Garnet solid electrolytes are one of the most promising electrolytes for solid-state batteries.However,Li_(2)CO_(3) is a critical issue that hinders the practical application of garnet-based solid-state lithium-ion ba...Garnet solid electrolytes are one of the most promising electrolytes for solid-state batteries.However,Li_(2)CO_(3) is a critical issue that hinders the practical application of garnet-based solid-state lithium-ion batteries.There are two sources of Li_(2)CO_(3) contamination.The main one is the aging of garnet electrolytes in the atmosphere.Garnet electrolytes can react with H_(2)O and CO_(2) in the air to form Li_(2)CO_(3),which reduces ion conductivity,increases electrode/garnet electrolyte interface resistance,and deteriorates the electrochemical performance of the battery.Various strategies,such as elemental doping,grain boundary manipulation,and interface engineering,have been suggested to address these issues.The other is the passivation layer(Li_(2)CO_(3),Li_3N,LiOH,Li_(2)O) formed on the surface of the lithium foil after long-term storage,which is ignored by most researchers.To better understand the current strategies and future trends to address the Li_(2)CO_(3) problem,this perspective provides a systematic review of journals published in this field from 2020-2023.展开更多
Garnet-type Li_7La_(3)Zr_(2)O_(12)(LLZO) has high ionic conductivity and good compatibility with lithium metal.High-temperature processing has been proven an effective method to decrease the interface resistance of ca...Garnet-type Li_7La_(3)Zr_(2)O_(12)(LLZO) has high ionic conductivity and good compatibility with lithium metal.High-temperature processing has been proven an effective method to decrease the interface resistance of cathodeILLZO.However,its application is still hindered by the interlayer co-diffusion with the cathode and high sintering temperature(>1200℃).In this work,a new garnet-type composite solid-state electrolyte(SSE) Li_(6.54)La_(2.96)Ba_(0.04)Zr_(1.5)Nb_(0.5)O_(12)-LiCoO_(2)(LLBZNO-LCO) is firstly proposed to improve the chemical stability and electrochemical properties of garnet with high-temperature processing.Small doses of LCO(3%) can significantly decrease the LCOISSE interface resistance from 121.2 to 10.1 Ω cm~2,while the sintering temperature of garnet-type LLBZNO decreases from 1230 to 1000℃.The all-solid-state battery based on the sintered LLBZNO-LCO SSE exhibits excellent cycling stability.Our approach achieves an enhanced LCOISSE interface and an improved sintering activity of garnet SSE,which provides a new strategy for optimizing the comprehensive performance of garnet SSE.展开更多
Li(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO) solid garnet-type electrolyte has been widely reported due to its outstanding safety and electrochemical stability.However,the inherent rigidity and brittleness of LLZTO lead...Li(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO) solid garnet-type electrolyte has been widely reported due to its outstanding safety and electrochemical stability.However,the inherent rigidity and brittleness of LLZTO lead to poor contact with anode/cathode and the operation failure of full cells.Herein,the dual-interlayers are constructed as the fast interfacial ion-migration channel by using Ti_(3)C_(2)T_(x)(MXene,Txis-O,-OH,-F) with trace ionic liquid(IL),which promote the intimate contact between LLZTO and anode/cathode and suppress Li-dendrites growth.Notably,IL can wet the cathode to promote intimate interface contact and be decomposed into some inorganic compounds(such as Li3N,LiF,and Li2Sx),resulting in reduced interfacial resistance and fast Li-ion transportation.Consequently,in the prepared Li-symmetric cell,the interfacial resistance on the anode side plunges to 33.1 Ω cm^(-2),and stably maintains over 1000 h without short circuit at 0.05 mA cm^(-2).The full cell of Li|LiFePO4delivers a high initial capacity of 158.52 mA h g^(-1)and outstanding retention of 90.18% after 100 cycles at 60℃ and 0.2 C.Our work provides an efficient strategy to design dual-interlayers between LLZTO and anode/cathode for the interfacial modification to enhance the performance of solid garnet batteries.展开更多
Magnetic bubbles have again become a subject of significant attention following the experimental observation of topologically nontrivial magnetic skyrmions. In recent work, tailoring the shape of the bubbles is consid...Magnetic bubbles have again become a subject of significant attention following the experimental observation of topologically nontrivial magnetic skyrmions. In recent work, tailoring the shape of the bubbles is considered a key factor for their dynamics in spintronic devices. In addition to the reported circular, elliptical, and square bubbles, here we observe triangular bubble domains in bismuth-doped yttrium iron garnet(Bi-YIG) using Kerr microscopy. The bubble domains evolve from discrete circular to latticed triangular and hexagonal shapes. Further, the orientation of the triangular bubbles in the hexagonal lattices can be flipped by decreasing the magnetic field. The sixfold in-plane magnetic anisotropy of Bi-YIG(111) crystal, which is presumably the mechanism underlying the triangular shape of the bubbles, is measured as1179 erg/cm~3. The study of the morphologies of topologically trivial bubbles in YIG offers insight into nontrivial spin textures, which is appealing for future spintronic applications.展开更多
Inorganic solid-state electrolytes(SSEs)are nonflammable alternatives to the commercial liquid-phase electrolytes.This enables the use of lithium(Li)metal as an anode,providing high-energy density and improved stabili...Inorganic solid-state electrolytes(SSEs)are nonflammable alternatives to the commercial liquid-phase electrolytes.This enables the use of lithium(Li)metal as an anode,providing high-energy density and improved stability by avoiding unwanted liquid-phase chemical reactions.Among the different types of SSEs,the garnet-type electrolytes witness a rapid development and are considered as one of the top candidates to pair with Li metal due to their high ionic conductivity,thermal,and electrochemical stability.However,the large resistances at the interface between garnet-type electrolytes and cathode/anode are the major bottlenecks for delivering desirable electrochemical performances of all-solid-state batteries(SSBs).The electrolyte/anode interface also suffers from metallic dendrite formation,leading to rapid performance degradation.This is a fundamental material challenge due to the poor contact and wettability between garnet-type electrolytes with electrode materials.Here,we summarize and analyze the recent contributions in mitigating such materials challenges at the interface.Strategies used to address these challenges are divided into different categories with regard to their working principles.On one hand,progress has been made in the anode/garnet interface,such as the successful application of Li-alloy anode and different artificial interlayers,significantly improving interfacial performance.On the other hand,the desired cathode/garnet interface is still hard to reach due to the complex chemical and physical structure at the cathode.The common methods used are nanostructured cathode host and sintering additives for increasing the contact area.On the basis of this information,we present our views on the remaining challenges and future research of electrode/garnet interface.This review not only motivates the need for further understanding of the fundamentals,stability,and modifications of the garnet/electrode interfaces but also provides guidelines for the future design of the interface for SSB.展开更多
The Aqishan lead-zinc deposit,located in the Jueluotag metallogenic belt of eastern Tianshan,Xinjiang,Northwest China,has a stratiform occurrence in the marine volcanic tuff of the Yamansu Formation.The ore body has a...The Aqishan lead-zinc deposit,located in the Jueluotag metallogenic belt of eastern Tianshan,Xinjiang,Northwest China,has a stratiform occurrence in the marine volcanic tuff of the Yamansu Formation.The ore body has a typical double-layer structure,having a stratified,stratoid,lenticular upper part and a veined,stockwork-like lower part.The occurrence of the upper orebody is consistent with that of the volcanic tuff wall rock.The ore minerals are mainly chalcopyrite,pyrite,sphalerite,galena and magnetite,the altered minerals mainly being silicified,such as sericite,chlorite,epidote,garnet.The garnetized skarn,being stratiform and stratoid,is closely related to the upper part of the orebody.Geological observations show that the limestone in the ore-bearing Yamansu Formation is not marbleized and skarnized.Spatially,it is associated with the ferromanganese deposits in the marine volcanic rocks of the Yamansu Formation.These geological features reflect the likelihood that the Aqishan lead-zinc deposit is a hydrothermal exhalation sedimentary deposit.The results from the EPMA show that the garnet is mainly composed of grossular-andradite series,contents being in a range of 34.791-37.8%SiO_(2),32.493-34.274%CaO,8.454-27.275%FeO,0.012-15.293%Al_(2)O_(3),0.351-1.413%MnO,and lower values of 0.013-1.057%TiO_(2).The content of SiO_(2) vs.CaO and FeO vs.Al_(2)O_(3) has a significant positive correlation.The results of ICP-MS analysis for the garnet show that the REE pattern is oblique to right in general.The total amount of rare earth elements is relatively low,ΣREE=71.045-826.52 ppm,which is relatively enriched for LREE and depleted for HREE.LREE/HREE=8.66-4157.75,La_(N)/Yb_(N)=23.51-984.34,with obvious positive Eu and Ce anomalies(δEu=2.27-76.15,δCe=0.94-1.85).This result is similar to the REE characteristics of ore-bearing rhyolite volcanic rocks,showing that the garnet was formed in an oxidizing environment and affected by clear hydrothermal activity.The U-Pb isotopic dating of garnet by fs-LA-HR-ICP-MS gives an age of 316.3±4.4 Ma(MSWD=1.4),which is consistent with the formation time of the Yamansu Formation.According to the study of deposit characteristics and geochemical characteristics,this study concludes that the Aqishan lead-zinc deposit is a hydrothermal exhalation sedimentary deposit,the garnet being caused by hydrothermal exhalative sedimentation.展开更多
The results of recent geothermobarometric and geochronological investigations of scarce eclogites of the NW Himalaya (Tso Morari (Ladakh), India and Kaghan Valley, Pakistan) have caused a major rethink of tectonometam...The results of recent geothermobarometric and geochronological investigations of scarce eclogites of the NW Himalaya (Tso Morari (Ladakh), India and Kaghan Valley, Pakistan) have caused a major rethink of tectonometamorphic models for India\|Asia collision. Numerous petrologic studies have been undertaken on the age and origin of metamorphism in the Higher Himalayan Crystallines (HHC) and Lesser Himalaya formations (LH) and their relationship to granite magmatism and movements along the Main Central Thrust (MCT) and South Tibetan Detachment Fault (STDF). However, all of these events are essentially Miocene (or younger) in age and can clearly be distinguished from subduction and exhumation processes undergone by the eclogites which are of Eocene age (Tonarini et al. 1993; Spencer & Gebauer; 1996; de Sigoyer et al. 1999) and relate to the very early stages of the collision. Eclogites of eastern Ladakh are mafic lenses found in granitic gneisses (Ordovician intrusive age: Girard & Bussy 1999) and their surrounding late Pre\|Cambrian to early Cambrian sedimentary units in the Tso Morari dome (see Steck et al. 1998). Detailed petrological and geochronological studies (Guillot et al. 1997; de Sigoyer et al. 1997, 1999) have identified an eclogite facies stage (2000±300)MPa, (580±60)℃ followed by isothermal decompression associated with glaucophane growth at around (1100±200)MPa. Dating of different phases by different methods yielded ages around 55Ma for this stage ((55±17) Ma, U\|Pb, Aln; (55±12) Ma, Lu\|Hf, Grt\|Cpx\|Rt; (55±7) Ma, Sm\|Nd, Grt\|Gln\|Rt). A subsequent amphibolite facies overprint at slightly higher temperature (610±70)℃ was dated at 45～48Ma (metabasite: (47±11) Ma, Sm\|Nd, Grt\|Hbl; metapelite: (45±4) Ma, Rb\|Sr, Mu\|Ap\|WR and (48±2) Ma, Ar\|Ar, Phe). By (30±1) Ma (Ar\|Ar, Bt\|Mu) retrogression into the greenschist facies had occurred (de Sigoyer et al. 1999). These data indicate a two stage history with early exhumation being much faster (>4mm/a) than the later evolution (1～2mm/a).展开更多
Eclogitic garnet-amphibole rocks are scattered around the Songshugou ultramafic bodies in QinlingMountains.Three metamorphic stages are recognized in terms of petrography,mineral chemistry andgeothermobarometry.The fi...Eclogitic garnet-amphibole rocks are scattered around the Songshugou ultramafic bodies in QinlingMountains.Three metamorphic stages are recognized in terms of petrography,mineral chemistry andgeothermobarometry.The first albite-amphibole stage was of greenschist facies metamorphism with typicalmineral assemblage of actinolite+epidote+chlorite+albite;the pressure and temperature conditions wereequal to or lower than500MPa and about400℃.The second prograde eclogitic garnet-amphibole stagewas of amphibole-eclogite facies metamorphism with typical mineral assemblage of garnet+hornblende±clinopyroxene+rutile without phagioclase,the pressure condition was at least1000 -1200MPa and the temper-ature about600℃.The third retrograde epidote-amphibole stage was of epidote-amphibolite facies withassemblage of plagoclase+hornblende+epidote+ilmenite/titanite,the temperature was500-600℃andthe pressure from 800MPa down to500MPa.All three stages took place in one single tectonothermal eventcalled Jimingian movement展开更多
Tetraethylenepentamine(C8H23N5,TEPA) has been used as a novel precipitant to synthesize yttrium aluminum garnet(Y3Al5O12,YAG) precursor from a mixed solution of aluminum and yttrium nitrates via a normal-strike co-pre...Tetraethylenepentamine(C8H23N5,TEPA) has been used as a novel precipitant to synthesize yttrium aluminum garnet(Y3Al5O12,YAG) precursor from a mixed solution of aluminum and yttrium nitrates via a normal-strike co-precipitation method without controlling the pH value during precipitation process.The original precursor was analyzed by thermogravimetry/differential scanning calorimetry(TG/DSC).The evolution of phase composition and micro-structure of the as-synthesized YAG powders were characterized by X-ray diffraction(XRD),Fourier transform infrared(FT-IR) spectroscopy and transmission electron microscopy(TEM).Compositionally pure YAG nanostructured powders were directly obtained by calcination of the precursor at 900 ℃ without the formation of any intermediate phases.The average particle size determined from TEM micrograph for the powder obtained at 1000 ℃ was approximately 50 nm.展开更多
With improvements on high-pressure experimental techniques in multi-anvil apparatus and the development of new analytical tools, major progress has been made on diffusion in garnets in the past several decades. The da...With improvements on high-pressure experimental techniques in multi-anvil apparatus and the development of new analytical tools, major progress has been made on diffusion in garnets in the past several decades. The data obtained in the experimental determination of diffusion coefficients in garnets are of fundamental importance for diffusion modeling and timescales of geological and planetary processes. In this review, we have compiled experimental data on self-diffusion(Si, O, cations), trace element diffusion(Li, Y, Ga, Cr, Sr, REEs), and interdiffusion(Ca–Fe/Mg, Si–Al) in garnet in the light of new advances and recent applications. In addition, some empirical relationships among diffusion parameters(pre-exponential factor D_0,activation energy E, ionic radius) are also discussed. We hope that this review can provide a useful data digest and guide to future study of diffusion in garnet.展开更多
Single-ion conducting solid polymer electrolytes are expected to play a vital role in the realization of solid-state Li metal batteries.In this work,a lithiated Nafion(Li-Nafion)-garnet ceramic Li6.25La3 Zr2 Al0.25O12...Single-ion conducting solid polymer electrolytes are expected to play a vital role in the realization of solid-state Li metal batteries.In this work,a lithiated Nafion(Li-Nafion)-garnet ceramic Li6.25La3 Zr2 Al0.25O12(LLZAO)composite solid electrolyte(CSE)membrane with 30μm thickness was prepared for the first time.By employing X-ray photoelectron spectroscopy and transmission electron microscope,the interaction between LLZAO and Li-Nafion was investigated.It is found that the LLZAO interacts with the Li-Nafion to form a space charge layer at the interface between LLZAO and Li-Nafion.The space charge layer reduces the migration barrier of Li-ions and improves the ionic conductivity of the CSE membrane.The CSE membrane containing 10 wt%LLZAO exhibits the highest ionic conductivity of2.26×10-4 S cm-1 at 30℃among the pristine Li-Nafion membrane,the membrane containing 5 wt%,20 wt%,and 30 wt%LLZAO,respectively.It also exhibits a high Li-ion transference number of 0.92,and a broader electrochemical window of 0-+4.8 V vs.Li+/Li than that of 0-+4.0 V vs.Li+/Li for the pristine Li-Nafion membrane.It is observed that the CSE membrane not only inhibits the growth of Li dendrites but also keeps excellent electrochemical stability with the Li electrode.Benefitting from the above merits,the solid-state LiFePO4/Li cell fabricated with the CSE membrane was practically charged and discharged at 30℃.The cell exhibits an initial reversible discharge specific capacity of 160 mAh g-1 with 97%capacity retention after 100 cycles at 0.2 C,and maintains discharge specific capacity of 126 mAh g-1 after500 cycles at 1 C.The CSE membrane prepared with Li-Nafion and LLZAO is proved to be a promising solid electrolyte for advanced solid-state Li metal batteries.展开更多
The garnet amphibolites from the newly identified Wanhe ophiolitic mélange in the Changning-Menglian suture zone(CMSZ)provide a probe to elucidate the evolution of the Triassic Palaeo-Tethys.An integrated petrolo...The garnet amphibolites from the newly identified Wanhe ophiolitic mélange in the Changning-Menglian suture zone(CMSZ)provide a probe to elucidate the evolution of the Triassic Palaeo-Tethys.An integrated petrologic,phase equilibria modeling and geochronological study of the garnet amphibolites,southeast Tibetan Plateau,shows that the garnet amphibolites have a peak mineral assemblage of garnet,glaucophane,lawsonite,chlorite,rutile,phengite and quartz,and a clockwise P-T path with a prograde segment from blueschist-facies to eclogite-facies with a peak-metamorphic P-T conditions of 2000–2100 MPa and 495–515℃,indicating a cold geothermal gradient of about 240–260℃/GPa.Theretrograde metamorphic P-T path is characterized by nearly isothermal decompression to lower amphibolite-facies and subsequent cooling to greenschist-facies.The metamorphic zircons have fractionated HREE patterns and significant negative Eu anomalies,and therefore the obtained zircon U-Pb age of 231±1.5 Ma is interpreted to be the timing of the amphibolite facies metamorphism occurrence.The present study probably indicates that the garnet amphibolites in the Wanhe ophiolitic mélange was the retrograded highpressure eclogite-facies blueschist,instead of the previously proposed eclogites,and the garnet amphibolites recorded the subduction and exhumation process of the Palaeo-Tethys Oceanic crust in the Triassic.展开更多
In No. 50 kimberlite pipe of Fuxian County, Liaoning Province, an eclogite inclusion(nodule), which is extremely rare in kimberlites, was discovered and phlogopite exsolutionlamellae were found in garnets of the inclu...In No. 50 kimberlite pipe of Fuxian County, Liaoning Province, an eclogite inclusion(nodule), which is extremely rare in kimberlites, was discovered and phlogopite exsolutionlamellae were found in garnets of the inclusion. Microscopic, TEM and energy spectral observa-tions and studies confirmed that these lamellae are phlogopite. They are colourless and acicularin section, generally 0.5-5μm in width and 10-100μm in length. Nevertheless, fine lamellae,0.05-0.1μm wide and 1-2μm long, are also well developed. Along [111] of the garnet, three setsof phlogopite lamellae show oriented arrangement approximately at angles of 60°-70°, indi-cating that these lamellae might be the product of exsolution from garnet as a result ofpressure-release when eclogite ascended from the relatively deep level to the relatively shallowlevel of the mantle. Tiny acicular exsolution minerals (or inclusions) are commonly found ingarnet and pyroxene in eclogite inclusions of kimberlites all over the world and it has been re-ported that the identified exsolution minerals include pyroxene and rutile. This is the first timethat phlogopite exsolution lamillae were found in eclogite inclusions in the world.展开更多
Here we report the occurrence of garnet porphyroblasts that have overgrown alternating silica-saturated and silica deficient microdomains via different mineral reactions. The samples were collected from ultrahigh-temp...Here we report the occurrence of garnet porphyroblasts that have overgrown alternating silica-saturated and silica deficient microdomains via different mineral reactions. The samples were collected from ultrahigh-temperature(UHT) metapelites in the Highland Complex, Sri Lanka. In some of the metapelites, garnet crystals have cores formed via a dehydration reaction, which had taken place at silicasaturated microdomains and mantle to rim areas formed via a dehydration reaction at silica-deficient microdomains. In contrast, some other garnets in the same rock cores had formed via a dehydration reaction which occurred at silica-deficient microdomains while mantle to rim areas formed via a dehydration reaction at silica-saturated microdomains. Based on the textural observations, we conclude that the studied garnets have grown across different effective bulk compositional microdomains during the prograde evolution. These microdomains could represent heterogeneous compositional layers(paleobedding/laminations) in the precursor sediments or differentiated crenulation cleavages that existed during prograde metamorphism. UHT metamorphism associated with strong ductile deformation, metamorphic differentiation and crystallization of locally produced melt may have obliterated the evidence for such microdomains in the matrix. The lack of significant compositional zoning in garnet probably due to self-diffusion during UHT metamorphism had left mineral inclusions as the sole evidence for earlier microdomains with contrasting chemistry.展开更多
The thermal structure of subduction zones exerts a major influence on deep-seated mechanical and chemical processes controlling arc magmatism, seismicity, and global element cycles. Accretionary complexes exposed inla...The thermal structure of subduction zones exerts a major influence on deep-seated mechanical and chemical processes controlling arc magmatism, seismicity, and global element cycles. Accretionary complexes exposed inland may comprise tectonic blocks with contrasting pressureetemperature(Pe T)histories, making it possible to investigate the dynamics and thermal evolution of former subduction interfaces. With this aim, we present new Lue Hf geochronological results for mafic rocks of the Halilbag?Complex(Anatolia) that evolved along different thermal gradients. Samples include a lawsoniteeepidote blueschist, a lawsoniteeepidote eclogite, and an epidote eclogite(all with counter-clockwise Pe T paths),a prograde lawsonite blueschist with a "hairpin"-type Pe T path, and a garnet amphibolite from the overlying sub-ophiolitic metamorphic sole. Equilibrium phase diagrams suggest that the garnet amphibolite formed at w0.6 -0.7 GPa and 800 -850℃, whereas the prograde lawsonite blueschist records burial from 2.1 GPa and 420℃ to 2.6 GPa and 520℃. Well-defined Lue Hf isochrons were obtained for the epidote eclogite(92.38 ± 0.22 Ma) and the lawsoniteeepidote blueschist(90.19 ± 0.54 Ma),suggesting rapid garnet growth. The lawsoniteeepidote eclogite(87.30 ± 0.39 Ma) and the prograde lawsonite blueschist(ca. 86 Ma) are younger, whereas the garnet amphibolite(104.5 ± 3.5 Ma) is older.Our data reveal a consistent trend of progressively decreasing geothermal gradient from granulite-facies conditions at ~104 Ma to the epidote-eclogite facies around 92 Ma, and the lawsonite blueschist-facies between 90 Ma and 86 Ma. Three Lue Hf garnet dates(between 92 Ma and 87 Ma) weighted toward the growth of post-peak rims(as indicated by Lu distribution in garnet) suggest that the HP/LT rocks were exhumed continuously and not episodically. We infer that HP/LT metamorphic rocks within the Halilbag?Complex were subjected to continuous return flow, with "warm" rocks being exhumed during the tectonic burial of "cold" ones. Our results, combined with regional geological constraints, allow us to speculate that subduction started at a transform fault near a mid-oceanic spreading centre. Following its formation, this ancient subduction interface evolved thermally over more than 15 Myr, most likely as a result of heat dissipation rather than crustal underplating.展开更多
Garnet is an important rock forming mineral of high pressure and ultrahigh pressure metamorphic rocks. Its popular isomorphism complicates its chemical composition and crystal structure. The selected area electron dif...Garnet is an important rock forming mineral of high pressure and ultrahigh pressure metamorphic rocks. Its popular isomorphism complicates its chemical composition and crystal structure. The selected area electron diffraction (SAED) and the high resolution electron microscopy (HREM) are used in this work to study the microstructures and ultrastructures of garnets in the jadeite quartzite from Dabie Mountains, China. The microstructures of the garnet occur mainly as free dislocations, dislocation walls, stacking faults, dislocation networks and sub grain boundaries. The dislocation density is ρ=n ×10 8/cm 2 ( n =1.7—7.5) and the deformation mechanism is the dislocation glide and dynamic recovery. The superstructures of the garnet crystal revealed by HREM occur mainly as dislocations, faults, domain structures and lattice deformations, indicating the strong stress during the formation of the jadeite quartzite.展开更多
The tectonic setting of Cretaceous granitoids in the southeastern Tibet Plateau,east of the Eastern Himalaya Syntax,is debated.Exploration and mining of the Laba Mo–Cu porphyry-type deposit in the area has revealed L...The tectonic setting of Cretaceous granitoids in the southeastern Tibet Plateau,east of the Eastern Himalaya Syntax,is debated.Exploration and mining of the Laba Mo–Cu porphyry-type deposit in the area has revealed Late Cretaceous granites.New and previously published zircon U–Pb dating indicate that the Laba granite crystallized at 89–85 Ma.Bulk-rock geochemistry,Sr–Nd isotopic data and in situ zircon Hf isotopic data indicate that the granite is adakitic and was formed by partial melting of thickened lower crust.The Ca,Fe,and Al contents decrease with increasing SiO2 content.These and other geochemical characteristics indicate that fractional crystallization of garnet under high-pressure conditions resulted in the adakitic nature of the Laba granite.Cretaceous granitoids are widespread throughout the Tibetan Plateau including its southeastern area,forming an intact curved belt along the southern margin of Eurasia.This belt is curved due to indenting by the Indian continent during Cenozoic,but strikes parallel to both the Indus–Yarlung suture zone and the Main Frontal Thrust belt.It is therefore likely that Cretaceous granitoids in both the Gangdese and southeastern Tibetan Plateau areas resulted from subduction of Neo-Tethyan lithosphere.展开更多
In order to obtain a safe,reliable,long-lived battery system without use of flammable,volatile,and relatively unstable organic liquid-based electrolytes,lithium garnet oxides with formulas Li_(7-x)La_3Zr_(2-x)Ta_xO_(1...In order to obtain a safe,reliable,long-lived battery system without use of flammable,volatile,and relatively unstable organic liquid-based electrolytes,lithium garnet oxides with formulas Li_(7-x)La_3Zr_(2-x)Ta_xO_(12)(x=0.2-1)were synthesized by the solid state reaction method.Single cubic phases were observed in the composition x range between 0.2 and 1.The lattice parameters decreased with the addition of Ta due to the smaller ionic radius of Ta^(5+)compared with that of Zr^(4+),following the Vegard’s law.The total conductivity of the x=0.3 composition is 6.03×10^(-5) S·cm^(-1)at room temperature with an activation energy of 0.30 eV.These lithium garnet oxides exhibit lithium ionic transport that is relevant to lithium battery application.展开更多
A lot of previous experimental studies on ultramafic rocks(SiO2 unsaturated system)(Ringwood and Major, 1971;Irifune et al., 1986;Gasparik, 1989;Ono and Yasuda, 1996) have demonstrated that characteristics of Si-rich ...A lot of previous experimental studies on ultramafic rocks(SiO2 unsaturated system)(Ringwood and Major, 1971;Irifune et al., 1986;Gasparik, 1989;Ono and Yasuda, 1996) have demonstrated that characteristics of Si-rich and Al-deficient in garnet are resulted from coupled substitution of SiⅥ+MⅥ=AlⅥ+AlⅥ and SiⅥ+NaⅧ=AlⅥ+MⅧ(M=Mg, Fe, Ca) at ultrahigh pressures(UHP)(>5 GPa). The degree of substitution will be enhanced by increasing pressure which has a positive correlation with the content of SiⅥ, but a negative correlation with the content of AlⅥ in supersilic garnet. These experimental results established a theoretical foundation for further understanding the formation mechanism of the exsolution of pyroxene in garnet observed in deep mantle xenoliths and some ultrahigh pressure rocks, and also for estimating the pressure conditions of the formation of supersilic garnet before exsolution(Haggerty and Sautter, 1990;Sautter et al., 1991;van Roermund et al., 1998;Ye et al., 2000). Although some experimental studies on SiO2 saturated system have been reported(Irifune et al., 1994;Ono., 1998;Dobrazhinetskya and Green.,2007;Wu et al., 2009), the stability conditions of supersilic garnet are still lack of unified understanding. Therefore, HP-HT experiments were carried out on felsic rocks under conditions of 6–12 GPa and 1000℃–1400℃. Combined with previous experimental data, we try to figure out the minimum stable pressure and geological significants of supersilic garnet in SiO2 saturated system. Our experimental results from SiO2 saturated system show the minimum stable pressure of supersilic garnet should be ≥10 GP of stishovite stability field. These results are similar as that from experiments using starting composition similar to average upper continental crust reported by Irifune et al(1994) who yielded that garnet gradually became supersilic and Al-deficient as pressures increased above 10 GPa, especially in a pressure interval between 13 and 18 GPa. Moreover, experiments with different starting materials(Ono, 1998;Dobrazhinetskya and Green, 2007;Wu et al. 2009) also indicate the stable pressure condition of supersilic garnet is mainly ≥9 –10 GPa in SiO2 saturated system if data of small-size grains at low temperature are ignored due to measuring errors. Thus, it can be concluded that the minimum stable pressure of supersilic garnet in SiO2 saturated system is distinctly different from that in SiO2 unsaturated ultramafic rock system. The minimum pressure of the former is ≥9–10 GPa of stishovite stability field, while that of the latter is >5 GPa. Therefore, whether independent SiO2 phase exist or rock system is SiO2 saturated must be taken into considered when estimating the peak pressure of exsolutions in supersilic garnet in UHP rocks. Furthermore, pressure of >5 GPa directly estimated by supersilic garnet based on conclusion from SiO2 unsaturation system rather than SiO2 saturation in previous sdudies may have been underestimated and need to be re-estimated. Supersilic garnets have been recognized by interior exsolutions of clinopyroxene in garnet pyroxene from Yinggelisayi South Altyn(Liu et al., 2005), and exsolutions of rodlike quartz+rutile in felsic gneiss from Songshugou North Qinling(Liu et al., 2003). According to the experimental results from SiO2 unsaturated system, the peak metamorphic pressure of the both SiO2 saturated rocks have been estimated to be >7 Gpa and >5 Gpa, respectively. However, combined with the new experimental results above, we re-estimated that the peak metamorphic pressure of these SiO2 saturated rocks should be≥9–10 GPa at least, implying an ultra-deep subduction to mantle depth of stishovite stability field. This research, together with previous findings(Liu et al., 2007, 2018), shows that continental subduction to mantle depth(300 km) of stishovite stability field and then exhumation to the surface is obviously more common than previously thought, and the rock types are also diverse. At the same time, it provides a new indicator and thought for recognizing the subduction to the mantle depth of stishovite stability field in UHP metamorphic belt.展开更多
The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety,high energy density and low cost.However,the poor ionic conductivity of solid electrolyte and lo...The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety,high energy density and low cost.However,the poor ionic conductivity of solid electrolyte and low interfacial stability has hindered the application of solid-state lithium battery.Here,a flexible polymer/garnet solid electrolyte is prepared with poly(ethylene oxide),poly(vinylidene fluoride),Li6.75La3 Zr1.75Ta0.25O12,lithium bis(trifluoromethanesulfonyl)imide and oxalate,which exhibits an ionic conductivity of 2.0 ×10^(-4) S cm^(-1) at 55℃,improved mechanical property,wide electrochemical window(4.8 V vs.Li/Li+),enhanced thermal stabilities.Tiny acidic OX was introduced to inhibit the alkalinity reactions between Li6.75La3 Zr1.75Ta0.25O12 and poly(vinylidene fluoride).In order to improve the interfacial stability between cathode and electrolyte,an Al2 O3@LiNi0.5Co0.2Mn0.3O2 based composite cathode framework is also fabricated with poly(ethylene oxide) polymer and lithium salt as additives.The solid-state lithium battery assembled with polymer/garnet solid electrolyte and composite cathode framework demonstrates a high initial discharge capacity of 150.6 mAh g^(-1) and good capacity retention of 86.7% after 80 cycles at 0.2 C and 55℃,which provides a promising choice for achieving the stable electrode/electrolyte interfacial contact in solid-state lithium batteries.展开更多
基金funded by The Central Government Guides Local Science and Technology Development Special Fund Projects(Grant No.YDZJSX2022B003)the Shanxi Province Science and Technology Major Projects(Grant No.202101120401008)。
文摘Garnet solid electrolytes are one of the most promising electrolytes for solid-state batteries.However,Li_(2)CO_(3) is a critical issue that hinders the practical application of garnet-based solid-state lithium-ion batteries.There are two sources of Li_(2)CO_(3) contamination.The main one is the aging of garnet electrolytes in the atmosphere.Garnet electrolytes can react with H_(2)O and CO_(2) in the air to form Li_(2)CO_(3),which reduces ion conductivity,increases electrode/garnet electrolyte interface resistance,and deteriorates the electrochemical performance of the battery.Various strategies,such as elemental doping,grain boundary manipulation,and interface engineering,have been suggested to address these issues.The other is the passivation layer(Li_(2)CO_(3),Li_3N,LiOH,Li_(2)O) formed on the surface of the lithium foil after long-term storage,which is ignored by most researchers.To better understand the current strategies and future trends to address the Li_(2)CO_(3) problem,this perspective provides a systematic review of journals published in this field from 2020-2023.
基金financially supported by the National Natural Science Foundation of China (52102323, 51972298)the China Postdoctoral Science Foundation (2021M703055)+1 种基金the National Key R&D Program of China (2021YFB4001401)the Key Research Program of the Chinese Academy of Sciences (ZDRWCN-2021-3-1)。
文摘Garnet-type Li_7La_(3)Zr_(2)O_(12)(LLZO) has high ionic conductivity and good compatibility with lithium metal.High-temperature processing has been proven an effective method to decrease the interface resistance of cathodeILLZO.However,its application is still hindered by the interlayer co-diffusion with the cathode and high sintering temperature(>1200℃).In this work,a new garnet-type composite solid-state electrolyte(SSE) Li_(6.54)La_(2.96)Ba_(0.04)Zr_(1.5)Nb_(0.5)O_(12)-LiCoO_(2)(LLBZNO-LCO) is firstly proposed to improve the chemical stability and electrochemical properties of garnet with high-temperature processing.Small doses of LCO(3%) can significantly decrease the LCOISSE interface resistance from 121.2 to 10.1 Ω cm~2,while the sintering temperature of garnet-type LLBZNO decreases from 1230 to 1000℃.The all-solid-state battery based on the sintered LLBZNO-LCO SSE exhibits excellent cycling stability.Our approach achieves an enhanced LCOISSE interface and an improved sintering activity of garnet SSE,which provides a new strategy for optimizing the comprehensive performance of garnet SSE.
基金financially supported by the National Natural Science Foundation of China(NSFC)(52172096)。
文摘Li(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO) solid garnet-type electrolyte has been widely reported due to its outstanding safety and electrochemical stability.However,the inherent rigidity and brittleness of LLZTO lead to poor contact with anode/cathode and the operation failure of full cells.Herein,the dual-interlayers are constructed as the fast interfacial ion-migration channel by using Ti_(3)C_(2)T_(x)(MXene,Txis-O,-OH,-F) with trace ionic liquid(IL),which promote the intimate contact between LLZTO and anode/cathode and suppress Li-dendrites growth.Notably,IL can wet the cathode to promote intimate interface contact and be decomposed into some inorganic compounds(such as Li3N,LiF,and Li2Sx),resulting in reduced interfacial resistance and fast Li-ion transportation.Consequently,in the prepared Li-symmetric cell,the interfacial resistance on the anode side plunges to 33.1 Ω cm^(-2),and stably maintains over 1000 h without short circuit at 0.05 mA cm^(-2).The full cell of Li|LiFePO4delivers a high initial capacity of 158.52 mA h g^(-1)and outstanding retention of 90.18% after 100 cycles at 60℃ and 0.2 C.Our work provides an efficient strategy to design dual-interlayers between LLZTO and anode/cathode for the interfacial modification to enhance the performance of solid garnet batteries.
基金support by the National Natural Science Foundation of China (Grant Nos. 52061135105 and 12074025)support by the National Natural Science Foundation of China (Grant Nos. 11974079, 12274083, and 12221004)the Shanghai Municipal Science and Technology Basic Research Project (Grant No. 22JC1400200)。
文摘Magnetic bubbles have again become a subject of significant attention following the experimental observation of topologically nontrivial magnetic skyrmions. In recent work, tailoring the shape of the bubbles is considered a key factor for their dynamics in spintronic devices. In addition to the reported circular, elliptical, and square bubbles, here we observe triangular bubble domains in bismuth-doped yttrium iron garnet(Bi-YIG) using Kerr microscopy. The bubble domains evolve from discrete circular to latticed triangular and hexagonal shapes. Further, the orientation of the triangular bubbles in the hexagonal lattices can be flipped by decreasing the magnetic field. The sixfold in-plane magnetic anisotropy of Bi-YIG(111) crystal, which is presumably the mechanism underlying the triangular shape of the bubbles, is measured as1179 erg/cm~3. The study of the morphologies of topologically trivial bubbles in YIG offers insight into nontrivial spin textures, which is appealing for future spintronic applications.
基金Engineering and Physical Sciences Research Council,Grant/Award Number:EP/S018204/1。
文摘Inorganic solid-state electrolytes(SSEs)are nonflammable alternatives to the commercial liquid-phase electrolytes.This enables the use of lithium(Li)metal as an anode,providing high-energy density and improved stability by avoiding unwanted liquid-phase chemical reactions.Among the different types of SSEs,the garnet-type electrolytes witness a rapid development and are considered as one of the top candidates to pair with Li metal due to their high ionic conductivity,thermal,and electrochemical stability.However,the large resistances at the interface between garnet-type electrolytes and cathode/anode are the major bottlenecks for delivering desirable electrochemical performances of all-solid-state batteries(SSBs).The electrolyte/anode interface also suffers from metallic dendrite formation,leading to rapid performance degradation.This is a fundamental material challenge due to the poor contact and wettability between garnet-type electrolytes with electrode materials.Here,we summarize and analyze the recent contributions in mitigating such materials challenges at the interface.Strategies used to address these challenges are divided into different categories with regard to their working principles.On one hand,progress has been made in the anode/garnet interface,such as the successful application of Li-alloy anode and different artificial interlayers,significantly improving interfacial performance.On the other hand,the desired cathode/garnet interface is still hard to reach due to the complex chemical and physical structure at the cathode.The common methods used are nanostructured cathode host and sintering additives for increasing the contact area.On the basis of this information,we present our views on the remaining challenges and future research of electrode/garnet interface.This review not only motivates the need for further understanding of the fundamentals,stability,and modifications of the garnet/electrode interfaces but also provides guidelines for the future design of the interface for SSB.
基金by a grant from the Xinjiang Geological Exploration Fund Project Management Center(Grant No.Y14-5-LQ05)。
文摘The Aqishan lead-zinc deposit,located in the Jueluotag metallogenic belt of eastern Tianshan,Xinjiang,Northwest China,has a stratiform occurrence in the marine volcanic tuff of the Yamansu Formation.The ore body has a typical double-layer structure,having a stratified,stratoid,lenticular upper part and a veined,stockwork-like lower part.The occurrence of the upper orebody is consistent with that of the volcanic tuff wall rock.The ore minerals are mainly chalcopyrite,pyrite,sphalerite,galena and magnetite,the altered minerals mainly being silicified,such as sericite,chlorite,epidote,garnet.The garnetized skarn,being stratiform and stratoid,is closely related to the upper part of the orebody.Geological observations show that the limestone in the ore-bearing Yamansu Formation is not marbleized and skarnized.Spatially,it is associated with the ferromanganese deposits in the marine volcanic rocks of the Yamansu Formation.These geological features reflect the likelihood that the Aqishan lead-zinc deposit is a hydrothermal exhalation sedimentary deposit.The results from the EPMA show that the garnet is mainly composed of grossular-andradite series,contents being in a range of 34.791-37.8%SiO_(2),32.493-34.274%CaO,8.454-27.275%FeO,0.012-15.293%Al_(2)O_(3),0.351-1.413%MnO,and lower values of 0.013-1.057%TiO_(2).The content of SiO_(2) vs.CaO and FeO vs.Al_(2)O_(3) has a significant positive correlation.The results of ICP-MS analysis for the garnet show that the REE pattern is oblique to right in general.The total amount of rare earth elements is relatively low,ΣREE=71.045-826.52 ppm,which is relatively enriched for LREE and depleted for HREE.LREE/HREE=8.66-4157.75,La_(N)/Yb_(N)=23.51-984.34,with obvious positive Eu and Ce anomalies(δEu=2.27-76.15,δCe=0.94-1.85).This result is similar to the REE characteristics of ore-bearing rhyolite volcanic rocks,showing that the garnet was formed in an oxidizing environment and affected by clear hydrothermal activity.The U-Pb isotopic dating of garnet by fs-LA-HR-ICP-MS gives an age of 316.3±4.4 Ma(MSWD=1.4),which is consistent with the formation time of the Yamansu Formation.According to the study of deposit characteristics and geochemical characteristics,this study concludes that the Aqishan lead-zinc deposit is a hydrothermal exhalation sedimentary deposit,the garnet being caused by hydrothermal exhalative sedimentation.
文摘The results of recent geothermobarometric and geochronological investigations of scarce eclogites of the NW Himalaya (Tso Morari (Ladakh), India and Kaghan Valley, Pakistan) have caused a major rethink of tectonometamorphic models for India\|Asia collision. Numerous petrologic studies have been undertaken on the age and origin of metamorphism in the Higher Himalayan Crystallines (HHC) and Lesser Himalaya formations (LH) and their relationship to granite magmatism and movements along the Main Central Thrust (MCT) and South Tibetan Detachment Fault (STDF). However, all of these events are essentially Miocene (or younger) in age and can clearly be distinguished from subduction and exhumation processes undergone by the eclogites which are of Eocene age (Tonarini et al. 1993; Spencer & Gebauer; 1996; de Sigoyer et al. 1999) and relate to the very early stages of the collision. Eclogites of eastern Ladakh are mafic lenses found in granitic gneisses (Ordovician intrusive age: Girard & Bussy 1999) and their surrounding late Pre\|Cambrian to early Cambrian sedimentary units in the Tso Morari dome (see Steck et al. 1998). Detailed petrological and geochronological studies (Guillot et al. 1997; de Sigoyer et al. 1997, 1999) have identified an eclogite facies stage (2000±300)MPa, (580±60)℃ followed by isothermal decompression associated with glaucophane growth at around (1100±200)MPa. Dating of different phases by different methods yielded ages around 55Ma for this stage ((55±17) Ma, U\|Pb, Aln; (55±12) Ma, Lu\|Hf, Grt\|Cpx\|Rt; (55±7) Ma, Sm\|Nd, Grt\|Gln\|Rt). A subsequent amphibolite facies overprint at slightly higher temperature (610±70)℃ was dated at 45～48Ma (metabasite: (47±11) Ma, Sm\|Nd, Grt\|Hbl; metapelite: (45±4) Ma, Rb\|Sr, Mu\|Ap\|WR and (48±2) Ma, Ar\|Ar, Phe). By (30±1) Ma (Ar\|Ar, Bt\|Mu) retrogression into the greenschist facies had occurred (de Sigoyer et al. 1999). These data indicate a two stage history with early exhumation being much faster (>4mm/a) than the later evolution (1～2mm/a).
基金The project is supported by National Nature Science Fountation of China No.48900015
文摘Eclogitic garnet-amphibole rocks are scattered around the Songshugou ultramafic bodies in QinlingMountains.Three metamorphic stages are recognized in terms of petrography,mineral chemistry andgeothermobarometry.The first albite-amphibole stage was of greenschist facies metamorphism with typicalmineral assemblage of actinolite+epidote+chlorite+albite;the pressure and temperature conditions wereequal to or lower than500MPa and about400℃.The second prograde eclogitic garnet-amphibole stagewas of amphibole-eclogite facies metamorphism with typical mineral assemblage of garnet+hornblende±clinopyroxene+rutile without phagioclase,the pressure condition was at least1000 -1200MPa and the temper-ature about600℃.The third retrograde epidote-amphibole stage was of epidote-amphibolite facies withassemblage of plagoclase+hornblende+epidote+ilmenite/titanite,the temperature was500-600℃andthe pressure from 800MPa down to500MPa.All three stages took place in one single tectonothermal eventcalled Jimingian movement
文摘Tetraethylenepentamine(C8H23N5,TEPA) has been used as a novel precipitant to synthesize yttrium aluminum garnet(Y3Al5O12,YAG) precursor from a mixed solution of aluminum and yttrium nitrates via a normal-strike co-precipitation method without controlling the pH value during precipitation process.The original precursor was analyzed by thermogravimetry/differential scanning calorimetry(TG/DSC).The evolution of phase composition and micro-structure of the as-synthesized YAG powders were characterized by X-ray diffraction(XRD),Fourier transform infrared(FT-IR) spectroscopy and transmission electron microscopy(TEM).Compositionally pure YAG nanostructured powders were directly obtained by calcination of the precursor at 900 ℃ without the formation of any intermediate phases.The average particle size determined from TEM micrograph for the powder obtained at 1000 ℃ was approximately 50 nm.
基金supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (XDB 18010401)the 1000Plan Program for Young Talents and Hundred Talent Program of CASNSF of China (41303048)
文摘With improvements on high-pressure experimental techniques in multi-anvil apparatus and the development of new analytical tools, major progress has been made on diffusion in garnets in the past several decades. The data obtained in the experimental determination of diffusion coefficients in garnets are of fundamental importance for diffusion modeling and timescales of geological and planetary processes. In this review, we have compiled experimental data on self-diffusion(Si, O, cations), trace element diffusion(Li, Y, Ga, Cr, Sr, REEs), and interdiffusion(Ca–Fe/Mg, Si–Al) in garnet in the light of new advances and recent applications. In addition, some empirical relationships among diffusion parameters(pre-exponential factor D_0,activation energy E, ionic radius) are also discussed. We hope that this review can provide a useful data digest and guide to future study of diffusion in garnet.
基金financially supported by the National Key R&D Program of China(Grant no.2016YFB0100100)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDA17020404)+2 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDA09010203)R&D Projects in Key Areas of Guangdong Province(Grant no.2019B090908001)DICP&QIBEBT(Grant no.DICP&QIBEBT UN201702)。
文摘Single-ion conducting solid polymer electrolytes are expected to play a vital role in the realization of solid-state Li metal batteries.In this work,a lithiated Nafion(Li-Nafion)-garnet ceramic Li6.25La3 Zr2 Al0.25O12(LLZAO)composite solid electrolyte(CSE)membrane with 30μm thickness was prepared for the first time.By employing X-ray photoelectron spectroscopy and transmission electron microscope,the interaction between LLZAO and Li-Nafion was investigated.It is found that the LLZAO interacts with the Li-Nafion to form a space charge layer at the interface between LLZAO and Li-Nafion.The space charge layer reduces the migration barrier of Li-ions and improves the ionic conductivity of the CSE membrane.The CSE membrane containing 10 wt%LLZAO exhibits the highest ionic conductivity of2.26×10-4 S cm-1 at 30℃among the pristine Li-Nafion membrane,the membrane containing 5 wt%,20 wt%,and 30 wt%LLZAO,respectively.It also exhibits a high Li-ion transference number of 0.92,and a broader electrochemical window of 0-+4.8 V vs.Li+/Li than that of 0-+4.0 V vs.Li+/Li for the pristine Li-Nafion membrane.It is observed that the CSE membrane not only inhibits the growth of Li dendrites but also keeps excellent electrochemical stability with the Li electrode.Benefitting from the above merits,the solid-state LiFePO4/Li cell fabricated with the CSE membrane was practically charged and discharged at 30℃.The cell exhibits an initial reversible discharge specific capacity of 160 mAh g-1 with 97%capacity retention after 100 cycles at 0.2 C,and maintains discharge specific capacity of 126 mAh g-1 after500 cycles at 1 C.The CSE membrane prepared with Li-Nafion and LLZAO is proved to be a promising solid electrolyte for advanced solid-state Li metal batteries.
基金supported by the National Natural Science Foundation of China(41802071,41773026 and 41303028)the Geological Survey of China-Nepal railway(202008000000180117).
文摘The garnet amphibolites from the newly identified Wanhe ophiolitic mélange in the Changning-Menglian suture zone(CMSZ)provide a probe to elucidate the evolution of the Triassic Palaeo-Tethys.An integrated petrologic,phase equilibria modeling and geochronological study of the garnet amphibolites,southeast Tibetan Plateau,shows that the garnet amphibolites have a peak mineral assemblage of garnet,glaucophane,lawsonite,chlorite,rutile,phengite and quartz,and a clockwise P-T path with a prograde segment from blueschist-facies to eclogite-facies with a peak-metamorphic P-T conditions of 2000–2100 MPa and 495–515℃,indicating a cold geothermal gradient of about 240–260℃/GPa.Theretrograde metamorphic P-T path is characterized by nearly isothermal decompression to lower amphibolite-facies and subsequent cooling to greenschist-facies.The metamorphic zircons have fractionated HREE patterns and significant negative Eu anomalies,and therefore the obtained zircon U-Pb age of 231±1.5 Ma is interpreted to be the timing of the amphibolite facies metamorphism occurrence.The present study probably indicates that the garnet amphibolites in the Wanhe ophiolitic mélange was the retrograded highpressure eclogite-facies blueschist,instead of the previously proposed eclogites,and the garnet amphibolites recorded the subduction and exhumation process of the Palaeo-Tethys Oceanic crust in the Triassic.
文摘In No. 50 kimberlite pipe of Fuxian County, Liaoning Province, an eclogite inclusion(nodule), which is extremely rare in kimberlites, was discovered and phlogopite exsolutionlamellae were found in garnets of the inclusion. Microscopic, TEM and energy spectral observa-tions and studies confirmed that these lamellae are phlogopite. They are colourless and acicularin section, generally 0.5-5μm in width and 10-100μm in length. Nevertheless, fine lamellae,0.05-0.1μm wide and 1-2μm long, are also well developed. Along [111] of the garnet, three setsof phlogopite lamellae show oriented arrangement approximately at angles of 60°-70°, indi-cating that these lamellae might be the product of exsolution from garnet as a result ofpressure-release when eclogite ascended from the relatively deep level to the relatively shallowlevel of the mantle. Tiny acicular exsolution minerals (or inclusions) are commonly found ingarnet and pyroxene in eclogite inclusions of kimberlites all over the world and it has been re-ported that the identified exsolution minerals include pyroxene and rutile. This is the first timethat phlogopite exsolution lamillae were found in eclogite inclusions in the world.
基金the National Research Council(NRC) of Sri Lanka(Grant Nos. 11-180 and 15-089)the Indo-Lanka Joint Grant from the Ministry of Technology and Research,Sri Lanka (MTR/TRD/AGR/3/1/04) for funding this projectsupport by the Stichting Dr Schurmannfonds, Grant Nos. 88/2012, 94/2013 and 101/2014
文摘Here we report the occurrence of garnet porphyroblasts that have overgrown alternating silica-saturated and silica deficient microdomains via different mineral reactions. The samples were collected from ultrahigh-temperature(UHT) metapelites in the Highland Complex, Sri Lanka. In some of the metapelites, garnet crystals have cores formed via a dehydration reaction, which had taken place at silicasaturated microdomains and mantle to rim areas formed via a dehydration reaction at silica-deficient microdomains. In contrast, some other garnets in the same rock cores had formed via a dehydration reaction which occurred at silica-deficient microdomains while mantle to rim areas formed via a dehydration reaction at silica-saturated microdomains. Based on the textural observations, we conclude that the studied garnets have grown across different effective bulk compositional microdomains during the prograde evolution. These microdomains could represent heterogeneous compositional layers(paleobedding/laminations) in the precursor sediments or differentiated crenulation cleavages that existed during prograde metamorphism. UHT metamorphism associated with strong ductile deformation, metamorphic differentiation and crystallization of locally produced melt may have obliterated the evidence for such microdomains in the matrix. The lack of significant compositional zoning in garnet probably due to self-diffusion during UHT metamorphism had left mineral inclusions as the sole evidence for earlier microdomains with contrasting chemistry.
基金Funding by the Deutsche Forschungsgemeinschaft (projectPO17-91)
文摘The thermal structure of subduction zones exerts a major influence on deep-seated mechanical and chemical processes controlling arc magmatism, seismicity, and global element cycles. Accretionary complexes exposed inland may comprise tectonic blocks with contrasting pressureetemperature(Pe T)histories, making it possible to investigate the dynamics and thermal evolution of former subduction interfaces. With this aim, we present new Lue Hf geochronological results for mafic rocks of the Halilbag?Complex(Anatolia) that evolved along different thermal gradients. Samples include a lawsoniteeepidote blueschist, a lawsoniteeepidote eclogite, and an epidote eclogite(all with counter-clockwise Pe T paths),a prograde lawsonite blueschist with a "hairpin"-type Pe T path, and a garnet amphibolite from the overlying sub-ophiolitic metamorphic sole. Equilibrium phase diagrams suggest that the garnet amphibolite formed at w0.6 -0.7 GPa and 800 -850℃, whereas the prograde lawsonite blueschist records burial from 2.1 GPa and 420℃ to 2.6 GPa and 520℃. Well-defined Lue Hf isochrons were obtained for the epidote eclogite(92.38 ± 0.22 Ma) and the lawsoniteeepidote blueschist(90.19 ± 0.54 Ma),suggesting rapid garnet growth. The lawsoniteeepidote eclogite(87.30 ± 0.39 Ma) and the prograde lawsonite blueschist(ca. 86 Ma) are younger, whereas the garnet amphibolite(104.5 ± 3.5 Ma) is older.Our data reveal a consistent trend of progressively decreasing geothermal gradient from granulite-facies conditions at ~104 Ma to the epidote-eclogite facies around 92 Ma, and the lawsonite blueschist-facies between 90 Ma and 86 Ma. Three Lue Hf garnet dates(between 92 Ma and 87 Ma) weighted toward the growth of post-peak rims(as indicated by Lu distribution in garnet) suggest that the HP/LT rocks were exhumed continuously and not episodically. We infer that HP/LT metamorphic rocks within the Halilbag?Complex were subjected to continuous return flow, with "warm" rocks being exhumed during the tectonic burial of "cold" ones. Our results, combined with regional geological constraints, allow us to speculate that subduction started at a transform fault near a mid-oceanic spreading centre. Following its formation, this ancient subduction interface evolved thermally over more than 15 Myr, most likely as a result of heat dissipation rather than crustal underplating.
基金This paperis supported by the National Natural Science Foundation of China( No.49872 0 69)
文摘Garnet is an important rock forming mineral of high pressure and ultrahigh pressure metamorphic rocks. Its popular isomorphism complicates its chemical composition and crystal structure. The selected area electron diffraction (SAED) and the high resolution electron microscopy (HREM) are used in this work to study the microstructures and ultrastructures of garnets in the jadeite quartzite from Dabie Mountains, China. The microstructures of the garnet occur mainly as free dislocations, dislocation walls, stacking faults, dislocation networks and sub grain boundaries. The dislocation density is ρ=n ×10 8/cm 2 ( n =1.7—7.5) and the deformation mechanism is the dislocation glide and dynamic recovery. The superstructures of the garnet crystal revealed by HREM occur mainly as dislocations, faults, domain structures and lattice deformations, indicating the strong stress during the formation of the jadeite quartzite.
基金supported by the State Key Research Development Program of China[grant number 2015CB452601]the National Natural Science Foundation of China[grant number 41373049,40772067]
文摘The tectonic setting of Cretaceous granitoids in the southeastern Tibet Plateau,east of the Eastern Himalaya Syntax,is debated.Exploration and mining of the Laba Mo–Cu porphyry-type deposit in the area has revealed Late Cretaceous granites.New and previously published zircon U–Pb dating indicate that the Laba granite crystallized at 89–85 Ma.Bulk-rock geochemistry,Sr–Nd isotopic data and in situ zircon Hf isotopic data indicate that the granite is adakitic and was formed by partial melting of thickened lower crust.The Ca,Fe,and Al contents decrease with increasing SiO2 content.These and other geochemical characteristics indicate that fractional crystallization of garnet under high-pressure conditions resulted in the adakitic nature of the Laba granite.Cretaceous granitoids are widespread throughout the Tibetan Plateau including its southeastern area,forming an intact curved belt along the southern margin of Eurasia.This belt is curved due to indenting by the Indian continent during Cenozoic,but strikes parallel to both the Indus–Yarlung suture zone and the Main Frontal Thrust belt.It is therefore likely that Cretaceous granitoids in both the Gangdese and southeastern Tibetan Plateau areas resulted from subduction of Neo-Tethyan lithosphere.
基金Funded by the National Natural Science Foundation of China(No.21276284)the Hunan Provincial Natural Science Foundation of China(2015JJ3074)+1 种基金the Science and Technology Project of Changsha(KL403147-11)the Postdoctoral Fund of Hunan Agricultural University(129263)
文摘In order to obtain a safe,reliable,long-lived battery system without use of flammable,volatile,and relatively unstable organic liquid-based electrolytes,lithium garnet oxides with formulas Li_(7-x)La_3Zr_(2-x)Ta_xO_(12)(x=0.2-1)were synthesized by the solid state reaction method.Single cubic phases were observed in the composition x range between 0.2 and 1.The lattice parameters decreased with the addition of Ta due to the smaller ionic radius of Ta^(5+)compared with that of Zr^(4+),following the Vegard’s law.The total conductivity of the x=0.3 composition is 6.03×10^(-5) S·cm^(-1)at room temperature with an activation energy of 0.30 eV.These lithium garnet oxides exhibit lithium ionic transport that is relevant to lithium battery application.
基金granted by the National Natural Science Foundation of China(Grant Nos.41430209)the Chinese Ministry of Science and Technology(Grant No.2015CB856100)the MOST Special Fund from the State Key Laboratory of Continental Dynamics(Grant No.201210133)
文摘A lot of previous experimental studies on ultramafic rocks(SiO2 unsaturated system)(Ringwood and Major, 1971;Irifune et al., 1986;Gasparik, 1989;Ono and Yasuda, 1996) have demonstrated that characteristics of Si-rich and Al-deficient in garnet are resulted from coupled substitution of SiⅥ+MⅥ=AlⅥ+AlⅥ and SiⅥ+NaⅧ=AlⅥ+MⅧ(M=Mg, Fe, Ca) at ultrahigh pressures(UHP)(>5 GPa). The degree of substitution will be enhanced by increasing pressure which has a positive correlation with the content of SiⅥ, but a negative correlation with the content of AlⅥ in supersilic garnet. These experimental results established a theoretical foundation for further understanding the formation mechanism of the exsolution of pyroxene in garnet observed in deep mantle xenoliths and some ultrahigh pressure rocks, and also for estimating the pressure conditions of the formation of supersilic garnet before exsolution(Haggerty and Sautter, 1990;Sautter et al., 1991;van Roermund et al., 1998;Ye et al., 2000). Although some experimental studies on SiO2 saturated system have been reported(Irifune et al., 1994;Ono., 1998;Dobrazhinetskya and Green.,2007;Wu et al., 2009), the stability conditions of supersilic garnet are still lack of unified understanding. Therefore, HP-HT experiments were carried out on felsic rocks under conditions of 6–12 GPa and 1000℃–1400℃. Combined with previous experimental data, we try to figure out the minimum stable pressure and geological significants of supersilic garnet in SiO2 saturated system. Our experimental results from SiO2 saturated system show the minimum stable pressure of supersilic garnet should be ≥10 GP of stishovite stability field. These results are similar as that from experiments using starting composition similar to average upper continental crust reported by Irifune et al(1994) who yielded that garnet gradually became supersilic and Al-deficient as pressures increased above 10 GPa, especially in a pressure interval between 13 and 18 GPa. Moreover, experiments with different starting materials(Ono, 1998;Dobrazhinetskya and Green, 2007;Wu et al. 2009) also indicate the stable pressure condition of supersilic garnet is mainly ≥9 –10 GPa in SiO2 saturated system if data of small-size grains at low temperature are ignored due to measuring errors. Thus, it can be concluded that the minimum stable pressure of supersilic garnet in SiO2 saturated system is distinctly different from that in SiO2 unsaturated ultramafic rock system. The minimum pressure of the former is ≥9–10 GPa of stishovite stability field, while that of the latter is >5 GPa. Therefore, whether independent SiO2 phase exist or rock system is SiO2 saturated must be taken into considered when estimating the peak pressure of exsolutions in supersilic garnet in UHP rocks. Furthermore, pressure of >5 GPa directly estimated by supersilic garnet based on conclusion from SiO2 unsaturation system rather than SiO2 saturation in previous sdudies may have been underestimated and need to be re-estimated. Supersilic garnets have been recognized by interior exsolutions of clinopyroxene in garnet pyroxene from Yinggelisayi South Altyn(Liu et al., 2005), and exsolutions of rodlike quartz+rutile in felsic gneiss from Songshugou North Qinling(Liu et al., 2003). According to the experimental results from SiO2 unsaturated system, the peak metamorphic pressure of the both SiO2 saturated rocks have been estimated to be >7 Gpa and >5 Gpa, respectively. However, combined with the new experimental results above, we re-estimated that the peak metamorphic pressure of these SiO2 saturated rocks should be≥9–10 GPa at least, implying an ultra-deep subduction to mantle depth of stishovite stability field. This research, together with previous findings(Liu et al., 2007, 2018), shows that continental subduction to mantle depth(300 km) of stishovite stability field and then exhumation to the surface is obviously more common than previously thought, and the rock types are also diverse. At the same time, it provides a new indicator and thought for recognizing the subduction to the mantle depth of stishovite stability field in UHP metamorphic belt.
基金Financial supports from the National Natural Science Foundation of China (51575030, 51532002 and 51872027)Beijing Natural Science Foundation (L172023)National Basic Research Program of China (2017YFE0113500)。
文摘The solid-state lithium battery is considered as an ideal next-generation energy storage device owing to its high safety,high energy density and low cost.However,the poor ionic conductivity of solid electrolyte and low interfacial stability has hindered the application of solid-state lithium battery.Here,a flexible polymer/garnet solid electrolyte is prepared with poly(ethylene oxide),poly(vinylidene fluoride),Li6.75La3 Zr1.75Ta0.25O12,lithium bis(trifluoromethanesulfonyl)imide and oxalate,which exhibits an ionic conductivity of 2.0 ×10^(-4) S cm^(-1) at 55℃,improved mechanical property,wide electrochemical window(4.8 V vs.Li/Li+),enhanced thermal stabilities.Tiny acidic OX was introduced to inhibit the alkalinity reactions between Li6.75La3 Zr1.75Ta0.25O12 and poly(vinylidene fluoride).In order to improve the interfacial stability between cathode and electrolyte,an Al2 O3@LiNi0.5Co0.2Mn0.3O2 based composite cathode framework is also fabricated with poly(ethylene oxide) polymer and lithium salt as additives.The solid-state lithium battery assembled with polymer/garnet solid electrolyte and composite cathode framework demonstrates a high initial discharge capacity of 150.6 mAh g^(-1) and good capacity retention of 86.7% after 80 cycles at 0.2 C and 55℃,which provides a promising choice for achieving the stable electrode/electrolyte interfacial contact in solid-state lithium batteries.
