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Sophisticated infrared detection technology, operating through atmospheric transmission windows (usually between 3 and 5 μm and 8–13 μm), can detect an object by capturing its emitted thermal radiation, posing a threat to the survival of targeted objects. As per Wien’s displacement law, the shift of peak wavelength towards shorter wavelengths as blackbody temperature rises, underscores the significance of the 3–5 μm range for ultra-high temperature objects (e.g., at 400 °C), emphasizing the crucial need to control this radiation for the objects’ viability. Additionally, effective heat management is essential for ensuring the consistent operation of these ultrahot entities. In this study, based on a database with high-temperature resist materials, we introduced a material-informatics-based framework aimed at achieving the inverse design of simultaneous thermal camouflage (low emittance in the 3–5 μm range) and radiative cooling (high emittance in the non-atmospheric window 5–8 μm range) tailored for ultrahigh-temperature objects. Utilizing the transfer matrix method to calculate spectral properties and employing the particle swarm optimization algorithm, two optimized multilayer structures with desired spectral characteristics are obtained. The resulted structures demonstrate effective infrared camouflage at temperatures up to 250 °C and 500 °C, achieving reductions of 86.7 % and 63.7 % in the infrared signal, respectively. At equivalent heating power densities applied to the structure and aluminum, structure 1 demonstrates a temperature reduction of 29.4 °C at 0.75 W/cm , while structure 2 attains a temperature reduction of 57.5 °C at 1.50 W/cm compared to aluminum, showcasing enhanced radiative cooling effects. This approach paves the way for attenuating infrared signals from ultrahigh-temperature objects and effectively managing their thermal conditions.

The Paleoproterozoic Bakhuis Granulite Belt (BGB) in Surinam, South America, shows ultrahigh-temperature metamorphism (UHTM) at temperatures of around 1000 °C which, unusually, produced peak-to-near-peak cordierite with sillimanite and, in some cases, Al-rich orthopyroxene on a regional scale. Mg-rich cordierite (Mg/(Mg + Fe) = 0.88) in a sillimanite-bearing metapelitic granulite has a maximum birefringence of second-order blue (ca. 0.020) indicative of a considerable amount of CO 2 (> 2 wt%) within its structural channels. SIMS microanalysis confirms the presence of 2.57 ± 0.19 wt% CO 2 , the highest CO 2 concentration found in natural cordierite. This high CO 2 content has enabled the stability of cordierite to extend into UHT conditions at high pressures and very low to negligible H 2 O activity. Based on a modified calibration of the H 2 O–CO 2 incorporation model of Harley et al. (J Metamorph Geol 20:71–86, 2002), this cordierite occupies a stability field that extends from 8.8 ± 0.6 kbar at 750 °C to 11.3 ± 0.65 kbar at 1050 °C. Volatile-saturated cordierite with 2.57 wt% CO 2 and negligible H 2 O (0.04 wt%) indicates fluid-present carbonic conditions with a CO 2 activity near 1.0 at peak or near-peak pressures of 10.5–11.3 kbar under UHT temperatures of 950–1050 °C. The measured H 2 O content of the cordierite in the metapelite is far too low to be consistent with partial melting at 1000–1050 °C, implying either that nearly all of any H 2 O originally in this cordierite under UHT conditions was lost during post-peak cooling or that the cordierite was formed after migmatization. The high level of CO 2 required to ensure fluid saturation of the c. 11 kbar UHT cordierite is proposed to have been derived from an external, possibly mantle, source.

This contribution evaluates the relation between protracted zircon geochronological signal and protracted crustal melting in the course of polyphase high to ultrahigh temperature (UHT; T > 900 °C) granulite facies metamorphism. New U–Pb, oxygen isotope, trace element, ion imaging and cathodoluminescence (CL) imaging data in zircon are reported from five samples from Rogaland, South Norway. The data reveal that the spread of apparent age captured by zircon, between 1040 and 930 Ma, results both from open-system growth and closed-system post-crystallization disturbance. Post-crystallization disturbance is evidenced by inverse age zoning induced by solid-state recrystallization of metamict cores that received an alpha dose above 35 × 1017 α g−1. Zircon neocrystallization is documented by CL-dark domains displaying O isotope open-system behaviour. In UHT samples, O isotopic ratios are homogenous (δ18O = 8.91 ± 0.08‰), pointing to high-temperature diffusion. Scanning ion imaging of these CL-dark domains did not reveal unsupported radiogenic Pb. The continuous geochronological signal retrieved from the CL-dark zircon in UHT samples is similar to that of monazite for the two recognized metamorphic phases (M1: 1040–990 Ma; M2: 940–930 Ma). A specific zircon-forming event is identified in the orthopyroxene and UHT zone with a probability peak at ca. 975 Ma, lasting until ca. 955 Ma. Coupling U–Pb geochronology and Ti-in-zircon thermometry provides firm evidence of protracted melting lasting up to 110 My (1040–930 Ma) in the UHT zone, 85 My (ca. 1040–955 Ma) in the orthopyroxene zone and some 40 My (ca. 1040–1000 Ma) in the regional basement. These results demonstrate the persistence of melt over long timescales in the crust, punctuated by two UHT incursions.

Zircon as a multi-objective typomorphic mineral commonly contains diverse trace elements with specific petrogenetic significances. The Hf abundance in zircon is sensitively indicative of melt fractionation during zircon growth on one hand, and on another, the Ti content is a robust temperature sensor of zircon crystallization and has been effectively utilized in thermometric estimation. A Hf-Ti negative correlation was previously reported in igneous zircons, and thus a potential Hf thermometry was then speculated. In this work, we performed reliable electron microprobe (EMP) measurements of Hf and Ti in ultrahigh temperature (UHT) zircons from the North China Craton, in optimizing point, line and grid analysis. The EMP contents of Hf and Ti both show a wide range of fluctuation owing to the smaller probe spot, and some of them are higher than the LA-ICPMS data. The Hf-Ti correlation in UHT zircons displays dual and thus complicated patterns in contrast with the previous consideration, which implicates some other factors controlling the geochemical behaviors of Hf and Ti in zircons. Generally, the estimated Ti temperatures based on the EMP analyses are obviously higher than the LA-ICPMS outcomes, but are well consistent with the actual peak condition of the parent rock. It explains the common underestimation of Ti temperatures in high-temperature metamorphic rocks, by using LA-ICPMS analyses.

Despite their immense potential for next‐generation energy storage, the practical implementation of temperature‐tolerant lithium metal batteries (LMBs) under extreme thermal conditions continues to face formidable challenges. In this study, an ultrahigh‐temperature‐tolerance polymer‐based electrolyte (UPE) prototype with a low‐entropy‐penalty effect is proposed. This electrolyte features a carefully engineered molecular configuration that enables stable operation of polymer‐based LMBs across a broad temperature range (25–150 °C). Comprehensive experimental and theoretical analyses confirm that the unique “ester‐ether‐fluorinated segment” architecture enables the formation of a robust coordination framework through Li⁺‐multivalent ether/ester interactions and effective Li+‐ether strong‐solvent‐cage decoupling. The resulting polymer electrolyte integrates reactive carboxyl groups, alkali‐metal‐soluble ether moieties, and fluorinated segments that provide inert yet efficient ion conduction pathways. This synergistic configuration achieves high ionic conductivity, significantly improved lithium‐ion transference numbers, and excellent interfacial compatibility with lithium metal. This work presents a molecular‐level polymer design framework, providing a compelling direction for the development of high‐performance, thermally stable lithium‐metal batteries. An innovative molecular‐level strategy is employed to engineer an advanced ultrahigh‐temperature‐tolerant polymer‐based electrolyte (UPE) through rational polymer structural design (up to 150 °C). By synergistically incorporating reactive carboxyl groups, ether electrolytes, and fluorinated molecular segments, Li metal pouch cells with UPE can achieve stable cycling under ultrahigh temperature conditions (120 °C).

Carbide ultrahigh‐temperature ceramics (UHTCs) exhibit high melting points and are regarded as promising candidate materials for applications in ultrahigh‐temperature conditions, such as high‐speed flight vehicles. However, a high melting point alone is inadequate because thermal shock is typically associated with intense shear and oxidation, which require carbide UHTCs to not only have elevated temperature resistance but also robust structural stability. Herein, we present a reduced graphene oxide (rGO)‐reinforced (HfZrTi)C medium‐entropy ceramic (HZTMEC) that maintains structural integrity under thermal shock up to 2400°C and forms a dense and flat oxide layer. Notably, the addition of rGO induced a hierarchical strain modification spanning multiple length scales. At the microscale, rGO doping enhances atomic strain, refines grain size, and expands the distribution of high‐strain regions, increasing dislocation density and hindering dislocation movement. At the mesoscale, the oxidation and volatilization of rGO during ablation create strip‐shaped micropores in the oxide layer, dispersing the transformation stress and thermal stress generated by thermal shock. Therefore, long‐term thermal stability without fracture over 2400°C was achieved in UHTCs. This study provides a valuable strategy for balancing ultrahigh‐temperature ablation resistance and structural stability. A novel strategy is developed by doping reduced graphene oxide (rGO) into a (HfZrTi)C medium‐entropy ceramic. This induces a hierarchical strain modification mechanism, synergistically inhibiting crack propagation at the microscale and dissipating stress at the mesoscale. The resulting composite maintains structural integrity under thermal‐mechanical‐oxygen coupling ablation, showing great potential for long‐term service up to 2400°C.

The peak temperature and timescale of ultrahigh-temperature (UHT) metamorphism are significant for understanding its thermal budget and geodynamic evolution. The spinel-bearing (sapphirine-absent) UHT granulite at the Xuwujia area in the Jining complex, North China Craton was revealed to have undergone a metamorphic evolution that involves the pre-Tmax (maximum temperature) heating decompression to the Tmax stage with an extreme temperature of ~1125 °C, the post-Tmax cooling to the fluid-absent solidus (~860 °C) at 0.8–0.9 GPa, and sub-solidus decompression. The Tmax condition was recorded by the inferred feldspar-absent peak assemblage of spinel ± garnet. The post-Tmax cooling evolution was indicated by the sequential appearances of plagioclase, K-feldspar, sillimanite and biotite, as well as the core-to-rim ascending grossular component in garnet. Moreover, some texturally zoned spinel has exsolved lamellae of magnetite in the core and shows rim-ward increase of Mg and Al, which suggests a temperature decrease from >1100 °C in local domains isolated from quartz. Spinel with exsolved magnetite lamellae or low Al/(Al + Fe3+) is therefore proposed as an indicator for UHT conditions in metapelites. Probability simulation on the collected zircon ages yields a timescale of ~40 Myr (95% confidence; during 1.90–1.94 Ga) for the supra-solidus cooling stage of the UHT metamorphism in the Jining complex. This extreme UHT metamorphism has reached the rock’s dry solidus (~1125 °C) and undergone slow cooling, which is interpreted to result from a post-orogenic plume activity with sufficient advective heating from hyperthermal mafic intrusions.

We report on an ultrarapid (6 s) consolidation of binder-less WC using a novel Ultrahigh temperature Flash Sintering (UFS) approach. The UFS technique bridges the gap between electric resistance sintering (≪1 s) and flash spark plasma sintering (20–60 s). Compared to the well-established spark plasma sintering, the proposed approach results in improved energy efficiency with massive energy and time savings while maintaining a comparable relative density (94.6%) and Vickers hardness of 2124 HV. The novelty of this work relies on (i) multiple steps current discharge profile to suit the rapid change of electrical conductivity experienced by the sintering powder, (ii) upgraded low thermal inertia CFC dies and (iii) ultra-high consolidation temperature approaching 2750 °C. Compared to SPS process, the UFS process is highly energy efficient (≈200 times faster and it consumes ≈95% less energy) and it holds the promise of energy efficient and ultrafast consolidation of several conductive refractory compounds.

Ultrahigh-temperature (UHT) metamorphism is critical for understanding the most extreme thermal evolution of continental crust. However, UHT metamorphism predominantly occurred in the Precambrian and is rarely observed in the modern Earth. Here, we report the discovery of ∼25 Ma UHT granulites from the Mogok metamorphic belt (MMB) in Myanmar via a combined study of petrology and geochronology. The studied pelitic granulites well preserve a peak mineral assemblage of garnet + sillimanite + plagioclase (antiperthite) + K-feldspar + quartz + Ti-rich biotite + rutile + ilmenite. Pressure ( P )-temperature ( T ) pseudosections and conventional geothermobarometry data only constrain the P - T conditions of the peak stage to <12 kbar and 780–890°C. However, high Zr contents in the matrix rutile (3005–4308 ppm) and high Ti contents (up to 9.2 wt% TiO 2 ) in the biotite demonstrate that the Mogok granulites may have experienced UHT metamorphism. The Zr-in-rutile thermometer and X Grs isopleth in the pseudosections yield peak P - T conditions of ∼12 kbar and >900°C. In situ SIMS and LA-ICP-MS U-Pb dating and trace element analyses show that both metamorphic zircon cores and rims have flat heavy rare earth element (HREE) patterns with negative Eu anomalies. The metamorphic zircon rims show the lowest HREE contents and yield 206 Pb/ 238 U ages of 24.9±0.5 and 25.4±0.6 Ma, respectively, representing the timing of UHT metamorphism. Our results indicate that the central MMB underwent ∼25 Ma UHT metamorphism, which is possibly induced by continental rifting along the thinned orogenic lithosphere. Our data, as well as reported Cenozoic UHT events, further suggest that UHT metamorphism can be produced in the modern plate tectonic regime by lithospheric extension.

Zircon crystals from a locally charnockitized Paleoproterozoic high-K metagranite from the Kerala Khondalite Belt (KKB) of southern India have been investigated by high-spatial resolution secondary ion mass spectrometry analysis of U–Th–Pb and rare earth elements (REE), together with scanning ion imaging and scanning ion tomography (depth-profiled ion imaging). The spot analyses constrain the magmatic crystallization age of the metagranite to ca. 1,850 Ma, with ultrahigh-temperature (UHT) metamorphism occurring at ca. 570 Ma and superimposed charnockite formation at ca. 520–510 Ma, while the ion imaging reveals a patchy distribution of radiogenic Pb throughout the zircon cores. Middle- to heavy-REE depletion in ca. 570 Ma zircon rims suggests that these grew in equilibrium with garnet and therefore date the UHT metamorphism in the KKB. The maximum apparent 207 Pb/ 206 Pb age obtained from the unsupported radiogenic Pb concentrations is also consistent with formation of the Pb patches during this event. The superimposed charnockitization event appears to have caused additional Pb-loss in the cores and recrystallization of the rims. The results of depth-profiling of the scanning ion tomography image stack show that the Pb-rich domains range in size from <5 nm to several 10 nm (diameter if assumed to be spherical). The occurrence of such patchy Pb has previously been documented only from UHT metamorphic zircon, where it likely results from annealing of radiation-damaged zircon. The formation of a discrete, heterogeneously distributed and subsequently immobile Pb phase effectively arrests the normal Pb-loss process seen at lower grades of metamorphism.