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It is known that high‐temperature phase (olivine structure) of NaMgPO4:Eu2+ (NMP:Eu2+) is a precious oxide phosphor suitable for LED devices, emitting red at 625 nm under blue excitation. However, mainly due to the stable glaserite structure in the wide range of low temperature, pure olivine‐phase NMP:Eu2+ is obtained only by using melt‐quenching and arc‐imaging furnace so far, which is inconvenient for the purpose of mass‐production or industry. Generally, a traditional solid‐state method is simpler and pollution‐free, which is more favorable in phosphor‐industry. Here, it is found that when quite small amount of Zn2+ is substituted for NMP:Eu2+ in solid‐state method, the purity of olivine phase is much improved and the luminescence intensity is significantly improved. For the Na(Mg,Zn)PO4:Eu2+ having new composition, crystal structure, optical properties, and color properties are investigated. The phase transition temperature before and after doping with Zn2+ are calculated by combining TG/DSC experimental measurements and first‐principles calculations. In addition, other characteristics related to the phosphor, such as structure, morphology, luminescence lifetime, thermal quenching properties, and quantum efficiency, are also studied in detail. Finally, it is demonstrated that this phosphor can be utilized in various applications through the manufacturing of LED devices, fluorescent pigments, and plant growth. [ABSTRACT FROM AUTHOR]

It is known that high‐temperature phase (olivine structure) of NaMgPO4:Eu2+ (NMP:Eu2+) is a precious oxide phosphor suitable for LED devices, emitting red at 625 nm under blue excitation. However, mainly due to the stable glaserite structure in the wide range of low temperature, pure olivine‐phase NMP:Eu2+ is obtained only by using melt‐quenching and arc‐imaging furnace so far, which is inconvenient for the purpose of mass‐production or industry. Generally, a traditional solid‐state method is simpler and pollution‐free, which is more favorable in phosphor‐industry. Here, it is found that when quite small amount of Zn2+ is substituted for NMP:Eu2+ in solid‐state method, the purity of olivine phase is much improved and the luminescence intensity is significantly improved. For the Na(Mg,Zn)PO4:Eu2+ having new composition, crystal structure, optical properties, and color properties are investigated. The phase transition temperature before and after doping with Zn2+ are calculated by combining TG/DSC experimental measurements and first‐principles calculations. In addition, other characteristics related to the phosphor, such as structure, morphology, luminescence lifetime, thermal quenching properties, and quantum efficiency, are also studied in detail. Finally, it is demonstrated that this phosphor can be utilized in various applications through the manufacturing of LED devices, fluorescent pigments, and plant growth. [ABSTRACT FROM AUTHOR]

The congruent melting compositions in the MF2–M'F2–RF3 systems (M ≠ M' = Ca, Sr, Cd, Ba, Pb; R are rare-earth elements (REEs)) have been determined based on thermodynamic topological analysis. Crystals of fluorite solid solution in the PbF2–CdF2–RF3 (R = Tb, Ho, Er, Tm, Yb, Lu) systems were grown by the vertical directional crystallization technique. Their phase composition and distribution of components over the crystalline boule length were investigated. Crystals of congruently melting solid solutions (Pb0.67Cd0.33) RxF (R = Tb, Ho, Er, Tm, Yb, Lu) were grown for the first time. Traces of low-temperature transformation—a phase isostructural to the Pb2YF7 compound (sp. gr. I4/m), in which Y sites are occupied by the corresponding R cations and Pb sites can be partially occupied by Cd cations—were found in the crystals with R = Ho, Er, Tm, and Yb. The crystals with R = Tb and Lu have a high degree of homogeneity and are suitable for optical studies. [ABSTRACT FROM AUTHOR]

LiRF4 (R = Y, Yb, Lu) nanoparticles (NPs), co-doped by Yb3+/Er3+ and Yb3+/Tm3+ ions, have been synthesized by high-temperature coprecipitation method. The influence of the molar ratio of precursors and the cation composition of matrices on the sizes and morphology of particles is investigated. The method of heterogeneous crystallization of these compounds using LiYF4 nanoseeds is optimized, which opens opportunities to controlled synthesis of LiRF4 NPs with required characteristics. Among the objects studied, LiYF4@LiYbF4:Tm3+@LiYF4 NPs demonstrate the most intense anti-Stokes photoluminescence in the UV (λ = 362 nm) and blue (λ = 450 nm) ranges, which exceeds the corresponding characteristics for β-NaYF4:Yb3+/Tm3+@NaYF4 particles. LiYF4@LiLuF4:Yb3+/Er3+@LiYF4 NPs are the most efficient IR converters in the (λ = 1530 nm) among the investigated isostructural matrices; their spectral-luminescence characteristics are close to those of the β-NaYF4:Yb3+/Er3+@NaYF4 compound with the equivalent degree of codoping. The results obtained give possibilities to consider LiYF4@LiYbF4:Tm3+@LiYF4 and LiYF4@LiLuF4:Yb3+/Er3+@LiYF4 NPs as a real alternative to the most widely used phosphors based on hexa-gonal β-NaYF4 host for photonics and biotechnology applications. [ABSTRACT FROM AUTHOR]

Intermetallic coatings from the Ni–Al system modified with rare earth elements (REE) additions are developed to protect the Ni-based superalloys against the increasingly demanding operating conditions, like those at ultra-supercritical (A-USC) power plants. The pack cementation process is generally limited to treatment of smaller parts, but simultaneously it allows to produce thick, well adhering and easily alloyed coatings. In this experiment, the Haynes® 263 alloy was subjected to pack cementation (PC) aluminizing process. The powder bed used in this experiment was prepared in two stages, i.e., first, the Al (8 wt.%), AlCl3 (4 wt.%), and Al2O3 (88 wt.%) powders were thoroughly mixed and only then, the Yb (1.5 wt.% of the all former) was added. The coating obtained through this process was investigated using scanning and transmission electron microscopy (SEM/TEM) methods. It helped to prove that the diffusive layer consisted mostly of Al14Cr3Ni2 ζ-phase, with significant amount of Al13 (Co, Cr)4 and (Ni, Co, Cr)3Al4 larger precipitates as well as numerous smaller ones, composed of (Al, Ni, Co, Cr, Ti) or (Al, Ni, Co, Cr, Mo). The additive layer consisting of Al3Ni2 phase with up to 6 at. % Co and 2 at. % Cr was covered by a discontinuous layer of α-Al2O3 occasionally decorated with particles of the same phase. Only the very surface was found to be occupied by an amorphous Yb2O3 oxide, which formed a thin (~ 5 nm), but simultaneously a continuous layer. The latter finding is the first experimental documentation of the location of REE in the coating obtained through PC process using a powder bed modified with elements from that group. [ABSTRACT FROM AUTHOR]

Metamorphosed dacitic porphyry dikes were first found in the western part of the Vorontsovka terrane, which is located in the Paleoproterozoic Volga–Don orogen at the margin of Archean Sarmatia and Volga–Ural cratons. The magmatic protolith age for the metadacites is ca. 2.07 Ga. These are ferrous, metaluminous calc-alkali I-type granitoids. The sodium specialization of the rocks and their low concentrations of Mg, Cr, Ni, and incompatible elements, with significant REE fractionation, the absence of Eu* anomalies, high Sr/Y ratio, remarkably high (Gd/Yb)n values (>10), and the radiogenic Nd isotopic composition indicate that the dacitic melts were derived from a juvenile mafic source. According to petrogenetic estimations, such conditions could be caused by the partial melting of depleted N-MORB basites in equilibrium with an eclogitic residue. The dacitic magmas were likely generated by the partial melting of mafic rocks at lower levels of the significantly thickened crust (>60 km) in relation to collision processes. [ABSTRACT FROM AUTHOR]

This study details the successful creation of a nanocomposite consisting of reduced graphene oxide (rGO) and Yb2O3 using a hydrothermal-assisted simple solution method. The research underscores the significance of this rGO: Yb2O3 composite material, which has emerged as a focal point of interest. The comprehensive analysis of the composite's structural features, as revealed by various techniques, offers vital insights into its distinctive properties. These insights hold profound implications for potential applications, especially in the field of advanced materials. The structural characterization techniques not only enhance our understanding of the composite's crystal structure, molecular vibrations, elemental composition, and surface chemistry but also highlight its potential as a superior material for various scientific and technological endeavors. Furthermore, this study emphasizes the importance of research and development efforts dedicated to rGO: Yb2O3 composite materials, particularly in the context of supercapacitor applications. Morphological examinations confirm the uniform distribution of Yb2O3 nanoparticles on both sides of the rGO sheets, with sizes below 50 nm. Notably, the nanocomposite exhibits significantly enhanced specific capacitance (1382.72 Fg−1 at 5 mVs−1) compared to pristine Yb2O3 nanoparticles (753.27 Fg−1 at 5 mVs−1). This improvement can be attributed to the synergistic interaction between rGO and Yb2O3, which enhances the charge storage capacity. Electrochemical characterization reveals dominant pseudo-capacitance behavior typical of batteries, making the nanocomposite a promising candidate for energy storage applications. In summary, this study illuminates the potential of graphene-based nanocomposites as high-performance energy storage materials and offers valuable insights for future research endeavors, including optimizing synthesis parameters and evaluating long-term stability. The rGO: Yb2O3 nanocomposite exhibits tremendous promise for advanced energy storage systems. [ABSTRACT FROM AUTHOR]

The work investigated the sorption of no-carrier-added 177Lu isolated from neutron-irradiated 176Yb2O3, and carrier-added 177Lu obtained by irradiation of natLu2O3, by commercial and oxidized nanodiamonds (NDs) of various grades from aqueous solutions to identify among them a promising carrier for further research in the field of nuclear medicine. A promising sorbent was found: oxidized NDs of the STP grade (ox-STP); conditions for the fast sorption of lutetium with it in an amount equivalent to 1.2 GBq of no-carrier-added 177Lu were determined, which corresponds to the activity used in therapy. [ABSTRACT FROM AUTHOR]

The synthesis of multicomponent and high-entropy compounds has become a rapidly developing field in advanced inorganic chemistry, making it possible to combine the properties of multiple elements in a single phase. This paper reports on the synthesis of a series of novel high-entropy layered rare earth hydroxychlorides, namely, (Sm,Eu,Gd,Y,Er)2(OH)5Cl, (Eu,Gd,Tb,Y,Er)2(OH)5Cl, (Eu,Gd,Dy,Y,Er)2(OH)5Cl, and (Eu,Gd,Y,Er,Yb)2(OH)5Cl, using a homogeneous hydrolysis technique under hydrothermal conditions. Elemental mapping proved the even distribution of rare earth elements, while luminescence spectroscopy confirmed efficient energy transfer between europium and other rare earth cations, thus providing additional evidence of the homogeneous distribution of rare earth elements within the crystal lattice. The average rare earth cation radii correlated linearly with the unit cell parameters (0.868 < R2 < 0.982) of the high-entropy layered rare earth hydroxychlorides. The thermal stability of the high-entropy layered rare earth hydroxychlorides was similar to that of individual hydroxychlorides and their binary solid solutions. [ABSTRACT FROM AUTHOR]

In this study, a series of rare-earth titanates with the general formula Re2TiO5 (Re = Er, Tm, Yb, and Lu) were synthesized and their microwave dielectric properties were reported. The impact of differences in rare-earth cation radii on the structure and dielectric properties was systematically analyzed. The findings indicated that ceramics of Re2TiO5 (Re = Er, Tm, Yb, and Lu) were crystallized into a cubic structure with space group Fd-3m, as confirmed by Rietveld refinement and selected-area electron diffraction patterns. The rare-earth elements were analyzed for their impact on microwave dielectric properties, considering factors such as ionic polarizability, packing fraction, and bond valence theory. The resulting materials exhibited excellent microwave dielectric properties with a low permittivity (6.95-7.21), high-quality factors (19 451-20 115 GHz), and low positive temperature coefficient of resonance frequency (19.34-20.90 ppm/°C). The origin of low permittivity was elucidated through the analysis of bond length, X-ray photoelectron spectroscopy, and impedance spectroscopy. This series of titanates exhibited unusually low permittivity characteristics in the microwave frequency range, which couldmeet the low signal transmission delay requirements in wireless communication. [ABSTRACT FROM AUTHOR]

Residual stress measurements in environmental barrier coatings (EBCs) can help in understanding coating durability and potential damage mechanisms.We demonstrate the capability of Raman spectroscopy to measure average residual stresses in two different β-RE2Si2O7 (RE = rare earth or Y3+, denoted as REDS) EBCswith a nominal (Yb,Y)2Si2O7 composition, focusing on macroscopic residual stresses acting at macroscopic length scales. Uniaxial compression measurements of dense β-(Yb,Y)2Si2O7 ceramics are used for calibration curves for applied stress versus Raman peak shift.We use these calibration curves to evaluate the macroscopic thermoelastic residual stress in the (Yb,Y)2Si2O7 layers from coefficient of thermal expansion (CTE) mismatch of two different (Yb,Y)2Si2O7-based EBCs on SiC-based substrates. Microscopic stress contributions to Raman peak shifts are subtracted using reference free-standing coatings and analytic estimates for inclusion stresses when (Yb,Y)2Si2O7 coatings have a high, variable volume fraction of (Yb,Y)2SiO5. The macroscopic thermal residual stress in these (Yb,Y)2Si2O7 EBCs is compressive, as expected from the smaller CTE of β-REDS versus SiC. These thermal residual stresses can vary between different YbYDS EBC coatings by more than a factor of three with ameasured layer residual stress of approximately -180MPa (compressive) for a high modulus, low CTE coating, and our measured values generally agree with calculated estimates. [ABSTRACT FROM AUTHOR]

Temperature stability of electrocaloric effect (ECE) is a thorny problem in ferroelectrics (FE). A general method is to design ferroelectric-to-relaxor phase transition at a sacrifice of electrocaloric (EC) strength. The Pb(Yb1/2Nb1/2)O3 antiferroelectrics (AFE) + Pb(Mg1/3Nb2/3)O3 relaxors strategy designed in this work is effective to tackle this dilemma [(1 -- x)PYN--xPMN, x = 0.08-0.36]. PMN addition induces a successive phase transition and dual phase boundaries of ferrielectric (FIE)-nonergodic relaxor (NER) and NER-ergodic relaxor (ER), where ferroelectric polarization/strain and ECE reach a localmaximum. Thermally stable ΔT is unexpectedly achieved in FIE (x = 0.14) and NER (x = 0.24), except for a generality for ER state (x = 0.30). A dome-like variation trend is observed in x = 0.14 and 0.24 with a wide temperature span of ~60 and ~55 K (±15%ΔTmax). Notably, x = 0.24 NER possesses a large directlymeasured ΔTmax ~0.64 K simultaneously. Dielectric/ferroelectric properties clarify that two-stage transition of AFE rigid-order de-texture and dissociation of de-textured AFE domains into polar nano-entities accounts for thermal stability of ΔT as the alternation of ordered antipolar domains to disorder relaxors serves as a buffer to compensate for the thermal-shock enhanced random field. This work not only accounts for the underlying mechanism for thermal stability of ΔT at FIE and NER side for the first time in physics but also provides an exotic approach to seek for high-performance EC materials in practical applications. [ABSTRACT FROM AUTHOR]

Photochromic reaction-induced reversible luminescence materials have attracted extensive attention and research in information storage, anticounterfeiting and other aspects. The reversible luminescence regulation could induced photochromic reaction by external fields stimulation. However, most of the bleaching methods stay in the high temperature thermal stimulation bleaching, which has low efficiency and long reaction time, thus limiting its application. In this work, the CaWO4: Yb3+, Ho3+, Bi3+ ceramics were prepared to realize the reversible regulation of photoluminescent and photochromism by light stimulation. The CaWO4: Yb3+, Ho3+, Bi3+ ceramics turn gray after being exposed to 254 nm ultraviolet light for 25 min, and then turn white under the irradiation of 532 nm laser for 10 s to restore to the original state. The cation vacancies and oxygen vacancies formed in co-doped Bi3+ CaWO4 ceramics lead to photochromic effect. CaWO4: Yb3+, Ho3+, Bi3+ ceramics realize reversible dual mode upconversion and downconversion luminescence, improving security and reliability in anticounterfeiting. The reversibility photoluminescent and photochromism of CaWO4: Yb3+, Ho3+, Bi3+ ceramics was verified by 245-nm ultraviolet coloration and 532-nm laser bleaching, which indicates that CaWO4: Yb3+, Ho3+, Bi3+ ceramics have potential application prospects as anticounterfeiting agents. [ABSTRACT FROM AUTHOR]

Dielectric capacitors have been widely studied in advanced electronics systems due to their rapid discharge rate and high-power density. Among them, relaxor ferroelectrics characterized by nanodomains possess broad application prospects as dielectricmaterialswith high energy density and high efficiency. In this paper, the dielectric characteristics, energy storage performance, and charge--discharge behavior of rare-earth Yb-doped Sr0.7Bi0.2TiO3 ceramics are systematically investigated. The Yb-doped SBT ceramics reduced the grain size, improved the insulation and thermal conductivity, and significantly improved the dielectric breakdown strength. Finally, a high recoverable energy density of 2.32 J/cm³ and an excellent energy storage efficiency of 92.2% were obtained at 300 kV/cm. In addition, pulsed charge--discharge tests show that Sr0.7Bi0.15Yb0.05TiO3 possesses a rapid discharge rate and high-power density with superior thermal stability. Based on these outstanding characteristics, Sr0.7Bi0.15Yb0.05TiO3 exhibits promising applications in pulsed power systems. [ABSTRACT FROM AUTHOR]

To better understand the geodynamic evolution of northeastern China during the Late Mesozoic, we analyzed zircon U–Pb geochronological, Lu–Hf isotopic, and geochemical data for Early Cretaceous volcanic rocks from the southeastern margin of the Songliao Basin. Newly identified A-type rhyolite and trachyandesite yielded zircon 206Pb/238U ages of ca. 123 Ma and 117 Ma, respectively. The rhyolites are high in SiO2 (72.24–78.89 wt%) and total alkali (K2O + Na2O = 8.81–10.03 wt%), and low in MgO (0.10–0.26 wt%), CaO (0.32–0.36 wt%), Ni (0.08–2.69 ppm), and Cr (0.39–4.87 ppm) concentrations, with negative Nb, Ta, and Sr anomalies. They are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) and depleted in high-field-strength elements (HFSEs); the calculated Zr saturation temperatures are high (828–915 °C). The A-type rhyolites possess variable zircon εHf(t) values ranging from + 5.69 to + 10.49. Petrogenetic analysis leads us to propose that the A-type rhyolites were probably formed by partial melting of a Neoproterozoic–Early Paleozoic juvenile lower crust. The trachyandesites have Nb/Ta (14.9–17.25), Zr/Hf (35.04–42.75), Rb/Sr (0.25–0.40), and Lu/Yb (0.14–0.15) ratios that are similar to those of mantle-derived magma, indicating a mantle source. They have εHf(t) values of + 4.71 to + 7.29 and show enrichment in LILEs and LREEs, and weak depletion in HFSEs, suggesting that the parent magma originated from partial melting of a depleted lithospheric mantle, and was subsequently metasomatized by subduction-related fluids, followed by extensive fractional crystallization during the magma evolution. Combined with the temporal and spatial distribution of Late Mesozoic igneous rocks from the southeastern margin of the Songliao Basin, we propose that Early Cretaceous volcanic rocks formed in an extensional tectonic setting that was closely related to rollback of the Paleo-Pacific (Izanagi) oceanic slab. [ABSTRACT FROM AUTHOR]

The Nagaland–Manipur Hill Ophiolite (NMHO) is an NNE-SSW trending linear ophiolite zone exposed in the northeastern states of Nagaland and Manipur in India. Basaltic rocks of NMHO are geochemically divisible into two broad groups in the Zr/Ti versus Nb/Y classification diagram. Samples with TiO2 < 2 wt% and Zr = 38–118 ppm plot within the basalt field, whereas samples with TiO2 > 2 wt% plot within the alkali basalt field. The latter can be subdivided into the alkali basalt group-1 (AB-1) with Zr = ~ 200 ppm and the alkali basalt group-2 (AB-2) with Zr = ~ 400 ppm. In a normal mid-ocean ridge basalt (N-MORB) normalized trace element pattern, basalt displays a near-horizontal trend from Lu to Pr at rock/N-MORB = ~ 1 and then increases slightly from Pr to Rb, whereas alkali basalt is relatively more enriched than basalt. In the chondrite-normalized rare earth element (REE) pattern, basalt displays near-horizontal trends with (La/Yb)CN ranging between 0.78 and 1.89. On the other hand, alkali basalt displays parallel and steadily increasing enrichment trends from Lu to La [(La/Yb)CN = 11.07–17.61], with a slight drop at Eu and Sm. Mantle melting models suggest: (1) partial melting of N-MORB-like sources at degrees of melting (F) = 4–8% for basalts; and (2) partial melting of ocean island basalt (OIB)-like sources at F = 7.5–17.8% for alkali basalt. Occurrences of basalts with N-MORB-like and and alkali basalt with OIB-like signatures within the NMHO complex suggest their origin from distinct magma batches with direct or indirect involvement of the Kerguelen plume. Chondrite normalised pattern for elements Nb, Zr and REE showing estimated compositions of source S1 and residue R1 for alkali basalt (estimated using DMI modeling) and source S2 for basalt (estimated using NBM modeling) in this study. DMM and OIB (Workman and Hart 2005) values are also shown for comparison. Average abyssal peridotite value is from Niu (2004) database. [ABSTRACT FROM AUTHOR]

Petrologic investigations of martian meteorite Northwest Africa (NWA) 13227 indicate it is an olivine-gabbroic shergottite, a relatively new shergottite group, which differs from previously described gabbroic shergottites due to relatively high quantities of olivine. NWA 13227 is comprised of phenocrystic, oscillatory-zoned pyroxene and olivine, set in a matrix of maskelynite, Fe-Cr-Ti oxides, phosphates, and sulfides. It displays gabbroic and poikilitic textures in 2D from back-scattered electron images, and in 3D from X-ray Computed Tomography (XCT) imaging, suggesting affinities to both poikilitic and gabbroic shergottites. Measured εHf and εNd values of bulk rock (-19.7 and −5.9, respectively) and its chondrite-normalized La/Yb ratio of 1.13 indicate the specimen is derived from a mantle reservoir relatively enriched in incompatible trace elements and is similar to that which produced most 'enriched shergottites.' Based on the Ti/Al ratio of pyroxene, phosphorous zoning in olivine, and minor components in phosphates and oxides, we infer that NWA 13227 began crystallizing under reducing conditions of QFM–2.6 and temperatures of ∼ 1100 °C, consistent with conditions in Mars' lower crust/upper mantle. The sample finished crystallizing at or near the surface under redox conditions between QFM–0.5 to QFM–0.1 and temperatures of ∼ 850 °C. The volatile element compositions in apatite indicate that NWA 13227 experienced degassing during the last stages of crystallization. The timing of crystallization is estimated at 225 Ma ± 50 Ma using a Lu-Hf and Sm-Nd source versus age model. [ABSTRACT FROM AUTHOR]

Subduction zone magmatism is a major control of volcanism, the generation of modern continental crust and the formation of economically important porphyry Cu–(Mo–Au) deposits. Reading the magmatic record of individual arc segments and constraining the rates of magmatic changes are critical in order to fully understand and quantify the processes that drive magma evolution in subduction settings during arc growth. This study focuses on the San Francisco Batholith and the Rio Blanco-Los Bronces porphyry deposit cluster in central Chile, which provides an igneous rock record over ~13.5 Myr of arc evolution. We use whole-rock geochemistry, zircon geochronology and Hf isotope geochemistry to track changes in the crustal magmatic system of this arc segment during crustal thickening and porphyry Cu deposit formation. By combining the analytical dataset with Monte Carlo fractional crystallisation and assimilation fractional crystallisation modelling, we test a model for significant crustal involvement during magma evolution. Systematic and continuous increases in Dy/Yb, La/Yb, V/Sc and Sr/Y in the magmas over time indicate a transition in the main fractionation assemblage from plagioclase-dominated to amphibole-dominated that reflects deeper crystallisation and/or a higher meltwater content. Concomitant decreases in εHf and Th/La as well as increasing Ba/Th are best explained by assimilation of progressively deeper crustal lithologies from low (Chilenia) to high Ba/Th (Cuyania) basement terranes. Our study highlights that an increasingly hydrous magma and a deepening locus of crustal magma differentiation and assimilation, driven by crustal thickening contemporaneous with increased tectonic convergence and ingression of the aseismic Juan Fernandez ridge, can account for all investigated aspects of the multi-Myr magmatic evolution leading up to the formation of the Rio Blanco-Los Bronces porphyry Cu deposits. Our findings corroborate the importance of high-pressure differentiation of hydrous magma for the formation of Andean-style porphyry deposits. Once magmas favourable for porphyry Cu mineralisation were generated in the lower crust, multiple episodes of efficient magma migration into the upper crust fed several, discrete, shallow magmatic-hydrothermal systems over ~3.5 Myr to form the world's largest known Cu resource at Rio Blanco-Los Bronces. [ABSTRACT FROM AUTHOR]

Mafic layered intrusions constitute a natural laboratory to investigate petrogenetic processes using trace element variations in apatite chemistry. Although these intrusions are related to large igneous provinces, there is a wide range of parameters that can affect the chemistry of the primary melt (i.e. composition of the source, pressure, temperature, oxygen fugacity), followed by possible crustal contamination. In this study, we use a comprehensive dataset of analyses of cumulus and intercumulus apatite from a variety of mafic layered intrusions to demonstrate the use of apatite as a powerful petrogenetic indicator. The dataset (determined in this study and compiled from the literature) comprises electron microprobe and LA-ICP-MS analyses, as well as in-situ LA-MC-ICP-MS analyses of Sr isotopes in apatite from well documented layered intrusions (Sept-Iles, Skaergaard, Bushveld, Panzhihua) and the Sudbury Igneous Complex. For the first time, we show that high values of (La/Nd)N, Th, U, Pb, and As in apatite correlate with high (87Sr/86Sr)initial and are related to contamination with continental crust. An elevated (Gd/Yb)N ratio might indicate melting of a mantle source deep enough to retain Yb in garnet. We also confirm that increasingly negative Eu anomaly and decreasing Sr/Y ratio in apatite are indicators of fractional crystallisation of plagioclase, and that high Sr/Y is indicative of early saturation of apatite and/or delayed crystallisation of plagioclase. The reversal to more primitive compositions caused by magma mixing is expressed by higher Sr, V, Mg and Sr/Y ratio, and lower REE + Y, As and Na concentrations in apatite following magma replenishment. Lastly, we show that apatite signature can efficiently distinguish a mafic from a felsic intrusion using its REE and Sr content coupled to its Eu anomaly. It is also possible to further identify the more primitive from the more evolved parts of a mafic layered intrusion, using the Lu, Th, V and volatile (F/Cl) content to distinguish intercumulus from cumulus apatite, respectively. Finally, identifying a mafic magmatic system using detrital apatite in till will prove useful for provenance and mineral exploration studies. [ABSTRACT FROM AUTHOR]

In this paper, La2Ce2O7 powders co-activated by Ho3+ and Yb3+ were synthesized by a high temperature solid-state reaction. Both Ho3+ and Yb3+ substitute the La3+ sites in the La2Ce2O7 lattice, where the Ho3+ concentration is 0.5 at.% and the Yb3+ concentration varies in the range of 10~18% at.%. Pumped by a 980 nm laser, the up-conversion (UC) green emission peak at 547 nm and the red emission at 661 nm were detected. When the doping concentration of Ho3+ and Yb3+ are 0.5 at.% and 14% at.%, respectively, the UC emission reaches the strongest intensity. The temperature-sensing performance of La2Ce2O7:Ho3+ with Yb3+ was studied in the temperature range of 303–483 K, where the highest relative sensitivity (Sr) is 0.0129 K−1 at 483 K. The results show that the powder La2Ce2O7:Ho3+, Yb3+ can be a potential candidate for remote temperature sensors. [ABSTRACT FROM AUTHOR]

High-entropy rare earth zirconates (RE 2 Zr 2 O 7) have attracted significant research attention for thermal barrier coatings (TBCs) application due to their superior performance. However, currently used high-entropy RE 2 Zr 2 O 7 shows only the modest improvements, thus limiting their overall performance enhancement. Therefore, novel high-entropy RE 2 Zr 2 O 7 (La 0.2 Nd 0.2 Gd 0.2 Er 0.2 Yb 0.2) 2 Zr 2 O 7 (HEC) was synthesized in this study by chemical co-precipitation method, which was characterized by dual-phase and significant differences in ionic radius and atomic mass. Compared with single-component RE 2 Zr 2 O 7 (RE = La, Nd, Gd, Er, and Yb) ceramics, HEC demonstrates significantly superior performance, including higher hardness (11.705 GPa), fracture toughness (1.693 MPa m1/2), and thermal expansion coefficient (11.1926 × 10−6/K, 1400 °C), and lower thermal conductivity (1.33–1.43 W/(m•K), 26–1000 °C). The comprehensive performance improvement can be attributed to the high-entropy effect, dual-phase nature, and significant differences in ionic radius and atomic mass. This study provides valuable insight into the development of high-entropy RE 2 Zr 2 O 7 and suggests their significant potential in TBCs. [ABSTRACT FROM AUTHOR]

Phase pure Tb1–xYbxAl3(BO3)4 (x = 0 – 1) crystalline powders were prepared by the combustion synthesis method. Down-conversion experiments under UV excitation of 375 nm revealed optimal concentration of Yb x = 0.5 providing intensive green luminescence with 24% of quantum efficiency. Also up-conversion luminescence via energy transfer from Yb3+ to Tb3+ using a low power IR diode laser operating at 980 nm was achieved. Here the most powerful green emission was obtained with x = 0.1. [ABSTRACT FROM AUTHOR]

Relying on a reverse energy transfer mechanism between erbium (Er3+) and ytterbium (Yb3+) ions, optical gains at wavelengths of 1550, 980, and 1067 nm are achieved in NaYF4: Er3+, and Yb3+ nanoparticles‐doped polymer waveguides under excitation of low‐power light‐emitting diodes (LEDs) instead of 976 or 1480 nm semiconductor laser as pump sources. The optical gains at 1550, 980, and 1067 nm are demonstrated in five waveguide structures: active‐rectangular, evanescent‐field with and without an aluminium (Al) reflector, and dual‐active hybrid with and without an Al reflector. The maximum relative optical gains of 6.6, 4.0, and 3.8 dBcm−1 are realized at 1550, 1067, and 980 nm, respectively, in a 5 mm long dual‐active hybrid waveguide with cross‐section of 4 × 10 µm, and a ≈100 nm‐thick Al reflector grown under the lower cladding layer under excitation of a 395 nm LED. This work proves the feasibility of using a low‐cost LED to realize multi‐wavelength amplification in a dense wavelength‐division multiplexing system and is thus valuable for the development of complex multi‐functional photonic‐integrated‐module mixed‐band optical communication systems. [ABSTRACT FROM AUTHOR]

Outbreaks of infectious viruses offer a formidable challenge to public healthcare systems and early detection of viruses is essential for preventing virus propagation. In this work, an ultrasensitive plasmon‐enhanced fluorescence resonance energy transfer (FRET) biosensor based on core‐shell upconversion nanoparticle (csUCNP) and gold nanoparticle (AuNP) for accurate detection of SARS‐CoV‐2 viral RNA is presented. In this biodetection assay, the Tm3+/Er3+ co‐doped csUCNP NaGdF4:Yb/Tm@NaYF4:Yb/Er acts as an energy donor and AuNP serves as an energy acceptor. The upconversion emission of Tm3+ and the design of the core‐shell structure led to a simultaneous surface plasmon effect of AuNP. The localized surface plasmon resonance (LSPR) arising from collective oscillations of free electrons significantly enhanced FRET efficiency between Er3+ and AuNP. The as‐prepared biosensor obtained a limit of detection (LOD) as low as 750 am, indicating that the integration of FRET and surface plasmon into one biodetection assay significantly boosted the sensitivity of the biosensor. In addition, samples extracted from clinical samples are also utilized to validate the effectiveness of the biosensor. Therefore, this innovative plasmon‐enhanced FRET biosensor based on Tm3+/Er3+ co‐doped csUCNP may pave the way for rapid and accurate biodetection applications. [ABSTRACT FROM AUTHOR]

The title compound, diytterbium enneaoxidotritellurate(IV), was obtained in its C-type crystal structure from the binary oxides at 1073 K using a CsCl flux. It crystallizes isotypically with C-type Tm2Te3O9 and Lu2Te3O9, closing this gap of knowledge.

This paper presents the results of a study of the state of ytterbium atoms in silicon, carried out using the methods of Fourier transform infrared spectroscopy (IR) and Raman spectroscopy (RS). Silicon samples doped with ytterbium impurities were analyzed using FSM-2201 and SENTERRA II Bruker spectrometers. Registration and identification of both crystalline and amorphous phase components in the samples was carried out. The results of the study confirm that doping silicon with ytterbium impurities leads to a decrease in the concentration of optically active oxygen by 30-40%, depending on the concentration of the introduced impurities. It was also found that an increase in the number of defects leads to a broadening of the amorphous zone. It is assumed that similar dependencies exist for the Si-Yb system; however, to the best of our knowledge, similar results have not been reported previously. It is noted that the relative intensity of the three Raman bands in Si-Yb systems in the LTIOS (The light and temperature induced ordered state) state changes, and the relative intensity of Si-Si decreases. This indicates that pendant bonds are mainly formed by the breaking of Si-Si bonds. It was also observed that the light intensity causing this condition is far from that required for laser or solid phase crystallization. Using the Raman spectroscopy method, a structural transformation was discovered, expressed in a densely packed array of nanocrystals with a size of less than 11 lattice parameters. Small clusters were under strong internal stress (up to 3 GPa), which probably prevents the cluster size from increasing beyond the critical value for irreversible crystallization.

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]

Data-driven machine learning approaches with precise predictive capabilities are proposed to address the long-standing challenges in the calculation of complex many-electron atomic systems, including high computational costs and limited accuracy. In this work, we develop a general workflow for machine learning-assisted atomic structure calculations based on the Cowan code’s Hartree–Fock with relativistic corrections (HFR) theory. The workflow incorporates enhanced ElasticNet and XGBoost algorithms, refined using entropy weight methodology to optimize performance. This semi-empirical framework is applied to calculate and analyze the excited state energy levels of the 4f closed-shell Yb I atom, providing insights into the applicability of different algorithms under various conditions. The reliability and advantages of this innovative approach are demonstrated through comprehensive comparisons with ab initio calculations, experimental data, and other theoretical results.

The lanthanide series elements are transition metals used as critical components of electronics, as well as rechargeable batteries, fertilizers, antimicrobials, contrast agents for medical imaging, and diesel fuel additives. With the surge in their utilization, lanthanide metals are being found more in our environment. However, little is known about the health effects associated with lanthanide exposure. Epidemiological studies as well as studies performed in rodents exposed to lanthanum (La) suggest neurological damage, learning and memory impairment, and disruption of neurotransmitter signaling, particularly in serotonin and dopamine pathways. Unfortunately, little is known about the neurological effects of heavier lanthanides. As dysfunctions of serotonergic and dopaminergic signaling are implicated in multiple neurological conditions, including Parkinson’s disease, depression, generalized anxiety disorder, and post-traumatic stress disorder, it is of utmost importance to determine the effects of La and other lanthanides on these neurotransmitter systems. We therefore hypothesized that early-life exposure of light [La (III) or cerium (Ce (III))] or heavy [erbium (Er (III)) or ytterbium (Yb (III))] lanthanides in Caenorhabditis elegans could cause dysregulation of serotonergic and dopaminergic signaling upon adulthood. Serotonergic signaling was assessed by measuring pharyngeal pump rate, crawl-to-swim transition, as well as egg-laying behaviors. Dopaminergic signaling was assessed by measuring locomotor rate and egg-laying and swim-to-crawl transition behaviors. Treatment with La (III), Ce (III), Er (III), or Yb (III) caused deficits in serotonergic or dopaminergic signaling in all assays, suggesting both the heavy and light lanthanides disrupt these neurotransmitter systems. Concomitant with dysregulation of neurotransmission, all four lanthanides increased reactive oxygen species (ROS) generation and decreased glutathione and ATP levels. This suggests increased oxidative stress, which is a known modifier of neurotransmission. Altogether, our data suggest that both heavy and light lanthanide series elements disrupt serotonergic and dopaminergic signaling and may affect the development or pharmacological management of related neurological conditions.

The spectrum of triatomic molecules with close rovibrational opposite parity levels is sensitive to the P , T -odd effects. This makes them a convenient platform for the experimental search of a new physics. Among the promising candidates, one may distinguish YbOH as a non-radioactive compound with a heavy atom. The energy gap between levels of opposite parity, l-doubling, is of great interest as it determines the electric field strength required for the full polarization of the molecule. Likewise, the influence of the bending and stretching modes on the sensitivities to the P , T -violation requires a thorough investigation since the measurement would be performed on the excited vibrational states. This motivates us to obtain the rovibrational nuclear wavefunctions, taking into account the anharmonicity of the potential. As a result, we get the values of Eeff and Es for the lowest excited vibrational state and determine the l-doubling. [ABSTRACT FROM AUTHOR]

The response of isochronal and isothermal ageing on the microstructure, microhardness and electrical properties of as-cast and deformed AlYbEr and AlYbErZr alloys were studied. The addition of Zr does not affect the grain size of the alloys in the initial state. Stability of grain size in both AlYbEr and AlYbErZr as-cast alloys was proved up to ageing at 450 °C for 32 h. On the other hand recrystallized grains were already observed in cold rolled alloys after ageing at 450 °C for 2 h. It was found that Zr supports massive recrystallization of the alloys after ageing at 450 °C. The presence of L12-structured particles with dimensions about 20–100 nm was proved in the initial state of all studied aloys. Investigation of microstructure of the AlYbEr alloy after treatment up to 450 °C and 540 °C proved a presence of particles rich on Er, Yb, some of these pin dislocations. The structure of these particles could be tetragonal with the D019 or D023 lattice. In the AlYbErZr alloy many fine L12 particles (contain Er, Yb and Zr) were observed. The L12 particles were observed after ageing at 640 °C for 4 h in both alloys. The addition of Zr to the alloy highlighted the core-shell structure of these particles, moreover some of them have the double core-shell structure in the AlYbErZr alloy, where the outer shell contains Yb and Er, the inner shell contains Zr and Yb and Er was detected in the core.

Perovskite solar cells have attained high photoconversion efficiencies by changing chemical compositions of the perovskites and layered structures of the devices. However, the perovskite compounds easily decompose in air atmosphere even at the room temperature, and the photovoltaic properties are degraded by the formed defects. The motivation of this work is to solve these instability problems, and the objective the present work is to improve the film quality of the perovskite compounds by introducing lanthanide elements and decaphenylcyclopentasilane (DPPS), which were expected to contribute to decrease of the defects by the passivation effects. Here, effects of neodymium trifluoride (NdF3) or ytterbium trifluoride (YbF3) addition to CH3NH3PbI3 perovskite solar cells inserted with DPPS were investigated. Introduction of NdF3 or YbF3 increased the lattice constants and promoted crystal growth of the perovskites, and surface treatment by DPPS suppressed the PbI2 formation as surface passivation. Combined additions of NdF3 or YbF3 and DPPS contributed to the improvement of both the conversion efficiencies of the present perovskite devices and the stabilities of the photovoltaic properties by inhibiting the decomposition.

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]

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]

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]

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]

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]

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 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]

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]

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]