamic processes related to the evolution of the Paleo-Tethys Ocean. Research on the Gicha Complex within this orogen is imperative for comprehending the intricate evolution of the region. This study presents new findings from zircon U‒Pb dating, Hf isotope analysis, and whole-rock elemental analyses of gabbro, olivine gabbro, and the recently discovered mylonitic rhyolite and diabase in the Gicha Complex. The zircon U‒Pb dating yields ages of 703 ± 3 Ma for the diabase, 296 ± 2 Ma for the gabbro, and 231 ± 1 and 228 ± 2 Ma for the mylonitic rhyolite, demonstrating that these rocks record the extended evolution from the breakup of Rodinia to the closure of the Paleo-Tethys Ocean. The Neoproterozoic diabase samples exhibit shoshonitic and arc-like geochemical properties, with positive zircon εHf(t) values ranging from 1.1 to 3.7 and high Th/Yb values ranging from 1.34 to 3.07, suggesting that they were generated by partial melting of enriched subduction-modified lithospheric mantle in an active continental margin. The early Permian gabbro samples are part of the tholeiitic series and exhibit low SiO2 and K2O contents; depletions in Nb, Ta and Ti; and enrichment in Pb, indicating derivation from a combination of depleted mantle peridotite and subduction-related components. The whole-rock geochemical features suggest that these rocks formed in a back-arc setting featuring a small, mature ocean basin. The mylonitic rhyolite samples exhibit weakly peraluminous characteristics (A/CNK = 0.98–1.12) with high-K calc-alkaline geochemical features. The samples are depleted in Ba, Nb, Ta, and Ti and enriched in Th, U, Pb, and LREEs and exhibit negative to positive zircon εHf(t) values ranging from − 0.5 to + 5.9, indicating that they originated from partial melting of Meso-Neoproterozoic juvenile lower crust. Geochronological, petrological, and geochemical analyses indicate that the subduction of oceanic crust occurred along the western margin of the Yangtze Block until the late Neoproterozoic (~ 703 Ma). [ABSTRACT FROM AUTHOR]

The Lord Howe Volcanic Complex (LHVC) is part of a seamount chain associated with the detached continental crust of Zealandia. We present petrographic and geochemical data for the LHVC, including the first reported data for Balls Pyramid and the first trace element data for Lord Howe Island, clarifying the tectonic affiliation and general mantle source characteristics. Classification and discrimination diagrams based on concentrations and ratios of immobile elements, such as rare earth and high field strength elements, Th, Ti, Y, and Mg, show the LHVC comprises transitional to alkali basalts and at least two, and probably three, shield building complexes, consistent with an intraplate tectonic setting. Primitive-mantle normalised trace element patterns, variation in Dy/Yb for a restricted range of Dy/Dy*, Zr/Yb > 90, and variations in Zr/Hf and P2O5/TiO2 through the eruptive sequences indicate the mantle source may be a laterally heterogeneous enriched garnet peridotite that has undergone varying degrees of partial melting and carbonatitic metasomatism, both within the LHVC and along the Lord Howe Seamount Chain. The LHVC is thus an ideal natural laboratory for probing the probability of small intraplate volcanic fields originating via mantle plumes or from previously subducted slabs stagnating at the mantle transition zone. [ABSTRACT FROM AUTHOR]

In recent years, the rare earth doped upconversion luminescent materials have been widely used in many fields. In practical applications, we observed that various dopants have distinct effects on different substances to some extent. In this context, we have successfully synthesized a dual-mode-excited Ca3TeO6 double perovskite. After introduce the Yb3+/Er3+ ions pair, the designed phosphor can emit green and red luminescence under 980 nm and 1550 nm excitation, respectively, making it suitable for diverse scientific and technological applications. The potential up-conversion mechanisms driven by different excitation sources have been investigated. Moreover, it was discovered that adjusting the molar ratio of Er3+ and Yb3+ ions enhances the performance of the studied materials, rendering them well-suited for application as a high-quality optical thermometer based on the FIR technique. Our results clearly indicate that Er3+/Yb3+ co-doped Ca3TeO6 phosphors allows for multiple optimizations and control of material properties, showcasing great potential for applications in various field. [ABSTRACT FROM AUTHOR]

In this study, trivalent rare-earth ion (Eu3+, Gd3+, and Yb3+)-substituted silicate-based bioactive glass scaffolds were prepared by robocasting method using sol–gel-derived bioactive glass powders for tissue engineering applications and cancer therapy. The structural, morphological, and mechanical properties of the prepared scaffolds as well as their in vitro bioactivity in simulated body fluid (SBF) were investigated in detail. In addition, an anticancer drug (5-FU) adsorption and release behavior of the scaffolds was studied as a function of time. In vitro, cytotoxicity and alkaline phosphatase activity were investigated using human skin fibroblast BJ and osteosarcoma SaOS-2 cells. Results showed that using lanthanide ion-containing (0.5, 1, 3, and 5 wt%) sol–gel-derived bioactive glass powders it was possible to successfully fabricate periodic, mesh-like patterned robocast glass scaffolds. All of the scaffolds prepared in the study sintered at 675 °C showed an amorphous structure. The compressive strength of scaffolds was in the range of 8.8 MPa to 13.6 MPa and the highest strength values were obtained in the Yb3+-containing scaffolds. Hydroxyapatite formation was obtained for the scaffolds immersed in SBF for 28 days. The fluorouracil adsorption amount was calculated to be ~ 25% for all types of scaffolds and the cumulative drug release was in the range of 20–25% depending on the dopant concentration. Results of the in vitro cell culture experiments revealed that all of the scaffolds fabricated in the study were not cytotoxic to fibroblast and osteosarcoma cells for up to 7 days under in vitro conditions. An increase was obtained for the ALP activities for both types of cells as the incubation time was increased. [ABSTRACT FROM AUTHOR]

Rare-earth substituted nanocrystalline hexagonal strontium ferrites with chemical formula Sr1 − xPrxFe12O19 (0 ≤ x ≤ 0.1) and Sr0.95Re0.05Fe12O19 (Re = La, Pr, Nd, Dy, Yb), were prepared by sol-gel autocombustion method. The effects of calcination temperature, rare earth ion concentration and rare earth ion radius on the structure and magnetic properties of nano-sized hexagonal strontium ferrites were investigated. X-ray diffraction (XRD) and Vibrating sample magnetometer (VSM) were applied for the systematical investigation of phase composition, crystal structure and magnetic properties of the samples respectively. The suitable calcination temperature of nanocrystalline strontium ferrites was determined to be 900 ℃, which was attributed to the relationship between the calcination temperature and the rotation of the domain wall. The coercivity (Hc) of Sr1 − xPrxFe12O19 reached a maximum at x = 0.05 and the saturation magnetization (Ms) decreased with the increase of Pr substituting content. This reduction followed the spin canting and magnetic dilution which results in the dislocation of super exchange interactions. For Re-substituted samples, the Hc increased with the decreasing ionic radius of substituted elements, while the Ms slightly decreased in comparison to the non- substituted sample. The synthesized samples could be used in permanent magnets, high-density magnetic recording medium, and microwave equipment. [ABSTRACT FROM AUTHOR]

In the present study, an anodizing process was applied to aluminum alloy (AA2024-T3) to enhance interlocking in dissimilar joints with glass fiber-reinforced polyetherimide (GF/PEI) composite, using ytterbium-doped laser fiber welding as a heat source. A factorial Central Composite Design (CCD) was conducted to determine the most appropriate processing and optimization parameters, with lap shear strength (LSS) as the response variable. The obtained and fractured joints were characterized. Anodizing effectively improved the interlocking between dissimilar joints, resulting in LSS values of around 16 MPa. Surface impressions were observed in joints with lower shear values, likely due to the ineffective heat distribution in the processed joint. In the AA2024-T3 alloy, the annealing process occurred, beginning with the segregation of the alloy elements at the grain boundaries and subsequently reducing its hardness. The SEM analysis of the laminate in the best welding condition revealed a well-established fracture surface, with cusps, fibers covered by the polymer matrix, and river marks, indicating good consolidation of the process applied to the metal/polymer junction, which is consistent with the highest shear values obtained. These findings have important implications for future research and industrial applications and can help advance the understanding of these materials and processes. [ABSTRACT FROM AUTHOR]

V2O5 and 1 mol% RE-doped V2O5 (RE = La, Er, Yb) thin films were prepared using the sol–gel method. The structure and morphology of the prepared films were investigated using XRD, HRTEM, SAD electron microscopy, FESEM, and EDS. XRD analysis revealed a strong c-axis orientation and noncrystalline structure. Gaussian fitting of the XRD peaks indicates a decrease in the crystallite size with RE doping, which is attributed to the increased internal stress and lattice distortion. TC analysis showed a preferred orientation along the c-axis. HRTEM observations confirmed the crystallinity of the nanosheets. The absorption, transmittance, and reflectance spectra were measured for normal-incidence light in the wavelength range 190–1100 nm. The obtained spectra were used to investigate the linear and non-linear optical properties via various optical parameters, including static refractive index, optical band gap energy, Urbach band tail energy, dispersion energy parameters using the Wemple and DiDomenico (WDD) single-oscillator model, nonlinear refractive index and first and third optical susceptibilities. The doped films exhibited lower optical bandgaps and the investigated linear and nonlinear optical parameters showed significant effects in RE-doped films compared to pure V2O5, indicating potential for various optical applications. The optical limiting of the prepared films was studied using two laser sources (650 nm and 533 nm), revealing significant optical limiting for RE-doped films compared with pure V2O5 films, where the optical limiting effect is related to the oscillator strength and Urbach band tail energy. This study shows that rare-earth doping has a significant impact on the structural and optical properties of V2O5 thin films, making them promising materials for various applications, such as optoelectronic devices and nonlinear optical applications. [ABSTRACT FROM AUTHOR]

The crustal thickening process is the key to understanding global tectonic evolution and climatic patterns. The Sr/Y, (La/Yb)N ratios of granitoids can be used to quantitatively estimate crustal thickness and reconstruct the crustal thickening process. We present the geochemical characteristics, petrogenesis, and geodynamic implications of Eocene dioritic enclaves (monzodiorite), host granitoid rocks (monzonite), and granite dikes of southern Tibet to reveal the crustal thickening process underway during the collision of India and Asia. The Quxu dioritic enclaves were produced by magma mixing and represent mafic end member. The adakitic host rocks were generated by partial melting of lower crust with normal thickness. The high Sr/Y, (La/Yb)N ratios of the Quxu host rocks were inherited from their magma source region. The ∼40% fractional crystallization of amphibole from magma resembling Quxu host rocks formed the Quxu granite dikes. The continuous crustal thickening history determined by the locally weighted regression analysis shows that the crustal thickness of the Lhasa terrane during 50-45 Ma was no more than 36-46 km, and the crust thickened quickly during the syn-collisional period. [ABSTRACT FROM AUTHOR]

The production method of no-carrier added Lutetium-177 (177Lu) was developed from a neutron-activated natural ytterbium (Yb) using column chromatography separation method. Dowex W50 X8 resin and a combination of alpha-hydroxyisobutyric acid (α-HIBA) and hydrochloric acid (HCl) were used as column filler and eluent, respectively. HCl increased the desorption and separation between 177Lu and Yb at a concentration of 0.25 M, while the optimal α-HIBA concentration was 0.15 M, resulting in 177Lu yield of 81.19 % and low impurities (175Yb: 9.28 %, and 169Yb: 2.09 %). Nevertheless, further study using an enriched 176Yb target is essential to significantly increase the specific activity of 177Lu. [ABSTRACT FROM AUTHOR]

(La0.2Yb0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 (HEZ) has shown considerable promise as a novel thermal barrier coating material for temperatures exceeding 1300 °C. This study systematically investigates the interfacial stability of (La0.2Yb0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 with yttria-stabilized zirconia (YSZ), which is of paramount importance for its application in double-layer thermal barrier coatings. Our findings highlight that rare earth elements with a smaller radius diffuse more easily into the YSZ lattice, resulting in a broader diffusion zone. Simultaneously, the incorporation of rare earth elements into the YSZ lattice inhibits tetragonal-to-monoclinic phase transformation. Compared to La2Zr2O7/YSZ, HEZ/YSZ demonstrates superior high-temperature stability, which could be attributed to the higher fracture toughness and lower thermal expansion coefficient of HEZ, the absence of t-m transformation and the formation of a continuous gradient diffusion layer that minimizes interface stress. This study offers a practical strategy for designing materials for durable double-layer thermal barrier coating systems. [ABSTRACT FROM AUTHOR]

Structural changes of Er- or Yb-ion doped LiNbO3 (LN) nanocrystals were studied in relation to the high-energy ball milling process. The evolution of the size of the particles and the formation of different phases were followed by dynamic light scattering and X-ray diffraction measurements, while the electronic transitions of rare-earth (RE) ions were investigated by absorption spectroscopy in the infrared spectral range. During the milling process, RE ions left the crystal lattice and an RE2O3 phase appeared to an increasing extent next to the LN. The change in the absorption spectra and the phases formed during the grinding process were found to be very similar for both investigated RE ions and were independent of their original concentration in the starting crystal samples. The extent of the RE loss was found to be 90% after 100 min of wet grinding. [ABSTRACT FROM AUTHOR]

Lawsonite is important as a carrier of H2O in subduction zones and as a petrological tracer. The trace-element content of lawsonite in mafic rocks has been used as a record of fluid–rock interactions but has received less attention in metamorphosed oceanic sediments. This study documents the major, and trace-element composition, together with 87Sr/86Sr isotopic ratios, of the different lawsonite types identified in the upper units of the Schistes Lustrés complex of the Western Alps, a paleo-accretionary prism of the Liguro-Piemont slow-spreading ocean subducted up to 40 km. The lawsonite-rich upper units of the Schistes Lustrés complex are principally composed of metamorphosed pelitic sediments and carbonates. Lawsonite content reaches 40 vol.% in the rock matrix and in veins. All lawsonite types originate from prograde metamorphic reactions which occurred up to peak metamorphism. Lawsonite compositions have been measured in situ with electron microscopy, microprobe, and laser-ablation mass spectrometry. Lawsonite separates have been measured for Sr content and 87Sr/86Sr isotopic ratios using TIMS. Bulk rock compositions have been measured with ICP-OES and ICP-MS. Analysis contamination by minute retrograde white mica inclusions in lawsonite crystals precluded using univalent cations for petrological interpretations. For other trace elements, the variability of lawsonite appears extremely high, with crystal compositions varying between samples and between crystals in individual samples. However, clear patterns emerge between lawsonite types, reflecting equilibrium and out-of-equilibrium processes unrelated to pressure–temperature conditions. At crystal scale, textural hourglass zoning predominates in lawsonite from the schist, while growth zoning is found in both schists and veins. The combination of both mechanisms results in spectacular zoning in Ti and in rare-earth element contents spanning four orders of magnitude. Over time, the La/Yb ratio decreases strongly (from ~100 to ~1), as La appears much more sensitive to surface effects leading to textural hourglass zoning. Interface-coupled dissolution–precipitation also contributes to decoupling of less mobile elements in the schist. This is best observed for Ti, but rare-earth element and chromium contents are affected too. These processes are considered to occur near closed-system conditions. Late lawsonite overgrowths with higher Sr contents are interpreted as reflecting system opening in the veins, yet sometimes observed in the schists. Strontium isotopic ratios measured on separated lawsonite crystals and on bulk rocks also show very large spreads. This indicates that the system did not equilibrate during blueschist-facies metamorphism, due to bulk rock heterogeneities during deposition and limited mineral reactivity at the local scale. Strontium isotopic ratios do not correlate with Sr content which rules out limestone devolatilization as the main driver of lawsonite overgrowths. In places, lawsonite is far more radiogenic than the host rocks, indicating either the destabilization of local Rb-rich phases (such as mica, illite, and smectite) or the infiltration of externally derived fluids. The overall compositional evolution of lawsonite records incremental system opening. However, lawsonite offers no evidence of large-scale mass transfer and external fluid influx in the Schistes Lustrés complex, even though the vein network is abundant and extends over time. [ABSTRACT FROM AUTHOR]

Bis(carbazolide) complexes M[3,6‐tBu2‐1,8‐(RC≡C)2Carb]2(THF)n (R=SiMe3, n=0, M=Ca, Yb; R=Ph, n=1, M=Ca, Yb; n=0, M=Yb) were synthesized through transamination reaction of M[N(SiMe3)2]2(THF)2 with two molar equivalents of carbazoles. The complexes feature M(η2‐C≡C)4 structural motif composed of M(II) ions encapsulated by four acetylene fragments due to atypical for alkaline‐ and rare‐earth metals η2‐interactions with triple C≡C bond. This interaction is evidenced experimentally by X‐ray diffraction, Raman spectroscopy in the solid state and by NMR‐spectroscopy in the solution. According to QTAIM analysis there are 4 bond critical points (3;−1) between the metal atom and each of the triple bonds, which are connected by a strongly curved, almost T‐shaped bond pathway. [ABSTRACT FROM AUTHOR]

In this study, the structural, electronic, optical, elastic, and thermodynamic properties of Ytterbium chalcogenides YbX (X = S, Se and Te) were computed within the first principles using generalized gradient approximation (GGA) as implemented in the pseudopotential plane wave approach. The equilibrium total energy for YbX (X = S, Se, and Te) was calculated as a function of the energy cutoff, k-point grid, and lattice parameter. An optimized lattice parameter of 5.6, 5.66, and 6.136 Å were calculated for YbS, YbSe, and YbTe, respectively. The energy band gaps of YbS, YbSe, and YbTe computed are 1.14, 1.32, and 1.48 eV, respectively. In addition, the low band gap (less than 3 eV) for ytterbium chalcogenides indicated that they may have potential applications in photovoltaic cells and laser diodes. Moreover, the negative dielectric function value for a certain frequency range indicates that these compounds are suitable for specific optical and microwave circuit applications. The result of elastic and thermodynamic property computation reveals that ytterbium chalcogenides are mechanically and thermodynamically stable, which can be useful in a variety of electronic device applications. [ABSTRACT FROM AUTHOR]

The possibility of using an atom chip and a diffraction grating to form a compact magneto-optical trap for ytterbium atoms, which can be used to develop compact atomic interferometers and optical clocks based on ultracold atoms, has been studied. An experiment on the laser cooling of the 171Yb and 174Yb isotopes in a first‑stage magneto-optical trap has been carried out to determine initial requirements for the mentioned elements. The design of the atom chip forming a magnetic field gradient up to 60 G/cm has been calculated. The optimal configurations of the diffraction grating that allow forming both the first- and second-stage magneto-optical traps have been evaluated. [ABSTRACT FROM AUTHOR]

This paper utilizes the TFA-MOD (Trifluoroacetate Metal-Organic Decomposition) method to prepare YB 2 C 3 O 7-δ (YBCO) superconducting films on a LaMnO 3 metal substrate. Using a self-made process curve, we investigate the nucleation and growth orientation of crystals at various temperatures under specific oxygen partial pressures (P O2). We successfully obtain an oxygen partial pressure-temperature phase diagram at a fixed time. This diagram provides critical insight into the trends that guide our regulation of parameters to ultimately achieve a relatively pure a -axis oriented YBCO film. Temperature and nucleation rate are important parameters that influence crystal nucleation orientation. The key conditions for producing a -axis-oriented YBCO films include low temperature, high Δ μ , and extended crystallization time. [ABSTRACT FROM AUTHOR]

Herein, Na 3 Y(VO 4) 2 :Nd3+,Yb3+,Ho3+/Er3+/Tm3+ are synthesized through the solid-state reaction method. By utilizing Yb3+-mediated energy transfer in Nd3+-sensitized various activators (Ho3+/Er3+/Tm3+) system, 808 nm excited multi-color upconversion luminescence is realized. Yb3+ plays an important role in energy transfer bridging, and the introduction of Yb3+ in Nd3+-sensitized system can significantly improve emission of activators by nearly two orders of magnitude. The main luminescence mechanism of Nd3+→Yb3+→Activators (Ho3+/Er3+/Tm3+) is proved via measuring the emission characteristics and luminescence decay curves. With efficient upconversion luminescence, the optical thermometry behaviors for Na 3 Y(VO 4) 2 :Nd3+,Yb3+,Ho3+/Er3+/Tm3+ are investigated. The maximum relative and absolute sensitivities are 1.08 % K−1 and 7.82 × 10−3 K−1 for Na 3 Y(VO 4) 2 :Nd3+,Yb3+,Er3+; 1.01 % K−1 and 4.22 × 10−3 K−1 for Na 3 Y(VO 4) 2 :Nd3+,Yb3+,Tm3+; and 1.08 % K−1 and 22 × 10−3 K−1 for Na 3 Y(VO 4) 2 :Nd3+,Yb3+,Ho3+, respectively. Based on the multi-color upconversion luminescence and high sensitivity thermometry performance, the Na 3 Y(VO 4) 2 :Nd3+,Yb3+,Ho3+/Er3+/Tm3+ phosphors have potential applications in fields of solid-state display and safety sign of high-temperature. [ABSTRACT FROM AUTHOR]

Due to their excellent nonlinear optical characteristics, tellurium-zinc glass and perovskite structures have gained significant attention. In particular, perovskite-type BaTiO 3 shows excellent potential for application in photonics devices. This study investigates structural, linear, and nonlinear optical properties of pure tellurium-zinc glass with embedded perovskites. Both glasses were prepared using the conventional melt-quenching method, and their structural modifications were analyzed through Raman spectroscopy. Optical absorption spectra revealed a redshift in the absorption edge, indicating a decrease in the band gap energy by the presence of the perovskite nanoparticles. When adding perovskite nanoparticles, Raman scattering results demonstrated decreased bridging and non-bridging oxygen ratio and structural changes. This suggests that the perovskite nanoparticles alter the local environment by affecting the Te-O- Zn2+ or Te=O bonds, resulting in a variation of the polarizability. Finally, the average nonlinear refractive for the glass containing perovskite nanoparticles is on the order of 0.3 × 10−18 m2 W−1 in the wavelength range of 580–990 nm, which is the same as of the pure glass. Thus, while the NP particles influence the arrangement of structural units and the linear optical response, their impact is not significant in the nonlinear refractive index. The observed modifications in structural and optical properties are relevant for advancing the use of perovskites in photonics. • Pure tellurium-zinc glass and perovskite BaTiO 3 tri-doped Er/Yb/Zn embedded in tellurium-zinc glass were prepared through the melt-quenching method. • Raman spectroscopy reveals changes in bridging and non-bridging oxygen ratios. • The band gap (E g) decreases in the presence of BaTiO 3 tri-doped Er/Yb/Zn from 3.5 to 3.2 eV. • The nonlinear refraction index was assessed by the femtosecond Z–scan technique. [ABSTRACT FROM AUTHOR]

Herein, a series of Y2W3O12:10%Yb3+/x%RE3+ (RE = Er/Ho/Tm) phosphors is prepared via a solid-state reaction. The upconversion and downshift luminescence properties of the phosphors were investigated under an excitation of 980 nm. The bright blue light emission from Tm3+ ion and the green and red light emissions from Ho3+(Er3+) ions were observed. The near-infrared light intensity of NIR-I (Tm3+, ∼850 nm), NIR-II (Er3+: ∼1550 nm; Tm3+: ∼1783 nm) and NIR-III (Ho3+: ∼2050 nm) were analyzed. In particular, the dramatic thermal enhancement phenomenon in visible and NIR regions was exhibited by the Y2W3O12:10%Yb3+/x%RE3+ (RE = Er/Ho/Tm) phosphors. Among them, the green light intensity of Er3+ ions increased 26.77 times, from 303 to 573 K. The NIR-II emission band (∼1783 nm) intensity of Tm3+ ions at 533 K increased 168.7 times compared to that at 313 K. The possible thermal enhancement mechanism is illustrated by the negative thermal expansion (NTE) and Frenkel defect of the Y2W3O12 host. Finally, the optical temperature sensing performances of Y2W3O12:10%Yb3+/x%RE3+ (RE = Er/Ho/Tm) samples are investigated according to the luminescence intensity dependence relationship on temperature. The maximum value of SR reached 4.24% K−1 at 353 K for Y2W3O12:10%Yb3+/0.6%Ho3+ phosphor. The results indicate that the Y2W3O12:10%Yb3+/x%RE3+ (RE = Er/Ho/Tm) phosphors possess anti-thermal quenching properties and are suitable for developing optical temperature sensors. [ABSTRACT FROM AUTHOR]

Bismuth-based fluoride nanoparticles have received a lot of interest as host materials for upconversion and have been recommended for lighting devices and biological applications. Bismuth is known to be an ecofriendly metal and as a result it is crucial to determine the true potential of bismuth-based nanoparticles for biological applications. However, even though these materials seem to be promising, K0.3Bi0.7F2.4:Yb,Er UCNPs are rarely explored for biological applications like photodynamic therapy (PDT). The ability of upconversion nanoparticles (UCNPs) to convert near-infrared (NIR) light into visible light makes them intriguing options for use in PDT. In this study we have succeeded in developing a new kind of UCNP (a rare earth-based host matrix/MB-based PDT drug, K0.3Bi0.7F2.4:Yb,Er@SiO2(MB)), with a particle diameter of less than 50 nm for NIR activated PDT. Upon excitation at 980 nm, emission from the UCNPs activates the photosensitizer methylene blue, resulting in the generation of reactive oxygen species. Our findings suggest that methylene blue-loaded UCNPs can be an intriguing framework for future NIR-triggered PDT in the treatment of cancer. We believe that such a PDT medication has the potential to become a theranostic nanomedicine for cancer treatment. [ABSTRACT FROM AUTHOR]

We use the methods of supercontinuum generation and nonlinear parametric transformations to develop a laser system that forms femtosecond pulses with a duration of several field oscillations and a central wavelength of 910 nm, which are synchronized with the seed radiation of the pump laser. The duration of femtosecond pulses was 20 fs at a repetition rate of 1 kHz and a pulse energy higher than 5 μJ. For further amplification to an energy higher than 40 mJ, a pump laser has been developed, and the main parameters of the parametric amplifier have been calculated. The developed laser system will be used as the starting part of the PEARL petawatt parametric laser system. [ABSTRACT FROM AUTHOR]

Sorption-luminescence method for ytterbium determination based on natural Transcarpathian clinoptilolite was proposed. The optimal luminophore preparation conditions are Yb(III) sorption on the precalcined at 300 °C clinoptilolite and further treatment of clinoptilolite-Yb(III) samples with 1-(2-pyridylazo)-2-naphthol and ethonium solution at pH 8.5. A sample of luminophore clinoptilolite-Yb(III)-PAN-ethonium was heated at 50°С. The linear calibration range of Yb(III) concentration with the detection limit of 5 ng·mL−1 is within 12.5–1000 ng·mL−1. The proposed method can be used for ytterbium determination in the presence of many rare earths. The method gives recoveries from 92.5% to 103% and RSD from 3.1% to 5.8% determination of ytterbium. [ABSTRACT FROM AUTHOR]

As gas turbine firing temperatures continue to increase for the sake of improved operating efficiency, the material's transition from Ni-based superalloy components toward ceramic matrix composites (CMCs) is concurrently in progress. Due to the complex nature of the turbine operating environment (envisaged ultrahigh temperatures, presence of water vapor, etc.), coating solutions for these CMCs are still on the forefront of design optimizations. Typically, rare-earth (RE) silicate environmental barrier coatings (EBCs) have been utilized to protect the CMCs from impinging water vapor; however, they lack the thermal insulation properties to enable continued use of simple and/or easily accessible bond coat materials (i.e., silicon). Combined thermal-environmental barrier coatings (T-EBCs) are such a multifaceted surface solution. T-EBCs have been considered in the past, but to this point have not been demonstrated to be technologically robust either due to high implementation costs or complex processing. This study utilizes and combines straightforward and well-established processes—such as plasma-sprayed 7 wt.% yttria-stabilized zirconia—to demonstrate the feasibility of MultiLayered T-EBCs comprised of zirconia-based oxides and RE silicate EBCs in a single coating. The results show that despite high thermal mismatch strains, the structures cannot only be deposited, but also in certain circumstances sustain cyclic thermomechanical loading. [ABSTRACT FROM AUTHOR]

The paper presents an automated system of radiochemical extraction of carrier-free Lu-177 from the ytterbium target. This system is based on the Russian equipment and software and includes three levels. The automated system utilizes the Simple-Scada 2 system, database management system MySQL, OwenCloud and OPC server from OVEN and InSAT. Sensors, controllers and input/output modules are provided by OVEN. OPC server receives signals by Modbus TCP and Modbus RTU protocols as well as upgraded data exchange protocols via fieldbus. [ABSTRACT FROM AUTHOR]

The mineralogical and geochemical characteristics of the K-rich granites from the Armoor granitic rocks in the northeastern portion of the Eastern Dharwar Craton (EDC) are presented. In order to understand its physicochemical conditions, the petrogenesis of the granitoid was explained from biotite chemistry and geochemical systematics. Studies of mineral chemistry expose that compositionally, K-feldspar and plagioclase in Armoor granite rocks range from An0, Ab3−5.9, Or94−96.9 and An5−29, Ab71.9−94.9, Or0−1.5, respectively. The mineral chemistry of biotite crystals exhibits composition that varies from primary to re-equilibrated primary biotites. Although biotites from the Armoor granites generally exhibit an I-type trend, with calc-alkaline parental magma in a subduction setting. Biotite chemistry of granites displays magnetite (oxidized) series nature, which has oxygen fugacity (fO2) = − 15.1 to − 16.7(log10 bar), under high oxidizing conditions. Temperature and pressure estimates for the crystallization of Armoor granites based on biotite composition are T = 612–716 °C and 1.0−0.4 kbar, respectively. Geochemically, these rocks are metaluminous to slightly peraluminous and magnesian, with calc-alkaline potassium-rich granite. On the chondrite normalized REE diagram, the granites have positive europium anomalies; rich Sr/Y, (Dy/Yb)N ratios and reduced Mg#, Rb/Sr, Rb, Sr indicate that the melting of earlier rocks, crystal accumulation and residual garnet source formed at high pressures. The examined granites show that they are produced from the melting of crustal sources. Thus, the extensive analyses of the described Armoor granite suggest that they were produced by crust sources and developed under oxidizing conditions in subduction setting. [ABSTRACT FROM AUTHOR]

The paper reports the results of U–Pb dating, Nd–Sr–Pb isotope systematics, and geochemical study of quartz diorites associated with ore-bearing (Cu–Pd–Au–Ag) gabbro of the Volkovsky massif, which is localized within the Urals Platinum Belt, at its eastern border with the Silurian–Devonian volcanogenic complexes of the Tagil megazone. The age of the quartz diorites according to U–Pb (TIMS) dating is 429 ± 9 Ma, MSWD = 0.009. Sr–Nd–Pb isotope characteristics (εNd(T) = +5.5...+6.7; (87Sr/86Sr)t = 0.70382–0.70392; 206Pb/204Pb = 18.38–18.57; 207Pb/204Pb = 15.56–15.58; 208Pb/204Pb = 38.14–38.30) indicate a juvenile source with a model age of 570–760 Ma. The obtained data fall within values typical of basalts of ensimatic island arcs. The geochemical features of the granitoids of the Volkovsky massif (low REE concentration, differentiated REE pattern (La/Yb = 8–14) with a weak positive Eu anomaly (Eu/Eu* = 0.9–1.4)) are consistent with the characteristics of melts obtained in experiments on hydrous melting of mafic rocks in equilibrium with amphibole–pyroxene residue. The anomalous concentration of strontium (more than 1000 ppm) in the quartz diorites is due to the high content of this element in a source. Such source could be the oldest rocks of the Urals Platinum Belt—olivine gabbro and metamorphic rocks of their surroundings. The identical ages of the quartz diorites of the Volkovsky massif and monzonitoids of the Kushvinsky massif allow us to consider these rocks as the result of the almost simultaneous mantle and crust melting at the final stage of the formation of the Tagil island-arc system. [ABSTRACT FROM AUTHOR]

The reaction of tris((2-dimethylaminomethyl)phenyl)methanol ((2-Me2NCH2C6H4)3COH) with potassium hydride in THF at –35°C affords dimeric alkoxide {[(2-Me2NCH2C6H4)3CO]K(THF)}2 (I) in a yield of 90%. The reaction of compound I with YbI2(THF)2 (1 : 1, 25°C) gives the Yb(II) alkoxyiodide complex {[(2-Me2NCH2C6H4)3CO]Yb(μ-I)(THF)2}2 (II) in a yield of 57%. Complex II in the crystalline state is dimeric due to two bridging iodide ligands. Unlike the Yb(II) compound, the exchange reaction of complex I with SmI2(THF)2 (1 : 1, 25°C) in THF followed by the addition of dimethoxyethane (DME) involves the oxidation of the metal to form the trivalent samarium complex [(2-Me2NCH2C6H4)3CO]2SmI (III), which is isolated in a yield of 60%. The molecular structures of the complexes are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2259700 (I), 2259701 (II), and 2259702 (III)). [ABSTRACT FROM AUTHOR]

Remarkable enhancement in green and red upconversion (UC) emissions by 124 and 88 %, respectively was achieved whereas down‐conversion (DC) luminescence in NIR‐II region (~1540 nm) was improved by 20 % in Th4+ co‐doped YF3 : Yb3+,Er3+ nanocrystalline particles. The same is ascribed to lowering of symmetry via formation of asymmetric Er−F bonds and less symmetric Y3+ sites due to distortions on Th4+ co‐doping. Benefiting from the distinct temperature response of stark sublevels of the 4S3/2 and 4F9/2 states, we have proposed a strategy for luminescence intensity ratios (LIR) based thermometry involving thermally coupled (TCL) stark sub‐levels. This can be promising in more accurate temperature read‐out at cryogenic temperatures (~ −193 °C). Using the same, high Sa and Sr values of 0.0139 K−1 (80 K) and 0.682 % K−1(80 K) were obtained for 4S3/2 (1)/4S3/2 (2)→4I15/2 transitions. Higher Sa and Sr values of 0.226 K−1 (80 K) and 2.627 %K−1(80 K) were obtained for 4F9/2 (1)/4F9/2 (2)→4I15/2 transitions. The high sensitivity values were obtained than that reported for the YF3 host. We believe this work with improved UC luminescence on Th4+ addition will be boon to cryogenic temperature‐sensing. [ABSTRACT FROM AUTHOR]

The quasi-binary system YbMg2-YbIn2 was studied around the equiatomic composition. In contrast to the ordered rare earth (RE) phases REMgIn (ZrNiAl type), ytterbium forms phases with different structures and pronounced Mg/In mixing (M sites). The structures of YbMg0.75In1.25 (CaLiSn type, P3m1, a = 501.95(7), c = 1087.3(2) pm, wR2 = 0.0490, 790 F2 values, 32 variables) and Yb6Mg6.41In5.59 (Yb6Ir5Ga7 type, P63/mcm, a = 1060.77(14), c = 970.27(16) pm, wR2 = 0.0484, 701 F2 values, 26 variables) were refined from single-crystal X-ray diffractometer data. YbMg0.75In1.25 is an AlB2 superstructure with a tripling of the subcell. The magnesium and indium atoms form three differently puckered layers of M6 hexagons. The Yb6Mg6.41In5.59 structure is derived from the hexagonal Laves phase YbMg2 (MgZn2 type, P63/mmc). A klassengleiche symmetry reduction leads to four crystallographically independent M sites for the rows of corner- and face-sharing tetrahedra which allow a composition close to the equiatomic one. The M–M distances in both structures cover the broad range from 289 to 331 pm, comparable to the sums of the covalent radii. Temperature dependent magnetic susceptibility studies of the polycrystalline YbMg0.75In1.25 and Yb12Mg13In11 samples indicate Pauli paramagnetism with room temperature values of 2.8(1) × 10−3 emu mol−1 (YbMg0.75In1.25) and 5.2(1) × 10−3 emu mol−1 (Yb12Mg13In11). [ABSTRACT FROM AUTHOR]

Magnetic and magnetocaloric properties of polycrystalline Gd3Co4Ge13 (Cubic, Yb3Rh4Sn13-type, Space group Pm-3n, No. 223, cP40) have been studied by carrying out dc magnetization measurements in applied magnetic fields up to 140 kOe. The compound Gd3Co4Ge13 orders antiferromagnetically at 9 K (TN). The antiferromagnetism appears to be weak and with increasing applied magnetic fields, ferromagnetic interactions become dominant. This field-induced antiferromagnetic to ferromagnetic state that is marked as a change from inverse to normal magnetocaloric effect in the isothermal magnetic entropy change vs temperature plot around TN. At 2 K, the magnetization shows a tendency toward saturation in applied magnetic field and a magnetic moment of 5.3 µB per Gd3+ is obtained in 140 kOe field. [ABSTRACT FROM AUTHOR]

A dual-channel material of {[(CH3)2NH2][Yb3(BDCP)2(H2O)3]·2DMF·3H2O}n (NUC-58) has been generated from the combination of wave-like [Yb2(CO2)6(H2O)2]n chains and [Yb(CO2)4(H2O)] units with the aid of 2,6-bis(2,4-dicarboxylphenyl)-4-(4- carboxylphenyl)pyridine, which has excellent physical and chemical properties including a larger specific surface area, high porosity, water resistance and thermal stability. NUC-58 is a rarely reported microporous MOFs with solvent-free dual channels. Thanks to its coexistence of Lewis acid–base sites including rich hexa/hepta-coordinated Yb3+ ions, C = O groups from μ1−η1:η1 CO2−, and Npyridine atoms, NUC-58 displays highly catalytic activity on the cycloaddition reaction of epoxides and CO2 into related cyclic carbonates under mild solvent-free reaction conditions. In addition, NUC-58 could be used as a fast, sensitive and highly efficiency sensor for Cu2+ detection in aqueous solution. Therefore, the work shows that microporous MOFs assembled from pyridine-containing polycarboxylic acid ligands and rare earth ions can serve as excellent catalytic and luminescent materials. A highly robust ytterbium (III)-organic framework of {[(CH3)2NH2]2[Yb3 (BDCP)2(NO3)(OH2)3]·2DMF·3H2O}n (NUC-58) for efficiently catalyzing the chemical fixation of CO2. [ABSTRACT FROM AUTHOR]

Mass transfer along grain boundaries (GBs) in two kinds of polycrystalline Yb 3 Al 5 O 12 (YbAG) wafers with chemical compositions that deviated slightly in both directions from the stoichiometric composition was investigated at high temperatures by the oxygen permeation technique with 18O 2. Oxygen permeation through both wafers proceeded with mutual diffusion of oxide ions from the higher oxygen partial pressure P O2 (hi) surface side to the lower P O2 (lo) surface side and with the diffusion of ytterbium ions in the opposite direction. The apparent activation energies for oxygen permeation due to GB diffusion of oxide ions and ytterbium ions were 420–440 and 260–300 kJ mol−1, respectively, and almost no difference in the activation energies due to the different chemical compositions was observed. However, the oxygen permeability constants, which were divided by the GB density, for the aluminum-rich YbAG were clearly lower than those for the ytterbium-rich YbAG. [ABSTRACT FROM AUTHOR]

The quasi-binary system YbMg2-YbIn2 was studied around the equiatomic composition. In contrast to the ordered rare earth (RE) phases REMgIn (ZrNiAl type), ytterbium forms phases with different structures and pronounced Mg/In mixing (M sites). The structures of YbMg0.75In1.25 (CaLiSn type, P3m1, a = 501.95(7), c = 1087.3(2) pm, wR2 = 0.0490, 790 F2 values, 32 variables) and Yb6Mg6.41In5.59 (Yb6Ir5Ga7 type, P63/mcm, a = 1060.77(14), c = 970.27(16) pm, wR2 = 0.0484, 701 F2 values, 26 variables) were refined from single-crystal X-ray diffractometer data. YbMg0.75In1.25 is an AlB2 superstructure with a tripling of the subcell. The magnesium and indium atoms form three differently puckered layers of M6 hexagons. The Yb6Mg6.41In5.59 structure is derived from the hexagonal Laves phase YbMg2 (MgZn2 type, P63/mmc). A klassengleiche symmetry reduction leads to four crystallographically independent M sites for the rows of corner- and face-sharing tetrahedra which allow a composition close to the equiatomic one. The M–M distances in both structures cover the broad range from 289 to 331 pm, comparable to the sums of the covalent radii. Temperature dependent magnetic susceptibility studies of the polycrystalline YbMg0.75In1.25 and Yb12Mg13In11 samples indicate Pauli paramagnetism with room temperature values of 2.8(1) × 10−3 emu mol−1 (YbMg0.75In1.25) and 5.2(1) × 10−3 emu mol−1 (Yb12Mg13In11). [ABSTRACT FROM AUTHOR]

Coal remains an important fuel for use in thermal power plants. However, coal-burning power plants produce large amounts of CFA, which contains TEs such as B, F, and Se, which are leached upon contact with water and act as potential polluters of aquifer systems and soil. To study the transformation of TEs, a thermodynamic calculation (FactSage 7.2) was used. Paper sludge ash was used as a calcium compound additive. The influence of blending a high-calcium additive on the environmental safety of TEs was investigated based on the effect of the mass addition ratio of PS ash. This study's results confirmed that the leaching processes of TEs, namely (CaO)2(Al2O3), CaF2, Ca10(PO4)F2, and CaSeO4(H2O)2, were caused by the formation of B, F, and Se compounds during the leaching process. Thus, it is clear that calcium has the greatest influence on the transformation of TEs due to their reaction, which, in turn, minimizes the effects of the TEs' release into the environment. The concentrations of TEs from the sample and addition of PS ash decreased slightly, indicating that the inhibition of TEs was enabled through the addition of PS ash. Although the PS ash YB had the highest calcium content, the PS ash YC gave the best results during the B and Se inhibition processes. The experimental observation was also evaluated for comparison. For the analysis of TEs' leaching ratios using the thermodynamic calculation and experiment, the experimental results were lower than those initially predicted. These results will help us to choose the best available control technology to minimize the effects of TEs released into the environment. [ABSTRACT FROM AUTHOR]

The study describes toluene ethylation using TsVM zeolite (SiO2/Al2O3 = 40) and a series of TsVM-based catalysts modified with rare-earth metals. To investigate the effects of the type and loading of rare-earth metals in the HTsVM catalyst on the selectivity towards total ethyltoluenes and p-ethyltoluene, the reaction was carried out in a continuous-flow fixed-bed reactor at atmospheric pressure and temperatures of 300–400°C. The HTsVM was modified with praseodymium, ytterbium, and holmium nitrates. The physicochemical and textural properties of the catalysts were characterized by XRD, FTIR spectroscopy, NH3-TPD, and low-temperature nitrogen adsorption. The specific surface area, acidity, total pore volume, and mesopore volume were found to decrease with an increase in the holmium loading of the catalyst. The zeolite catalysts loaded with 4.0–5.0 wt % Ho exhibited optimum stability and high p-ethyltoluene selectivity (79.5–81.4%) in combination with adequate toluene conversion (19.4–20.3%). [ABSTRACT FROM AUTHOR]

A three-step sequential extraction was carried out by modified BCR approach for fractionation of metals, including rare earths in red mud. Acetic acid leaching, hydroxylamine hydrochloride + nitric acid leaching, hydrogen peroxide + acid ammonium acetate leaching, and orthophosphoric + nitric acid digestion in microwave were performed to determine ion exchangeable (F1), reducible (F2), oxidizable (F3), and residual (F4) fractions of metals, respectively. Accordingly, the highest readily soluble phases were obtained for Ca, Na, and K, while the reducible were Al, Zn, Cu, and Li. Rare earth elements (REEs) except for Eu were mostly identified in residual fraction. Most of Eu (88.7%) was detected in the reducible fraction, while the negligible part in residual. Chondrite normalization was implemented for obtaining REE anomalies. The remarkable Eu and Gd negative anomaly differences were determined between the red mud and its origin, Mortaş bauxite. The LREE to HREE ratio and LaN/YbN scores of 8.42 and 7.82, respectively indicated the LREE enrichment to HREE. By performing multivariate analysis, six and five-group clusters were obtained for REEs and non-REE metals in terms of fractional distribution, proving the easier release potential of Eu, La, Gd, K, Na, and Ca. [ABSTRACT FROM AUTHOR]

For white-light emitting diode (WLED) applications, a green-to-orange emission nitridosilicate-based phosphor is created. The observed wide-band radiation in the green-orange range is caused by Eu2+ and Yb2+ at the trap point of a doubly doped SrSi2O2N2:Eu2+,Yb2+ (SSON:Eu,Yb) nitridosilicate phosphor. The green-color radiation's decay duration was measured to validate the energy transfer among activator ions. The co-doping various ratios' influence of activator ions on luminescence features was investigated. The resulting phosphor's radiation is a function of the activator ion concentrations and raising the Yb2+ concentration causes red-color radiation to dominate the green radiation. To generate white illumination, the resulting phosphor was coupled with an InGaN blue-LED chip having a pumping wavelength of 450 nm. Two stages were taken to achieve hue balance management. Initially, the green to orange proportion was tuned by varying the Eu2+ and Yb2+ ions' concentrations. At the second stage, the Commission Internationale de L'Eclairage, International Commission on Illumination (CIE) coordinates were changed from [0.2805; 0.2014] to [0.4071; 03789] by raising the amount of phosphor powder used. White illumination produced under optimal conditions has a hue rendering indicator of 89. The designed single-stage dual-hue-releasing nitridosilicate phosphor and blue-LED chip displayed remarkable hue steadiness over a wideband of forwardbias currents (100 to 500 mA at 3 V). [ABSTRACT FROM AUTHOR]

The development of eco-friendly thin-film thermoelectric generators for microenergy harvesting applications is highly desired. Ge-based materials have recently attracted significant research interest because of their superior performance at room temperature as human-compatible thermoelectric constituents. We examined the synthesis of Yb3Ge5 thin films and assessed their thermoelectric properties, considering the exceptional ability of Yb as a heavy metal to scatter phonons. The components of the resulting thin film were strongly dependent on the Yb/Ge deposition ratio and the subsequent annealing temperature. An increase in the Yb content augmented the formation of Yb2O3, whereas an increase in the Ge content facilitated the formation of Ge crystals. These trends were more evident at higher annealing temperatures. By controlling the YbGe composition, a power factor of 1470 µW m−1 K−2 was obtained at an annealing temperature of 700 °C, along with a low thermal conductivity of 3.1 W m−1 K−1. Machine-learning-facilitated data analysis revealed that the high power factor originated from Yb3Ge5. Notably, the power factor reached 1370 µW m−1 K−2 even at a temperature of 500 °C, causing the expansion of heat-resistant plastic films. Thus, we established the impressive potential of Yb3Ge5 as a suitable material for eco-friendly thin-film thermoelectric generators. [ABSTRACT FROM AUTHOR]

Magnetic and magnetocaloric properties of polycrystalline Gd3Co4Ge13 (Cubic, Yb3Rh4Sn13-type, Space group Pm-3n, No. 223, cP40) have been studied by carrying out dc magnetization measurements in applied magnetic fields up to 140 kOe. The compound Gd3Co4Ge13 orders antiferromagnetically at 9 K (TN). The antiferromagnetism appears to be weak and with increasing applied magnetic fields, ferromagnetic interactions become dominant. This field-induced antiferromagnetic to ferromagnetic state that is marked as a change from inverse to normal magnetocaloric effect in the isothermal magnetic entropy change vs temperature plot around TN. At 2 K, the magnetization shows a tendency toward saturation in applied magnetic field and a magnetic moment of 5.3 µB per Gd3+ is obtained in 140 kOe field. [ABSTRACT FROM AUTHOR]

The R23Cu7Mg4 (R = Ca, Eu) intermetallics, studied by single-crystal X-ray diffraction, were found to be isostructural with the Yb23Cu7Mg4 prototype (hP68, k4h2fca, space group P63/mmc), forming a small group inside the bigger 23:7:4 family, otherwise adopting the hP68-Pr23Ir7Mg4 crystal structure. The observed structural peculiarity is connected with the divalent character of the R component and with a noticeable volume contraction, resulting in the clear clustering of title compounds inside the whole 23:7:4 family. The occurrence of fragments typical of similar compounds, particularly Cu-centered trigonal prisms and Mg-centered core–shell polyicosahedral clusters with R at vertices, induced the search of significant structural relationships. In this work, a description of the hexagonal crystal structure of the studied compounds is proposed as a linear intergrowth along the c-direction of the two types of slabs, R10CuMg3 (parent type: hP28-kh2ca, SG 194) and R13Cu6Mg (parent type: hR60-b6a2, SG 160). The ratio of these slabs in the studied structure is 2:2 per unit cell, corresponding to the simple equation, 2 × R10CuMg3 + 2 × R13Cu6Mg = 2 × R23Cu7Mg4. This description assimilates the studied compounds to the {Ca, Eu, Yb}4CuMg ones, where the same slabs (of p3m1 layer symmetry) are stacked in a different way/ratio and constitutes a further step towards a structural generalization of R-rich ternary intermetallics. [ABSTRACT FROM AUTHOR]

New series of Ho3+/Yb3+ and Tm3+/Yb3+ codoped Na5Rb7Sc2(WO4)9 phosphors have been prepared by a conventional solid state reaction method. A powder XRD study has revealed that all the synthesized tungstates are isostructural and crystallize in the trigonal crystal system (sp. gr. R32, Z = 3). Upconversion luminescence in the 460–850 nm spectral range, associated with transitions in Ho3+ or Tm3+ ions, has been detected under 980 nm laser diode excitation. The optimal Ho3+/Yb3+ and Tm3+/Yb3+ ratios have been determined. Possible mechanisms of energy transfer between lanthanide ions have been discussed. The luminescence characteristics of the representative samples, Na5Rb7Sc1.925Yb0.045Ho0.03(WO4)9 and Na5Rb7Sc1.9Yb0.09Tm0.01(WO4)9, have been studied at 298–498 K to evaluate their temperature measurement performance. The calculated values of the absolute and relative sensitivities indicate that the studied tungstates are promising phosphors for non-contact thermometry. [ABSTRACT FROM AUTHOR]

Luminescence thermometry has recently been gaining popularity in science and technology fields. However, most reported works have used the fluorescence intensity ratio (FIR) to obtain the temperature based on thermally coupled energy levels (TCLs), which have hindered the sensitivity of the technique and limited its applications. Here, NaYF4:Yb/Tm@NaYF4:Yb/Ho microcrystals were prepared using a hydrothermal method. Based on the non-thermally coupled energy levels (NTCLs) of the double luminescent ionic centers Tm3+ and Ho3+, the materials exhibited temperature-dependent luminescence in the range of 304 K to 574 K. The maximum sensitivities were found to be Sa = 0.135 K−1 at 574 K and Sr = 1.101% K−1 at 484 K based on red (Tm3+) and green (Ho3+) emission bands. This study has provided a promising new strategy to break the TCL restriction and has shown the material to have potential applications in luminescence thermometry. [ABSTRACT FROM AUTHOR]

Until now, double perovskite tellurates have not been reported to exhibit inherent NIR photoluminescence. Therefore, the current study's revelation of inherent NIR luminescence in SrLaLiTeO6 double perovskite centered at 970 nm under 340 nm excitation is particularly intriguing. This phenomenon is attributed to the photoluminescence of Te4+ ions. This study also examines the NIR luminescence of Cr3+–Yb3+ co-doped SrLaLiTeO6. The host and SrLaLiTeO6:3%Cr3+, y%Yb3+ (y = 1, 2, 4, 6, 8, 10 mol%) were synthesized using the solid-state ceramic route. The successful incorporation of Cr3+ and Yb3+ ions into the host lattice was confirmed through XRD, Raman, and diffuse reflectance spectral analyses. Under 270 nm excitation, the photoluminescence (PL) of SrLaLiTeO6:Cr3+ exhibits a blueshift of the PL band to 965 nm due to the 4T2(4F) → 4A2g(4F) emission component of Cr3+ ions. The excited-state lifetime of SrLaLiTeO6:0.5%Cr3+ was measured at 36 μs, but this decreased to 26 μs as the Cr3+ concentration reached 10 mol%, primarily due to the enhancement of non-radiative energy transfer between Cr3+ ions. Incorporating Yb3+ into the system results in additional spectral lines with an enhanced intensity in the range of 970 nm to 1125 nm when excited at 270 nm. These emission lines correspond to the 2F5/2 → 2F7/2 transitions of Yb3+ ions, indicating an efficient energy transfer from Cr3+ to Yb3+. Furthermore, the study also reveals that Yb3+ emission is observed even without Cr3+ ions in SrLaLiTeO6 under 340 nm excitation, suggesting the possibility of energy transfer from the host to Yb3+ ions. The thermal stability and crystal field parameters of the synthesized phosphors are also explained in detail. To explore the potential of these phosphors in practical applications, phosphor-converted NIR LEDs were fabricated using SrLaLiTeO6, SrLaLiTeO6:3% Cr3+, and SrLaLiTeO6:3% Cr3+, 1%Yb3+. [ABSTRACT FROM AUTHOR]

Upconversion luminescence (UCL) is a fluorescence process where two or more lower-energy photons convert into a higher-energy photon. Lanthanide (Ln3+)-doped UCL materials often suffer from weak luminescence, especially when directly synthesized by a hydrothermal (HT) process due to the existing hydroxyl group and undesirable arrangement of dopants within host lattices which quench luminescence and limit energy transfer. Therefore, additional heat treatment processes are required to enhance their UCL emission, even though direct hydrothermal synthesis without further heat treatment has the advantages of low energy consumption, fast synthesis, and wide applicability to generate UCL materials. In this study, via a HT process without annealing, we have produced Yb3+ and Er3+ co-doped SrMoO4 submicron spindles with a strong green UCL emission which can be seen with the naked eye, which HT produced oxide-based UCL materials often fail to demonstrate. We have investigated different HT synthesis conditions, such as temperature, time, pH and dopant composition, which control the nucleation, growth, lattice structure arrangement, and ultimately their UCL properties through XRD, SEM, EDS and UCL measurements. The bright green UCL from the SrMoO4:Yb,Er submicron spindles is further enhanced by post-synthesis annealing within a molten NaNO3/KNO3 system to prevent particle size growth. The green UCL intensity from the annealed SrMoO4:Yb,Er submicron spindles surpasses samples produced by the solid-state method and is comparable to that from the commercial NaYF4:Yb,Er sample. We have further studied the temperature-dependent luminescence of both the HT-prepared and molten-salt annealed SrMoO4:Yb,Er submicron spindle samples. The strong UCL from our SrMoO4:Yb,Er submicron spindles could warrant their candidacy for bioimaging and anticounterfeiting applications. [ABSTRACT FROM AUTHOR]