Low-temperature Crystallization Research Articles

Flörkeite, (K3Ca2Na)[Al8Si8O32]·12H2O: A Rare Zeolite from Pyrometamorphic Rocks of the Hatrurim Complex, Israel

Abstract Flörkeite, a rare zeolite with PHI (phillipsite) framework type, was found in numerous amygdaloidal voids in pyrometamorphic rocks of the Hatrurim Basin, Hatrurim Complex, Israel. This is the second reported occurrence of flörkeite previously found in a Ca-rich xenolith from a quarry at the Bellerberg volcano near Ettringen, East Eifel volcanic area, Germany. The mineral with the empirical crystal chemical formula (K2.91Ca2.00Na0.91)[Al7.96Si8.04O31.94]·12H2O (P-1, no. 2, a=19.9366 2, b=14.2517 1, c=8.89350 10 Å, α=88.2480 1, β=125.0960 10, γ=89.6350 10, V=2019.19 4 Å3, and R=3.41%) did not show significant differences with respect to that of the type locality. The Raman spectrum of flörkeite is here reported for the first time. No significant differences are noticed compared to phillipsite-K. The main band ~470 cm-1, characteristic of the PHI-type structures, is independent on framework order and Si/Al ratio. The zeolite mineralization of amygdules in pyrometamorphic rocks results from meteoric water circulations in Al-rich rocks during their cooling. The crystallization sequence of zeolite corresponds to the Ca/(K+Na) ratio decrease. Flörkeite formed at the end of a low-temperature crystallization sequence, indicating the predominant role of potassium in crystallization. The occurrence of flörkeite in different pyrometamorphic rocks implies the relatively uniform, regional mineral-forming conditions, and open hydrologic system of zeolitization. In pyrometamorphic rocks of the Hatrurim Basin, the process of zeolitization is characterized by low silica activity and high pH conditions.

In Situ Trace Elements in Quartz and K-Feldspar from Felsic Igneous Rocks: A Titanium-in-K-Feldspar Geothermometer for Natural Magmatic Systems

Abstract Scanning electron microscope, cathodoluminescence (CL) imaging and laser ablation–inductively coupled plasma–mass spectrometry analyses were conducted on coexisting pairs of quartz and K-feldspar from 14 samples of various types of felsic igneous rocks. Difference of the concentration of trace elements in quartz and K-feldspar among plutonic, pegmatitic and volcanic rocks is closely related to the rock-forming process and P–T condition. In general, a decreasing Ti concentration and increasing Al, Li, and Ge concentrations from plutonic to pegmatitic quartz suggest a higher degree of magmatic fractionation and lower crystallization temperature. Sensitive elements to magma differentiation in K-feldspar such as Ba, Sr, and LREE show a decreasing trend from various granitic rocks to pegmatite, while Rb, Cs, Li, Ge, and P exhibit increasing trends. The K-feldspar from various types of felsic igneous rocks typically shows similar CL textures but relatively higher luminescence intensity compared with coexisting quartz. Both quartz and K-feldspar phenocrysts in the volcanic rhyolite have a bright rim and a dark core in CL images, corresponding to bimodal Ti concentrations. Among all samples, Ti concentrations in both quartz and coexisting K-feldspar positively correlate with their CL intensities, suggesting the activation of Ti-impurity in these minerals leads to increased CL intensity. Meanwhile, there is a good positive correlation between Ti concentrations in quartz and those in K-feldspar with an R2 value of 0.86. It is considered that Ti concentrations in the both minerals are mainly temperature dependent at relatively constant pressure on basis of a fair aTiO2 restriction. Here, for the first time, we calculated a titanium-in-K-feldspar (TitaniKfs) thermometer in the form of log (XTi, kfs/aTiO2) = −(3430 ± 268)/T(K) + (5.081 ± 0.298) for natural felsic magma systems. The Ti contents of K-feldspar (in ppm by weight) increase exponentially with reciprocal T at temperatures ranging from 500°C to 800°C, at 200–300 MPa. An application of this thermometer to granitic rocks from Xinjiang and Inner Mongolia in China fits well with other geothermometers. In addition, the present TitaniKfs thermometer is expected to be particularly useful in determining the temperature condition of K-feldspar-bearing extraterrestrial materials such as lunar rocks.

Effect of Si addition on the magnetic properties of FeNi-based alloys with L10 phase through annealing amorphous precursor

As a promising candidate of rare-earth free hard magnetic materials, L1 0 -FeNi has been paid much attention in the last decades. However, it is difficult to be artificially fabricated due to its low thermal stability and sluggish diffusion ability of atoms below the crucial temperature of 320 °C. In this study, a promising method of annealing amorphous precursor was extensively developed through (Fe 50 Ni 50 ) 84−x Si x P 16 (x = 0, 4 at%) and (Fe 50 Ni 50 ) 86−x Si x P 14 (x = 2, 4, 8 at%) alloys. Especially, the effect of Si on the formation of L1 0 phase in annealed FeNi-based alloys was investigated and clarified. It is found Fe 42 Ni 42 P 16 with a much low crystallization temperature could be an appropriate basic amorphous alloy for the formation of L1 0 phase. The addition of Si enhanced the thermal stability of Fe-Ni-P amorphous alloys. Interestingly, Si could stabilize the L1 0 phase in annealed samples and increase its disordering temperature above which L1 0 -FeNi phase could deteriorate into soft magnetic phase. As expected, appropriate Si addition indeed improved the hard magnetic properties of the annealed alloys and samples with high coercivity above 900 Oe was obtained. Further Si addition would deteriorate the magnetic-crystalline anisotropy of L1 0 phase and decrease the coercivity of annealed Fe-Ni-Si-P alloys. Nevertheless, the results indicate that increasing the order-disorder transition temperature through element doping in L1 0 lattice would be a promising strategy for the massive formation of L1 0 -FeNi like other ordered phases (i.e. L1 2 -FeNi, L1 0 -CoPt), and could substantively contribute to the artificial fabrication of FeNi-based rare-earth free magnets in future. • Sample with the high coercivity above 900 Oe is obtained by annealing Fe-Ni-Si-P amorphous alloy. • The addition of Si increases the crystallization temperatures and thermal stability of Fe-Ni-P amorphous alloys. • Si could enhance the thermal stability and the disordering temperature of L1 0 phase. • Excessive Si addition would deteriorate the intrinsic magnetic hardness of L1 0 phase.

Enrichment of nervonic acid in Acer truncatum Bunge oil by combination of two-stage molecular distillation, one-stage urea complexation and five-stage solvent crystallization

Nervonic acid is the world's first and only potent substance that can repair damaged nerve fibers and promote nerve cell regeneration with high nutritional value. The wide variety of fatty acids in plant oils and fats with similar structures makes the large-scale separation and purification of high-purity nervonic acid very difficult. A new combined process of molecular distillation, urea inclusion and solvent crystallization was established to prepare high-purity nervonic acid with the mixed fatty acids obtained after saponification and acidification of Acer truncatum Bunge oil as raw materials. First, according to the difference in the mean free path of fatty acids, molecular distillation was used to separate and remove C16 saturated fatty acid of palmitic acid and four C18–C20 fatty acids of stearic, oleic, linoleic, and linolenic acids. The content of C16–C20 fatty acids decreased from 72.92% to 19.22% after two-stage molecular distillation processes, in which the contents of saturated fatty acid of palmitic acid decreased to about 0.5%. Then, according to the difference in carbon chain length and saturation of fatty acid, the contents of C22–C24 saturated fatty acids of tetracosanoic and docosanoic acids decreased to 0.21% and 0.07% by urea inclusion with urea/free fatty acid preparation by saponification (SPOMFs) ratio as 0.6. In addition, all saturated fatty acids were basically separated. Finally, according to the difference in the solubility of fatty acids in solvents, the C18–C20 unsaturated fatty acids of oleic, linoleic, and linolenic acids and C22 unsaturated fatty acid of erucic acid were removed by solvent crystallization. The content of C18–C20 unsaturated fatty acids decreased to less than 5% with pentanol as the solvent after the first stage solvent crystallization. The content of erucic acid decreased to 3.47% with anhydrous ethanol as the solvent after the second to fifth stage solvent crystallization. The combined process of molecular distillation, urea inclusion and low temperature crystallization innovatively adopted an efficient, simple and easy-to-industrial solvent crystallization method to separate erucic and nervonic acids, obtaining nervonic acid with purity of 96.53% and final yield of 47.99%.

An efficient synthesis strategy for MOR zeolite

MOR zeolite has been widely applied in petrochemistry due to its special pore structure. Tetraethylammonium hydroxide (TEAOH) is a typical organic structure directing agent (OSDA) for the preparation of MOR with high SiO2/Al2O3 molar ratio. TEAOH is easy to decompose under high temperature which limits its further recycling. Herein, an efficient and rapid synthesis strategy for MOR zeolite with the assistance of organic/inorganic additives is developed. Introduction of N-methyl-2-pyrrolidone (NMP) and Na+ into the synthetic gel could effectively promote the nucleation of MOR and the whole crystallization could be completed within 22 h at 150 °C. Especially, both the low crystallization temperature and Na+ in the synthesis system can inhibit the decomposition of TEAOH, which is benefit for the recycle of the TEAOH. Through this strategy, nano-sized MOR zeolite (200–300 nm) with large mesoporous volume is successfully synthesized with a low dosage of TEAOH at 130 °C. And this sample exhibits super catalytic stability in isobutene oligomerization reaction due to its good diffusion property.

Far-field brittle deformation record in the eastern Paris Basin (France)

AbstractJurassic carbonate strata in the eastern Paris Basin exhibit several generations of faults, tension gashes and stylolites. Although their relative chronology can sometimes be determined according to cross-cutting relationships, the duration of major deformation phases and their influence on fluid flow and carbonate cementation are still uncertain. This contribution aims to clarify the timing of brittle deformation and associated calcite cementation. Tension gashes filled by calcite in Jurassic carbonates were sampled in outcrops and boreholes and dated through U–Pb geochronology. Almost all the sampled fractures were cemented during the Cenozoic period. Continuous deformation spread from c. 50 to 30 Ma. Tension gashes oriented N10° to N20° dated at 48–43 Ma show the main Pyrenean contractional stage. A second set of calcites were dated at c. 35–33 Ma and document a Late Eocene – Oligocene extension. A transition from the compressional to the extensional regime is expressed by tension gashes dated between 43 and 35 Ma. Finally, tension gashes oriented N150° to N175°, dated between 32 and 18 Ma, may result from the propagation of the horizontal stress generated by the Alpine orogen or by late Pyrenean deformation. Clumped isotope thermometry on five samples revealed both low crystallization temperatures (from 27 to 53 °C) and the meteoric origin of calcite-precipitating fluids. Our research therefore documents a continuous fracturing from Ypresian to Rupelian times, and less expressed brittle deformation during the Miocene period.

(Invited, Digital Presentation) Nondegenerate Hydrogen-Doped Polycrystalline Indium Oxide (InOx:H) Thin Films for High-Mobility Thin Film Transistors

Transparent metal oxide semiconductors (OSs) have been extensively investigated for use as the active channel layer of thin film transistors (TFTs) for next-generation flat-panel displays, nonvolatile memories, image sensors, and pH sensors, to name a few. Among OSs, the amorphous In–Ga–Zn–O (IGZO) has attracted particular attention for TFT applications owing to its high field effect mobility (μFE) of more than 10 cm2V−1s−1, steep subthreshold swing (S.S.), extremely low off-state current, large-area uniformity, and good bias stress stability. Although the μFE of an IGZO TFT is approximately one order of magnitude higher than that of an amorphous Si TFT, further improvement of the μFE of OS TFTs is required to expand their range of applications as an alternative to polycrystalline Si TFT.Single-crystalline In2O3 has a Hall mobility as high as 160 cm2V−1s−1, which makes amorphous (a-) or polycrystalline (poly-) InOx a potential material for enhancing the μFE of OS TFTs. However, undoped InOx thin films is known as a degenerate semiconductor with high background electron density of over 1020 cm-3, which is attributed to the presence of native defects, such as oxygen vacancies, making them unsuitable for a channel material of OS TFTs. In this presentation, nondegenerate hydrogen-doped polycrystalline InOx (poly-InOx:H) thin films were successfully prepared by low-temperature solid phase crystallization (SPC). A degenerate amorphous InOx:H thin film was deposited by sputtering in Ar, O2, and H2 gases, and an amorphous to polycrystalline phase transition (SPC) of the film was achieved after PDA at more than 175 °C. By PDA at 250 °C in air, a nondegenerate poly-InOx:H film could be obtained with a carrier density as low as 2.4 × 1017 cm−3, which is approximately three orders of magnitude lower than that of the initial a-InOx:H film. The TFTs with a 50 nm thick nondegenerate poly-InOx:H channel could be fully depleted by a gate electric field. A maximum μFE of 125.7 cm2V−1s−1 was exhibited by the TFT with the poly-InOx:H channel. The use of a nondegenerate poly-InOx:H film is a promising approach to boost the μFE of OS TFTs.

(Invited) Hydrogenated Polycrystalline In2O3 (In2O3:H) Thin-Film Transistor with High Mobility Exceeding 100 cm2V−1s−1 Via Solid-Phase Crystallization

Oxide semiconductors have been extensively studied as active channel layers of thin-film transistors (TFTs) for electronic applications. However, the field-effect mobility (μ FE) of oxide TFTs is not sufficiently high to compete with that of low-temperature-processed polycrystalline-Si TFTs (50–100 cm2V−1s−1). Here, we propose a simple process to obtain high-performance TFTs, namely hydrogenated polycrystalline In2O3 (In2O3:H) TFTs grown via the low-temperature solid-phase crystallization (SPC) process. In2O3:H TFTs fabricated at 300 °C exhibit superior switching properties with µ FE = 139.2 cm2V−1s−1. The hydrogen introduced during sputter deposition plays an important role in enlarging the grain size and decreasing the subgap defects in SPC-prepared In2O3:H. The proposed method does not require any additional expensive equipment and/or change in the conventional oxide TFT fabrication process. We believe these SPC-grown In2O3:H TFTs have a great potential for use in future electronic applications.

(Digital Presentation) Low Temperature Formation of Binary and Ternary Group-IV Poly-Layers Via Sn-Nanodots Nuclei

Polycrystalline group-IV alloys, such as Si1-xGex, Ge1-xSnx, and Si1-x-yGexSny, have attractive benefits for thermoelectric generators which can directly convert heat energy into electricity with less environmental impact. Grain boundaries in the polycrystalline material can successfully reduce thermal conductivity which is essential to operate the thermoelectric devices under temperature difference [1]. Besides, mass differences between component elements of the alloy contribute to modulate phonon characteristics [2].In terms of the synthesis of the polycrystalline group-IV alloys, it has been challenging to realize crystallization, which typically needs high temperature annealing, simultaneously with controlling composition, especially Sn content which is limited by low solid solubility into Ge and Si as 1 at.% and 0.1 at.%, respectively, under equilibrium condition [3].As one of the solutions to obtain the polycrystalline group-IV alloys having high Sn content, using crystalline Sn nanodots as nuclei is effective for the growth of crystalline alloys at low temperature. The low temperature growth, which is the growth far away from the equilibrium, enables introduction of Sn more than its solubility limit [4].Amorphous Sn layer deposited on SiO2 substrate can be easily transformed into crystalline Sn nanodots by just applying an annealing in vacuum. We demonstrated the formation of polycrystalline Ge1-xSnx and Si1-xSnx alloys by deposition of Ge and Si on the Sn nanodots at the substrate temperature of 150 °C and 225 °C, respectively [5,6]. Adatoms, namely Ge and Si, were alloyed with the Sn nanodots acting as crystal nuclei. However, we found that Ge preferentially reacts with Sn nanodots when Si and Ge are simultaneously deposited on the Sn nanodots. In this case, Si remains as amorphous, meaning the effect of nucleus for the low temperature crystallization is not effective for Si if Ge exists. This result suggests that Si has to be crystallized prior to Ge.One can notice that the polycrystalline Si1-xSnx can be formed by the Sn nanodots mediated formation process as mentioned above. Therefore, we have proposed the 2-step formation process consisting of poly-Si1-xSnx crystallization and Ge alloying with the poly-Si1-xSnx which can be considered as a virtual substrate [6]. Using the 2-step formation process, whole deposited region was successfully crystallized with alloying Si, Ge, and Sn. The estimated Si and Sn content in the as-grown polycrystalline Si1-x-yGexSny layer were as high as 10.8% and 3.5%, respectively. The impact of introduction of Sn on phonon characteristics will be discussed at the presentation if time allows.Acknowledgements: This work was supported by JSPS KAKENHI Grant Number JP18K13786 and 21K04137 from the Japan Society for the Promotion of Science.

Crystallization Kinetics in Atomic Layer Deposited (ALD) Thin Films: Opportunities of Time and Chemical Environment

Atomic layer deposition (ALD) frequently produces amorphous films, however crystalline phases are often desired for various electrical, chemical, and optical applications. Thus, understanding the fundamental crystallization kinetics of films deposited by ALD is important in designing process pathways to achieve low-temperature crystallization, ultra-thin film (<50 nm) crystallization, controlled microstructures, and epitaxial growth. This presentation will discuss our work to study the crystallization kinetics in ALD TiO2 thin films and challenge some pre-conceived notions about thickness and temperature requirements for ALD film crystallization. We will focus on a prototypical TiO2 ALD process using tetrakis(dimethylamino)titanium(IV) (TDMAT) and water at between 140 °C and 220 °C. Initially, we will discuss data collected on post-deposition, isothermal crystallization kinetics at temperatures ranging from 140 to 200 °C. These time-dependent transformation kinetics are fit to the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model, revealing a continuous nucleation process and a two-dimensional growth mechanism, consistent with the observed grain sizes. We also use images collected over short annealing times to independently determine the crystal nucleation rate, which allows us to determine that the activation energies for nucleation (1.32–1.35 eV K-1 atom-1) are about one order of magnitude greater than the activation energies for grain growth (0.12–0.24 eV K-1 atom-1), sugggesting that nucleation is the more significant barrier to crystallization in this system. Finally, we will show how a modification to the process’s chemical environment can lower this barrier to nucleation leading to dramatic in situ crystallization (with no post-deposition annealing) at unusually low process temperatures and film thicknesses (< 15 nm).

High performance LiFePO4 nanomaterial obtained by a tavorite-to-olivine phase transition at low-temperature

The main problem currently faced in the large-scale production of LiFePO4 by solid-phase methods is the high energy consumption caused by solid/melt-phase lithiation process. Herein, LiFePO4 nanoparticles are successfully obtained by a phase transition from the tavorite LiFePO4OH structure to the olivine LiFePO4 structure at low-temperature (550–600 °C). This desirable LiFePO4OH precursor is prepared via a wet pre-lithiation process, and its thermodynamic feasibility is demonstrated by thermodynamic calculation. The liquid-phase lithiation followed by a simple carbothermal reduction process (c.f., the solid/melt-phase lithiation process of the traditional solid-state method) results in a superior mass transfer efficiency and reaction uniformity. It therefore prevents the requirement for a higher temperature and longer sintering process. It is also indicated that on the premise of the lattice perfection, a lower crystallization temperature is not only conducive to widening the effective ion diffusion channels of LFP, inhibiting further crystal growth, and shortening the diffusion path, but it also reduces the synthetic cost. As a result, a crystallization temperature of 600 °C (or 550 °C) is optimal, and the resulting LiFePO4 electrode can deliver an appealing high rate capacity of 147.7 mA h g−1 at 10 C. It is expected that this novel synthetic route could be employed for the large-scale commercial production of high performance LiFePO4 cathode materials at a low cost.

Impact of Ferroelectric Layer Thickness on Reliability of Back‐End‐of‐Line‐Compatible Hafnium Zirconium Oxide Films

Due to its ferroelectricity, hafnium oxide has attracted a lot of attention for ferroelectric memory devices. Amongst different dopant elements, zirconium is found to be beneficial due to the relatively low crystallization temperature of hafnium‐zirconium‐oxide (HZO), thus it is back‐end‐of‐line (BEoL) compatible. The thickness of HZO has a significant impact on ferroelectric device reliability. High operation temperatures and high endurance are important criteria depending on the application. Herein, various HZO thicknesses (7, 8, and 10 nm) in MFM (metal‐ferroelectric‐metal) capacitors are investigated at varying operation temperatures (25 to 175 °C) at varying electric fields (±3 to ±5.4 MV cm−1) with respect to polarization, leakage current, endurance, and retention. 7 nm HZO showed promising results with an endurance of 107 cycles, with a low leakage current density, and almost no retention loss after 10 years. Extrapolated results at operation conditions (±2 MV cm−1 and 10 MHz) showed an endurance of 1010 cycles.

Genesis of the Kiruna-type Nixintage iron deposit, Chinese Western Tianshan, NW China: Constrains of ore geology, geochemistry and geochronology

The Nixintage iron deposit is located in the central segment of the Awulale metallogenic belt, Chinese Western Tianshan. Iron ores are mainly hosted by andesitic tuff and andesite of the Carboniferous Dahalajunshan Formation. The paragenetic sequence includes a magmatic magnetite-apatite stage (I); a magmatic–hydrothermal stage (II), and three substages can be divided, including magnetite-albite substage (II-1), magnetite-chlorite-pyrite substage (II-2), magnetite-quartz-calcite substage (II-3); and a late hydrothermal quartz-calcite-sulfides stage (III). Anhedral, fine-grained magnetite associated with apatite in brecciated and matrix ores formed in stage I with relatively variable compositions, most probably indicate the fast crystallization under a disequilibrium condition. The high-grade magnetite orebodies mainly formed in the stage II, are featured by widespread hydrothermal mineral assemblages associated with the ores. Magnetite formed in this stage has medium-to-high concentrations of V, low-to-medium concentrations of Ti, Cr, relative depletion of Mg, Ni, K, and these data mainly plot in the Kiruna and porphyry fields of discriminant diagrams that comparable to magnetite from typical Kiruna-type iron deposits. Both stages I and II magnetites show similar wide δ18O ranges and with peak values at 6.0–10.0 ‰, heavier than typical Kiruna-type deposits, while could be attributed to the relatively low crystallization temperature inferred by microthermometric data of a previous study. The δ34S values of pyrite formed in different stages range between 0.1 and 2.4 ‰, comparable to the sulfur isotopic composition of the mantle-derived magma. These features indicate that stage I iron mineralization was generated by the extrusion of iron phosphorous oxide melts separated from the parental silicate magma. Subsequent deuteric fluids exsolved from basaltic to andesitic melts during the late stage of volcanism, generated magmatic–hydrothermal iron mineralization in stage II, and the continuous evolution of the deuteric fluids formed stage III hydrothermal veins. In summary, integrated evidence suggests the Nixintage is a Kiruna-type iron deposit.Zircon U-Pb ages of ore-hosting andesite and andesitic tuff are 317.6–314.4 Ma, and timing for iron mineralization was inferred at the same time, i.e., ca. 315 Ma. Previously published petro-geochemical data combined with our geochronological data of these rocks, suggest the ore-related volcanism in Nixintage probably originated from the partial melting of the mantle wedge modified by subducted fluids under a Late Carboniferous continental arc setting. Consequently, a genetic model for the studied deposit could be created. Furthermore, the southeast of the Nixintage nearer to the vent might have potential for prospecting large Kiruna-type iron deposits.

Formation of imperfect crystals in poly(ε-caprolactone) at high melt-supercooling

• Fast scanning calorimetry permits homogeneous crystal nucleation in PCL. • Crystallization of PCL near the glass transition yields non-lamellar, imperfect crystals. • Low-temperature crystallization of PCL suppresses spherulitic crystal growth. Poly(ε-caprolactone) (PCL) was crystallized at high melt-supercooling in a fast scanning chip calorimeter, with this instrumentation needed to reach the temperature range of homogenous crystal nucleation by fast cooling the melt. Subsequently, after slow heating the polymer to ambient temperature, the semicrystalline morphology and X-ray structure were evaluated. Nucleation and crystallization at low temperature yields a featureless structure at the micrometer-length scale, indicating non-spherulitic crystal growth. Images of the nanometer-scale structure suggest presence of irregular grown short lamellae or particle-like domains, and the absence of sharp peaks in the X-ray scattering pattern indicates formation of small or defective crystals. In conclusion, due to the high nuclei density, crystallization of PCL near the glass transition leads to formation of imperfect crystals, and slow heating to ambient temperature does not allow their reorganization to yield long-range orthorhombic order, typically observed on crystallization at low melt-supercooling.

Hydrolysis of cellulose to fermentable sugars by using 2,5-furandicarboxylic acid as a recyclable catalyst in green solvent of GVL/ H2O

Hydrolysis of cellulose into C6 sugars is the starting point and entry point for biomass refining and is an important pathway for biofuel production. However, biomass-based 2,5-furandicarboxylic acid (FDCA) is a highly catalytic promising but underutilized organic carboxylic acid. In this paper, we investigated the use of easily recoverable FDCA as a catalyst for the hydrolysis of cellulose to produce C6 sugars in a γ-valerolactone/water (GVL/H2O) green solvent system. FDCA has high inherent acidity (pKa = 2.76) and stability with unique solubility in aqueous solutions and many solvents. These properties allows it to meet both high temperature solubility for efficient homogeneous hydrolysis reactions and low temperature crystallization catalysts for high purity recovery. This process not only solves the problem of solid-solid mass transfer between solid acid and cellulose which limits the hydrolysis rate, but also eliminates the problem of difficult separation and recovery of liquid acid catalysts. The results showed when initial concentration of microcrystalline cellulose was 0.7 wt%（equivalent to 7 g/L）, and the initial dosage of FDCA was 2.0 wt%, the maximum yield of C6 sugars reached 72.9% (40.1% glucose and 32.8% fructose) in GVL/H2O (60/40, V/V) with a reaction at 200 °C for 30 min. More importantly, FDCA can achieve 80% recovery and ＞99% spectroscopic purity recovery. This study reveals the potential of FDCA as a catalyst in the catalytic conversion of biomass, which provides a new pathway for the green and efficient conversion of biomass resources.

Body-temperature programmable ultra-soft shape memory elastomers for comfort fitting

Shape memory materials can be utilized to realize fast shape customization for personalized comfort fitting experiences. In this paper, a series of body-temperature programmable shape memory elastomers are developed for comfort fitting. Unlike the reported ones, in which the shape switch is realized due to body-temperature phase transition (around 37 °C), these newly developed ones are fabricated with silicone rubber (as elastic component) and a kind of polycaprolactone (PCL, as transition component) that has melting point of about 56 °C and much lower crystallization temperature. The thermal properties, shape memory performances, mechanical behaviors under uni-axial tension at room temperature and at human body temperature (37 °C) are investigated. The specialty of these shape memory elastomers is that the programming is not carried out at around melting point of the transition component. Instead, it could be done upon cooling to 37 °C. The temporary shape is fixed only after completion of PCL crystallization. As the melting point of PCL is much higher (56 °C), the mechanical properties of these shape memory elastomers are ensured rather stable near 37 °C, which eliminates the concern of shaping/fitting failure when ambient temperature fluctuates. Besides, ultra-softness and high stretchability at room temperature are revealed as well. Excellent shape memory performance of these elastomers at 37 °C is also confirmed. The shape fixity ratio is over 90% when PCL content reaches wt% of 35%. In such a way, these elastomers are able to well duplicate the local shapes of human body in actual fitting. Upon reheating to 80 °C, they also can completely recover to their original shapes. The fitting time window at 37 °C is revealed around 5 min, which is rather appropriate in practice. The yielding behaviors during tension and long-term shaping/fitting performance of these elastomers are also discussed. A simple wearable orthotic device for hallux valgus is developed for proof-of-concept. It is concluded that these newly developed shape memory elastomers are well suited candidates for comfort fitting.

The bulk enthalpy of melting of α’-crystals of poly (l-lactic acid) determined by fast scanning chip calorimetry

Related to the wide scatter of information in the literature, recently the bulk enthalpy of melting of α-crystals of poly (l-lactic acid) (PLLA) has been re-determined by correlating the crystallinity-dependent heat capacity at a temperature slightly higher than the glass transition temperature and the corresponding enthalpy of melting [Macromol. Rap. Comm. 2022, 43, 2200148], using fast scanning chip calorimetry (FSC). For α-crystals, a value of 104 J/g is suggested, valid at 190 °C. Here, the initial study is expanded such to obtain the bulk enthalpy of melting of PLLA α’-crystals, containing conformational defects and forming at lower crystallization temperatures than the α-phase. Samples containing different amount of α’-crystals were generated by varying the time of isothermal crystallization at 90 °C. Extrapolation of the obtained relationship between the heat capacity at the crystallization temperature, that is, the crystallinity, and the enthalpy of melting on subsequent fast heating, suppressing the transition into α-crystals and simplifying therefore the analysis of the melting process of the formed α’-crystals, toward fully crystallized PLLA yields a bulk enthalpy of melting of 72 J/g at the thermal stability limit of α’-crystals of 150 °C. The used experimental approach to obtain the bulk enthalpy of melting of polymer crystals relies on the presence of a two-phase structure/absence of a glassy rigid amorphous fraction at the temperature of analysis of the crystallinity via the heat capacity (90 °C). Annealing experiments slightly below the analysis temperature support this assumption by absence of enthalpy-recovery peaks on subsequent heating.

Improvement of Ferroelectricity with Two-Dimensional Enwrapping Structure

The effect of the layered InSe intercalation structure on the ferroelectric properties of HfO2 was investigated. At low crystallization temperatures, the ferroelectric phase is formed more easily. Stronger polarization and better reliability can be achieved. This result indicates that the InSe intercalation structure is promising for engineering the ferroelectric properties of HfO2.

Influence of Grain Boundary Scattering on the Field-Effect Mobility of Solid-Phase Crystallized Hydrogenated Polycrystalline In2O3 (In2O3:H).

Hydrogenated polycrystalline In2O3 (In2O3:H) thin-film transistors (TFTs) fabricated via the low-temperature solid-phase crystallization (SPC) process with a field-effect mobility (μFE) exceeding 100 cm2 V−1 s−1 are promising candidates for future electronics applications. In this study, we investigated the effects of the SPC temperature of Ar + O2 + H2-sputtered In2O3:H films on the electron transport properties of In2O3:H TFTs. The In2O3:H TFT with an SPC temperature of 300 °C exhibited the best performance, having the largest µFE of 139.2 cm2 V−1 s−1. In contrast, the µFE was slightly degraded with increasing SPC temperature (400 °C and higher). Extended X-ray absorption fine structure analysis revealed that the medium-range ordering in the In2O3:H network was further improved by annealing up to 600 °C, while a large amount of H2O was desorbed from the In2O3:H films at SPC temperatures above 400 °C, resulting in the creation of defects at grain boundaries. The threshold temperature of H2O desorption corresponded well with the carrier transport properties; the µFE of the TFTs started to deteriorate at SPC temperatures of 400 °C and higher. Thus, it was suggested that the hydrogen remaining in the film after SPC plays an important role in the passivation of electron traps, especially for grain boundaries, resulting in an enhancement of the µFE of In2O3:H TFTs.

Evolved magmatic arcs of South Borneo: Insights into Cretaceous slab subduction

Combined U-Pb zircon data of granitic, dioritic, and gabbroic suites reveal development of arc-related magmatism in South Borneo throughout the Late Mesozoic but dominantly in the Cretaceous (144–72 Ma). Cretaceous igneous suites constitute the Schwaner-Singkawang, Kuching-LongPahangai, and Meratus-West Java magmatic arc zones. Arc-related felsic suites are low-K tholeiitic, and calc-alkaline to high-K calc-alkaline. Most of them are metaluminous (A/CNK 0.7–1.1), I-type, and have high large-ion lithophile element (LILE) contents, low high-field strength element (HFSE) contents, and low crystallization temperatures (688–769 °C). A few rocks have adakite characteristics, such as high Sr/Y and low Y. Late Cretaceous granitic suites from South Schwaner, which evolved at elevated temperature (761–852 °C), have diverse compositions that range from I-type transitional to A-type. The highly fractionated chemistry of these samples is attributed to an intraplate stretching tectonic setting. This regime is consistent with tectonic controls of the synchronous tholeiitic suites within North Schwaner. Two subduction systems beneath Sundaland converged and interacted during the Cretaceous. The Paleo-Pacific subduction in the north built arc-trench architectures, as shown by the Early Cretaceous Lupar Line mélange, the Schwaner to Singkawang magmatic arc, and the Late Cretaceous Lupar Line mélange and Kuching-LongPahangai arc. The Meso-Tethys subduction in the southeast produced the Cretaceous Schwaner-Singkawang magmatic arc, Meratus to Luk-Ulo mélanges, and Meratus-West Java magmatic arc. When entered into Late Cretaceous, slab rollback led to crustal stretching in the Schwaner to Singkawang regions, with the production of A-type transitional and tholeiitic suites. Though debatable, we infer the SW Borneo block to be a Sundaland continuation; Semitau shows an affinity for South Cathaysia. Both of the terranes would accrete onto Sundaland during the Indosinian orogeny.