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In this paper, molecular dynamics (MD) simulations and machine learning (ML) methods are combined to obtain the transport properties, such as viscosity and thermal conductivity, of five basic elements, which are computationally hard to obtain at the nanoscale and extremely demanding to estimate accurately through an experimental procedure. Starting from an experimental database from literature sources, we extend the (P‐T) space on which the transport properties are calculated by employing MD simulations and ML predictions, in a synergistic mode. Results refer to all fluid states (gas, liquid, supercritical), under ambient and supercritical conditions, suggesting an alternative path that can be accurately followed to bypass expensive experiments and costly numerical simulations. Nine different ML algorithms are exploited and assessed on their prediction ability, with tree‐based architectures achieving increased accuracy on the implied data set. The proposed computational platform runs fast in a common python Jupyter environment, both for MD and ML, and can be adjusted and extended for the calculation of material properties both in interpolation and extrapolation applications. [ABSTRACT FROM AUTHOR]

An unusual self‐assembly pattern is observed for highly ordered 1500‐nm‐thick films of monodisperse 13‐nm‐sized colloidal PbSe quantum dots, originating from their faceted truncated cube‐like shape. Specifically, self‐assembled PbSe dots exhibited attachment to the substrate by <001> planes followed by an interconnection through the {001} facets in plan‐view and {110}/{111} facets in cross‐sectional‐view, thus forming a cubic superlattice. The thermoelectric properties of the PbSe superlattice thin films are investigated by means of frequency domain thermoreflectance, scanning thermal probe microscopy, and four‐probe measurements, and augmented by computational efforts. Thermal conductivity of the superlattice films is measured as low as 0.7 W m−1 K−1 at room temperature due to the developed nanostructure. The low values of electrical conductivity are attributed to the presence of insulating oleate capping ligands at the dots’ surface and the small contact area between the PbSe dots within the superlattice. Experimental efforts aiming at the removal of the oleate ligands are conducted by annealing or molten‐salt treatment, and in the latter case, yielded a promising improvement by two orders of magnitude in thermoelectric performance. The result indicates that the straightforward molten‐salt treatment is an interesting approach to derive thermoelectric dot superlattice thin films over a centimeter‐sized area. [ABSTRACT FROM AUTHOR]

Lead halide perovskites have been replaced by the environmentally acceptable and effective lead‐free double perovskite material. Double perovskites are innovative compounds for sustainable energy and budding substitutes to organic as well as lead‐based solar cells. In the current study, it has been expounded on the structural, electronic, thermoelectric, as well as thermodynamic characteristics of newly designed double perovskites In2TiX6 (X = Br, I) by means of ab‐initio computations relied on the FP‐LAPW tactics and semi‐classical Boltzmann transport theory with PBE‐GGA as exchange correlation potential. To obtain accurate value of band gaps (1.294 eV and 1.025 eV), TB‐mBJ approximation has been used along with PBE‐GGA. The best combinations of both compounds have spectroscopic limited maximum efficiency (SLME) values 33.96% and 31.63%, that are appropriate for solar cell absorbers, at 300 K, respectively. We have also computed Debye temperature θD$$ \left({\theta}_D\right) $$ and Grüneisen parameter γ$$ \left(\gamma \right) $$ to find the lattice thermal conductivity for both the investigated alloys. Thermoelectric properties have been labeled by Seebeck coefficient, electrical as well as thermal conductivities, and figure of merit. The peak values of Seebeck coefficient of 248 μV/K and 202 μV/K are observed for In2TiBr6 and In2TiI6 respectively in the p‐type regions. Attained results illustrates that the investigated In2TiX6 may be contender in thermoelectric due to their high figure of merit in low as moderate temperatures. Our results suggest that these materials are viable for use in thermoelectric devices. [ABSTRACT FROM AUTHOR]

The discovery of ductile Ag2(S, Se, Te) materials opens a new avenue toward high‐performance flexible/hetero‐shaped thermoelectrics. Specifically, the cubic‐structured materials are quite attractive by combining remarkable plasticity, decent thermoelectric figure of merit (zT), and no phase transition above room temperature. However, such materials are quite few and the understanding is inadequate on their mechanical and thermoelectric properties. Enlightened by the high‐entropy principles, a series of pseudo‐ternary Ag2S‐Ag2Se‐Ag2Te alloys is designed and comprehensive diagrams of composition‐structure‐plasticity‐zT are compiled. Subsequently, the compositional region for the cubic phase is outlined. As a high‐entropy example featuring with anion‐site alloying and disordered Ag ions, Ag2‐xS1/3Se1/3Te1/3 materials exhibit impressively large elongations of 60–97%, ultralow lattice thermal conductivities of ≈0.2 W m−1 K−1, and decent zT values of 0.45 at 300 K, 0.8 at 460 K. The materials can be readily rolled into thin foils, showing excellent flexibility. Finally, a six‐leg in‐plane device is fabricated, achieving an output voltage of 13.6 mV, a maximal power of 12.8 µW, and a power density of 14.3 W m−2 under the temperature difference of 30 K, much higher than the organic counterparts. This study largely enriches the members of cubic ductile inorganic materials for the applications in flexible and hetero‐shaped energy and electronic devices. [ABSTRACT FROM AUTHOR]

In this manuscript, structural, electronic, magnetic, and thermoelectric aspects of AFeO3 (A = Ca, Sr, Ba) have been calculated by means of the Full‐Potential Linearized Augmented Plane Wave Method (FP‐LAPW) using spin‐polarized Density Functional Theory (DFT). The calculated structural parameters have been found to be in good resemblance with previously available work. Enthalpy of formation and cohesive energy along with tolerance factor confirms structural stability. Electronic properties by Trans Blaha modified Becke–Johnson potential (TB‐mBJ) suggest metallic behavior in the spin‐up channel and semi‐conducting behavior in the spin‐down channel that supports half‐metallic behavior with mixed covalent and ionic bonding. Density of States (DOS) analysis confirms the major contribution of Fe‐3d‐states in the conduction band and O‐2p states in the valence band. The half‐metallic nature is further confirmed by the integer value of the total magnetic moment. The real and imaginary parts of dielectric functions, optical conductivities, absorption coefficients, reflectivity, and energy loss function have been calculated to evaluate suitability for optical applications. Thermoelectric properties with temperature range 300–900 K against chemical potential including figure of merit, Seebeck coefficient, thermal conductivities, and power factor, were examined using BoltzTraP code. Findings suggest that AFeO3 (A = Ca, Sr, Ba) compounds suitable for spintronic, thermoelectric as well as energy harvesting applications. [ABSTRACT FROM AUTHOR]

This paper presents the effect of salt concentration on the electrochemical, thermal, and structural properties of the solid polymer electrolyte (SPE) prepared with the polymer sodium carboxymethylcellulose (NaCMC) and the salt sodium triflate (NaCF3SO3). The electrolyte was prepared in the form of membranes using solution cast technique. Deionized water was used as a common solvent for both the precursor materials. The membranes were characterized using electrochemical impedance spectroscopy (EIS), Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), and differential scanning calorimetry (DSC). XRD results show reduction in crystallinity of the electrolyte with an increase in the salt concentration. The FTIR result confirms polymer‐salt interaction. The ionic conductivity of the electrolyte membrane was found to be dependent on the concentration of NaCF3SO3. The maximum ionic conductivity of the SPE membranes was observed to be 1 × 10−4 Scm−1 at room temperature (36°C). DSC results show an increase in glass transition temperature (Tg) with increasing salt concentration. The total ionic transference number of the highest conducting sample was found to be ~1, which shows that the conductivity of SPE membranes is predominantly due to the transport of ions. [ABSTRACT FROM AUTHOR]

The present work gives an insight into the structural, thermal, and electrical analysis of novel nanocomposite solid polymer electrolyte films prepared using the solution casting technique by incorporating cobalt oxide nanoparticles into methyl cellulose‐magnesium acetate polymer electrolyte matrix. The impact of ceramic oxide on the complexation of the salt with the polymer chain is evident from FTIR analysis. The crystallinity of the electrolyte systems decreases upon the incorporation of nanofiller into the matrix. Electrochemical Impedance Analysis of the samples shows enhancement in the conductivity of the electrolytes. Nanocomposite electrolyte systems with 2 wt% (5.93 × 10−4 S/cm) and 3 wt% (5.77 × 10−4 S/cm) of cobalt oxide exhibit maximum room temperature ionic conductivity compared to other electrolyte systems. DSC thermogram reveals the creation of free volume in the matrix with the incorporation of the filler. A primary battery is fabricated using the nanocomposite electrolyte system with 3 wt% of the nanofiller, and its open circuit potential and discharge characteristics have been analyzed. Highlights: Novel nanocomposite SPEs with cobalt oxide were prepared via solution casting.FTIR and XRD studies revealed modification in the microstructure.Cobalt oxide incorporation enhanced ionic conductivity of SPE.A primary battery fabricated using the highest conducting SPE. [ABSTRACT FROM AUTHOR]

Transcritical cycles working with CO2‐based mixtures gain considerable attention due to thermodynamic efficiency gain compared to pure sCO2 in hot environments. Previous literature works prove that the adoption of CO2 mixtures provides a reduction of the levelized cost of electricity in concentrated solar power applications and medium–high temperature heat recovery. However, for techno‐economic analysis and heat exchanger design, proper evaluation of transport properties of the CO2‐based mixtures in power cycle conditions is necessary. Herein, it deals with the analysis of the proper transport properties models for CO2 mixtures to assess their actual thermal behavior. A literature review on transport properties models, and their validation with available experimental data, proves that the friction theory is suitable for CO2 blended with dopants having high molecular complexity. The impact of the different model selection on the recuperator sizing, considering optimized power cycle conditions, is assessed on the CO2 mixtures with hexafluorobenzene and decane: The TRAPP and Chung–Lee–Starling models are imported from Aspen Plus, while the friction theory model is implemented and calibrated in an in‐house MATLAB code. The optimal design of the recuperator for the CO2 + C6F6 mixture in a 100 MWel power block coupled with a solar power plant located in Sevilla is carried out. [ABSTRACT FROM AUTHOR]

Transport properties of polyvinyl alcohol/ZnO nanocomposites (PVA/ZnO) of varying ZnO nanofiller are studied focussing on their potential application in electronic device application. The structural, morphological, and elemental composition studies of the prepared samples are done by X‐ray diffraction (XRD), scanning electron microscope (SEM), and energy‐dispersive X‐ray analysis (EDX). XRD confirms the formation of nanocomposites. SEM image shows the dispersion of ZnO nanoparticles on the surface of PVA matrix. EDX verifies that no external impurities are present in the nanocomposite samples. Frequency‐ and temperature‐dependent dielectric measurement of the samples reveals maximum dielectric constant at PVA/15 wt% ZnO nanocomposite. Dielectric loss results show a lossless behavior at higher frequencies (<0.2), indicating their suitability for high‐frequency applications. The AC conductivity studies reveal that electrical conduction mechanism in the nanocomposites is governed by the correlated barrier hopping mechanism. Activation energy of the samples reveals the presence of two thermally activated transport mechanism above and below 353 K. The imaginary part of electric modulus with frequency shows a single relaxation peak indicating the transition from long‐range to short‐range mobility with increasing frequency and temperature above 353 K. The contribution of grain and grain boundary in the electrical conduction process is confirmed from the Nyquist plot. [ABSTRACT FROM AUTHOR]

Recently, by forming a P‐rich P–S system, the P3S monolayer has been predicted to have good resistance to air oxidation, large band gap, high absorption, and superior mobility. Inheriting this prediction, a series of ternary Janus P6XY (X/Y = S, Se, and Te; X ≠ Y) monolayers based on P3X nanosheet are designed and studied. The structures of P6XY monolayers are confirmed to be stable based on the evaluation of calculated results for phonon spectra, ab initio molecular dynamic simulations. It is also found that P6XY compounds possess anisotropic mechanical characteristics. All Janus structures are indirect semiconductors with large energy gaps varying from 2.12 to 2.60 eV calculated by the hybrid functional. Besides, biaxial strain significantly affects the electronic properties of the P6XY monolayers. In particular, the biaxial strains can induce a transition from indirect to direct bandgap in all three P6XY structures. The carrier mobility in the three proposed structures exhibits directional anisotropy and high electron mobility value, up to 1.27 × 103 cm2 V−1 s−1, which are suitable for applications in high‐performance and direction‐dependent nanoelectronic devices. [ABSTRACT FROM AUTHOR]

In recent decades, considering environmental issues, partial replacement of Portland cement with supplementary cementitious material (SCM), namely ground granulated blast furnace slag (GGBS), has been in the spotlight of research. On the other hand, carbon‐based nanomaterials, especially graphene oxide (GO), are recognized as an extraordinary additive with special characteristics that can be included in cementitious materials. In this research, the impact of GGBS on the mechanical properties and durability of GO‐modified mortars was investigated at 28 and 90 days. The results demonstrate that by increasing the content of GGBS, a decrease in the flexural and compressive strength compared to plain cement sample was seen. On the other hand, incorporation of GGBS and GO led to higher strength compared to GO‐cement mortar. Also, the compressive strength of the sample containing 20% GGBS and 0.03% GO was 38.7% higher than the plain cement sample at 90 days. On the other hand, adding GGBS to a GO‐reinforced sample resulted in a more durable specimen against chloride and acid environments. The sample made of 40% GGBS in GO‐modified mortar not only has the best efficiency in harsh environments but also has the lowest water absorption. This mortar improved the migration coefficient, mass loss in HCl solution, and initial sorptivity by 20.1%, 57.7%, and 37.1%, respectively. Moreover, the mentioned sample had a denser microstructure with smaller cracks compared to other samples, based on scanning electron microscope (SEM) images. [ABSTRACT FROM AUTHOR]

We report on a theoretical study of the elastic, thermic and transport properties of the quaternary full Heusler alloy Co2VGa0.25Al0.75 using a full‐potential linearized augmented‐plane wave—method based on Wien2k program. We made this study by the use of three different approximations: the generalized gradient approximations (GGA), within GGA+ Hubbard parameter and the modified Becke–Johnson (mBJ). The calculated band structure (BS) and density of states (DOS) of Co2VGa0.25Al0.75 showed a half‐metallic (mBJ), nearly half‐metallic (GGA) and metallic (GGA + U) behavior. Moreover, the magnetic computed magnetic moments by GGA + U are higher compared to GGA and mBJ results. We studied the thermal properties of Co2VGa0.25Al0.75 compound, through the Debye model. This alloy seem is a good candidate of spintronic devices. Finally, we examined the transport characteristics within Boltzrap function. Moreover, we found significant values of the figure of merit (ZT), which makes our material ideal for thermoelectric power generation. [ABSTRACT FROM AUTHOR]

The elucidation of the factors determining liquid structures and transport properties of ionic liquids is important for the design and development of ionic liquid electrolytes. This personal account introduces the importance of computational methods for studying ionic liquids. Molecular dynamics simulations provide detailed information on liquid structures of ionic liquid such as the structures of solvated cation complexes in equimolar mixtures of glymes and Li[TFSA] and the effects of the charges of electrode on liquid structure near the electrode. Ab initio calculations reveal that the magnitude of the attraction between ions and conformational flexibility ions play important roles in determining transport properties of ionic liquids. First principle molecular dynamics simulations elucidate why solvated cation complex is stable in the equimolar mixtures, although the Li+‐[TFSA]− interaction is greater than Li+‐glyme interaction. [ABSTRACT FROM AUTHOR]

The study examines the effects of metal salt doping on polyethylene oxide (PEO) solid polymer electrolyte films. Sodium Bromide (NaBr) doped PEO films are prepared using a solution casting technique. The study finds that Na+ rom NaBr interacts with PEO's ether group (C–O–C) through complexation, as confirmed by Fourier Transform Infrared (FTIR) Spectroscopy. X‐ray diffraction analysis reveals that NaBr reduces PEO's degree of crystallinity. The addition of NaBr improves PEO's thermal stability, as shown by thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) images show smooth surface morphology of the polymer electrolyte films. The study also finds that the polymer electrolytes are non‐Debye in nature, based on dielectric studies. The highest ionic conductivity of 1.01 × 10−5 S/cm is observed for the 12.5 wt% NaBr doped PEO, with a low activation energy of 0.246 eV. Wagner's polarization technique is used to determine the charge carrier transport numbers, and the transient ionic current technique confirmed the presence of a single ionic species in the polymer electrolyte. Overall, the study suggests that 12.5 wt% NaBr doped PEO films have appropriate electrical properties for developing charge storage devices. [ABSTRACT FROM AUTHOR]

All‐d Heuslers are a category of novel compounds combining versatile functionalities such as caloric responses and spintronics with enhanced mechanical properties. Despite the promising transport properties (anomalous Hall (AHC) and anomalous Nernst (ANC) conductivities) shown in the conventional Co2XY Heuslers with p‐d hybridization, the all‐d Heuslers with only d‐d hybridization open a new horizon to search for new candidates with outstanding transport properties. In this work, the AHC and ANC are evaluated for thermodynamically stable ferro/ferri‐magnetic all‐d‐metal regular Heusler compounds based on high‐throughput first‐principles calculations. It is observed that quite a few materials exhibit giant AHCs and ANCs, such as cubic Re2TaMn with an AHC of 2011 S cm‐1, and tetragonal Pt2CrRh with an AHC of 1966 S cm‐1 and an ANC of 7.50 A m‐1K‐1. Comprehensive analysis on the electronic structure reveals that the high AHC can be attributed to the occurrence of the Weyl nodes or gapped nodal lines in the neighborhood of the Fermi level. The correlations between such transport properties and the number of valence electrons are also thoroughly investigated, which provides a practical guidance to tailor AHC and ANC via chemical doping for transverse thermoelectric applications. [ABSTRACT FROM AUTHOR]

Low dimensional materials have attracted great research interest from both theoretical and experimental point of views. These materials exhibit novel physical and chemical properties due to the confinement effect in low dimensions. The experimental observations of graphene open a new platform to study the physical properties of materials restricted to two dimensions. This featured article provides a review on the novel properties of quasi one‐dimensional (1D) material known as graphene nanoribbon. Graphene nanoribbons can be obtained by unzipping carbon nanotubes (CNT) or cutting the graphene sheet. Alternatively, it is also called the finite termination of graphene edges. It gives rise to different edge geometries, namely zigzag and armchair, among others. There are various physical and chemical techniques to realize these materials. Depending on the edge type termination, these are called the zigzag and armchair graphene nanoribbons (ZGNR and AGNR). These edges play an important role in controlling the properties of graphene nanoribbons. The present review article provides an overview of the electronic, transport, optical, and magnetic properties of graphene nanoribbons. However, there are different ways to tune these properties for device applications. Here, some of them, such as external perturbations and chemical modifications, are highlighted. Few applications of graphene nanoribbon have also been briefly discussed. [ABSTRACT FROM AUTHOR]

Label‐free, low‐noise, and ultrahigh‐sensitive biosensors based on liquid‐gated silicon (Si) nanowire (NW) field‐effect transistors (FETs) have recently emerged as promising diagnostic tools that can be used for healthcare monitoring and point‐of‐care applications. However, the sensing capabilities and performance of such devices still critically depend on several factors, including the quality and intrinsic properties of the materials used. In particular, the important role of determining device performance is assigned to the gate insulator layer, which acts as a sensing surface in such NW‐based biosensors and still requires optimization. Herein, several advanced multilayer structures: Si NW/SiO2/diamond‐like carbon FETs, are investigated. The high quality of the diamond‐like carbon layer obtained by low‐temperature physical vapor deposition is confirmed by X‐ray photoelectron spectroscopy and Raman spectroscopy studies. Current–voltage and noise spectroscopy reflect the high‐quality transport properties in these structures. [ABSTRACT FROM AUTHOR]

Numerical techniques for the computation of posterior distribution ease restrictions on inference models, and multiple plasma parameters can be simultaneously inferred with detailed modelling of uncertainties. In addition, data that depend on multiple parameters in a complex manner can also be utilized. This paper discusses frameworks that further expand the inference capability by including transport properties in plasmas. A prior belief based on a transport equation helps to localize the posterior distribution, and when ample diagnostic capability is available, even unknown parameters in the transport model can be estimated. Furthermore, these transport parameters can be directly inferred when the profiles of the measurable plasma parameters can be easily calculated for the given transport properties. [ABSTRACT FROM AUTHOR]

Electron–phonon mediated superconductivity is deeply investigated in two boron based monolayer materials, namely, B3S$B_{3}S$, a metal exhibiting the ability to superconduct, and a new metal, B3Se$B_{3}Se$, presenting perfect kinetic stability. Calculations based on density functional perturbation theory combined with the maximally localized Wannier function also reveal that both materials exhibit anisotropic planar hexagonal structure like graphene. The key parameters involved in the superconductor behavior are all calculated. The electronic density in the Fermi surface is given to provide the environment for enhanced electron–phonon coupling. The longitudinal and transverse vibration modes of optical phonons mainly contribute to the electron–phonon coupling strength. Furthermore, the binding energy between the bosonic Cooper pair superfluid is quantified and determined. The critical temperature for the two materials is 20 and 10.5 K, respectively. The results obtained show the potential use of such materials for superconducting applications. [ABSTRACT FROM AUTHOR]

This article investigates the influence of NaPF6 salt content (0–30 wt.% in a varying interval of 5 wt.%) on the structural, electrical, and biodegradable properties of HEC/NaPF6 solid biopolymer electrolyte (SBE) films. The interaction of salt with the HEC polymer matrix is confirmed by FTIR and SEM studies. The elemental composition and mapping confirm the appearance of NaPF6 moieties in the HEC polymer matrix. XRD deconvolution reveals that HEC samples with 20 wt.% (H4) and 10 wt.% of salt (H2) have a significantly lower crystallinity index than pure HEC polymer. The H2 and H4 samples show the highest room temperature conductivity values (1.62 × 10−5 and 1.13 × 10−5 S cm−1, respectively) among all other prepared samples since carrier concentration influences the ionic conductivity and shares a similar order of conductivity. Thus, the H2 and H4 samples are employed as electrolyte separators in the sodium ion battery, and the results suggest that the H2‐based electrolyte system is more significant. Battery matrices like open circuit voltage (V), current density (μA cm−2), power density (mW kg−1), energy density (Wh kg−1) and discharge capacity (μA h−1) were calculated and found to be 2.48, 5.49, 44.60, 1.69, and 71.05, respectively for H2 electrolyte based cell. Wagner polarization reveals that H2 and H4 constitute the predominant charge carriers (ions) with total ion transference numbers of ⁓0.98 and ⁓0.99, respectively. To evaluate sample degradability, H2 and H4 samples were subjected to 20 and 5‐day biodegradation processes, during which the polymers completely (100%) broke down. [ABSTRACT FROM AUTHOR]

The carbochlorination in molten salt is an effective method for titanium extraction form low‐grade titanium slag with a high calcium and magnesium content. However, in industrial practice, the fluidity of molten salt will gradually decrease with the increase of CaCl2 content. It is important to elucidate the influencing mechanism of CaCl2 content on the microstructure and diffusion properties of molten salt for the rational selection of a molten salt system and clean utilization of titanium slag. In this study, the densities of molten salt systems with different CaCl2 contents are measured according to the Archimedes principle. Then, using the first‐principles molecular dynamics (FPMD) method, the ionic structure and transport properties of NaCl‐MgCl2‐CaCl2 ternary molten salt systems under different CaCl2 contents are qualitatively and quantitatively described by determining the partial radial distribution functions (PRDF), coordination number (CN), angular distribution functions (ADF), and diffusion coefficient (DC). The results show that with the addition of CaCl2, Ca2+ ion complexed with Cl− ion to form larger ionic clusters, which reduced the proportion of free Cl− ion and restricted the diffusion of Cl− ion. [ABSTRACT FROM AUTHOR]

We have studied the evolution of structural and dynamic properties of liquid Fe as a function of pressure for 11 thermodynamic states close to the melting line. The pressure range considered goes from ambient pressure to 323 GPa, and the study has been carried out by using the ab‐initio molecular dynamics technique. The agreement between the calculated static structure and the available experimental data is very good, including details like an asymmetric second peak, which remains over most of the whole pressure range and suggests a significant local icosahedral short‐range order in the liquid. The dynamical structure is studied through the characteristics of the propagating density fluctuations and the associated longitudinal and transverse particle currents. The transverse dispersion relations expose two branches of modes for all pressures, whose range of appearance is analyzed and put in connection with the double‐peak structure of the Fourier spectra of velocity autocorrelation functions. We have also investigated the existence of fingerprints of transverse acoustic excitation modes in the dynamic structure factor for the high pressure states similar to those observed in the inelastic X‐ray scattering intensity data of liquid Fe at ambient pressure. The calculated electronic density of states shows that with increasing pressure there is a widening of the conduction band along with a decreasing significance of spin polarization. Finally, we also report results for transport coefficients like self‐diffusion, shear viscosity and adiabatic sound velocity, which are compared with the available experimental data. Plain Language Summary: The Earth's core is mainly composed of iron, with an inner solid core below a depth of 5,150 km, where the pressure exceeds 3.3 million atmospheres, and an outer liquid core, between 2,900 and 5,150 km below the Earth's surface, where the pressure ranges from 1.3 to 3.3 million atmospheres, with absolute temperatures from 4000 to 6500 K. The experimental determination of the properties of liquid iron at these conditions is extremely difficult, and therefore alternative types of studies are very convenient in order to understand the behavior of the liquid outer core. In this paper we perform computer simulations to study the properties of liquid iron from ambient pressure to values typical of the boundary between the outer liquid core and the inner solid core. This is done by starting from very basic ingredients, such as the electronic structure of atomic iron. From these, Quantum Physics leads to interatomic forces, which are used in the computer simulations to generate atomic configurations typical of the liquid at several temperatures and pressures. Finally the properties of the liquid, such as its structure, viscosity, and several others, are obtained using Statistical Physics tools. Key Points: Liquid iron is studied ab initio for pressures up to 323 GPaStatic and dynamic structural properties are consideredTransport properties are obtained [ABSTRACT FROM AUTHOR]

Transport properties of the ionic component of dense plasmas are investigated on the basis of effective potentials taking into account the presence of an external alternating electrical (laser) field. The latter generates single‐particle oscillations of electrons and significantly changes the screening of the test charge in plasma. Therefore, transport coefficients become non‐monotonic function of the oscillation frequency. The results for the diffusion and viscosity coefficients are presented. These transport coefficients are computed using the generalized Coulomb logarithm within the Chapman‐Enskog model for the fluid description. It was revealed that the oscillation of the electrons in the alternating external field with the frequency ω≳2ωp$$ \omega \gtrsim 2{\omega}_p $$ (with ωp being plasma frequency) results in the significant reduction of the ionic diffusion and viscosity coefficients. In contrast, at ω≲ωp$$ \omega \lesssim {\omega}_p $$, the ionic diffusion and viscosity coefficients are larger compared to the case without the external field impact. [ABSTRACT FROM AUTHOR]

The multigram synthesis of K2[Fe3S4] starting from K2S and FeS is presented, and its electronic and magnetic properties are investigated. The title compound obtains a defect variant of the K[Fe2Se2] structure type. Dielectric and impedance measurements indicate a dielectric constant of 1120 at 1 kHz and an outstanding ionic conductivity of 24.37 mS cm–1 at 295 K, which is in the range of the highest reported value for potential solid‐state electrolytes for potassium‐ion batteries. The Seebeck coefficient of the n‐type conductor amounts to −60 µV K−1 at 973 K. The mismatch of the measured electrical resistivity and the predicted metal‐like band structure by periodic quantum chemical calculations indicates Mott insulating behavior. Magnetometry demonstrates temperature‐dependent, large exchange bias fields of 35 mT, as a consequence of the coexistence of spin glass and antiferromagnetic orderings due to the iron vacancies in the lattice. In addition, the decreasing training effects of 34% in the exchange bias are identified at temperatures lower than 20 K. These results demonstrate the critical role of iron vacancies in tuning the electronic and magnetic properties and a multifunctional material from abundant and accessible elements. [ABSTRACT FROM AUTHOR]

Tetrahedrites, a class of naturally‐occurring sulfosalts, recently emerged as interesting thermoelectric materials due to their semiconducting electronic properties combined with glass‐like thermal transport. Here, we demonstrate that the high thermoelectric performance of synthetic tetrahedrites can be maintained while being mixed with tetrahedrite minerals. The combination of ball‐milling and spark plasma sintering yields chemically‐homogeneous, dense polycrystalline samples with thermoelectric performance equivalent to those obtained in purely synthetic compounds with peak ZT values of ∼0.6 at 623 K. While ball‐milling significantly lowers the crystallite size, a complete solid solution between both types of tetrahedrites is only achieved through the sintering process. Not only do these findings confirm interesting prospects for the direct use of natural ores in the preparation of tetrahedrites, but they also further evidence the importance of the chemical compositions of the two initial tetrahedrites on the optimization of the thermoelectric properties of the final compound. [ABSTRACT FROM AUTHOR]

2D materials are identified as Si alternatives for channels in next‐generation electronic devices. However, lack of high‐performance (HP) p‐type field‐effect transistors (FETs) acts as a block to the development of efficient complementary circuits. Here, p‐type monolayer GeC with planar structure is evaluated as a promising channel material to resolve the corresponding problems. The monolayer GeC possesses a direct bandgap of 2.07 eV with high hole mobility up to 6600 cm2 V–1 s–1. Coupling with ballistic quantum transport simulations, the results show that both n‐ and p‐FETs can hold the on‐currents exceeding 1200 µA µm–1 for HP devices. Particularly, for p‐type, the on‐currents with the channel shrinking from 10 to 3 nm can reach as high as 2991—1660 µA µm–1, which is of great value for the design of complementary circuits in 2D electronics. In addition, the figures of merits for GeC FETs, such as delay time, power dissipation, and energy‐delay product, are also assessed, fulfilling the demands of the International Technology Roadmap for Semiconductors (ITRS) and the International Roadmap for Devices and Systems (IRDS) for HP applications. Hence, this study demonstrates great potential of 2D GeC for future competitive electronic devices. [ABSTRACT FROM AUTHOR]

One‐dimensional (1D) analogues of two‐dimensional (2D) layered materials, especially nanotubes exhibit unique properties, which are distinct from the 2D flakes. The nanotubes and fullerene‐like nanoparticles from layered transition metal dichalcogenides (TMDs) are one of the prime foci of this field in the last 30 years. In this concise review, we present the advancement made in the TMDs nanotubes and fullerene‐like nanoparticles over the last few years. The synthesis and structure of TMDs nanotubes such as WS2/MoS2 are briefly described. The mechanical properties of single WS2 nanotubes were examined by in‐situ electron microscopy techniques and are briefly discussed. Their reinforcement effects in polymer composites are also presented, as well as their superior tribological behavior. The unique optoelectronic properties of WS2 (MoS2) nanotubes are presented. Thus, the bulk photovoltaic effect and superconductivity exhibited by WS2 nanotubes, which are a manifestation of their 1D structure and low symmetry, are revisited briefly. The strong light‐matter interaction of nanotubes resulting in polariton quasiparticles and their evolution as a function of nanotube diameter are explained. Last but not least, a new family of misfit layered nanotubes and their exceptional physical properties are briefly touched upon. [ABSTRACT FROM AUTHOR]

In this present work, we have synthesized silver nanoparticles (AgNPs) using the chemical reduction method and systematically studied the effect of AgNPs of different loading into polyvinyl alcohol/sodium bromide (PVA/NaBr) polymer electrolytes. X‐ray diffraction and Fourier transform infrared spectroscopy confirmed the variation in the crystallinity and complexation with AgNPs loading, respectively. AgNPs are uniformly distributed in the polymer matrix as depicted in FESEM. According to transport property studies, it is observed that carrier concentration has a strong influence on ionic conductivity. Additionally, I‐t studies showed that most charge carriers are ions and not electrons. The sample PVA/NaBr with AgNPs, prepared from 6 mM AgNO3 solution (PNAg6) with ionic conductivity 1.22 × 10−4 S cm−1 (one order increase with respect to undoped sample) and highest electrochemical stability window (ESW) of 2.86 V, can be chosen as a suitable candidate for energy storage device applications. [ABSTRACT FROM AUTHOR]

Chemically recyclable polymers have attracted increasing attention since they are promising materials in a circular economy, but such polymers appropriate for packaging applications are scarce. Here a combined thermal, mechanical, and transport (permeability and sorption) study is presented of a circular polymer system based on biobased trans‐hexahydrophthalide which, upon polymerization, can lead to amorphous, homochiral crystalline, and nanocrystalline stereocomplex materials. This study uncovers their largely different transport properties of the same polymer but with different stereochemical arrangements and synergistic or conflicting effects of crystallinity on transport properties versus thermal and mechanical properties. Overall, the homocrystalline chiral polymer shows the best performance with an outstanding barrier character to gases and vapors, outperforming commercial poly(ethylene terephthalate) and polyethylene. The results presented herein show that it is possible to modify the crystalline structure of the same polymer to tune the mechanical and transport properties and generate multiple materials of different barrier characters. [ABSTRACT FROM AUTHOR]

Due to its advantageous thermophysical qualities, U3Si2 piques the interest of the nuclear industry as an accident‐tolerant fuel to replace uranium dioxide (UO2). Herein, the structural, electrical, thermodynamic, and transport features of the U3Si2 compound are investigated using the full‐potential linearized augmented plane wave approach within the density functional theory, and within the generalized gradient approximation related to spin orbit and Hubbard. The ground statistic parameters that are estimated, such as the lattice constants and bulk moduli, are qualitatively consistent with previous experimental and theoretical evidence. The density of states analysis reveals that U3Si2 is a metal complex. In addition, the macroscopic thermal effects of U3Si2 are calculated using the quasi‐harmonic Debye model, which includes lattice vibrations. Experimental and theoretical findings are compared with the calculated variations in volume, heat capacity, entropy, and Debye temperature as a function of temperature in the range of 0–1500 K. Some thermal properties are projected to be pressure dependent in the range of 0–20 GPa. In the temperature range of 0–1500 K, the semiclassical Boltzmann transport equation is utilized to estimate electron transport parameters such as the Seebeck coefficient, thermal and electrical conductivity. [ABSTRACT FROM AUTHOR]

In this paper, high‐entropy (MgCoNiCuZn)1‐xLixO oxides (x = 0, 0.1, 0.15, 0.2, and 0.3) were synthesized via reactive flash sintering (RFS), and the effect of RFS process on the microstructure and electrical property of the materials were studied. The Li‐doped materials exhibited a mixed ionic–electronic transport behavior. The oxidation of Co2+ into Co3+ upon Li incorporation into the materials synthesized via the conventional solid‐state reaction route was not evidenced in the flash sintered materials. Instead, the charge unbalance in the Li‐doped materials synthesized via RFS was compensated by oxygen vacancies and holes in the valence band of the oxides, which were accounted for the ionic conduction and electronic conduction, respectively. The ionic conductivity increased upon increasing the Li concentration as more oxygen vacancies were formed. The attraction between defects with different charges (LiM/ and VO••), which formed defect complexes, led to a decrease in the mobility of the defects, thus resulting in a less pronounced increase in the ionic conductivity at high Li concentrations. The change in the charge compensation mechanism of the materials indicates that the microstructure of such kind of oxides could be altered through RFS, and thus the property may be manipulated. [ABSTRACT FROM AUTHOR]

In 1937, Baber, Landau, and Pomeranchuk postulated that collisions between electrons generates a contribution to the electric resistivity of metals with a distinct T2 temperature dependence. The amplitude of this term is small in common metals, but dominant in metals hosting either heavy carriers or a low concentration of them. The temperature dependence is set by the size of the scattering phase, but the microscopic source of dissipation is not straightforward. To explain how electron–electron collisions lead to momentum leak, Umklapp events or multiple electron reservoirs have been invoked. This interpretation is challenged by several experimental observations: the persistence of T‐square resistivity in dilute metals (in which the two mechanisms are irrelevant), the successful extension of Kadowaki–Woods scaling to dilute metals, and the observation of a size‐dependent T‐square thermal resistivity (T/κ$T/\kappa$) and its WiedemannFranz correlation with T‐square electrical resistivity. This paper argues that much insight is provided by the case of normal liquid 3He where the T‐square temperature dependence of energy and momentum diffusivity is driven by fermionfermion collisions. The amplitude of T‐square resistivity in 3He and in metals share a common scaling. Thus, the ubiquitous T‐square electrical resistivity ultimately stems from the Fermi‐liquid temperature dependence of momentum diffusivity. [ABSTRACT FROM AUTHOR]

2D materials with high carrier mobility and anisotropy have attracted extensive research interest. The single‐layer NbNSe has anisotropic elasticity, and the Young's modulus is up to 106 N m−1. The Fermi velocity is as high as 3.5 × 105 m s−1, and the transition between semiconductor and metallic states can be achieved by applying a uniaxial tensile strain of 2%. In addition, anisotropic electron transport properties indicate that currents along the b direction can reach 12.4 μA under a bias voltage of 2.0 V. These findings provide a physical basis for the design and synthesis of a new 2D material. [ABSTRACT FROM AUTHOR]

Herein, NaxFe1–yMnyO2 (y = 0.4, 0.5, 0.6, 0.7, and 0.8) oxides, which are a potential cathode materials group for Na‐ion batteries, are presented. Samples are prepared by solid‐state synthesis and crystallized in P2‐type structure (P63/mmc). Mössbauer spectroscopy studies revealed that in pristine and deintercalated samples the whole iron occurs at a high‐spin Fe3+ state. Electrochemical impedance spectroscopy measurements exhibited the thermally activated electrical conductivity of Na0.67Fe1–yMnyO2 with relatively high activation energies (≈0.4 eV). Obtained results are supported by the electronic structure calculations (KKR‐CPA method), which indicates that total density of states at the Fermi level increases with manganese content in the sample. Electrochemical properties of Na|Na+|NaxFe1–yMnyO2 test cells and the specific charge/discharge capacities analysis confirmed that only the manganese ions in NaxFe1–yMnyO2 are active in electrochemical processes and higher content of manganese results in obtaining higher specific capacities (≈150 mAh g−1 for y = 0.8 under C/10 current load). [ABSTRACT FROM AUTHOR]

Rechargeable Li‐ion battery technology has progressed due to the development of a suitable combination of electroactive materials, binders, electrolytes, additives, and electrochemical cycling protocols that resulted in the formation of a stable electrode‐electrolyte interphase. It is expected that Na‐ion technology will attain a position comparable to Li‐ion batteries dependent on advancements in establishing a stable electrode‐electrolyte interphase. However, Li and Na are both alkali metals with similar characteristics, yet the physicochemical properties of these systems differ. For this reason, a detailed study on the electrode‐electrolyte interphase properties, composition, and structure is required to understand the factors that influence the battery's behavior. Herein, the research that has been performed on the electrode‐electrolyte interphase for both anode and cathode in the most important families of electrode materials, including carbonate ester‐based and advanced electrolytes such as ether‐based carbonates and ionic liquids is presented. [ABSTRACT FROM AUTHOR]

While alloying is a powerful handle for materials engineering, it is an ongoing challenge to navigate the large and complex parameter space of these materials. This applies in particular for thermoelectrics and even more so clathrates. Here, a combination of density functional theory calculations, alloy cluster expansions, Monte Carlo simulations, and Boltzmann transport theory calculations is used to identify compositions that yield high power factors in the pseudo‐ternary clathrates Ba8AlxGayGe46−x−y and Ba8GaxGeySi46−x−y, while accounting for weight and raw material costs. The results show how a cost‐efficient performance can be achieved by reducing the number of Al and Ga atoms per unit cell, while compensating the resulting increase in the carrier concentration via an extrinsic dopant. The approach used in this study is transferable and can be a useful tool for mapping the thermodynamic and transport properties of other multinary systems. [ABSTRACT FROM AUTHOR]

Herein, we describe the synthesis, characterization and electrochemical performance of four phosphonium‐based ionic liquids (ILs) as electrolytes, Physicochemical properties such as viscosity, density, ionic conductivity, and thermal stability of ILs and conventional organic solvent ethylene carbonate (EC)/diethyl carbonate (DEC) were experimentally determined at different temperatures. All ILs showed thermal stability greater than 300 °C, surpassing the stability of the conventional organic solvent, whose flash points were 145 and 23 °C for EC and DEC, respectively. Nevertheless, at room temperature, all ILs are much more viscous than EC/DEC. The composite Si ‐[P2224][FSI] (triethyl‐n‐butylphosphonium bis(fluoromethylsulfonyl)imide) and Si‐EC/DEC anodes exhibit initial specific capacities at 0.15 A/g of 2409 and 2631 mAh/g, respectively. This demonstrates that despite the inferior transport properties of ILs, short alkyl‐substituted phosphonium ILs like [P2224][FSI] are potentially competitive for the new generation of electrolytes for LIBs. NMR, DSC, TGA, and galvanostatic discharged/charged were used as characterization techniques. [ABSTRACT FROM AUTHOR]

Halide mixing is a key strategy to tune the emission wavelength in lead halide perovskites but is also effective in improving the performance of halide perovskite solar cells. Yet, a clear and global picture of how halide alloying and related spatial in/homogeneous distribution influence the electronic and optical properties of halide perovskites is currently lacking. Considering the preeminent mixed iodine/bromine perovskite as a case study, state‐of‐the‐art hybrid density functional theory calculations are performed, exploring the full space of chemical composition and accounting for phase segregation effects. It is shown that, at low doping regime, halide impurities do not act as trap states and that a quasi‐linear opening of the bandgap occurs with increasing the bromine content. Phase segregation at the nanoscale, in turn, drastically affects the electronic structure of mixed halide systems, with namely bromine rich domains acting as barrier to hole diffusion. The energetic disorder probed by optical absorption in these mixed systems is surprisingly insensitive to configurational disorder, but mostly dominated by the coexistence of phases with various degrees of halide segregation. [ABSTRACT FROM AUTHOR]

Oxidized Mg2Si films are annealed in low vacuum at various annealing temperature, and the degradation mechanism of Mg2Si during exploitation at high temperature is investigated. The crystal structure, surface morphology, depth profile, Raman scattering, and electrical properties are measured by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Hall effect system, respectively. XRD results show that MgO exists apparently in Mg2Si films, and as the annealing temperature increases, the content of MgO increases. The surfaces of films present distinct hexagon structures. The results of depth profiles show that the oxygen content decreases gradually from the surface to the subsurface. Raman spectroscopy analysis suggests that as the annealing temperature increases, the intensity of MgO peak enhances gradually. Hall measurement results indicate that the carrier concentration and mobility decrease significantly with the increase in annealing temperature. The films show n‐type at lower annealing temperature, while they present p‐type at higher annealing temperature, which indicates obvious conversions from n‐ to p‐type. [ABSTRACT FROM AUTHOR]

Zinc has the potential for widespread use as an environmentally friendly and cost‐effective anode material pending the resolution of rechargeability issues caused by active material loss and shape change. Here, a self‐assembled Nafion‐coated Celgard 3501 (NC‐Celgard) separator is shown to enable unprecedented cycle life of a Zn anode in alkaline electrolyte at high depth‐of‐discharge (DODZn). Using commercially relevant energy‐dense electrodes with high areal capacities of 60 mAh cm–2, Zn–Ni cells tested at 20% DODZn cells achieve over 200 cycles while 50% DODZn cells achieve over 100 cycles before failure. The 20% and 50% DOD cells deliver an average of 132 and 180 Wh L–1 per cycle over their lifetime respectively. Rechargeability is attributed to the highly selective diffusion properties of the 300 nm thick negatively charged Nafion coating on the separator which prevents shorting by dendrites and inhibits redistribution of the active material. Crossover experiments show that the NC‐Celgard separator is practically impermeable to zincate ([Zn(OH)4]2–), outperforming commercial Celgard, cellophane, Nafion 211 and 212 separators while still allowing hydroxide transport. This work demonstrates the efficacy of selective separators for increasing the cycle life of energy‐dense Zn electrodes without adding significant volume or complexity to the system. [ABSTRACT FROM AUTHOR]

A new homogenization scheme is proposed to model the effects of surface phenomena occurring at the pore fluid/solid interface on the effective transport properties of multiscale and reactive geosystems, e.g., clayey geomaterials. This new scheme is a generalization of the so‐called differential scheme (DS) used to infer the effective properties of a composite made up of several materials. It is named the fractional differential scheme and is based on two key elements: (i) the concept of realizability of the DS itself and (ii) a fractional integral formulation of the DS for a porous medium considered as a two‐component composite. The formulation of the fractional DS introduces two parameters: a cementation exponent m and a fractional order α. The cementation exponent m is related to the microstructure of the material. The fractional order α accounts for the amplitude of the "surface" transport of ions resulting from the physico‐chemical interactions between hydrated cations and swelling clay minerals. Both parameters m and α are inverted from two sets of data: electrical conductivity measurements obtained on clayey rocks and effective diffusion coefficient measurements acquired from a Na‐montmorillonite geomaterial. The inversion results demonstrate that the fractional DS model is able to capture the dependence of the cation concentration on the effective transport properties of the clayey materials under study. Our results also show that the fractional order α can be considered an indirect indicator of the amplitude of physico‐chemical interactions between hydrated cations and swelling clay minerals occurring at the pore fluid/solid interface. [ABSTRACT FROM AUTHOR]

A new correlation for some transport properties of aqueous solutions, based on the data published by Sawada et al. [1], is proposed. The main objective of the new fit is to give a smooth transition to the properties of pure water to allow the use of the fit in the region of very dilute solutions. Additionally, the quality of the fit to the experimental data is improved compared to the original correlation. An extrapolation of the new correlation in the other direction, i.e., to higher mass fractions and temperatures, is smooth but does not fully capture the trend described by other experimental datasets. To this end, the correlation has to be refined further. [ABSTRACT FROM AUTHOR]

The current work analyzes the electronic, structural, mechanical, thermoelectric (TE), and optical properties of alkali‐based transition metal chalcogenides A2MoS4 (A = K, Rb, Cs) and Cs2MoSe4 using methods based on first principles. The electronic, structural, and mechanical properties are analyzed using projected augmented wave (PAW) potentials. The electronic structure calculations show them to be direct bandgap semiconductors. From the TE properties, it is found that all the compounds possess huge thermopower especially for the holes, and this along with low lattice thermal conductivity enables us to predict A2MoS4 (A = K, Rb, Cs) and Cs2MoSe4 to be a good class of material for TE applications. Also, the optical properties are found to be nearly isotropic in the low energy region, which also might fetch potential applications in the visible range. The nearly isotropic optical properties along with giant thermopower are the highlights of the current study, which sets a platform for exploring future device applications. [ABSTRACT FROM AUTHOR]

The current work analyzes the electronic, structural, mechanical, thermoelectric (TE), and optical properties of alkali‐based transition metal chalcogenides A2MoS4 (A = K, Rb, Cs) and Cs2MoSe4 using methods based on first principles. The electronic, structural, and mechanical properties are analyzed using projected augmented wave (PAW) potentials. The electronic structure calculations show them to be direct bandgap semiconductors. From the TE properties, it is found that all the compounds possess huge thermopower especially for the holes, and this along with low lattice thermal conductivity enables us to predict A2MoS4 (A = K, Rb, Cs) and Cs2MoSe4 to be a good class of material for TE applications. Also, the optical properties are found to be nearly isotropic in the low energy region, which also might fetch potential applications in the visible range. The nearly isotropic optical properties along with giant thermopower are the highlights of the current study, which sets a platform for exploring future device applications. [ABSTRACT FROM AUTHOR]

In this work, the thermoelectric properties of Cu‐Sb system compounds have been investigated to understand their relation with the electronic structures. The approach used is a theoretical one that combines the density functional theory, the Boltzmann transport theory, and the quantum theory of atoms in molecules. The results show that the Seebeck effect in metallic systems originates from the existence of various types of chemical bonds. However, this feature is not sufficient enough to generate effective thermoelectric effect. As in semi‐conducting compounds, the intrinsic driving force for thermoelectric effect remains the variation of the density of states near the Fermi level. [ABSTRACT FROM AUTHOR]

Leaching of contaminants through fractured aquitards such as clayey tills may occur due to typically slow matrix advection and diffusion, or it can be dramatically enhanced in the presence of preferential flow through fractures and macropores. Sorption also plays a crucial role since it can significantly impact contaminant leaching and residence times. These different mass‐transfer mechanisms imply a distinct transport behavior and very different time scales for contaminant leaching toward underlying aquifer systems. However, the prevalent controls on contaminant transport and their effects are difficult to assess. This paper shows a detailed characterization of flow and transport processes under water‐saturated conditions in two large undisturbed columns (LUCs) collected from two visually similar fractured/macroporous clayey tills typical for the Northern hemisphere. Flow‐through tracer and pesticide experiments revealed a contrasting transport behavior. In one column, transport through fractures/macropores was dominant, whereas matrix advection and diffusion had a distinct influence on solute transport in the other column. Detailed 3D discrete‐fracture‐matrix models were developed to illuminate prevalent controls on contaminant transport and to quantitatively interpret the flow‐through experiments with a minimal number of fitting parameters. Nonequilibrium sorption kinetics were included to reproduce the transport behavior of the considered pesticide. The parameters determined from the two LUC experiments were integrated in a vertical cross‐section model to investigate the influence of varying fracture properties on vertical solute transport through surficial clayey till aquitards. The analysis showed that small fracture apertures in deeper parts of the aquitard could substantially prolong solute migration times and control solute fluxes. Key Points: Tracer and pesticide transport experiments in water‐saturated large undisturbed columns (LUCs) with visually similar clayey tills showed contrasting behaviorInterpretation of LUC setups with 3D DFM model including nonequilibrium sorption kinetics based on detailed experimental characterizationDiscrete‐fracture‐matrix modeling of field conditions using LUC parameters to investigate vertical pesticide migration through surficial clayey till aquitards [ABSTRACT FROM AUTHOR]

The equiatomic germanide LaNiGe was synthesized from the elements by arc‐melting and subsequent annealing at 1173 K for 14 days. Its non‐centrosymmetric LaPtSi type structure was refined from single‐crystal X‐ray diffractometer data: I41md, a = 420.80(6), c = 1440.3(3) pm, wR = 0.0477, 284 F2 values and 14 variables. The nickel and germanium atoms build up a three‐dimensional [NiGe]δ– polyanionic network (2 × 241 and 1 × 242 pm Ni–Ge) in which the lanthanum atoms fill cavities with coordination number 12. This picture of chemical bonding is supported by an evaluation of the electron localization function. Physical properties of LaNiGe were studied by means of magnetic susceptibility, magnetization, specific heat and electrical resistivity measurements. The compound was found to be a Pauli paramagnet with a molar magnetic susceptibility of about χ = 1.6 × 10–4 emu·mol–1·Oe–1. The temperature dependence of the electrical resistivity shows Bloch‐Grüneissen‐Mott behavior indicating the metallic character of LaNiGe, which is in full agreement with the results of electronic structure and density of states calculations. No superconducting transition was observed in the temperature regime down to 1.72 K. [ABSTRACT FROM AUTHOR]

Water‐in‐salts form a new family of electrolytes with properties distinct from the ones of conventional aqueous systems and ionic liquids. They are currently investigated for Li‐ion batteries and supercapacitors applications, but to date most of the focus was put on the system based on the LiTFSI salt. Here we study the structure and the dynamics of a series of water‐in‐salts with different anions. They have a similar parent structure but they vary systematically through their symmetric/asymmetric feature and the length of the fluorocarbonated chains. The simulations allow to determine their tendency to nanosegregate, as well as their transport properties (viscosity, ionic conductivity, diffusion coefficients) and the amount of free water, providing useful data for potential applications in energy storage devices. [ABSTRACT FROM AUTHOR]

Vanadium‐doped Bi2–xTe2.4Se0.6 single crystals, with x = 0.015 and 0.03, are grown by the Bridgman method. Bandstructure characterization by angle‐resolved photoemission spectroscopy (ARPES) measurements shows gapless topological surface states for both vanadium concentrations. The Van‐der‐Pauw resistivity, the Hall charge carrier density, and the mobility in the temperature range from 0.3 to 300 K are strongly dependent on vanadium concentration, with carrier densities as low as 1.5 × 1016 cm−3 and mobilities as high as 570 cm2 V−1s−1. As expected for transport in gapless topological surface states, the resistivity, carrier density, and mobility are constant below 10 K. The magnetoresistance shows weak antilocalization for both vanadium concentrations in the same temperature range. The weak antilocalization is analyzed with the Hikami–Larkin–Nagaoka model, which yields phase‐coherence lengths of up to 250 nm for x = 0.015. [ABSTRACT FROM AUTHOR]

The durability performance of concrete structure is intimately related to the mass transport properties for the surface layers of concrete members. However, due to several effects, such as segregation, jamming effect and so on, the quality of the surface layer for reinforced member might be obviously different from their core material and material prepared and cured in the laboratory (labcrete). This study aims at understanding the mass transport properties of surface layers from reinforced concrete member, and clarifying the differences among them and those for accompanied labcrete. Specimens prepared from both a full‐scale reinforced beam and labcrete are subjected to experimental investigations on their gas permeability, capillary sorptivity, chloride diffusivity, and chloride migration coefficients. It is found that, for the same specimen, the gas permeability is approximately linear to capillary sorptivity. While the chloride diffusivity is smaller than the rapid migration coefficient. The durability potential of surface layers for the reinforced beam is inferior to that of the inner core material. While the latter is further obviously worse than that of labcrete. In engineering practice, special attention should be paid to ensure the quality of surface layer. When making quantification or prediction for the durability potential of concrete structure, it is more appropriate to use specimens from surface layers of field concrete members rather than those from labcrete. [ABSTRACT FROM AUTHOR]