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Near-infrared (NIR) phosphors based on Cr3+ doped garnets present great potential in the next generation of NIR light sources. Nevertheless, the huge searching space for the garnet composition makes the rapid discovery of NIR phosphors with high performance remain a great challenge for the scientific community. Herein, a generalizable machine learning (ML) strategy is designed to accelerate the exploration of innovative NIR phosphors via establishing the relationship between key parameters and emission peak wavelength (EPW). We propose a semi-supervised co-training model based on kernel ridge regression (KRR) and support vector regression (SVR), which successfully establishes an expanded dataset with unlabeled dataset (previously unidentified garnets), addressing the overfitting issue resulted from a small dataset and greatly improving the model generalization capability. The model is then interpreted to extract valuable insights into the contribution originated from different features. And a new type NIR luminescent material of Lu3Y2Ga3O12: Cr3+ (EPW~750 nm) is efficiently screened, which demonstrates a high internal (external) quantum efficiency of 97.1% (38.8%) and good thermal stability, particularly exhibiting promising application in the NIR phosphor-converted LEDs (pc-LED). These results suggest the strategy proposed in this work could provide new viewpoint and direction for developing NIR luminescence materials. [ABSTRACT FROM AUTHOR]

In the study of the Khanmeikhoi Formation of the central zone of the Kharbei amphibolite–gneiss complex, it was shown that the amphibolites, schists, and plagiogneisses common here form two primary igneous series: low-alumina tholeiitic metabasalts of normal alkalinity and a differentiated series of high-alumina rocks from metatrachybasalts to metarhyolites with high alkalinity. According to the zoning of garnets, progressive and regressive branches of metamorphism are recorded, the peak conditions of which, according to calculations using the winTWQ program, correspond to the high-temperature stage of the amphibolite facies at high pressures (T = 690–750°C, P = 8.1–9.4 kbar). For the first time, metamorphic zircon from Grt-Bi plagiogneiss with low Th/U ratios of 0.01–0.04 and weakly expressed positive cerium (Ce/Ce* = 1.4–1.7) and negative europium (Eu/Eu* = 0.7–0.9) has been identified in the anomalies, the age of which, according to the results of the U–Pb LA-ICP-MS isotope method, is estimated to be Early Carboniferous (359–341 Ma). This time apparently characterizes the transition from the peak of metamorphism to the regressive stage associated with the exhumation of rocks. The results obtained indicate the formation of the Kharbei amphibolite–gneiss complex during the formation of the Ural orogen and allow us to consider it as an indicator of Paleozoic collision processes. [ABSTRACT FROM AUTHOR]

A sample of micaceous schist of the Cushamen Metamorphic Complex in the Cushamen area (northwestern North Patagonia, Argentina) preserves a complex mineral assemblage, including staurolite, andalusite, garnet, sillimanite, biotite, quartz, and plagioclase. This unit proves an opportunity to analyse a complex mineral association often related to disequilibrium stages or polymetamorphic contexts. Through detailed petrological analysis combining mineral chemistry, X-ray compositional maps, conventional thermobarometry, and phase equilibria analysis, we reconstructed the pressure–temperature (P–T) path of this schist. The schist unit preserves a polymetamorphic history characterized by M1, M2, and M3 events. The M1 event is represented by biotite, muscovite, quartz, and plagioclase. The M2 event, associated with local mid-Carboniferous pluton intrusion, is characterized by andalusite and garnet assemblages, with peak conditions at ~ 3.3 kbar and ~ 563 °C. The main M3 event, at the time of the Carboniferous–Permian boundary, is defined by garnet, staurolite, sillimanite, biotite, muscovite, plagioclase, and quartz. This event records a progressive P–T evolution from ~ 3.5 kbar and ~ 553 °C to ~ 4.9–5.6 kbar and ~ 620–635 °C, nearing peak conditions. This work highlights the importance of comprehensive approaches in P–T trajectory reconstructions and the critical role of selecting the reactive bulk composition, particularly in rocks with complex mineral assemblages. In addition, this study significantly contributes to understanding the metamorphic evolution of the Cushamen Complex, a unit for which there is limited knowledge regarding its structural and metamorphic evolution. This complex is part of the igneous-metamorphic basement of North Patagonia region (Argentina), which records the Paleozoic evolution of the southwestern margin of Gondwana. [ABSTRACT FROM AUTHOR]

Background: Lithium penetration-induced fracture within solid electrolytes (SEs) is a major issue hindering the commercialization of solid-state lithium-ion batteries (SS-LIBs). Such fracture has been frequently observed during electrochemical plating of lithium (Li)-metal anodes, but its mechanistic origin is still largely unclear. Objective: We present the first quantitative operando analysis of the fracture characteristics of a model SE material under battery-relevant electrochemical cycling conditions. Methods: Full-field deformation during Li deposition-induced cracking of garnet-type LLZTO was measured using the digital image correlation (DIC) method. The obtained displacement data were denoised via equilibrium smoothing, and then fitted to the linear elastic asymptotic crack-tip field to extract the electrochemical fracture toughness values under different current densities. Results: The physics-based equilibrium smoothing method demonstrated effectiveness in enhancing the accuracy of DIC measurements. The electrochemical fracture toughness obtained was substantially lower than the mechanical fracture toughness of the same material determined through indentation, attributed to combined effects of electrochemical embrittlement and a transition in fracture mode from intergranular to transgranular. Conclusion: The discrepancy between the two types of fracture toughness suggests that electrochemical cycling could have a significant impact on the fracture mode and resistance of a solid electrolyte. [ABSTRACT FROM AUTHOR]

Garnet-type Li6.1Ga0.3La3Zr2O12 (LGLZO) exhibits high ionic conductivity and extremely low electronic conductivity. The electrochemical properties strongly depend on the characteristics of the grain boundaries and pores in the oxide–ceramic electrolyte. Currently, the main issue of LGLZO is its large grain boundary resistance due to high-temperature sintering. Herein, we propose an effective method for reinforcing the chemical and structural characteristics of the grain boundaries using a Li2O-B2O3-Al2O3 (LBA) sintering aid. In this study, the LBA sintering aid is critical because it fills grain boundaries and void spaces. As a result, LGLZO solid-state electrolytes with sintering aids significantly enhance the ionic conductivity and reduce the activation energy, especially in the grain boundary region. Another crucial issue is the formation of Li dendrites in LGLZO. Since dendritic Li propagates along the grain boundaries, the optimized LGLZO solid-state electrolyte demonstrates excellent stability against Li metals. Overall, the LGLZO electrolyte with the LBA sintering aid exhibits stable long-term cycling performance due to the well-designed grain boundaries. The addition of Li2O-B2O3-Al2O3 (LBA) sintering aid to Li6.1Ga0.3La3Zr2O12 (LGLZO) solid electrolytes enhances grain boundary characteristics and reduces porosity. This modification leads to a substantial increase in ionic conductivity and mechanical stability, while effectively preventing Li dendrite formation. The optimized LGLZO sample with LBA exhibits improved long-term cycling performance, making it a promising candidate for high-performance all-solid-state batteries. These findings underscore the critical role of grain boundary engineering in enhancing the electrochemical properties of garnet-type electrolytes. [ABSTRACT FROM AUTHOR]

The Dahongshan Group, situated at the southwestern margin of the Yangtze Block, represents a geological unit characterized by relatively high-grade metamorphism in the region. This paper investigates the garnet-biotite schist from the Laochanghe Formation of the Dahongshan Group, employing an integrated approach that includes petrological analysis, phase equilibrium modeling, and zircon U–Pb dating. The schist is mainly composed of garnet, biotite, plagioclase, quartz, rutile, and ilmenite. Phase equilibrium modeling revealed the peak metamorphic conditions of 8–9 kbar and 635–675 °C. By further integrating the prograde metamorphic profile of garnet and geothermobarometric results, a clockwise P–T metamorphic evolution path is constructed, which includes an increase in temperature and pressure during the prograde stage. LA–ICP–MS zircon U–Pb dating and zircon Ti thermometry constrains the post-peak metamorphic age of 831.2 ± 7.2 Ma. Integrated with previously reported results, it is revealed that the southwestern margin of the Yangtze Block experienced a large-scale regional metamorphism during the Neoproterozoic (890–750 Ma), which is related to the collisional orogenic process. This may be associated with the late-stage assembly of the Rodinia supercontinent or with local compression and subduction processes during the breakup of the Rodinia supercontinent. [ABSTRACT FROM AUTHOR]

The laser material Y3Al5O12 (YAG), originally known in the form of a single crystal, has become widespread and widely commercialized in the form of optical ceramics. The desire to expand by the size effect the functionality of materials made from nanocrystals actualizes studying the influence of their structure on the optical (vibrational and electronic) and other properties of new promising materials with the YAG base, including glass ceramics. In this work, models of crystalline yttrium aluminum garnet fragments have been calculated using the DFT/uPBEPBE/SDD, DFT/uPBEPBE/lanl2DZ, and DFT/uB3PW91/SDD methods. Infrared spectra have been calculated using the DFT/uPBEPBE/lanl2DZ method, and absorption bands at calculated wave numbers have been correlated with the measured ones. The electronic absorption spectrum and level energies have been calculated using the DFT/RB3PW91/SDD method. [ABSTRACT FROM AUTHOR]

Banchang is the largest Cu-Mo deposit (348 Mt @ 0.32% Cu and 428 Mt @ 0.07% Mo) in the Qinling orogenic belt, Central China. Orebodies are hosted in the contact between several granitoid dikes and graphite-bearing marble of the Neoproterozoic Yanlinggou Formation. Wallrock alteration comprises garnet skarn, pyroxene skarn, chlorite skarn, and stockwork chlorite-altered marble. Three hydrothermal stages are indicated: (I) prograde skarn stage, (II) retrograde skarn stage, and (III) main sulfides stage. New zircon U-Pb data show two magmatic events, including early Paleozoic granite porphyry (442 − 427 Ma), and late Mesozoic biotite monzogranite porphyry and late Mesozoic granite porphyry (147 − 146 Ma). The zircon trace element compositions show that the late Mesozoic granitoids with ∆FMQ = -0.7 to 2.3 (avg. 0.5; EuN/EuN* > 0.6) resemble the Cu ore-related granitoid in the Qinling orogenic belt and indicate high oxygen fugacity and water contents in the magma. The early Paleozoic granitoids have ∆FMQ= -2.4 to 0.6 (avg. -0.7; EuN/EuN* < 0.2). Electron Probe Microanalysis (EPMA) on the prograde garnet and pyroxene reveal predominantly andradite (And40 − 94Gro0−51) and diopside (Di53 − 98Hd10−55) compositions, respectively. The garnet Fe3+ contents decreases whereas the pyroxene Fe2+ contents increases from the late Mesozoic granitoid dikes to the marble. This suggests a gradual evolution of the skarn from an oxidized to a reduced state. Stage III sulfide minerals have δ34S = -2.1 to 4.8‰, indicating a magmatic origin. The temporal-spatial relationships, magmatic oxygen fugacity and water contents, zoning of prograde skarn minerals, and the source of sulfur indicate a genetic link between the skarn mineralization and late Mesozoic granitoid dikes. This study proposes a distal Cu-Mo skarn ore deposit model associated with granitoid dikes and some implications for mineral exploration in the Qinling orogenic belt and elsewhere. [ABSTRACT FROM AUTHOR]

Garnet and zircon in a marble-hosted eclogite from the Dabie ultrahigh-pressure (UHP) terrane, eastern China record a wealth of information on multistage pervasive fluid–rock interactions and Hf mobility in deep continental subduction zones. The eclogite has a peak mineral assemblage of garnet + omphacite + phengite + coesite + magnesite ± dolomite + rutile. Five (inner patchy core, outer core, mantle, inner rim, outer rim) compositional zones were recognized for garnet. According to phase equilibria modeling, the inner patchy and outer cores of garnet likely document a prograde breakdown of lawsonite to UHP peak (3.0–4.5 GPa and 630–750 °C), while a Ca-metasomatism could have also played a role in their formation. The other three garnet zones resulted from multistage garnet re-equilibration at eclogite-facies conditions during isothermal exhumation. The stepwise compositional changes between these different garnet zones suggest that dissolution and reprecipitation played a key role in the garnet re-equilibration, while the repeated actions of such a re-equilibration mechanism reflect multistage pervasive fluid–rock interactions. Zircon from the rock develops three eclogite-facies domains (1, 2, 3). Textural relationships suggest that domain 2 formed in between domain 1 and 3. LA-ICP-MS analyses yielded 206Pb/238U ages of 233 ± 6 Ma, 232 ± 2 Ma and 222 ± 3 Ma for domain 1, 2 and 3, respectively. Domain 1 includes coesite and magnesite and its Th/U is usually higher than 0.1. This domain is interpreted to have formed in the absence of allanite during prograde UHP metamorphism. Domain 2 shows slightly lower ∑MREEs (middle rare earth elements; 7.5–13.5 ppm) and lower Ti (3.0–6.0 ppm) contents than domain 1 (∑MREEs = 10.5–21.0 ppm; Ti = 4.5–7.0 ppm) and most likely formed at the UHP peak. Domain 3 contains much lower ∑MREEs (3.5–6.0 ppm) and higher Ti (7.5–11.0 ppm) contents than domain 1 and 2, which is interpreted to have formed in the stability field of epidote during decompression. Domain 2 (0.282354–0.282607) and 3 (0.282449–0.282636) display lower initial 176Hf/177Hf values than domain 1 (0.282563–0.282667), suggesting that external fluids introduced Hf into the eclogite. These findings not only shed new light on the flow mode of fluids and their role in resetting mineral compositions in deep subduction zones, but also suggest that Hf (a key high-field strength and tracer element) can be efficiently mobilized by (U)HP fluids. Moreover, this study highlights the influence of epidote-group minerals and pressure on the chemistry (Th/U ratio and REE and Ti contents) of zircon. [ABSTRACT FROM AUTHOR]

Garnet peridotite xenoliths have been rarely reported from suboceanic mantle. Petrographic and geochemical characteristics of garnet-bearing oceanic peridotite xenoliths provide precious information on dynamics of the suboceanic lithosphere and asthenosphere interaction. We examined a lherzolite xenolith included in olivine nephelinite lava from Aitutaki Island, a member of the Cook-Austral volcanic chain. The lherzolite xenolith contains reddish fine-grained (< 5 µm in size) mineral aggregates (FMAs) with size range of 0.5–6 mm, consisting of olivine, calcic and sodic plagioclases, aluminous spinel, native iron, and nepheline. Microstructural observations and chemical data corroborate that the FMA is a decomposed pyrope-rich garnet including chromian spinel grains with an irregular highly indented morphology in the center. The FMA is surrounded by pyroxene-poor and olivine-rich aureole. The spatial and morphological relationships of FMA and chromian spinel with pyroxene-depleted margin suggest a reaction of aluminous spinel + pyroxenes → pyrope-rich garnet + olivine, which requires a compression before decomposition of the garnet to FMA. An orthopyroxene grain shows slight but clear chemical zoning characterized by increase in Al, Ca, and Cr from the grain center to the rim. The zoning patterns of Al and Ca in the orthopyroxene grain can be modeled by diffusion-controlled solid-state reactions induced by pressure and temperature changes, keeping surface concentrations in equilibrium with the other coexisting mineral phases. The results indicate that the mantle, from which the lherzolite xenolith was derived, underwent isothermal decompression followed by a weak heating on a time scale of a few tenths of million years before the xenolith extraction. From the deduced compression and decompression histories, we hypothesize that the mantle beneath Aitutaki Island was once dragged down to a garnet-stable deep mantle region and brought up later by small-scale sublithospheric convection. [ABSTRACT FROM AUTHOR]

Due to its high energy density and better safety performance, all-solid-state lithium batteries are regarded as important energy storage devices to replace the traditional liquid electrolyte Li-ion batteries. However, the problems of poor wettability of Li metal anode | solid-state electrolyte interface and easy growth of lithium dendrite have not been well solved. Here, we have constructed Fe-doped Li7-3xFexLa3Zr2O12 (Fe-LLZO) and Li6.5La3Zr1.5Ta0.5O12 (LLZTO) garnet-type double-layer solid electrolyte. The high density of Li7-3xFexLa3Zr2O12 electrolyte and its interfacial wettability to Li metal not only effectively reduced the interface impedance between Li and solid electrolyte but also could stably cycle for more than 200 h without the growth of lithium dendrites at the rate of 0.1 mA cm−2. In addition, the all-solid-state lithium battery (Li|Fe0.1-LLZO|LLZTO|LFP) with LiFePO4 as a cathode also showed excellent cycle stability and C-rate performance. [ABSTRACT FROM AUTHOR]

This study investigates the uncommon formation of laterite from garnet–sillimanite–gneiss (grt-sil-gn) in the Matale area, a hilly region of Sri Lanka. Geographically, laterites typically form in lowland wet zone of the country, but this research explores their genesis in a unique, less-studied hilly environment. Employing a comprehensive approach combining field observations, petrographic studies, and chemical mapping, we elucidate the contrasting mechanisms of lateritization on the dip slope and scarp slope of a cuesta landform. Our findings reveal a significant influence of weathering conditions and supergene processes on laterite formation. Dip slopes experience intense supergene activity due to deeper groundwater, promoting downward fluid flow and mineral dissolution. Conversely, scarp slopes exhibit isovolumetric leaching with reduced infiltration and enhanced fluid interaction, leading to lateritization along fractures in partially weathered grt-sil-gn. Intense supergene processes on the dip slopes involve downward fluid migration and mineral dissolution, aided by a deep groundwater table. In contrast, scarp slopes exhibit laterite formation through isovolumetric leaching in areas with reduced water infiltration and heightened fluid interaction. Evidence of lateritization includes the formation of gibbsite, hematite, or goethite, attributed to fluctuating oxic and anoxic conditions caused by fluid variations. Additionally, kaolinite patches emerged on the exterior of fully altered garnet, resulting from the weathering products and leachates of quartz, sillimanite, and feldspar. This research emphasizes the critical role of external factors, such as weathering and supergene processes, alongside parent rock composition, in influencing laterite formation. It significantly advances our understanding of lateritization in grt-sil-gn, particularly in hilly areas with lower rainfall compared to usual laterite formation zones. [ABSTRACT FROM AUTHOR]

Solid-state lithium metal batteries are one of the most promising options for next-generation batteries pursuing high-energy density and high-safety. However, the inevitable volatilization of lithium compounds during sintering leads to low relative density and low ionic conductivity of solid-state electrolytes. Herein, the dynamic lithium-compensation mechanism is proposed to facilitate the densification of Ta-substituted garnet-type electrolyte (Li6.5La3Zr1.5Ta0.5O12 (LLZT)) through the reversible manipulating of Li2O atmosphere. Li2ZrO3 is used as mother powder additive, which reacts with Li2O in sintering atmosphere and forms Li6Zr2O7. Li2ZrO3/Li6Zr2O7 buffer pair manipulates the sintering Li2O atmosphere, which is vital for LLZT, within the Li2O partial pressure range corresponding to Li2ZrO3 and Li6Zr2O7. Furthermore, the reversibility mechanism of buffer pair for Li2O absorption and release is revealed. The obtained LLZT exhibits a relative density of over 96% and an ionic conductivity exceeding 7 × 10−4 S·cm−1 with no abnormal grain growth. The symmetric cell demonstrates an excellent lithium dendrite suppressing ability (stable cycling at a current density of 0.3 mA·cm−2 for over 1000 h). Such dynamic lithium-compensation strategy has been successfully applied in atmosphere manipulation of LLZT sintering process, which reduces the dependence of LLZT on the Li2O atmosphere, making it conducive to large-scale preparation of electrolyte ceramics. [ABSTRACT FROM AUTHOR]

This study tests experimentally the hypothesis that calculated bulk compositions of multiphase solid inclusions present in minerals of ultrahigh pressure rocks, can be equated to the composition of the former trapped fluids. We investigated samples from the ultrahigh pressure garnet peridotites of the Bohemian Massif, spatially associated with ultrahigh pressure crustal rocks and representing a former subduction interface environment. Inclusions present in garnets, composed of amphibole + Ba-mica kinoshitalite + carbonates (dolomite + magnesite + norsethite), were taken to their entrapment conditions of c. 4.5 GPa and 1075 ºC. They (re)crystallized into a garnet fringe at the boundary between inclusion and host garnet, kinoshitalite ± olivine, carbonatite melt, and a hydrous fluid. Although the latter may have exsolved from the carbonatite melt upon quenching, microstructures suggest it was present at trapped conditions, and mass balance indicates that it corresponds to a Na-K-Cl-F-rich saline aqueous fluid (brine). Experiments demonstrate the stability of kinoshitalite at 4.5 GPa and 1075 ºC, and suggest that Ba-rich mica + carbonatite melt + brine coexisted at near-peak conditions. Barium is compatible in the carbonatite melt and mica with respect to the brine, with a partition coefficient between carbonatite melt and mica of ≈ 2.5–3. The garnet fringe formed from incongruent reaction of the former inclusion assemblage due to reversing the fluid(s)-host garnet reaction that occurred upon natural cooling/decompression. Loss of H2 or H2O from the inclusions due to volume diffusion through garnet and/or decrepitation, during geological timeframes upon decompression/cooling, may have prevented rehomogenization to a single homogeneous fluid. Our study shows that great care is needed in the interpretation of multiphase solid inclusions present in ultrahigh pressure rocks. [ABSTRACT FROM AUTHOR]

Rutile inclusions in almandine-spessartine garnet from a peraluminous pegmatoid from the Moldanubian zone (Bohemian Massif, AT) show distinct changes in aspect ratio, shape preferred orientations (SPO) and crystallographic orientation relationships (COR) along the transition between microstructurally different growth zones in the garnet core and rim. For identification of the COR characteristics we pool specific CORs based on their common axial relationship into three COR groups: Group 103R/111G, Group 001R/111G and Group 001R/100G. The rutile inclusions in the garnet core domains are elongated along the four Grt ⟨ 111 ⟩ directions and are dominated by COR Group 103R/111G. The garnet rim zone additionally contains rutile needles elongated along Grt ⟨ 100 ⟩ . Here, Group 001R/111G and 001R/100G are more abundant than in the garnet core. Needle-shaped rutile in the rim shows a systematic correlation between SPOs and CORs as needles elongated parallel to Grt ⟨ 111 ⟩ are dominated by Group 103R/111G and 001R/111G, whereas those needles elongated parallel to Grt ⟨ 100 ⟩ exclusively pertain to CORs of 001R/100G. Furthermore, the frequency of each particular SPO in the garnet rim clearly depends on the local growth direction of the particular Grt{112} sector. Facet-specific variations in rutile SPO frequencies in different sectors and growth zones of garnet were observed even between equivalent directions, indicating that the microstructures and textures of rutile inclusions reflect varying parameters of garnet growth. The characteristic differences in COR groups of different garnet growth zones are referred to compositional changes in the bulk melt or compositional boundary layer, associated with magmatic fractional crystallisation. [ABSTRACT FROM AUTHOR]

Garnet oxide is one of the most promising solid electrolytes for solid-state lithium metal batteries. However, the traditional interface modification layers cannot completely block electron migrating from the current collector to the interior of the solid-state electrolyte, which promotes the penetration of lithium dendrites. In this work, a highly electron-blocking interlayer composed of potassium fluoride (KF) is deposited on garnet oxide Li6.4La3Zr1.4Ta0.6O12 (LLZTO). After reacting with melted lithium metal, KF in-situ transforms to KF/LiF interlayer, which can block the electron leakage and inhibit lithium dendrite growth. The Li symmetric cells using the interlayer show a long cycle life of ~3000 hours at 0.2 mA cm−2 and over 350 hours at 0.5 mA cm−2 respectively. Moreover, an ionic liquid of LiTFSI in C4mim-TFSI is screened to wet the LLZTO|LiNi0.8Co0.1Mn0.1O2 (NCM) positive electrode interfaces. The Li|KF-LLZTO | NCM cells present a specific capacity of 109.3 mAh g−1, long lifespan of 3500 cycles and capacity retention of 72.5% at 25 °C and 2 C (380 mA g−1) with an average coulombic efficiency of 99.99%. This work provides a simple and integrated strategy on high-performance quasi-solid-state lithium metal batteries. Formation of dendrites in solid-state lithium batteries hampers their application. Here, authors deposit a thin film of potassium fluoride on a garnet solid electrolyte that in-situ transforms to a mixed fluoride layer, which blocks electron leakage and inhibits lithium dendrite growth. [ABSTRACT FROM AUTHOR]

Ecological restoration of bauxite residue has received extensive attention, and organic matter plays a crucial role in the soil formation process of bauxite residue. However, the interaction between organic matter and alkaline minerals in bauxite residue is not well understood. In this work, molecular spectroscopic techniques combined with isothermal titration calorimetry (ITC) were employed to investigate the interactions between humic acid (HA) and four representative alkaline minerals in bauxite residue (calcite, garnet, sodalite, and cancrinite). The results show that the adsorption processes of HA onto calcite and garnet were primarily governed by monolayer surface adsorption and controlled by surface reactions, which were different for sodalite and cancrinite. Both garnet and cancrinite had strong binding affinities with fluorescent HA, while cancrinite only bound with a small fraction of HA. In contrast, the bindings of calcite and sodalite with fluorescent HA were weak. The ITC results indicate distinct thermodynamic properties of different alkaline minerals in the interaction with HA. The molar enthalpy of calcite was − 45.88 kJ/mol, which was much higher than those of garnet, sodalite, and cancrinite, suggesting that calcite exhibited a relatively uniform interaction mechanism with HA dominated by enthalpy change, while the others showed heterogeneous entropy-driven mechanisms. The findings contribute to a better understanding on the microscale connections between organic matter and alkaline minerals in bauxite residue. [ABSTRACT FROM AUTHOR]

Skarn and Fe-Zn-Pb mineralization at the Wondong deposit located in the Taebaeksan Basin of the central-eastern region of Korean Peninsula occurs along the contact between the Upper Cretaceous quartz-feldspar porphyry (QFP) and carbonate rocks of the Ordovician Makgol Formation. The QFP is relatively fresh and has a sharp contact with the garnet skarn. Skarn is dominant in the carbonate rocks but is rare in the QFP. It consists almost of grandite throughout the skarn but has mineralogical zonation of proximal garnet, intermediate pyroxene, and distal wollastonite with increasing distance from the contact between the QFP and garnet skarn. Garnet becomes Fe-rich, and pyroxene tends to be enriched in Fe and Mn toward the marble front. Massive Fe mineralization, replacing garnet skarn, is restricted proximal to the QFP. In contrast, although the Zn-Pb mineralization is found in all areas it mostly occurs in the carbonate rocks beyond the skarn. Zinc-Pb mineralization occurred as stockwork and vein in the QFP and the garnet skarn consists of sphalerite, galena, Al-rich garnet, and calcite with a minor quantity of arsenopyrite. In contrast, the carbonate replacement of the Zn-Pb mineralization beyond skarn consists of sphalerite, pyrrhotite, galena, diopsidic pyroxene, and calcite with minor minerals such as arsenopyrite, löellingite, and chalcopyrite. Sphalerite, principal ore mineral, becomes darker and Fe- (up to 34.4 mol% FeS) and Mn-rich (up to 1.5 mol% MnS) with increasing distance from the QFP. Arsenopyrite is closely associated with sphalerite tends to be decreased in As away from the QFP. All sulfide minerals from Zn-Pb mineralization in the Wondong deposit have δ34S values ranging from 2.9 to 5.9‰, which are attributed to the magmatic source. In addition, the narrow range and subtle variation of the δ34S values for all sulfides throughout the Wondong deposits are not interpreted to be involved in the mixing of multiple sulfur sources. Geological, petrographic, mineralogical, and isotopic geochemical investigations show that the early skarn was formed in an environment of high fluid: rock ratios at the contact between the QFP and Makgol Formation and it was dominated by grandite, indicating the oxidizing nature of the skarn-forming fluids. The ore deposition began after the formation of the main garnet dominated skarn. The ore-forming fluids responsible for Zn-Pb mineralization are characterized by a less oxidizing nature, as defined by comparatively Al-enriched garnet in vein type mineralization in and around the QFP. Farther, the fluids producing the carbonate replacement of the Zn-Pb mineralization are unlikely to be engaged in external effects such as mixing with multiple sulfur sources even though it travels over long distance. [ABSTRACT FROM AUTHOR]

The Dom Feliciano Belt is the South American part of an extensive Neoproterozoic orogenic system that developed during the late Cryogenian–early Cambrian close to the margin of southwest Gondwana. The link of its evolution with the tectonic processes in its African counterpart is still not well understood. P–T estimates, Lu–Hf garnet–whole-rock ages, U–Pb monazite SIMS ages and REE garnet and monazite data from samples of the Porongos and Passo Feio complexes indicate diachronous tectonic evolution of the central Dom Feliciano Belt foreland. Metasedimentary rocks of the eastern Porongos Complex reached previously estimated metamorphic peak conditions of ~ 560–580 °C and 5.8–6.3 kbar at 654 ± 2 Ma, based on Lu–Hf isochron garnet–whole-rock age data. This episode represents an early orogenic thickening in the foreland as a response to the beginning of the transpressive convergent evolution of the belt. The monazite age of 614 ± 6 Ma (U–Pb SIMS) is interpreted as associated with post-exhumation magmatic activity in the foreland and suggests that the eastern Porongos Complex was exhumed sometime between ca. 660 and 615 Ma. The main metamorphic and deformation event in the Porongos Complex's western region occurred at ~ 545–565 °C and 4.3–5.3 kbar at 563 ± 1 Ma (garnet–whole-rock Lu–Hf isochron age). The exhumation of this part of the foreland is dated using monazite crystallising during garnet breakdown and suggests retrograde metamorphism at 541 ± 7 Ma (U–Pb SIMS). The main metamorphic fabric in the Passo Feio Complex further to the west developed at 571 ± 2 Ma (garnet–whole-rock Lu–Hf isochron age) at 560–580 °C and 4.7–6.4 kbar. The western part of the Porongos Complex and the Passo Feio Complex have deformed at similar P–T conditions and apparent geothermal gradients at ca. 570–565 Ma. These regions record a second crustal thickening event in the Dom Feliciano Belt foreland and the orogenic front migration towards the west as a response to the onset of crustal thickening on the African side of this long-lived transpressive orogenic system. [ABSTRACT FROM AUTHOR]

Granite genesis is crucial to understanding the evolution of continental crust, yet many concerns about granite genesis remain not well answered, such as whether I-type granite contains metasedimentary components, what controls granite compositional diversity, and how granitic plutons are constructed. To explore these issues, we conducted a detailed study on the two-mica plagiogranite, tonalite, and biotite plagiogranite units of the Wujinxia composite pluton in the eastern Qilian orogen, NE Tibetan Plateau. These units comprise two-mica plagiogranite, tonalite (with diorite enclave), and biotite plagiogranite. Zircon U–Pb data reveal that three granitic units formed at ~ 487 Ma, ~ 464 Ma, and ~ 430 Ma, respectively. Magmatic and xenocrystic garnet were identified from the tonalite and biotite plagiogranite, respectively. The two-mica plagiogranite, tonalite, and biotite plagiogranite all belong to low-K series rocks (K2O/Na2O = 0.10–0.26), and were derived from deep crustal sources mainly consisting of juvenile mafic rocks, with involvement of minor metasedimentary rocks in the magma sources of the two-mica plagiogranite and tonalite. The diorite enclave within the tonalite was probably derived from an enriched mantle-derived basaltic magma. Mineral compositions, thermobarometric calculations, and whole-rock geochemical data indicate that the low-K intrusive units of the Wujinxia composite pluton resulted from multiple magmatic systems at different depths. The results suggest that I-type granites can contain metasedimentary components by partial melting of a mixed crustal source, and high-Mn content helps the preservation of high-Ca garnet within such rocks. For a composite pluton spanning a large compositional variation, its compositional diversity is jointly controlled by magma source composition, melting condition and thermal evolution of individual magma pulses, and the resulted assembly style during pluton construction. [ABSTRACT FROM AUTHOR]

Metamorphosed banded iron formation (BIF) in granulite-amphibolite facies, tonalitic orthogneisses from a series of locations in the Kolli Massif of southern India are described and analysed with regard to their lithologies, whole rock chemistry, mineral reaction textures, and mineral chemistry. On the basis of their mineral reaction textures along magnetite-quartz grain boundaries these BIFs are grouped according to their predominant silicate mineralogy: 1) amphibole; 2) orthopyroxene; 3) orthopyroxene–clinopyroxene; 4) orthopyroxene-clinopyroxene-garnet; 5) clinopyroxene-garnet-plagioclase; and 6) Fe-Mg silicates are absent. Two-pyroxene and garnet-pyroxene Fe-Mg exchange thermometry, coupled with thermodynamic pseudo-section modelling of whole rock data from one of the magnetite-quartz-orthopyroxene-clinopyroxene-bearing lithologies, indicates that the magnetite-quartz-orthopyroxene-clinopyroxene-garnet assemblages formed at ~900 to 1200 MPa and 750 to 900 °C under relatively low H2O activities. Magnetite-quartz-orthopyroxene reaction textures were experimentally replicated at 800 and 900 °C and 1000 MPa in a synthetic BIF using isolated magnetite grains in a quartz matrix to which was added a hypersaline Mg- and Al-bearing fluid (approximately 1% by mass), which permeated along all the grain boundaries. The fact that Fe-Mg silicate reaction textures did not form in one of the BIF samples, which had experienced the same P-T conditions as the other BIF samples, suggests that, unless a BIF initially incorporated Mg, Al, and Ca during formation with or was infiltrated from the surrounding rocks by Mg-, Al-, and Ca-bearing saline fluids, these silicate minerals could not and would not have formed from the inherent magnetite and quartz during granulite-facies and amphibolite-facies metamorphism. [ABSTRACT FROM AUTHOR]

As a tectonic window into the Lesser Himachal Himalaya, India, a group of metasediments and gneissic rocks, known as the Jutogh Group and Wangtu Gneissic Complex (WGC), occurs near the Jhakri thrust to the west and Wangtu to the east. In the Jutogh Group, chlorite-mica schist, garnet-staurolite schist and sillimanite-schist develop successively. The formation of chemically zoned garnet, which destabilized low-temperature assemblages, is predicted to be at 550–650 °C and 0.8–0.9 GPa by phase equilibria modelling. The retrograde segment consists of exhumation and cooling, yielding a tight clockwise P–T path. Moreover, textural observations and in-situ U-Th-Pb chemical dating indicate that metasedimentary rocks contain Cambrian monazites. These monazites have ages that cluster around 500 Ma. The ƐNd[1.8Ga] of Jutogh rocks ranges from − 1.0 to -8.1, with depleted mantle-model ages between 3.07 and 2.25 Ga. The garnet core and its leachates yield an Sm-Nd isochron age of 472 Ma. Another Sm-Nd isochron age of 454 Ma is obtained from biotite, garnet rim, and garnet rim leachate. According to phase equilibrium modelling, Sm-Nd dating, and monazite geochronology, the Jutogh Group experienced metamorphism along the northeast margin of Gondwana during the Cambro-Ordovician accretion. [ABSTRACT FROM AUTHOR]

Gadolinium aluminium garnet (Gd3Al5O12) nanopowders, with 30 at% lutetium substitution have been successfully synthesized using the co-precipitation method. Several sources, such as aluminium nitrate or sulphate, have been used to develop the (Gd0.7Lu0.3)3Al5O12 (GdLuAG) compound via normal and reverse add titration using ammonium hydrogen carbonate (AHC) as a precipitant. Different techniques such as X-ray diffraction, FTIR, Raman scattering, BET and SEM/EDS analysis were performed in this study. The X-ray results confirmed that the garnet compound crystallized in the cubic structure with group space Ia 3 ¯ d. The crystallite sizes of the powders were determined by using Rietveld refinement analyses. The FTIR results of vibrational characteristics exhibit the internal and external bonds of GdLuAG. The He–Ne laser 633 nm Raman spectra showed a response in the second phonon region exhibiting strong fluorescence in the near-infrared (NIR). The GdLuAG internal Raman active mode in the visible range and excited by a 785 nm diode laser were measured. The X-ray, BET and SEM results indicated that aluminium nitrate reverse titration compound calcined at 1150°C is the best homogeneous and uniform sample. [ABSTRACT FROM AUTHOR]

Epidote group minerals, including allanite, clinozoisite and epidote are common in a range of metamorphic, igneous and hydrothermal systems, and are stable across a wide range of pressure–temperature (P–T) conditions. These minerals can incorporate substantial amounts of rare earth elements (REEs) during their crystallisation, making them potential candidates for Lu–Hf geochronology to provide age constraints on various geological processes. Here we report on a first exploration into the feasibility of in situ Lu–Hf geochronology for epidote group minerals from various geological settings and compare the results with age constraints from other geochronometers. Magmatic allanite samples from pegmatites and monzogranites in the Greenland anorthosite complex, Coompana Province and Qingling Orogen provided dates consistent with magmatic events spanning from c. 2660 to 1171 Ma. In the Qingling pegmatites, a younger phase of hydrothermal allanite was dated at c. 215 Ma, consistent with the timing of regional REE mineralisation. Allanite from the Yambah Shear Zone, Strangways Metamorphic Complex, yielded Lu–Hf age of c. 430 Ma. It predates the garnet and apatite growth at c. 380 Ma, suggesting the Lu–Hf system can be preserved in allanite during prograde amphibolite-facies metamorphism. Additionally, Lu–Hf dates for hydrothermal clinozoisite and epidote are consistent with the timing of hydrothermal alteration and mineralisation in a range of settings, demonstrating the utility of the technique for mineral exploration. Despite the current lack of matrix-matched reference materials, the successful application of laser ablation Lu–Hf geochronology to epidote group minerals offers valuable geochronological insights into various geological processes that can be difficult to access through other geochronometers. [ABSTRACT FROM AUTHOR]

The initiation of ductile shear zones commonly occurs spatially associated with fluid-rock reactions along brittle precursors. In many cases the relative timing of fracturing, fluid infiltration, reaction, and recrystallisation is unclear, making it difficult to disentangle mechanisms of shear zone initiation from subsequent deformation and recrystallisation. Here we present the study of the transition from a dry plagioclase-diopside-garnet-scapolite host granulite-facies lithology to (1) a low strain amphibolite-facies rock, and (2) a transition from low strain to high strain amphibolite-facies lithologies. Hydration of the granulite-facies precursor at amphibolite-facies conditions produces an assemblage comprised dominantly of plagioclase-amphibole-zoisite-clinozoisite-kyanite-scapolite-quartz. Detailed study of plagioclase chemistry and microstructures across these two transitions using Electron Backscatter Diffraction (EBSD) and Wavelength Dispersive Spectrometry (WDS) allows us to assess the degree of coupling between deformation and fluid-rock reaction across the outcrop. Plagioclase behaves dominantly in a brittle manner at the hydration interface and so the initial weakening of the rock is attributed to grain size reduction caused by fracture damage and fluid infiltration at amphibolite-facies conditions. Extensive fracturing-induced grain size reduction locally increases permeability and allows for continuing plagioclase and secondary mineral growth during shear. Based on plagioclase microstructures, such as, an inherited but dispersed crystallographic preferred orientation (CPO), truncation of chemical zoning, and the dominance of fine (5–150 µm), slightly elongate, polygonal grains we conclude that deformation is dominantly facilitated by dissolution–precipitation creep assisted by grain boundary sliding in the shear zone. [ABSTRACT FROM AUTHOR]

Texturally and chemically sector-zoned garnet crystals in two contiguous metapelitic rocks from the Danba dome, eastern Tibetan Plateau (SW China) were investigated. A petrographic boundary in one of the rocks (sample 21DB103) separates a thin section into two zones. Whereas one zone containing sector-zoned garnet and fined-grained matrix is enriched in graphite and quartz, the other zone encompasses garnets with relatively regular habit in a coarse-grained matrix poor in graphite and quartz. The two zones are distinct with regards to the chemical compositions of biotite and plagioclase, as well as the major and trace element zoning patterns of garnet. Electron back-scattered diffraction analysis shows that all the investigated garnet crystals in this sample are single crystals. Relatively higher P-T conditions are estimated for the initial growth of sector-zoned garnet (~ 5.0 kbar / ~540 ℃) compared to the regular garnet (~ 3.8 kbar / ~510 ℃) in this rock, possibly indicating that growth of the sector-zoned garnet postdates growth of the regular garnet. Texturally and chemically radial sectors with garnet-quartz intergrowths and irregular sectors of garnet are preserved in the other graphite-rich rock (sample 21DB104). Isopleth thermobarometry applied to the core of the largest garnet crystal exhibiting sector zoning in this sample reveals P-T conditions of initial garnet crystallization (~ 4.4 kbar / ~512 ℃) that deviate far (~ 0.8 kbar/~45 ℃) from equilibrium, potentially indicating significant overstepping required for garnet nucleation. Plagioclase inclusions in garnet display varying trace element abundances, indicating their replacements of different preexisting phases. These results suggest that abundant graphite may play a pivotal role in changing fluid conditions and reducing the solubility of SiO2 to grow sector-zoned garnet, as well as impeding matrix coarsening. Development of sector-zoned core and dodecahedral faces of garnet may be related to rapid growth with changes in crystal morphology. Irregular sectors may have developed through fluid infiltration and local chemical adjustments. [ABSTRACT FROM AUTHOR]

Hybridization of the lunar mantle during the overturn (sinking) of Fe- and Ti–rich ilmenite-bearing clinopyroxenite cumulates (IBC) in the lunar interior is called upon to explain the high TiO2 abundances of lunar basalts. Chemical reactions that occur after juxtaposition of IBC and mantle peridotite are poorly constrained. We experimentally investigated these reactions in experiments that adjoin an IBC glass against presynthesized dunite in a reaction couple at temperatures of 1100–1300 °C and pressures of 0.5–2.02 GPa for 0.33–31.66 h. These conditions produced experiments near to well above the solidus temperature of the IBC. Near solidus experiments produce garnet in the IBC at 2 GPa. Supersolidus experiments exhibit dissolution of olivine material into the IBC melt and the formation of clinopyroxene at the IBC melt-dunite interface. Dunite dissolution is attributed to the olivine undersaturated composition of the IBC melt. In both near- and supersolidus experiments, compositional variations produced by solid-state diffusion across the IBC melt-dunite interface are observed. When pressure increases, temperature decreases, or IBC melts become closer to olivine saturation, dissolution slows, and the effects of solid-state diffusion in the dunite become more evident. Similar chemical exchange reactions would occur in the lunar mantle as downwelling IBC and lunar peridotites are juxtaposed by cumulate overturn. Hybridized lunar mantle sources are expected to contain 47–84% normative peridotite and 16–53% IBC. Simple numerical simulations suggest that in addition to dissolution–precipitation reactions, mechanical mixing may be required to produce volumetrically significant hybridized mantle sources over geologically-relevant timescales. [ABSTRACT FROM AUTHOR]

The Ga-doped Li7La3Zr2O12 (LLZO) solid state electrolyte (SSE) is synthesized via the solid-state reaction. The structural study of the SSE is conducted with the help of X-ray diffraction and the Rietveld method. The SSE crystallizes in the Li6.25Ga0.15La2.90Zr2O12 phase with cubic space group number 220 and the unit cell parameter of 13.02081 Å, and the La2Zr2O7 impurity phase with cubic space group number 227 and the unit cell parameter of 10.79475 Å. The obtained lattice planes in the refinement are confirmed by TEM. The core of the Li ion migration channel is defined as the loop formed by Li32, Li1, Li2, and Li22 sites with the minimum Li⋯Li distance and occupational disorganization of Ga-doped LLZO SSE. The electron density plots of the Li6.25Ga0.15La2.90Zr2O12 phase show the maximum electron distribution inside the unit cell for lanthanum atoms. XPS confirms the presence of all the precursors, i.e., Li, La, Zr, Ga, and O in the synthesized compound. The elemental composition is confirmed by EDX. In the direct current charge-discharge behaviour of the Li symmetric cell, no voltage breakdown is observed even at 6 mA/cm2 current density and after 400 charge/discharge cycles for over 200 h. [ABSTRACT FROM AUTHOR]

Magnetic ceramics (ferrites) have long held a prominent position in various applications owing to their favorable properties. In the realm of ferrites, yttrium iron garnet (YIG) possesses distinctive optical and magneto-optical properties. In this area, Ce and Pr elements can synergistically amplify the magneto-optical properties of garnet, although the solubility limitation of Ce restricts the addition of large amounts of this element. In the synthesized composition of CexEu0.25Pr0.25Y2.5-xFe5O12 (x = 0.25, 0.35, 0.5) in the current research, a fixed amount of 0.25 mol of Pr has been considered, and to prevent the deposition of CeO2, 0.25 mol of Eu has been included as an additive. Additionally, a hypothesis has been proposed suggesting that the controlled depletion (3–8 wt%) of iron oxide can effectively boost the solubility of Ce in garnets. For the synthesis of samples, the optimized solid-state method has been used at two sintering temperatures of 1350 and 1420 °C in the air using oxide precursors. X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) mapping analyses have been utilized to investigate the crystallographic and phase properties. The findings reveal that Eu effectively elevates Ce solubility by 0.25 mol, aligning with expectations when co-doped with the other two elements possessing larger ionic radii than Y. This study represents the first instance of these elements being co-doped into garnet. Furthermore, the conducted tests provide support for the proposed hypothesis concerning the influence of Fe2O3 reduction on increasing Ce solubility. Consequently, this investigation achieves the successful incorporation of 0.35 mol of cerium into the garnet structure through a 3 wt% reduction of Fe2O3. [ABSTRACT FROM AUTHOR]

The aluminous calcium-ferrite type phase (CF) and new aluminous phase (NAL) are thought to hold the excess alumina produced by the decomposition of garnet in MORB compositions in the lower mantle. The respective stabilities of CF and NAL in the nepheline-spinel binary (NaAlSiO 4 –MgAl 2 O 4 ) are well established. However with the addition of further components the phase relations at lower mantle conditions remain unclear. Here we investigate a range of compositions around the nepheline apex of the nepheline-kalsilite-spinel compositional join (NaAlSiO 4 –KAlSiO 4 –MgAl 2 O 4 ) at 28–78 GPa and 2000 K. Our experiments indicate that even small amounts of a kalsilite (KAlSiO 4 ) component dramatically impact phase relations. We find NAL to be stable up to at least 71 GPa in potassium-bearing compositions. This demonstrates the stabilizing effect of potassium on NAL, because NAL is not observed at pressures above 48 GPa on the nepheline-spinel binary. We also observe a broadening of the CF stability field to incorporate larger amounts of potassium with increasing pressure. For pressures below 50 GPa only minor amounts ( < 0.011 (1) K K + N a + M g ) of potassium are soluble in CF, whereas at 68 GPa, we find a solubility in CF of at least 0.088 (3) K K + N a + M g . This indicates that CF and NAL are suitable hosts of the alkali content of MORB compositions at lower mantle conditions. For sedimentary compositions at lower mantle pressures, we expect K-Hollandite to be stable in addition to CF and NAL for pressures of 28–48 GPa, based on our simplified compositions. [ABSTRACT FROM AUTHOR]

U–Pb ages were determined by split-stream LA-SF/MC-ICPMS in garnets from UHT granulite xenoliths (Star mine, South Africa; 124 Ma). They give a considerable age range of 400 million years with well-defined maximas at 3.09, 3.01 and 2.75 Ga. The oldest peak overlaps with the changeover from tonalites to K-granites at 3.14–3.04 Ga and with zircon ages of the mid-crustal granulites of the Vredefort dome (3.1 Ga) in the wake of the 3.2 Ga collision of three terrains that compose the Witwatersrand block. Subduction (or sagduction) of the uppermost crust in an ultrahot orogen setting brought shales and greenstones to the lower crust. Ultrahigh temperature (UHT) conditions are the result of high mantle potential temperatures and self- heating by the radioactive inventory of the subducted lithologies. Metamorphism, anatexis to very high degrees and melt extraction left UHT granulites as residue. Rejuvenation of UHT conditions was brought about by Dominion Group magmatism between 3.0 and 2.95 Ga. Magmatic uprise caused intense shearing in the lower crust followed by recrystallisation of the shear zones to generate the younger garnet age group. Ventersdorp flood basalt volcanism caused similar processes at around 2.72 Ga and generated the third garnet age group. Zircon gives U–Pb ages mainly around 2.72 Ga (both literature and our own data) i.e. zircon adjusted or newly crystallized at the youngest UHT event. Only few zircon grains retained older ages up to 2.94 Ga. Still unconstrained, but very high closure temperatures (≥ 1100 °C) for the U–Pb system in garnet keep the memory of the oldest ages in UHT granulites. Such ages can only be reset by recrystallization. This way, garnet records a prolonged high-temperature history of the lower crust of the Kaapvaal craton. [ABSTRACT FROM AUTHOR]

The scientific community is exploring novel all-solid-state batteries (ASSBs) as a substitute for conventional lithium-ion batteries with liquid electrolytes. These ASSBs possess several attractive advantages, including improved safety, extended temperature range, and improved energy density. Solid-state electrolytes (SSE) have become significant parts of ASSBs. For example, garnet-type Li7La3Zr2O12 (LLZO) SSE has shown promise among the various forms of SSEs. LLZO demonstrates ionic conductivity of 10−3 to 10−4 S/cm and remarkable chemical durability in combination with lithium metal. Because of these qualities, LLZO is a good option for solid-state Li-metal batteries. Various advancements have been made in garnet-type SSEs and ASSBs since the discovery of LLZO in 2007, resulting in enhanced electrochemical durability and energy density. The advantages of LLZO include durability and safety under elevated temperatures, high-temperature stability, and safety of garnet-type electrolytes. This review article examines current developments in garnet-type LLZO electrolytes, considering experimental research and theoretical findings. We discuss the synthetic methodology, modifications, the robustness of these garnet-based electrolyte materials, novel blueprints for nanostructures, understanding of the electrolyte decomposition pathway, and routes to overcome the electrolyte decomposition pathway with regard to LZZO. Additionally, battery architectures and integrations are explored. The review provides a comprehensive outlook for garnet-based LLZO electrolyte research, focusing on its applications in different solid-state battery concepts, such as Li-ion, Li-S, and Li-air batteries. It highlights the opportunities and perspectives that garnet-type LLZO electrolytes offer, serving as a roadmap for future advancements in SSEs and batteries. [ABSTRACT FROM AUTHOR]

Gadolinium‒aluminum‒gallium garnet crystals are grown with charge compositions Gd3AlxGa5– xO12 (x = 1–3) and Gd3Al2Ga3O12:Ce3+. The effect high-temperature annealing in air has on the optical properties of these crystals is established. It is shown that annealing does not affect the state of cerium oxidation. X-ray fluorescence reveals a deficiency of gallium in all the investigated crystals. [ABSTRACT FROM AUTHOR]

This article focuses on the issues related to the primary nature and metamorphism of gneisses from the Larba block of the Dzhugdzhur–Stanovoy fold area, which are based on the study of the mineralogical composition of supracrustal rocks. The PT-parameters for the highest temperature and pressure metamorphic transformations of rocks of the Larba block are estimated as P = 6.5–8.5 kbar and T > 800°C. Relatively low-temperature garnet–biotite and garnet–biotite–chlorite mineral parageneses were formed at the regressive stage of metamorphism at ~4–6 kbar and temperatures up to 500–600°C. Wide variations in paragneiss compositions indicate that the studied gneisses were derived from protoliths of different composition. Overall, Larba metasedimentary rocks had weakly and moderately weathered source areas. Most of the compositions of paragneisses are located in the field of chlorite–montmorillonite, montmorillonite–kaolinite–hydromica, and chlorite clays formed from the mafic protolith. The low alkalinity in combination with a high MgO content indicates the presence of rock erosion products with a significant admixture of basic volcanic material in the detrital material. Migmatization of the rocks is the most significant factor that distorts the reconstruction of the original rock composition. [ABSTRACT FROM AUTHOR]

Mineralogical and U–Pb (ID-TIMS) geochronological studies of garnets from three types of scarn associations of the Khovu-Aksy Ag–Bi–Cu–Ni–Co deposit (Republic of Tuva) are carried out. The U–Pb garnet age estimate (404 ± 2 Ma) is close to the Early Devonian stage of basite and alkaline-basite magmatism identified within the Tuva trough of the Altai-Sayan folded area. The age of the scarn formation and the associated early stage of mineralization of the Khovu-Aksy Ag–Bi–Cu–Ni–Co deposit has been established for the first time. [ABSTRACT FROM AUTHOR]

The temperature dependences of the heat capacity were measured and the general patterns of the formation of the phonon spectrum of single crystals of solid solutions of yttrium-lutetium aluminum garnets Y3 – xLuxAl5O12 at 0 ≤ x ≤ 3 were investigated in the temperature range from 1.9 to 220 K. According to the data obtained at temperatures below 10 K, the Debye temperatures were calculated. The features of the phonon spectrum in the intermediate temperature range are interpreted as a superposition of optical modes for yttrium and lutetium garnets. It is shown that the low heat capacity values due to the contribution of acoustic phonons for Y2.25Lu0.75Al5O12 correlate with anomalies in the concentration dependences of the phonon transport, the absorption of acoustic waves, and the shape of the aluminum NMR line. [ABSTRACT FROM AUTHOR]

Mineral reactions were studied in metamorphic rocks from the Meyeri tectonic zone, and the P–T path of the development of this structure was calculated. According to the P–T path, the Proterozoic granulite complex of the Svecofennian Belt was thrust onto low-temperature rocks of the Archean Karelian Craton. Relict staurolite and other minerals preserved as inclusions in the garnet porphyroblasts made it possible to identify the pre-peak stage of metamorphism with P–T parameters no higher than the low-temperature amphibolite facies of moderate and low pressure. The peak metamorphic conditions of the tectonic zone are estimated at T > 700°C and P ~ 7 kbar using the composition of relict minerals, while the temperature on the prograde trend of metamorphism was 500–600°C at a pressure of about 5 kbar. The post-peak stage began with a distinct decompressional P–T path at the aforementioned high temperatures, with a change from granulite hypersthene-containing assemblages to lower-temperature hydrous ones. The subsequent metamorphic retrogression was characterized by the development of numerous hydrous minerals as a result of the activation of fluids in the shear zone. The P–T path of the tectonic zone is clockwise and reflects the exhumation of the Svecofennian granulite complex during the orogenic events. [ABSTRACT FROM AUTHOR]

A series of Mesozoic granites related to the subduction of the ancient Pacific plate are widely developed in the eastern part of the North China Craton. These granites contain garnet as a minor phase. Garnet records important information such as magma composition, temperature and pressure, and is an important object in the study of petrological evolution of granites. We take the late Jurassic garnet–bearing monzogranite in Xingcheng, Liaoning as the research object, and the magmatic evolution process in the study area is discussed by the in–situ element geochemical variation and the Raman effect of magmatic garnet girdle. It is found that the garnet has a zonation structure in which the contents of MnO and CaO increase and then decrease, while the contents of FeO and MgO decrease and then increase from the core to the edge. Through the simulation of the crystallization sequence of garnet and biotite, it is found that the garnet has "M" type "spessartine bell–shaped profile", Mn/(Ca + Mg + Fe) value and Mn/Fe value, which reflects that the crystallization pattern of minerals in the magma is dominated by biotite crystallization to garnet crystallization. It is considered that forward and reverse girdle can exist in the same garnet; the separation and crystallization of minerals in the late magmatic evolution is the main reason for the change in the compositional profile of the garnet. This is consistent with the late evolution of granitic magmas in the northeastern of the North China Craton after the late Jurassic. [ABSTRACT FROM AUTHOR]

Phosphor-converted light-emitting diodes (pc-LEDs) with broadband near-infrared (NIR) emissions have garnered significant research interest. Their performance is primarily determined by the type of NIR phosphor used. Herein, a broadband NIR-emitting phosphor, Y3Sc2Al3O12:Cr3+, is synthesized. The blue-light excitation of the Y3Sc2Al3O12:Cr3+ phosphor produces a broadband emission spectrum ranging from 640 to 1000 nm with a full width at half maximum (FWHM) of 113 nm. The NIR emission intensity maintains approximately 50% of the initial room-temperature intensity at 423 K. The structure–property relationship is also comprehensively studied. Encapsulating the as-obtained NIR phosphor into prototype pc-LEDs produces an NIR output power of 58.1 mW at a 1230 mA driving current and a photoelectric conversion efficiency of 3.5% at 30 mA. Finally, night-vision applications are implemented using the as-fabricated pc-NIR-LEDs device. [ABSTRACT FROM AUTHOR]

A sample of Y2.85Ca0.15Sn0.08Ti0.05Mn0.07Fe4.8O12 doped with four different ions was prepared using the solid method and a subsequent procedure. X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and scanning electron microscope (SEM) were used to analyze the sample's structural features, elemental distribution, and surface morphology. The study used the B-H magnetic characteristic analyzer and superconducting quantum interferometer magnetic performance measurement system to analyze the magnetic properties of Y2.85Ca0.15Sn0.08Ti0.05Mn0.07Fe4.8O12. The correlation becomes more surprising as the frequency increases, indicating a decrease in permeability when the magnetic field H reaches 200 A/m. Ion substitution leads to changes in magnetic crystal anisotropy, affecting permeability as the external magnetic field strength increases. We analyze the correlation between saturation magnetization and temperature in the 520–540 K range and explain the variation of saturation magnetization with temperature. The study shows that saturation magnetization decreases as temperature increases. This result suggests that saturation magnetization decreases as temperature increases. The increased super-exchange effect due to Ti and Mn occupying the (d) sites is much stronger than the reduced effect caused by Sn occupying the (a) sites. Therefore, the saturation magnetization of the Y2.85Ca0.15Sn0.08Ti0.05Mn0.07Fe4.8O12 sample is higher than that of the undoped sample. The Curie temperature (Tc) of the Y2.85Ca0.15Sn0.08Ti0.05Mn0.07Fe4.8O12 sample is lower than that of the undoped sample. [ABSTRACT FROM AUTHOR]

This study investigates the naturally occurring radionuclides in Egyptian black sands collected from the Mediterranean Sea Coast, an area rich in sediments from the White Nile, Blue Nile, and Atbara rivers. The black sands mainly comprise two groups of minerals: the gangue group, consisting of quartz, feldspar, amphiboles, pyroxenes, epidote, and micas, and the economic minerals group, which includes magnetite, garnet, zircon, monazite, and uncommon commercial minerals like thorite. A gamma spectrometry with a NaI (Tl) detector was employed to analyze black sand samples for the presence of radionuclides. Additionally, radium equivalent activities (Raeq), absorbed dose rate, annual effective dose, gamma radiation hazard index (Iγ), external hazard index, internal hazard index (Hin), and lifetime cancer risk (ELCR) were calculated based on the measured activity concentrations of 226Ra, 232Th, and 40K. This comprehensive analysis contributes valuable insights into the radiological properties and potential hazards associated with Egyptian black sands. Due to the significant radioactive risk associated with these black sand samples, specifically in the Mediterranean Sea Alexandria coastal area, must be considered while using them as building materials. Measured values include Ra-226 (56 Bq/kg), Th-232 (77 Bq/kg), and K-40 (55 Bq/kg). [ABSTRACT FROM AUTHOR]

In order to enhance the ionic conductivity of solid polymer electrolytes (SPEs) and their structural rigidity against lithium dendrite during lithium-ion battery (LIB) cycling, we propose porous garnet Li6.4La3Zr2Al0.2O12 (LLZO), as the filler to SPEs. The porous LLZO with interlinked grains was synthesized via a resol-assisted cationic coordinative co-assembly approach. The porous structure of LLZO with high specific surface area facilitates the interaction between polymer and filler and provides sufficient entrance for Li+ migration into the LLZO phase. Furthermore, the interconnection of LLZO grains forms continuous inorganic pathways for fast Li+ migration, which avoid the multiple diffusion for Li+ in interface. As a result, the SPEs with porous LLZO (SPE-PL) show a high ionic conductive of 0.73 mS·cm−1 at 30 °C and lithium-ion transference number of 0.40. The porous LLZO with uniformly dispersed pores also acts as an ion distributor to regulate ionic flux. The lithium-symmetrical batteries assembled with SPE-PL show a highly stable Li plating/stripping cycling for nearly 3000 h at 0.1 mA·cm−2. The corresponding Li/LiFePO4 batteries also exhibit excellent cyclic performance with capacity retention of 75% after nearly 500 cycles. This work brings new insights into the design of conductive fillers and the optimization of SPEs. [ABSTRACT FROM AUTHOR]

Iron oxide–apatite (IOA or Kiruna-type) deposits typically consist of a magnetite-apatite-actinolite/diopside assemblage and are spatially associated with extensive Na-(Ca) alteration and brecciation. The origin of these deposits is highly controversial and has been ascribed to the separation of iron-oxide/sulfate-(carbonate) melts, magnetite emulsions, or metasomatic replacement by aqueous fluids from silicate magmas. Here, we propose a new model based on the findings from a cluster of IOA deposits located in the early Cretaceous Ningwu andesitic volcanic field, eastern China. In these deposits, magnetite coeval with apatite and actinolite occurs as coarse-grained veins, massive replacement, and fine-grained disseminations in the albitized, often brecciated, apical zones of diorite porphyry intrusions, the overlying andesites, and adjacent sedimentary rocks. The primary magnetite grains from ores with various textures contain similar and variable trace element compositions with up to 5 wt% Ti + V and show the characteristics of high-temperature hydrothermal magnetite in magmatic-hydrothermal systems. Diopside and garnet as well as magnetite contain fluid inclusions with multiple daughter minerals (vapor + halite + sylvite ± anhydrite ± iron chloride ± liquid ± hematite), which show extremely high salinities of more than ~ 90 wt% NaClequiv, homogenization temperatures of 745–846 °C, and Cl/Br mole ratios of 2000–6000. In combination with oxygen isotopes of the magnetite-apatite assemblage and the association with shallow-seated ore-hosting porphyry, available evidence suggests that these deposits formed from hydrosaline liquid exsolved from subvolcanic dioritic magmas with high Cl/H2O at magmatic temperatures (~ 800 °C). Decompression from lithostatic to hydrostatic condition and the interaction with country rocks explain the abundance of breccia bodies and widespread sodic alteration in IOA deposits. [ABSTRACT FROM AUTHOR]

Jinchanghe is a Zn-Pb-Fe-Cu skarn deposit in the northern Baoshan block, southwestern China. It is a typical distal skarn deposit with orebodies in the Cambrian Hetaoping Formation limestone and calcareous siltstone. The skarn minerals display a vertical zonation with garnet skarn in the lower part and pyroxene skarn in the upper part. Economic metals are also zoned with Fe at the base, Cu in the middle, and Zn-Pb in the upper part. The skarn formation and Zn-Pb-Fe-Cu mineralization is divided into four paragenetic stages: a pre-ore stage dominated by prograde garnet and pyroxene, an oxide stage represented by Fe mineralization associated with retrograde ilvaite, actinolite and epidote alteration, a sulfide stage characterized with Cu–Zn-Pb sulfides, and a post-ore stage with barren calcite, quartz and chlorite. Fluid inclusion microthermometry indicates that the hydrothermal fluids of the Jinchanghe skarn system evolved from the pre-ore stage (450–480 °C and 11.7–15.5 °C wt% NaCl equiv), through the oxide stage (230–280 °C and 6.5–12.2 wt% NaCl equiv), the sulfide stage (190–230 °C and 1.3–10.3 wt% NaCl equiv), and eventually to the post-ore stage (120–180 °C and 1.6–4.6 wt% NaCl equiv). Correspondingly, the δ18Ofluid values decrease from 1.8–7.1‰ to 1.0–6.4‰, -1.0 to 1.3‰, and -3.6 to -1.4‰. This indicates that the pre-ore fluids comprise a magmatic component but mixed with some meteoric water, and in the later stages meteoric water has become dominant in the hydrothermal system. Zinc and sulfur isotope compositions reveal that the Zn and S forming the sulfides have a dominantly magmatic origin. The coupled decreases of fluid temperature, salinity, and δ18Ofluid values during the mineralization indicate simultaneous mixing with meteoric water and ore precipitation, suggesting that fluid mixing was critical in ore deposition. The gradual increase of δ13CCO2 values in equilibrium with the hydrothermal calcite (-5.2 to -1.6‰) from the sulfide stage to the post-ore is attributed to the reaction between the fluids and the carbonate wallrocks, implying a role that fluid-rock interaction has taken in the sulfide deposition. Fluid mixing and fluid-carbonate reaction are the two major factors controlling the formation of the Jinchanghe deposit. [ABSTRACT FROM AUTHOR]

This study was carried out in the weathering profile on gneiss in the Mandoga area (south Cameroon plateau), on the petrological characterization of the weathered phases. Gneiss is made up of quartz, feldspars, biotite, muscovite, garnet, kyanite, and zircon, with negative Eu anomaly (Eu/Eu* = 0.63). The profile shows three groups of phases: coarse saprolite at the bottom of the weathering horizon, the phases of the fine saprolite, and those of the uppermost part of the weathering profile. The mineralogical composition differs from the coarse saprolite to the top soil. All phases comprised kaolinite, quartz, and goethite. They characterize a pedoclimatic environment-rich in water, favorable to the stability of hydrated minerals. The negative Eu anomaly in all phases reflects the lithodependance of horizons at the expense of the gneiss, the parent rock. The Ce anomalies are linked to the pedodynamic conditions. In the same way, the behavior of REE in the different phases confirms the variation of the geochemical processes of the two pedodynamic domains. The phases from the fine saprolite are enriched in LREE than in HREE and match an overlapping of geochemical pedodynamic processes. Thus, the phases are marked by the geochemical signature along the weathering profile. [ABSTRACT FROM AUTHOR]

We applied elastic thermobarometry on garnet-bearing migmatites along two transects through the crustal section at Sierra Valle Fértil-La Huerta, Argentina. We performed quartz-in-garnet barometry and zircon-in-garnet thermometry on metapelites from different paleo-depths across the crustal section. Our work recovers entrapment pressures ranging from 240 to 1330 MPa and entrapment temperatures between 691 and 1574 °C. The entrapment conditions are broadly consistent with anticipated pressures and temperatures along the crustal section derived previously using conventional, thermodynamic thermobarometers. The quartz-in-garnet barometer reproduces those conventionally established entrapment conditions when samples only experienced conditions within the alpha-quartz stability field. Raman-derived pressures for samples that experienced beta-quartz reference conditions are commonly much higher than those established by conventional barometry. Samples that preserve compressive (positive) residual pressures best reproduce reference entrapment pressures. Entrapment temperatures show high variability and overestimation of temperature conditions compared to conventional results. These results indicate elastic thermobarometry over- or under-estimates crystallization conditions in rocks crystallized at high temperatures, as is common in the Famatinian Arc deep-crust. We suggest that modeling quartz behavior across the alpha–beta transition may present challenges, as does shape maturation, viscous deformation, and radiation damage in zircon. [ABSTRACT FROM AUTHOR]

Orogenic peridotites in the crystalline basement of the northwestern Bohemian Massif contain multiphase solid inclusions (MSI), which are interpreted to be crystallisation products of trapped former carbonate–silicate melts metasomatizing their host rocks. We applied conventional thermobarometry and forward thermodynamic modelling to constrain the P–T evolution ranging from the peak metamorphic conditions of the investigated harzburgite and lherzolite, through entrapment of the melts in the outer parts of garnets, to the (re)-equilibration of the MSI assemblages. The peak conditions of c. 1100 °C/4.5–5.5 GPa are recorded by garnet cores and large pyroxene porphyroclasts. The melt entrapment, during which garnet outer parts grew, was associated with influx of the metasomatizing liquids and probably took place during the early stage of the exhumation. Thermodynamic model of amphibole-free MSI assemblage comprising kinoshitalite/Ba-rich phlogopite (approximated by phlogopite in the model), dolomite, magnesite, clinopyroxene, orthopyroxene, garnet and chromite provided robust estimate of P and T of its (re)-equilibration, c. 900–1000 °C, 1.8–2.2 GPa. Furthermore, the lack of olivine reflects co-existence of COH fluid with high X(CO2) = CO2/(CO2 + H2O) ≥ 0.6. Models employing identical P–T–X(CO2) parameters successfully reproduced the other two amphibole-bearing assemblages observed. The modelled stability fields show perfect alignment with a characteristic isobaric segment of the solidus curve of carbonated peridotite. This co-incidence implies that the (re)-equilibration corresponds to the termination of the melt crystallisation once the near-isothermal exhumation path intersected the solidus. Decreased solubility of silicates at the carbonated peridotite "solidus ledge", inferred from the published experimental data, as well as concentric textures of some MSI indicates sequential crystallisation from the early silicates to late dolomite. The carbonated "solidus ledge" is a relatively narrow boundary in the lithospheric mantle capable of an abrupt immobilisation of fluxing or transported carbonated melts. The investigated rocks are estimated to store approximately 0.02 kg C/m3 (or 6 ppm C) occurring as carbonates in the MSI. [ABSTRACT FROM AUTHOR]

This work investigates the relationships between partial melting, melt extraction, pluton growth and silicic volcanism in garnet-bearing felsic volcanic rocks that were extruded in the Iberian Pyrite Belt, at ca. 345 Ma. The garnets are of peritectic origin, displaying textural and chemical features of disequilibrium crystallization during partial melting reactions involving biotite at high temperatures (up to 870 °C) in the middle-lower crust. Major element composition suggests compositional equilibrium with the entrained and pinitized peritectic cordierite, but reveals some subsequent homogenization by diffusion. Trace element maps and spot analyses of garnet show, nonetheless, significant trace element variations, reflecting biotite and Y-REE-P-rich accessory phase breakdown during partial melting reactions. Peritectic garnet and cordierite growth resulted in the preservation of Th- and Y-rich prograde suprasolidus monazite, which constrains the timing of partial melting of the metapelitic protolith at ca. 356.8 ± 2.4 Ma. The zircon cargo further shows that a significant amount of zircon crystals from previously crystallized felsic melts were also remobilized and erupted. These were likely stored in an upper crustal pluton that grew episodically since ca. 390 Ma during voluminous melt generation periods within the middle to lower crust, which also resulted in voluminous volcanism. The geochemical trends of the felsic volcanic rocks reflect the entrainment of xenoliths of peritectic garnet, cordierite and feldspar, and as such, the garnet-bearing felsic volcanic rocks represent an erupted mixture of a lower-temperature (ca. 770 °C) silicic melt and autocrysts, and peritectic phases and zircon crystals from previously crystallized and stored felsic melts. [ABSTRACT FROM AUTHOR]

Drawing from our research and an extensive review of publications, we have compiled data from goniometric studies concerning the morphology of mineral inclusions in diamonds sourced from both kimberlites and placers. Specifically, we have examined the morphology of olivine, garnet, and chrome-spinelide inclusions. In the majority of instances, the crystalline shape of these mineral inclusions has been instrumentally confirmed to mirror that of diamonds. The formation of such shapes is attributed to the influence of the negative morphology of diamond crystals, the host mineral, on mineral inclusions. The shape of these inclusions reflects various features of diamond morphology, encompassing simple forms, habits, outlines, and surface topography of faces. Compelling evidence supporting the syngenesis of mineral inclusions with diamond-shaped crystals and the diamonds within which they are found lies in indicators of their simultaneous growth. These indicators include the presence of induction pseudo-edges, pseudo-faces, and pseudo-vertices on inclusion crystals. [ABSTRACT FROM AUTHOR]

Three variably old groups of banded iron formation (BIF) are known in the Kostomuksha Greenstone Belt (KGB) of the Karelian Craton. This paper deals with the earliest of them, Mesoarchean (2.87–2.81 Ga) BIF-1. BIF-1 occurs among the komatiite–basalt unit of the KGB. BIF-1 consists mainly of quartz and magnetite, with varying amounts of amphibole, biotite, and garnet; the variations of SiO2 (48.3–58.6 wt %) and (21.34–33.82 wt %) suggest that the rocks are BIF. BIF-1 of the KGB, as well as most Archean BIFs, contain high concentration, display a contrasting positive Eu anomaly, lack of Ce anomaly, and the depletion of LREE relative to HREE. However, they differ from other BIFs in the higher Al2O3, TiO2, MgO, K2O, Cr, Ni, Zr, Ba, Cu and Zn concentrations. BIF-1 was formed in a marine basin at an anoxic atmosphere due to hydrothermal fluids, the proportion of which varies from 20 to 80%, and a terrigenous component derived mainly from basalts, komatiites, and dacites of host rocks. Mesoarchean BIF-1 of the KGB was accumulated in a small rift structures within an oceanic volcanic plateau, the formation of which is associated with the influence of a mantle plume on the oceanic lithosphere. [ABSTRACT FROM AUTHOR]