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Due to their high ionic conductivity, lithium lanthanum zirconium oxides (LLZO, Li7La3Zr2O12) of the garnet type are useful in a variety of applications and are good choice for solid state lithium‐ion batteries. The nature of dopants and their stoichiometry significantly impacts ionic conductivity. In this study, to explore the large design space of doped LLZO, we used optimized machine learning techniques based on random sampling screening of the Lazy classifier. Molecular, structural, and electronic descriptors were used to derive features for training the algorithms. The light gradient boosting machine and random forest algorithms exhibited a classification accuracy exceeding 95%. Notably, the relative density of LLZO was identified as the most correlated attribute to doped LLZO ionic conductivity. These findings highlight the potential of data‐driven algorithms in driving innovation and facilitating the development of novel materials. [ABSTRACT FROM AUTHOR]

In recent years, NIR (Near-Infrared) phosphor-converted LEDs (pc-LEDs) have played an indispensable role in the field of plant lighting. This study presents the development of a novel garnet-based phosphor ceramic, YAGG:0.035Cr3+, obtained through a high-temperature solid-state method. Through optical and structural performance analysis, it was found that the sample can be effectively excited by a commercial 450 nm blue LED, emitting near-infrared light in the range of 650–850 nm. This emission spectrum overlaps with approximately 74% of P FR spectrum absorbed by plant growth, and it achieves QY of around 40%. Notably, this ceramic demonstrates excellent thermal luminescence properties, maintaining approximately 96% of its integrated emission intensity at 423 K compared to room temperature. To explain this outstanding thermal performance, we analyzed that the gradual substitution of the 4T 2 level for the 2E level leads to the dominance of the 4T 2 -4A 2 transition process in PL. Furthermore, the YAGG:0.035Cr3+ phosphor ceramic was packaged with a 450 nm LED, and the emitted light intensity exhibited a linear relationship with the driving current. Even under high-power driving conditions of 1000 mA, the luminescence did not reach saturation. These results effectively demonstrate the potential application of YAGG:0.035Cr3+ phosphor ceramic in the field of plant lighting. [ABSTRACT FROM AUTHOR]

Spark plasma sintering (SPS) is a fast and efficient method for preparing functional ceramics. This article investigates the phase evolution, thermal expansion and chemical stability of traditional (Y 1.2 Nd 1.8 Fe 5 O 12) and high-entropy ((Y, Gd, Sm, Eu, Dy) 3 Fe 5 O 12) garnet ceramics. Prepared under conventional SPS (50 MPa) conditions at 900–1100 °C. The results indicate that using SPS sintering method can significantly reduce the sintering temperature (1100 °C) and time (3 min) of garnet ceramics. (Y, Gd, Sm, Eu, Dy) 3 Fe 5 O 12 (1.6 × 10−6 K−1) exhibits superior thermal expansion stability compared to Y 1.2 Nd 1.8 Fe 5 O 12 (5.4 × 10−6 K−1). The strong REE-O bond energy and severe lattice distortion of high entropy garnet ceramics hinder the migration and diffusion of cations, resulting in higher leaching resistance of high-entropy garnet ceramics (∼10−7 g m−2 d−1-10−8 g m−2 d−1) compared to traditional garnet ceramics (∼10−5 g m−2 d−1-10−6 g m−2 d−1). Therefore, SPS has broad application prospects in the low-temperature preparation of high-entropy garnet ceramics for immobilization of actinide elements. [ABSTRACT FROM AUTHOR]

The stability of CO2 fluid in the Earth's mantle is restricted by the carbonation of rock-forming minerals. Among those, the reaction with garnet is of particular interest because it constrains the stability of CO2 fluid in eclogites, whose minerals have been found in the CO2-bearing diamonds. In this work, we determined the equilibrium boundary for the reaction Mg3Al2Si3O12 (Prp) + 3CO2 (fluid) = Al2SiO5 (Ky) + 2SiO2 (Coe/Qz) + 3MgCO3 (Mgs) over the pressure interval 3–6 GPa using a multi-anvil press. Owing to the slow kinetics, the reaction was studied in both forward (left to right) and reverse (right to left) directions in experiments with durations extending up to 260 h. Our newly determined boundary is situated 3 GPa/950 ± 50 °C, 4.5 GPa/1150 °C, and 6 GPa/1350 ± 50 °C and has the equation P(GPa) = 0.0075 × T (°C) – 4.125. The boundary crosses the graphite-to-diamond transition curve near 4.7 GPa and 1180 °C. Thus, the assemblage garnet + CO2 fluid is stable in the diamond (Dia) stability field under P-T conditions of the continental geotherm with a heat flow of 41 mW/m2. [ABSTRACT FROM AUTHOR]

The direct dating of gem-quality garnet mineralization has been extremely limited, even though it has been known for decades that garnet may be dated by the U–Pb method. Here, we demonstrate the application of in situ laser U–Pb geochronology on gem-quality tsavorite to determine the timing of mineralization from two localities in the Mozambique Belt, Tanzania. U–Pb dating of tsavorite from Merelani and Umba provides ages of 569.5 ± 6.8 Ma and 540.0 ± 5.8 Ma, respectively. Due to the high closure temperature of the U–Pb system in garnet, we argue that these ages correspond to tsavorite mineralization. These ages postdate the East African Orogeny (650–620 Ma), the most significant metamorphic episode recorded in the Mozambique Belt, which had been previously considered to be the main tsavorite mineralization event. Instead, these dates correspond to the later Kuungan orogenic episode (570–530 Ma), associated with the final amalgamation of Gondwana. The mineralization of tsavorite tens of millions of years after the East African Orogeny in the Mozambique Belt illustrates the benefits of direct dating of gem-quality garnet to determine mineralization timing and style. [ABSTRACT FROM AUTHOR]

The homomorphic substitution of the garnet group is common in nature. Two rare color-changing andradite garnets are studied in this paper. One color changes from yellowish-green in the presence of daylight to maroon under incandescent light; the other color changes from brownish yellow to brownish red. In this study, conventional gemological instruments, infrared (IR) spectroscopy, ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy, Raman spectroscopy, and electron probe microanalysis (EPMA) were used to explore the gemology and coloration mechanisms of color-changing garnets. Experiments revealed that the color-changing gemstones in the study are andradite garnets. There are two transmission windows in the UV–Vis spectrum: the red region (above 650 nm) and the green region (centered at 525 nm). The chemical compositional analysis indicates that the samples are very low in Cr (<1 ppm) and high in Fe2+ (from 2.31 wt.% to 4.66 wt.%). The combined spectra and chemical compositional analysis show that Fe2+ is the main cause of the color change. Based on the IR spectrum (complex water peaks), UV–Vis–NIR spectrum (similar to that of Namibian andradite garnet), and chemical compositional analysis (low Cr content), it is concluded that color-changing andradite may be related to skarn rock genesis. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes constructed from polymers have high safety, outstanding thermal stability, and minimal flammability as their merits. Many researchers have been working on creating high-performance Li-based batteries composed of solid polymers. Composite polymer electrolyte (CPEs) electrochemical characteristics, which might include conductivity of ions, ion transfer numbers, and electrochemical durability, play an essential role when assessing the performance of energy conservation and conversion systems. Inorganic additions may enhance ionic conductivity by producing an ion transport percolation network. Additionally, the most effective filler composition can improve CPE electrochemical process stability, diminishing adverse responses and deterioration throughout gadget operations. In this article, we talk about active filler-based composites of polymers that make excellent solid electrolytes for the large-scale production of solid-state battery packs. We review the analysis and performance of active filler-based composite polymer electrolytes and look into the design of high-performance composite electrolytes. [ABSTRACT FROM AUTHOR]

Tm-doped Y3Al5O12 (YAG) single crystals with different Tm concentrations (0.1, 0.5, 1.0, and 2.0%) were grown using the floating zone method. X-ray-induced scintillation spectra, scintillation decay curves, and γ-ray-induced pulse height spectra of the obtained Tm-doped YAG single crystals were investigated. All the samples showed emission peaks due to the 4f-4f transitions of Tm3+ ions, and the decay times were around 40-20 µs under X-ray excitation. The 0.5% Tm-doped YAG sample showed the highest light yield under 662 keV γ-ray excitation among the samples. The optimal dopant concentration of Tm-doped YAG single crystals was confirmed to be 0.5%. [ABSTRACT FROM AUTHOR]

The practical implementation of garnet‐type solid electrolytes, such as Li6.4La3Zr1.4Ta0.6O12 (LLZTO), faces the significant challenge of Li dendrites. Though artificial interfacial strategies are effective in dendrite suppression, further investigation is needed to understand the mechanism of homogeneous Li deposition and its practicability under real‐world conditions. Herein, a bilayer interface is constructed to address these issues. Such a bilayer interface consists of one conformal Li2O‐rich layer, generated by rubbing LLZTO pellets inside molten Li with low‐dose In2O3, and another Li2O layer deposited through atomic layer deposition (ALD). The regulatory effect of the initial Li2O‐rich layer on achieving uniform Li deposition is explored, and the critical current density is enhanced to 2.4 mA cm−2. However, simple interfacial strategy is insufficient to prevent anodic degradation for cycling at room temperature without stack pressure, leading to increased current leakage and directly reducing Li+ within the electrolyte. After insulating it with a second ALD‐Li2O layer that minimally hampers ionic conduction, the Li/Li symmetric cells achieve long cycling life exceeding 1000 h at 0.5 mA cm−2 and maintain stable operation even at 2 mA cm−2. This work provides valuable insights for interfacial strategies towards practical solid‐state batteries. [ABSTRACT FROM AUTHOR]

Garnet-type Li 7 La 3 Zr 2 O 12 is currently being extensively studied as a potential candidate to replace the conventional liquid electrolytes due to prominent ionic conductivity and structural stability. The microstructure is the one of the important factor to obtain the electrochemical performances, resulting from Li-ion kinetics, local current density. Herein, we synthesize the Li 6.1 Ga 0.3 La 3 Zr 2 O 12 with various Li 2 O–B 2 O 3 –SiO 2 concentration (1, 3, 5, and 10 wt%) as a glass additive and investigate the effect on the crystallization, relative density, lithium ion conductivity and critical current density. Our findings reveal that proper amount of Li 2 O–B 2 O 3 –SiO 2 could enhance the sinterability, thus enabling facile and continuous lithium ion conduction with suppressing propagation of Li dendrite through the pores. Therefore, it can be concluded that appropriate concentration of Li 2 O–B 2 O 3 –SiO 2 can be regarded as a breakthrough to construct better solid electrolyte for all-solid-state lithium ion batteries. [ABSTRACT FROM AUTHOR]

Yttrium iron garnet (YIG: Y3Fe5O12) is an ideal magnetic material with potential applications in microwave and spintronic devices. A key prerequisite for seamless integration into current semiconductor electronics is the growth of high-quality YIG films on substrates beyond isostructural Gadolinium gallium garnet. In this context, we present the successful fabrication of YIG thin films with varying thickness (70 ≤ t ≤ 380) on fused quartz substrates utilizing radio-frequency (rf) magnetron sputtering. The Rietveld refinement of the X-ray diffraction data uncovers the formation of body-centered cubic single-phase polycrystalline YIG with the space group of Ia-3d. Saturation magnetization (4πMS) and coercivity (HC), as determined by the physical property measurement system (PPMS), exhibit a dependence on the film's thickness (t). Remarkably, the film with t = 380 nm shows a 4πMS value of 1775, closely resembling the bulk YIG value, with an exceptionally low coercivity (HC < 5 Oe). From ferromagnetic resonance (FMR) measurements, the estimated effective saturation magnetization (4πMeff) is found to be very much different from the 4πMS obtained from PPMS and is attributed to the presence of stressed-induced magnetic anisotropy (HK) in YIG films. The FMR linewidth (ΔH) of the YIG films is found to be quite sensitive to HK and the minimum ΔH value of 80 Oe is observed in the film with the lowest HK. The findings indicate that YIG films deposited on quartz substrates have potential advantages for their application in semiconductor-integrated devices. Importantly, this study delves into the fundamental intricacies of YIG growth on non-garnet substrates and offers a well-optimized recipe for generating high-quality YIG thin films through RF sputtering. [ABSTRACT FROM AUTHOR]

Solid‐state batteries (SSBs) based on Li‐rich Mn‐based oxide (LRMO) cathodes attract much attention because of their high energy density as well as high safety. But their development was seriously hindered by the interfacial instability and inferior electrochemical performance. Herein, we design a three‐dimensional foam‐structured GaN−Li composite anode and successfully construct a high‐performance SSB based on Co‐free Li1.2Ni0.2Mn0.6O2 cathode and Li6.5La3Zr1.5Ta0.5O12 (LLZTO) solid electrolyte. The interfacial resistance is considerably reduced to only 1.53 Ω cm2 and the assembled Li symmetric cell is stably cycled more than 10,000 h at 0.1–0.2 mA cm−2. The full battery shows a high initial capacity of 245 mAh g−1 at 0.1 C and does not show any capacity degradation after 200 cycles at 0.2 C (≈100 %). The voltage decay is well suppressed and it is significantly decreased from 2.96 mV/cycle to only 0.66 mV/cycle. The SSB also shows a very high rate capability (≈170 mAh g−1 at 1 C) comparable to a liquid electrolyte‐based battery. Moreover, the oxygen anion redox (OAR) reversibility of LRMO in SSB is much higher than that in liquid electrolyte‐based cells. This study offers a distinct strategy for constructing high‐performance LRMO‐based SSBs and sheds light on the development and application of high‐energy density SSBs. [ABSTRACT FROM AUTHOR]

The article discusses the history and significance of gem mining in southern California, specifically focusing on the pegmatite deposits in San Diego County and southern Riverside County. The region was once a leading source of gem tourmaline and spodumene in the early 20th century, but was later surpassed by discoveries in other parts of the world. However, commercial gem mining has experienced a resurgence in the past two decades, particularly in San Diego County. The article also highlights the production of other gems such as beryl, topaz, garnet, quartz, and apatite in the region. The author emphasizes that gem mining in southern California is still ongoing and new discoveries are being made. [Extracted from the article]

The phase composition and spectral-luminescent properties of samples of a luminescent ceramic, based on oxide compositions with makeup described by the general formula Y2.98–xCexAl5.02O12, where x = 0.05, 0.10, 0.20, 0.30, 0.45, and 0.60 formula units (f.un), were investigated. It is demonstrated that the phase composition of ceramic powders depends substantially on the cerium concentration and the calcination atmosphere. It was ascertained that the maximum concentration of cerium cations in the garnet lattice on calcination in air is equal to about 0.1 f.un, and in an argon and hydrogen atmosphere approximately 0.16 f.un The photoluminescence of ceramic samples excited by a 445 nm laser was investigated. It is shown that ceramic samples obtained by sintering in argon and hydrogen have a higher luminescence intensity compared to samples synthesized in vacuum. The possibility of shifting the wavelength of the maximum luminescence intensity from 546 to 570 nm by changing the cation composition and the sintering conditions of the ceramics was demonstrated. It is shown that oxidative annealing of ceramic samples adversely affects the intensity and position of luminescence maxima in highly cerium-doped oxide compositions Y2.98–xCexAl5.02O12. [ABSTRACT FROM AUTHOR]

The document titled "Literature of Interest" is a compilation of recent articles and studies related to gemology and mineralogy. It covers a wide range of topics including the characteristics and origins of gemstones, spectroscopic analysis of minerals, and identification of raw materials and imitations. The document also includes articles on cultural heritage, such as the identification of archaeological glyptics and the historical significance of gemstone mines. Additionally, there are articles on diamonds, gem localities, and various other topics related to gemstones and minerals. The document concludes with sections on organic/biogenic gems, news press articles, and compilations of images, gem news, and lab notes. [Extracted from the article]

The influence of the components of supercritical C–O–H fluid (at a content of 7.5 wt %) on the melting relations in the multicomponent diamond-forming system olivine–jadeite–diopside–(Mg–Fe–Ca–Na carbonates)–(C–O–H) was studied experimentally at 6 GPa and 700–1200°C under the conditions of the upper mantle. The peritectic reaction of olivine and jadeite-bearing melt with the formation of garnet was suggested as a key mechanism for the ultramafic–mafic evolution of diamond-forming melts. The CO2 component of the C–O–H fluid reacts with silicate components to form carbonates. The H2O component, together with carbonate compounds of the diamond-forming system, reduces the temperature of its liquidus and solidus boundaries significantly. After the completion of crystallization of a completely miscible silicate–carbonate–(C–O–H fluid) melt, a phase of supercritical aqueous fluid and hydrous carbonate nesquehonite MgCO3·3H2O identified by Raman spectroscopy appear in the subsolidus of the diamond-forming system. [ABSTRACT FROM AUTHOR]

Non-conventional machining processes offer significant advantages over conventional ones, especially in terms of the productivity, cost, and surface integrity of the produced parts due to their higher flexibility. Abrasive waterjet machining, in particular, constitutes an ecologically friendly process with a negligible thermal impact on a workpiece, and it has considerable capabilities for obtaining the desired outcome by regulating some of its numerous parameters. Among these parameters, the abrasive type is particularly important due to its hardness, mesh size, and shape, which lead to considerable deviations on the obtained depth, kerf characteristics, and productivity. Thus, in this work, a comprehensive comparison is conducted on the use of garnet and silicon carbide particles for the slot milling of the Ti-6Al-4V alloy under different conditions. The capabilities of both abrasive materials are evaluated by statistical analysis regarding the depth of penetration, kerf width, kerf taper angle, and material removal rate (MRR), which are obtained under the same process conditions. Finally, a multi-objective optimization based on grey relational analysis (GRA) is performed for several different practical cases. It was found that, although silicon carbide is more efficient in optimizing individual process outputs, the use of a garnet abrasive can lead to considerably better trade-offs between two or more objectives of the machining process. [ABSTRACT FROM AUTHOR]

High-MgO (>9 wt %) basaltic rocks can be primary magmas and are used to constrain the geochemistry and temperature of the mantle. However, high MgO contents can also result from mixing between evolved melts and antecrysts or xenocrysts, and thus, the whole-rock composition might not represent the solidified equivalents of primary magma. Whether such mixing with crystals can result in erroneous interpretations of mantle processes remains unclear. This study presents a petrological and geochemical investigation of the post-collision high-MgO (>9 wt %) Lugu volcanic rocks in the southern Qiangtang terrane, central Tibet. The Lugu volcanic rocks comprise porphyritic and intersertal alkali basalts. Zircon U–Pb ages and 40Ar/39Ar dating suggest that the two types of alkali basalts were erupted at c. 29 Ma. Based on detailed petrographic observations and geochemical analysis, the porphyritic alkali basalts may represent near-primary melts, which are characterised by low SiO2 contents (40.9–45.1 wt %), high CaO/Al2O3 ratios (1.1–1.5), and arc-like trace element patterns. We suggest these basalts were derived by partial melting of enriched garnet peridotite (>3 GPa) in the presence of H2O and CO2. These geochemical features are different from those of the c. 30-Ma (ultra)-potassic rocks in the Qiangtang terrane, indicating that a heterogeneous lithospheric mantle existed beneath the Qiangtang terrane during the Oligocene. In contrast, although the intersertal alkali basalts have high MgO contents (>9 wt %), evidence from mineral chemistry indicates that the whole-rock compositions of the intersertal alkali basalts represent mixtures of evolved residual melts and cumulate crystals. They were the product of polybaric fractional crystallisation and the subsequent mixing of crystals and residual melts in a magmatic plumbing system. Furthermore, when intersertal alkali basalts are assumed to be primary melts, they would have been derived by partial melting of shallow (~2.5 GPa) CO2-poor pyroxenite or peridotite. These conditions are different from interpretations of the nature of the mantle source and melting conditions for porphyritic alkali basalts. Our results highlight that the interpretation of petrogenetic processes should be preceded by detailed mineralogical investigations. [ABSTRACT FROM AUTHOR]

The beauty of an eclogite is something to behold: any petrologist marvels in the combination of red garnet and green omphacite that are the main mineral constituents of the rock. But besides their stunning appearance, there is much more to eclogites: fundamental concepts in metamorphic petrology and geodynamics were developed based on scientific investigations of eclogites. It is well established that they derive from precursor rocks of basaltic composition and form under high‐pressure conditions at more than c. 45 km depth, but other aspects of their occurrences and geological significance remain debated. The relative scarcity of eclogites among crustal rocks renders them largely unknown to the layperson, so following the 200th anniversary of the term eclogite in 2022, there is an opportunity to take a closer look at this fascinating rock. [ABSTRACT FROM AUTHOR]

The interaction and infiltration behavior between typical calcium–ferrum–alumina–silicate (CFAS) and Yb4Hf3O12 ceramics at 1300, 1400, and 1500°C for different duration times were investigated. At 1300°C, the CFAS melt first crystallized and then generated massive anorthite with high‐melting point, reducing the wettability of CFAS melt and physically blocking CFAS penetration paths. As the temperature increased to 1400°C and 1500°C, the wettability of the molten CFAS correspondingly increases. A continuous reaction layer, composed of apatite, fluorite, and garnet, was formed over Yb4Hf3O12 ceramic due to the penetration of CFAS melt. Furthermore, the infiltration rate of CFAS decreases with increasing corrosion time because of the barrier effect primarily derived from the as‐mentioned continuous reaction layer. [ABSTRACT FROM AUTHOR]

The results of detailed petrological studies of mafic granulites from the Yubileinaya (Alakit-Markha field) and Novinka (Upper–Muna field) kimberlite pipes, where retrograde metamorphic P–T paths were reconstructed for the first time using mineral geothermobarometry, are provided. These P–T paths demonstrate subisobaric transition of the rocks from the P–T conditions of low-grade granulite facies to low-grade amphibolite facies at the depth of the middle crust. It was found that the compositions of garnet, clinopyroxene, and orthopyroxene depend on the adjacent mineral, reflecting the different closure temperatures of the exchange mineral reactions. The higher temperatures are determined using a two-pyroxene geothermometer, while the lower ones are found by application of garnet–clinopyroxene and garnet–orthopyroxene geothermometers. Phase equilibria modeling showed the thermodynamic conditions of the low-grade amphibolite facies: 540°C, 0.76 GPa, lgfO2 = QFM + 1.7 (Yubileinaya pipe); 530°C, 0.72 GPa, lgfO2 = QFM + 2.2 (Novinka pipe). The stability of the granulite paragenesis of garnet + clinopyroxene + orthopyroxene + plagioclase under such P–T conditions is a poorly known phenomenon reflecting a deficit of aqueous fluid during the crystallization of gabbroids and their subsequent cooling in the deep segments of cratons. [ABSTRACT FROM AUTHOR]

The U–Pb age of accessory zircon of the magmatic protolith for various metamorphic rocks of the UHP Maksyutovo complex is determined by the U–Th–Pb SIMS (SHRIMP II) method. The protolith age is most confidently estimated for metabasite shales in two samples (648 ± 3 and 566 ± 3 Ma). The age of zircon from shales, the chemical composition of which corresponds to andesidacites, is 549 ± 4 Ma. The age of the protolith from garnet–omphacite metabasite rocks is 501 ± 5 Ma. Individual crystals of magmatic zircon 893 ± 6 Ma in age, representing a xenogenic population, are separated from eclogites. The age value of 561 ± 10 Ma is taken for the protolith of eclogites, according to the data of the previous researchers. Magmatic complexes with an age close to the age range obtained for the protolith (549–648 Ma) are known in the Uraltau zone and represent fragments of the volcanic–plutonic belt of the active continental margin. The integrated age of metamorphism in the Maksyutovo complex from two samples of this area is 380 ± 3 Ma. [ABSTRACT FROM AUTHOR]

This investigation establishes an integrated method for rare earth elements (REE) exploration through a very promising and advanced exploration prospect in the Alces Lake area (SK, Canada) by assessing the integrated analysis of several multisource geophysical datasets. The resulting outcome provides important lithostructural information to the well-exposed, mineralized middle-to-lower crust at Alces Lake, comprising deep-seated poly-phase folds, ductile shear zones, and brittle faults. Geophysical–geological models of the Alces Lake property were constructed at different scales. The area of interest is located within the Beaverlodge Domain, about 28 km north of the Athabasca Basin's northern margin. It contains some of the highest-grade rare earth elements (REE) in the world with the REE hosted predominantly in monazites within quartzo-feldspathic granitic to biotite–garnet–monazite–zircon-rich restite-bearing/cumulate mush melt pegmatites of anatectic origin (abyssal). Geophysical magnetic, gravity, and radiometric data were used together with Shuttle Radar Topography Mission (SRTM) images to facilitate the processing, modeling, and interpretation. Consequently, major structures were identified at different scales; however, the emphasis was given to studying those at the district/camp scale. The REE zones discovered to date occur within a large district-scale refolded synformal anticline. The eastern limb of this folded structure comprises a 30–40 km long, NW-trending shear zone/fault corridor with deep-seated structural crustal roots that may have served as the major pathway for ascending fluids/melts and facilitated the emplacement of mineralization. Thus, shear zones, faults, and folds in combination with lithological contacts/rheological contrasts appear to control residual/cumulate pegmatite emplacement and monazite deposition. Anomalies obtained from the airborne equivalent thorium survey data prove to be the most useful for REE pegmatite exploration. The results herein provide new interpretation and modeling perspectives leading to a better understanding of the distribution and lithostructural controls of REE on the property, and to new guidelines for future exploration programs at Alces Lake and elsewhere in northern Saskatchewan. [ABSTRACT FROM AUTHOR]

An in situ electron microprobe study of detrital minerals yielded important insights into the diagenetic history of the Cretaceous-to-Paleogene flysch sandstones from the Chvalčov site, Rača Unit, Flysch Belt of the Outer Western Carpathians. Detrital titanite and a Fe-Ti mineral (probably ilmenite) were almost completely altered to TiO2 minerals, which also newly crystallized in intergranular spaces of sandstone. Brookite, anatase, and, exceptionally, rutile were identified by Raman spectroscopy. Authigenic TiO2 phases show complex composition with occasionally elevated contents of Fe, Nb, Zr, V, Sc, Cr, Al, Y, and/or P, which were likely sourced from altered neighboring heavy minerals. In addition, rare authigenic LREE- and Y-enriched apatite rims were observed on detrital apatite. The remobilization of REE, Y, and HFSE was likely mediated by acidic early diagenetic fluids enriched in fluoride and sulfate anions. The superimposed formation of calcite cement was associated with the dissolution of detrital garnet, feldspars, and quartz. The compositions of detrital apatite and garnet (Alm60-82Prp4-30Sps0-24Grs0-19) are comparable with those from adjacent parts of the Flysch Belt. Detrital rutile is enriched in Nb, V, Cr, and Zr. Our study illustrates the intensity of diagenetic alteration of detrital minerals in flysch sandstones as well as the usefulness of in-situ electron-microprobe investigations for the recognition of processes influencing heavy minerals in diagenetically altered sediments. [ABSTRACT FROM AUTHOR]

Two types of aluminous paragneiss from the Loosdorf complex (Bohemian Massif, NE Austria) contain coarse‐grained granulite assemblages and retrograde reaction textures that are investigated to constrain the post‐peak history of the Gföhl unit in the southern Bohemian Massif. Both types have a peak assemblage garnet–biotite–sillimanite–plagioclase–K‐feldspar–quartz–granitic melt ± kyanite ± ilmenite ± rutile, recording peak metamorphic conditions of ∼0.9–1.1 GPa and ∼780–820°C estimated by isochemical phase equilibrium modelling. The first sample type (Ysper paragneiss) developed (i) cordierite coronae around garnet and (ii) cordierite–spinel and cordierite–quartz reaction textures at former garnet–sillimanite interfaces. Calculated chemical potential relationships indicate that the textures formed in the course of a post‐peak near‐isothermal decompression path reaching ∼0.4 GPa. Texture formation follows a two‐step process. Initially, cordierite coronae grow between garnet and sillimanite. As these coronae thicken, they facilitate the development of local compositional domains, leading to the formation of cordierite–spinel and cordierite–quartz symplectites. The second sample type (Pielach paragneiss) exhibits only discontinuous cordierite coronae around garnet porphyroblasts but lacks symplectites. The formation of cordierite there also indicates near‐isothermal decompression to 0.4–0.5 GPa and 750–800°C. This relatively hot decompression path is explained by the contemporaneous exhumation of a large HP–UHT granulite body now underlying the Loosdorf complex. The timing of regional metamorphism in the granulites and the southern Bohemian Massif in general is well constrained and has its peak at ∼340 Ma. Monazite from Loosdorf paragneiss samples yield a slightly younger age of ∼335 Ma. Although the ages overlap within error, they are interpreted to reflect near‐isothermal decompression and exhumation resulting in the formation of the observed reaction textures. [ABSTRACT FROM AUTHOR]

The Flinton Group is a metasedimentary succession of the Grenville Province in SE Ontario, potentially allowing insight into the tectono‐thermal evolution of continental crust during the Mesoproterozoic. At its Green Bay locality, Flinton Group metapelites of the staurolite zone contain abundant, post‐kinematic garnet porphyroblasts. Whereas the larger garnet crystals are typically impinged, smaller crystals are isolated from each other, occasionally exhibiting elongated shapes with apparently trigonal morphology. Central sections of the garnet population of a representative sample reveal that garnet is composed of different compositional and microstructural domains. In the largest crystals of the population, garnet contains rectangular to rhombic domains, marked by sharp increases in the concentrations of Nb, V, Ti, and Cr. These domains are associated with irregularly shaped patches, characterized by spatially heterogenous enrichments of Ca and LREE, and depletions in the contents of P, Y, MREE, and HREE, accompanied by increased densities of comparatively coarse‐grained quartz inclusions hosting apatite. Microstructural relationships indicate that these domains correspond to portions of garnet that pseudomorphed biotite, with the enrichments of Nb, V, Ti, and Cr outlining the original biotite shapes. The compositional patterns formed by Ca, P, Y, and REE indicate that apatite participated in the grain‐fluid interactions that operated during the metasomatic replacement of biotite by garnet. The statistical analyses of the garnet number and size distributions confirm that garnet initially nucleated on biotite, controlled by the kinetics of attachment and detachment processes at the garnet/biotite interface, resulting in the typical impingement habit. In situ Lu–Hf garnet geochronology applied to garnet that did not pseudomorph biotite, and hence is enriched in HREE, points to a first metamorphic event at c. 1080 ± 31 Ma. Subsequent pseudomorphism of staurolite by white mica in a Al2O3‐ and FeO‐mobile system resulted in the concomitant crystallization of a new garnet generation, forming overgrowths on the first garnet generation and nuclei in the fine‐grained matrix. Garnet that nucleated during this event grew to isolated and elongated crystals with apparently trigonal morphology, aligned in a direction c. perpendicular to the rock matrix foliation. The open‐system behaviour during this event limits the use of whole‐rock‐based geochronological and thermobarometrical applications. However, previously published in situ U–Pb ages of monazite included in the rims of the garnet crystals and in the rock matrix indicate that this event took place at c. 976 ± 4 Ma, likely associated with a period of increased hydrothermal activity late in the metamorphic history of the Grenvillian Orogeny. Diffusion geospeedometry calculations indicate that garnet growth during this hydrothermal event lasted for less than 6 Myr. [ABSTRACT FROM AUTHOR]

The burgeoning phosphor‐converted near‐infrared light‐emitting diodes (pc‐NIR LEDs) have important applications in special illumination and spectroscopy analysis. However, the development of efficient NIR‐emitting phosphors with high performance is still a challenge. In this work, a chemical unit co‐substitution strategy is proposed to realize the excitation transition regulation and successfully achieve high‐performance NIR luminescence in Ca3‐yNayMg1‐ySb2‐xAl2+yO12: xCr3+ (0 ≤ x ≤ 0.05, 0 ≤ y ≤ 1) garnet‐type solid solution phosphors. Through the excitation transition modulation from the 4A2 ground state to the 4T1(4P) and 4T1(4F) excitation state, the excitation intensity at the blue light region is largely enhanced by 25.6 times. Moreover, the NIR‐emitting efficiency and thermal stability are improved, with the optimal luminescence internal quantum efficiency of 90.6% and thermal stability of 97%@423 K, without any flux‐assisted sintering or reduction atmosphere protection. The structure regulation induced small Stokes shift, weak electron‐phonon coupling effect, and decreased non‐radiative transition are responsible for the excellent NIR‐emitting performance. Finally, the NIR pc‐LED is fabricated with photoelectric efficiencies of 18.7%@100 mA and NIR output powers of 63 mW@100 mA, presenting potential applications in nondestructive internal defect detection, veins imaging, and night vision surveillance. [ABSTRACT FROM AUTHOR]

Thermoelectric materials and devices have the potential to directly convert heat into electricity, making them crucial for advancing the energy structure system and achieving the dual-carbon goal. However, the conventional methods of preparing thermoelectric materials and designing devices still face significant challenges, limiting the widespread application of thermoelectric technology. Ferromagnetic metal heterostructured nanomultilayers play a crucial role in generating, transporting, and detecting spin currents. Studying the properties and physical mechanisms of spin-dependent magnetic-thermal-electrical effects in the core material is essential for advancing spin thermoelectrics in the future. In this paper, we investigate the spin-related thermoelectric effects in artificial spin-valve heterostructured nanomultilayers. The spin-current generating layer is made of rare-earth garnet, while the spin-current detecting layer consists of ferromagnetic alloy thin films with different compositions of Fe–Co. It is being investigated to obtain thermal voltage signals with excellent stability and high resolution as well as to achieve the amplification and positive/negative adjustment of these signals. This study can serve as a reference for designing thermoelectric materials and aiding in the development of future high-efficiency spin-thermoelectric conversion devices. [ABSTRACT FROM AUTHOR]

The gneisses of the Sarwar‐Junia Fault Zone (SJFZ), in the Mangalwar Gneissic Complex, a part of the Banded Gneissic Complex (BGC‐II) of northwest India recorded two phases of metamorphism. The pelitic gneiss from SJFZ mainly consists of biotite, sillimanite, garnet, quartz, K‐feldspar and plagioclase. On the other hand, the granitic gneiss from SJFZ mainly consists of quartz, plagioclase, K‐feldspar and biotite. From zircon and monazite geochronology, the protolith of pelitic gneiss was deposited on basement granitic gneiss and the metamorphism occurred at ca. 950 Ma affecting both the granitic gneiss and the pelitic gneiss. Estimation of the P‐T conditions of metamorphism and pseudosection modelling of the pelitic gneiss revealed that the peak stage metamorphic condition of M2 culminated at ~850°C and ~7 kbar pressure followed by a near‐isobaric cooling. Large garnet porphyroblasts in contact with retrograde biotite shows Fe‐Mg resetting close to the core region, which implies a slow cooling. Therefore, the possible exhumation during the subduction‐collision tectonics was very slow, if not completely ceased, at ca. 950 Ma. The shared tectonothermal history of the Sandmata Metamorphic Complex and Mangalwar Metamorphic Complex in the BGC‐II is now evident from the present study of the SJFZ, and confirms the presence of Grenvillian‐aged tectonothermal events in the eastern part of BGC‐II. The abovementioned near‐isobarically cooled and hydrated crust of the SJFZ records subsequent event(s) of shallow crustal brittle faulting as evident by the presence of pseudotachylyte veins and cataclastic fabric observed in the studied gneisses. Brittle faulting possibly occurred between ca. 905 Ma and ca. 750 Ma, as interpreted from the present geochronological data. [ABSTRACT FROM AUTHOR]

The Araguaia Orogen, located in Central Brazil, represents an Ediacaran-Cambrian collisional orogen associated with the final assembly of West Gondwana. Two contrasting tectonic models have been proposed for the evolution of this orogen, involving different histories for the Amazonian palaeocontinent drift: (i) subduction of a large ocean and final collision of the Amazonian palaeocontinent with Gondwana between ~ 560 and 500 Ma and (ii) intracontinental orogeny after early amalgamation of the Amazonian palaeocontinent at ca. 620 Ma. Detailed tectono-metamorphic studies in this key locality for the evolution of Gondwana are also still scarce. Hence, in this study we present a detailed metamorphic investigation of two metapelite samples (schists) and one garnet amphibolite aiming to unravel the pressure-temperature-time (P-T-t) paths for the higher grade rocks exposed in this orogen. Pressure-temperature estimates based on thermodynamic modelling using isochemical phase diagrams in the MnNCKFMASHTO system for the schists constrained a single and continuous prograde metamorphic path (burial and heating) from ~ 4–6 kbar and ~ 450–500°C to ~ 7–8 kbar and ~ 580–650°C. The near-peak metamorphic conditions of the garnet amphibolite were estimated from classic geothermobarometry at 7.5 ± 0.8 kbar and 552 ± 40°C. Lutetium-hafnium garnet dating constrained an average age for the prograde metamorphism at around 537–533 Ma. These results show that the Araguaia Orogen records one single metamorphic event during the late Ediacaran-early Cambrian, and likely represents part of a collisional system developed between the Amazonian Craton and Parnaíba Block after the closure of the Clymene Ocean. [ABSTRACT FROM AUTHOR]

Medium and high grade kyanite-bearing graphitic metapelites of the basement of the Torrox Unit (Upper Alpujarride, Western Mediterranean) show kyanite-andalusite-kyanite replacements and coexisting garnet types with complex compositional zoning and growth-dissolution stages. This allows inferring two clockwise P-T paths associated with contrasted orogenic cycles of latest Carboniferous – earliest Permian and Eocene(?)-Miocene age, respectively. Dated (306 ± 77 Ma) prograde medium grade garnet cores with relatively low to moderate Ca content indicates pre-Alpine barrovian metamorphism in the kyanite stability field (ca. 600°C, 0.7–0.8 GPa). This implies a prograde pressurization of the sequence followed by decompression, as inferred from andalusite replacements after kyanite. Deeper in the sequence, anatectic granitic orthogneisses contain high-grade graphitic kyanite-bearing metapelitic restitic enclaves. Dating of rutile (with inclusions of kyanite) and monazite (shielded in biotite) from the pelitic enclaves provided pre-Alpine ages (ca. 300 Ma) rejuvenated due to Alpine overprint. Such pressurization event is not consistent with a late Variscan stage, commonly identified with a tectonic scenario characterized by orogenic collapse and decompression at ca. 300 Ma. Instead, we propose a post-Variscan collision event related to the closure of the western Paleotethys. On the other hand, Ca-rich cores of garnet porphyroblasts in the medium-grade metapelites formed at 1.1–1.2 GPa, 500°C, implying a metamorphic gradient of ca. 11.5°C/km related to Eocene (?) subduction. Kyanite+phengite replacements after andalusite are related to this stage. Late Mg-rich Ca-poorer overgrowths in garnet porphyroblasts document increasing temperature during the first stage of decompression (down to 0.9 GPa at ca. 650°C) with increasing thermal gradient up to ca. 20°C/km. These two complete metamorphic cycles of pressurization and heating followed by decompression allow reconciling previous contradictory conclusions about the paragenetic and thermal gradient development during the Paleotethyan and Alpine cycles in different units of the Betic-Rif belt. [ABSTRACT FROM AUTHOR]

The Mazraeh Cu skarn deposit, NW Iran, is situated at the lithological contact between an Oligo--Miocene granodiorite and Cretaceous limestones. The causative granodiorite has I-type medium- to high-K calc-alkaline composition that formed in a subduction arc setting. Metasomatism generated exoskarn and endoskarn characterized by a temporal and spatial mineral-chemistry zonation with massive garnet and garnet-pyroxene proximal and epidote-amphibole skarn at the distal zones of the exoskarn. Our data reveal a multi-stage evolution of the hydrothermal system. Accordingly, the prograde stage was formed by barren, oxidized, high-temperature and hypersaline magmatic fluids, which suggests that the parental magma was emplaced at low lithostatic pressure conditions (~1.5 km depth). By contrast, during the retrograde stage the regime changed from lithostatic to hydrostatic conditions, resulting in a significant decrease in pressure and oxygen fugacity, boiling, cooling, and mixing, respectively. Dilution by meteoric fluids led to additional cooling and lower salinity of the ore fluids. Sulfur isotope compositions (δ34S = -2.8‰-1.3‰) of sulfides indicate a unique magmatic source of the sulfur. The δ18Ofluid and δDfluid values of the prograde stage fluid also indicate a magmatic origin, while their gradual depletions from the prograde to retrograde stage imply increased mixing with meteoric water. We propose that the fluid mixing scenario continued over the entire life cycle of the mineral system in an open hydrostatic regime as reflected in the oxygen isotope values. It is suggested that boiling and fluid mixing played a significant role in the formation of this giant Cu skarn deposit. [ABSTRACT FROM AUTHOR]

Petrologic and geochronologic data for metapelitic lower crustal xenoliths from New Mexico (USA) and Chihuahua (Mexico) states provide evidence for both a magmatic and collisional component to the enigmatic Mesoproterozoic Picuris orogeny. These garnet-sillimanite-bearing metapelites are found within the southern Rio Grande rift at Kilbourne Hole and Potrillo Maar in southern New Mexico and northern Chihuahua. Geothermobarometry and rutile with Quaternary U-Pb dates indicate equilibration in the local lower crust, which is actively undergoing ultra-high temperature (UHT) metamorphism (Cipar et al., 2020). The samples contain older detrital zircons dating back to the Paleoproterozoic, marking their deposition at the surface. Coupled zircon U-Pb dates and trace-element ratios (e.g., Gd/Yb) show a clear transition from oscillatoryzoned, low-Gd/Yb detrital magmatic zircon to featureless, high-Gd/Yb metamorphic zircon between 1500 and 1400 Ma, marking the transition from subduction to collision during this period. Metamorphic zircon and monazite grew in two major intervals. The first, between ca. 1450 and 1350 Ma, documents the journey of the sediments to depth within the orogen and provides evidence of extended Mesoproterozoic metamorphism in the region. The second corresponds with UHT metamorphism that commenced at ca. 32 Ma and is associated with the Rio Grande rift. Whereas nearly all garnets are homogeneous in both major and trace elements, a single garnet from one sample has a core defined by abundant quartz and acicular sillimanite inclusions. The core and rim of this garnet is homogeneous in major and most trace elements, but the rim is enriched in the slowest diffusing elements, Zr and Hf, which likely indicates rim growth at higher temperatures. We interpret the garnet core to have grown at the time of emplacement of the sediments into the lower crust. Because this occurred in the sillimanite stability field and because the metamorphic zircon and monazite all have negative Eu anomalies, indicating their equilibration with feldspar (stable at depths of <45 km), we conclude that the sediments were not emplaced via subduction and/or relamination of forearc sediments, but were instead metamorphosed under warmer, shallower conditions in an orogenic setting. Collectively, the data point to a collisional orogen during the inferred timing of the Picuris orogeny. These samples may therefore define the location of the Picuris suture zone, a key feature of this orogenic event. [ABSTRACT FROM AUTHOR]

Metamorphic rocks encode invaluable information on the burial and exhumation history of rocks that is critical to our understanding of orogens. In this work, zircon U--Pb dating, pseudosection, and garnet zoning modeling were performed on samples from the North Altyn area, SE Tarim Craton, NW China. Zircon U--Pb geochronological data indicate that the peak metamorphism occurred at ca. 2.0 Ga. Pseudosection isopleth thermobarometry using garnet growth zoning of the sample from the northern part of the North Altyn area (Kalatashtagh) reveals a decompression and heating path to a peak temperature of 735 °C and 0.74 GPa under the equilibrium crystallization model. The preservation of growth zoning under high temperature requires relatively rapid cooling. In contrast, garnet from the southern part of the North Altyn area (Aktashtagh) preserves diffusion zoning. Metamorphic peak occurs at 670-735 °C and 0.67-0.73 GPa, which suggests a high dT/dP-type metamorphism. Diffusion zoning modeling suggests an extremely slow cooling rate of 1-5 °C/m.y., which indicates prolonged (~100 m.y.) crustal residence time at high temperature. This requires a long-term heat supply, most likely from radiogenic heat from buried sediments or heat conducted from the asthenosphere. The high dT/dP and slow cooling rate, combined with extensive crustal anatexis from previous studies, indicate that the late Paleoproterozoic North Altyn Orogen is a long-lived hot orogen rather than a subduction--accretionary complex. We propose a tectonic model that involves a ca. 2.1-2.0 Ga arc--back-arc system in the SE Tarim Craton. The back-arc basin was subsequently closed by northward underthrusting due to arc--arc/ continental collision at ca. 2.0-1.95 Ga during the integration of the Tarim Craton into the Columbia/Nuna supercontinent. [ABSTRACT FROM AUTHOR]

In the 1980s, large parts of the Bohemian Massif in Austria were explored for the occurrence of raw materials (Göd, 1988), and a trace content of topaz was discovered in channels draining the eastern slope of the Ostrong (Lower Austria). Orthogneiss bodies in the Ostrong Nappe System are shown to be the source of these topaz occurrences, and Raman spectroscopy indicates that topaz is fluorine rich. So far, this is the only occurrence of topaz-bearing orthogneiss within the entire Moldanubian Superunit. The orthogneiss shows a tectonic overprint and exhibits a weak to well-developed foliation, as well as local folding. Samples taken near the tectonic boundary of the Ostrong to the Drosendorf Nappe Systems show stronger shear deformation with a pronounced mylonitic foliation and stretching lineation. Detailed geo-chemical investigations of the major and trace elements indicate a classification as S-type granite with a high degree of differentiation and a peraluminous character. The orthogneiss has a high SiO2 content of 72.8–77.3 wt%, as well as a noteworthy high fluorine content of up to 2760 ppm. Mineral compositions show zoned plagioclase with an albite component of about 87–99 mol%, increasing towards the grain margin. Garnet occurs rarely, but consistently in those samples near the tectonic boundary of the Ostrong- to the Drosendorf Nappe Systems. Garnet is almandine-dominated, shows no zoning and is single-phased. Sillimanite is common and samples near the tectonic boundary also contain kyanite. To determine the previously unknown protolith age of the orthogneiss, U-Pb zircon dating was applied. Three zircon fractions from two samples yield concordia ages of 475.3 ± 1.0 Ma, 474.8 ± 2.9 Ma, and 473.5 ± 1.5 Ma, identical in assigned uncertainties, reflecting magmatic zircon growth. Furthermore, the short prismatic habit of zircon grains indicates a plutonic rather than volcanic origin of the protolith. Dating results also provide a minimum sedimentation age for the rocks of the Ostrong Nappe System within Austria. In comparison with other metagranitoids and orthogneisses of the Moldanubian Nappes, the investigated orthogneiss shows strong similarities with the Gföhl Gneiss and the Moldanubian Granulite. The orthogneiss therefore is considered as a more fractionated equivalent of the Gföhl Gneiss. In conclusion we suggest to name the studied orthogneiss Laimbach Orthogneiss in the rank of a lithodeme (NACSN, 2005), after the locality Laimbach am Ostrong (48°19′01″N; 15°07′19″E), which is located centrally with respect to the occurrences of this gneiss. [ABSTRACT FROM AUTHOR]

The article is dedicated to the investigation of orange garnets from Miocene-Pliocene deposits of the Balta suite and the Sarmatian stage in the Vinnytsia area. The Vinnytsia area is located on the southwestern slope of the Ukrainian Shield. The crystalline basement on most of the area is represented by granitoids of the Berdychiv complex of Paleoproterozoic age, and to a lesser extent by enderbites and charnockites of the Lityn complex of Neoarchean age. Among these, there are mafic and ultramafic bodies ranging from 0.5 to 2 meters in thickness. The sedimentary cover with a total thickness of up to 20 m is represented by sands and clays of the middle Sarmatian, Balta, and Quaternary sediments. These deposits are enriched with mantle minerals, predominantly pyrope, and four diamond crystals have also been discovered. We studied the chemical composition (253 crystals) and morphology (278 crystals) of the orange garnets. The studied samples are mostly represented by garnets of pyrope and pyrope-almandine composition, a small part is represented by grossulars. Most of the garnets are unrounded crystal fragments ranging in size from 0.2 to 0.6 mm, exhibiting signs of intense hypergene changes. These are evident in the development of positive (block) and negative relief features, appearing as drop-shaped, cone-shaped, small hilly microrelief and various forms of etching channels. The morphological features suggest that these garnets were probably relocated a short distance from their primary sources and had been present in the weathering crust for an extended period. The original sources of garnets are most likely Precambrian and located on active tectonic zones, which led to their destruction. According to chemical composition data, among orange garnets low-chromium websterite and lowcalcium eclogite varieties, as well as garnets of high-iron mantle pyroxenites are dominated. The presence of titanium impurities in many garnets indicates the possible diamond-bearing nature of some primary sources. [ABSTRACT FROM AUTHOR]

X-ray diffraction and electron microscopy were used to examine the crystal structure features of ultrathin (3–50 nm) yttrium orthoferrite films, obtained by magnetron sputtering of stoichiometric composition target on α-Al2O3 substrates with orientation. The morphology and crystal structure of the films differ significantly depending on their thickness. In the thinnest films, several phases are formed, including yttrium orthoferrite with an orthorhombic crystal lattice (o-YFeO3), yttrium hexaferrite with a hexagonal crystal lattice (h-YFeO3), iron-yttrium garnet (Y3Fe5O12), and iron oxides such as hematite and maghemite. The study examines the local composition and determines the orientation ratios between the crystallized phases and the substrate. The films with a thickness greater than 10 nm predominantly exhibit a highly textured phase of o-YFeO3 with a small admixture of iron-yttrium garnet. [ABSTRACT FROM AUTHOR]

This contribution presents new insights into the origin and age relationships of the Geyer tin deposit in the Erzgebirge, Germany. Tin mineralization occurs in skarns, greisen, and in cassiterite-bearing fluorite-quartz veins. Skarn alteration replaces marble layers of the Cambrian Jáchymov Group and occurs in two clearly distinct stages. The first skarn stage forms skarnoid textured assemblages of clinopyroxene, garnet, and wollastonite with no tin phases recognized. Garnet U-Pb ages of this skarn stage (~322 Ma) relate the earlier skarn stage to the emplacement of the Ehrenfriedersdorf granite (~324 to 317 Ma). The second stage of skarn alteration is marked by the occurrence of malayaite and cassiterite associated with garnet recording ages of 307 to 301 Ma. Greisen- and skarn-hosted cassiterite-bearing veins provide U-Pb ages in the range of 308 to 305 Ma, relating greisenization and vein formation to the same magmatic-hydrothermal event as the second skarn stage. This suggests that tin mineralization at Geyer is related to a distinctly younger magmatic-hydrothermal event, clearly postdating the Ehrenfriedersdorf granite, which was previously assumed as the source of the tin-rich fluids. Fluid inclusions show salinities in the range of 1.0 to 31.5 % eq. w(NaCl±CaCl2) and homogenization temperatures between 255 and 340 °C. Cassiterite-associated fluid inclusions show indications for heterogeneous entrapment and dilution of hydrothermal with meteoric fluids. Dilution of high-salinity fluids with low-salinity fluids and cooling of the system was probably a decisive process in the precipitation of cassiterite in the Geyer Sn system. [ABSTRACT FROM AUTHOR]

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Fluid infiltration into (meta-)carbonate rocks is an important petrologic process that induces metamorphic decarbonation and potential mineralization of metals or nonmetals. The determination of the infiltration time and the compositional features of reactive fluids is essential to understand the mechanism and process of fluid–rock interactions. Zirconolite (ideal formula: CaZrTi 2 O 7) is an important U-bearing accessory mineral that can develop in metasomatized metacarbonate rocks. In this study, we investigate the occurrence, texture, composition, and chronology of various types of zirconolite from fluid-infiltrated reaction zones in dolomite marbles from the Mogok metamorphic belt, Myanmar. Three types of zirconolite are recognized: (1) the first type (Zrl-I) coexists with metasomatic silicate and oxide minerals (forsterite, spinel, phlogopite) and has a homogeneous composition with high contents of UO 2 (21.37 wt %–22.82 wt %) and ThO 2 (0.84 wt %–1.99 wt %). (2) The second type (Zrl-II) has textural characteristics similar to those of Zrl-I. However, Zrl-II shows a core–rim zonation with a slightly higher UO 2 content in the rims (average of 23.5 ± 0.4 wt % (n=8)) than the cores (average of 22.1 ± 0.3 wt % (n=8)). (3) The third type (Zrl-III) typically occurs as coronas around baddeleyite and coexists with polycrystalline quartz. Zrl-III has obviously lower contents of UO 2 (0.88 wt %–5.3 wt %) than those of Zrl-I and Zrl-II. All types of zirconolite have relatively low rare earth element (REE) contents (< 480 µ g g -1 for Σ REE). Microtextures and compositions of the three zirconolite types, in combination with in situ zirconolite U–Pb dating using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), reveal episodic fluid infiltration and element mobilization in the dolomite marbles. The first-stage infiltration occurred at ∼ 35 Ma, leading to the formation of Mg-rich silicates and oxides and accessory minerals (Zrl-I, baddeleyite, and geikielite). The reactive fluid was characterized by high contents of Zr, Ti, U, and Th. After that, some Zrl-I grains underwent a local fluid-assisted dissolution–precipitation process, which produced a core–rim zonation (i.e., the Zrl-II type). The final stage of fluid infiltration, recorded by the growth of Zrl-III after baddeleyite, took place at ∼ 19 Ma. The infiltrating fluid of this stage had relatively lower U contents and higher SiO 2 activities than the first-stage infiltrating fluid. This study illustrates that zirconolite is a powerful mineral that can record repeated episodes (ranging from 35 to 19 Ma) of fluid influx, metasomatic reactions, and Zr–Ti–U mineralization in (meta-)carbonates. This mineral not only provides key information about the timing of fluid flow but also documents the chemical variation in reactive fluids. Thus, zirconolite is expected to play a more important role in characterizing the fluid–carbonate interaction, orogenic CO 2 release, and the transfer and deposition of rare metals. [ABSTRACT FROM AUTHOR]

Plutonic xenoliths have been found within a pipe and a related phreatomagmatic leucitite deposit in the Eğirdir lake area, belonging to the Potassic-Ultrapotassic Afyon volcanic Province, West Anatolia. They consist of kamafugite-type, feldspar-bearing syenite, pyroxenite, leucitolite, some small-sized melilitolite and garnet-rich xenoliths, and a carbonatite. A new occurrence of kalsilite is described as either homogeneous acicular crystals or tabular two phases-exsolved crystals in the kamafugite-type and melilitolite xenoliths. Rock textures and compositions indicate cumulates and near-liquid composition rocks corresponding to relatively evolved magmas. All the rocks are strongly silica-undersaturated, Ca-, Mg-, and K-rich, and Al-poor. The fractional crystallization model includes clinopyroxene, apatite, phlogopite, melilite and leucite. Fe-Ti oxides and garnet may be also concerned. The PH2O during crystallization and differentiation is not more than 0.8 GPa. Major elements, trace elements, and REE patterns for xenoliths, which indicate near-liquid compositions, are typical of ultrapotassic series in a post-collisional geodynamic context, as it is the case for the Roman and Central ultrapotassic Italian provinces. The stable isotope 13C and 18O values of the calcio-carbonatite plot close to the primary carbonatite field, whereas the carbonates of the feldspar-bearing syenite and the peperite matrix suggest a low-T extensive contamination process. The origin of the carbonatite from kamafugite-type magmas by immiscibility or by fractional crystallization remains questionable; an origin by fractionation-melting of a metasomatized mantle source should be tested in the future. [ABSTRACT FROM AUTHOR]

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Cubic-phase Li7La3Zr2O12 (LLZO) garnet is considered as a promising solid electrolyte due to high Li-ion conductivity and good chemical stability against electrode material. However, the desired cubic-phase formation of LLZO relies on the doping elements. To further improve the electrochemical performance and control the retention of lithium, a composite solid electrolyte based on Cu and Ta co-doped LLZO was fabricated by flash sintering (FS) in the present work due to the FS process characterized short sintering times and low furnace temperature, which could effectively restrain "Li-loss". Based on the optimized Ta-LLZO conducted in our previous study, the effects of Cu2+ content on the ionic conductivity and sintering behavior of the doped composites were discussed. The results show that Cu2+ doping effectively stabilized the cubic structure of the co-doped composites and simultaneously promotes sinter-ability in FS process. Moreover, it is demonstrated that the room-temperature total conductivity of the Cu and Ta co-doped LLZO solid electrolyte is improved significantly by decreasing the grain boundary resistances and improving the densifications with the increasing of Cu2+ content. In addition, the maximum ionic conductivity of 2.83 × 10–3 S cm−1 and relative density 96.6% of the composite with Cu2+ doping content 0.35 mol could be reached. [ABSTRACT FROM AUTHOR]

Experimental results on the magnetostatic surface wave (MSSW) propagation in an yttrium-iron garnet film with a periodical array of metal stripes on the surface are presented. An effect of the pass bands formation in the MSSW transmission characteristics contrasting to the known Bragg stop bands inherent in a periodical structure is reported and discussed. Our findings provide one more way to affect the spin wave propagation and realize a control in magnonic devices. [ABSTRACT FROM AUTHOR]

Despite significant interest in persistent luminescence materials, the focus of all recent works remains on the exploitation of materials in powder form. Here, a new point of view based on persistent luminescence in single crystals is presented. The garnet crystals [(Gd 0.67 Y 0.33) 3-x Ce x)](Al 2-y Cr y)Ga 3 O 12 and [(Gd 0.33 Y 0.67) 3-x Ce x ](Al 2-y Cr y)Ga 3 O 12 (GYAGG) codoped with Ce3+ and different concentrations of Cr3+ have been elaborated and their persistent luminescence properties are fully characterized within this work. The persistent luminescence of Ce3+, Cr3+-codoped GYAGG single crystals is optimized due to their high optical quality, very good crystallinity and a volume effect where the whole material can be excited and charged by the excitation light. Furthermore, thanks to their transparency, robustness and homogeneity; in-depth optical spectroscopy characterization is possible, shedding light on the mechanism responsible for the afterglow. [ABSTRACT FROM AUTHOR]

Eu3+ doped CaY 2 Al 4 SiO 12 garnet phosphors were synthesized by using the sol-gel method. The crystal structure of the synthesized phosphors was characterized by X-ray diffraction and Rietveld refinements. The results of X-ray diffraction and Rietveld refinements of the powders sintered at 1400 °C showed the formation of a single phase and the effective concentration of Eu3+ ions in this garnet host lattice. The composition of the substitutional solid solutions of CaY 2-x Eu x Al 4 SiO 12 (x = 0.01, 0.03, 0.06, 0.09, 0.12, and 0.15) exhibit efficient red photoluminescence peaking at 596 nm, which can be assigned to the 5D 0 → 7F 1 intra-configurational transition of Eu3+ located at the dodecahedral site in the garnet structure. The photoluminescence properties, such as excitation and emission spectra, decay curves, and quantum yield, are presented. The thermal stability of the as-prepared phosphors was determined. Additionally, the optical bandgap for the samples was estimated with UV–visible diffuse reflectance spectra using the Tauc relation. The correlation between the structural features and luminescence properties was determined. These phosphors with high thermal stability and high color purity can be potentially used in white-light-emitting diodes. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Cationic surfactant CTAB was used to improve the dispersion of LLZTO with PEO. • CTAB modified electrolyte have better organic–inorganic interface contact. • CTAB modified electrolyte show higher interfacial stability and ionic conductivity. • CTAB modified electrolyte exhibit better rate capability and cycling stability. The garnet-type solid electrolyte Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) was modified with a cationic surfactant Cetyltrimethylammonium Bromide (CTAB) to improve the dispersion of LLZTO inorganic particles in Poly (ethylene oxide) (PEO) electrolyte (PEO-LLZTO@CTAB) by a liquid phase casting method. During fabrication, the cationic modifier CTAB is uniformly adsorbed on the surface of LLZTO particles, which can effectively reduce their surface energy and lead to a thin CTAB surface coating layer. This fabricated PEO-LLZTO@CTAB can avoid the aggregation of LLZTO particles in the composite solid-state electrolyte (CSSE) and improve the interfacial contact at the PEO/LLZTO interface, thus reducing the overall resistance of PEO-LLZTO@CTAB/Li half-cell and inhibiting the dendrite growth during cycling. The all-solid-state batteries (ASSBs) with LiFePO 4 (LFP) as the cathode, PEO-LLZTO@CTAB as the electrolyte and Li as the anode exhibit a high initial discharge capacity of 146.6 mAh-g−1, excellent rate performance and high-capacity retention of 91.0 % after 300 cycles at 0.2 C multiplier and 60 °C within the voltage range of 2.7–4.0 V. [ABSTRACT FROM AUTHOR]

For use as an electrolyte in All Solid State Batteries (ASSB), a solid electrolyte must possess ionic conductivity comparable to that of conventional liquid electrolytes. To achieve this conductivity range, the series Li 6.8-y Ge 0.05 La 3 Zr 2-y Ta y O 12 (y = 0, 0.15, 0.25, 0.35, 0.45) has been synthesized using a solid-state reaction method and studied using various characterization techniques. The highly conducting cubic phase is confirmed from XRD analysis. Structural information was collected using SEM and density measurements. The prepared ceramic sample containing 0.25 Ta, sintered at 1050 °C for 7.30 hrs, shows the maximum ionic conductivity of 6.61 x 10-4 S/cm at 25 °C. The air stability of the same ceramic has also been evaluated after exposure for 5 months. The minimum activation energy associated with the maximum conductivity of 0.25 Ta is 0.25 eV. The DC conductivity measurements were done to confirm the ionic nature of conductivity for all ceramic samples. The stable result of ionic conductivity makes the 0.25 Ta containing ceramic sample a promising candidate for solid electrolytes for ASSB applications. [ABSTRACT FROM AUTHOR]

The rapid growth in phosphor‐converted near‐infrared light‐emission diodes (NIR‐LEDs) has led to the development of NIR emitter with high efficiency, broadband emission and high thermal stability. In this work, an efficient broad NIR emission of Cr3+ in novel Ca3Sc2Ge3O12 (CSGO) garnet‐based host was developed for the first time, which located at 700 to 1000 nm peaking at 817 nm with a broad bandwidth of ~128 nm. Such a broadband NIR emission originated from the preferential occupancy of Cr3+ in Sc3+ sites with weak octahedral field, which was manifested by the luminescence spectrum and decay behaviors. The Cr3+‐doping concentration was regulated to achieve a good internal quantum efficiency (IQE) of 72.1 % and a fantastic thermal stability (at 423 K, sustained approximately 85 % of the initial intensity). The mechanism for concentration and thermal quenching was further investigated. Benefiting from the excellent luminescence features, a prototype NIR‐LEDs was assembled via integrating the optimized samples with commercial blue InGaN LED chips, which exhibited a satisfactory photoelectric property and a brilliant performance in night vision. These results demonstrated the as‐obtained sample to be a great potential candidate for NIR‐LEDs. [ABSTRACT FROM AUTHOR]

Metal organic decomposition (MOD) for the metal oxides thin films fabrication has been used in various studies over the past 30 years. MOD is a simple and inexpensive method for manufacturing optical grade polycrystalline thin films, including bismuth-substituted yttrium iron garnet. We present a variant of the previously described MOD method and discuss a chemical route for fabricating thin porous oxide films with a thicknesses of more than 100 nm, which non-epitaxially crystallized on fused silica substrates into Bi x Y 3-x Fe 5 O 12 layers (x = 0.5 and 1.5). Studies of the structural and magneto-optical properties of the layers show that the garnet layers crystallized under optimal conditions are characterized by high values of the specific Faraday rotation. Importantly, crystallization can be done locally by laser irradiation, and wet etching makes possible to remove non-crystallized areas, thus extending microfabrication capabilities. [ABSTRACT FROM AUTHOR]