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We synthesized a new nanocomposite bearing nitrogen-doped graphene as a carbon additive to the nickel oxide nanoparticles-titanium dioxide nanotubes heterojunction. The main purpose was the comparison of its structural and electronic properties, hence potential applications, with its undoped, reduced graphene oxide (GO) homolog. The beneficial effect of graphene on TiO2 heterojunctions is an accepted fact in the materials science field, mainly in favor of the nitrogen-doped one. Our data show that both graphenes have little influence on the band offset values of the NiO–TiO2 heterojunction. Still, the presence of reduced, undoped GO allows an improved electron transfer process from titania, causing a better charge carriers' separation. This correlates well with their observed photocatalytic activity under visible light exposure, for the degradation of four emerging contaminant pollutants (amoxicillin, acetaminophen, ibuprofen, and β -estradiol). In addition, the band alignment of the NiO–TiO2 heterojunction with graphenes, and the corrected thermodynamic potentials of the organic pollutants explain well the observed photocatalytic behavior. [ABSTRACT FROM AUTHOR]

In this paper, we delve into recent advancements in the fabrication of high-performance n-type oxide semiconductor thin-film transistors (TFTs) through crystallization pathways. The last two decades have seen a rapid proliferation of applications employing amorphous oxide semiconductor (AOS) transistors, from display technologies to semiconductor chips. However, with the growing demand for ultra-high-resolution organic light-emitting diodes, flexible electronics, and next-generation electronic devices, interest in oxide semiconductors exhibiting high mobility and exceptional reliability has grown. However, AOS TFTs must balance the competing demands of mobility and stability. Here, we explore various crystallization methods of enhancing the device performance of oxide semiconductors, alongside the intrinsic challenges associated with crystalline oxide semiconductors. Our discussion highlights the potential solutions presented by controlling crystalline quality in terms of grain size and orientation. We propose that advanced manufacturing techniques coupled with a profound understanding of materials science are needed to effectively address these issues. [ABSTRACT FROM AUTHOR]

A benchmark problem is formulated which is well suited for the validation of mesoscopic phase-field models for grain-boundary migration in polycrystals. First, an analytical steady-state solution of the sharp moving boundary problem is derived for a symmetric lamellar structure, which is valid for arbitrary bulk driving forces and triple junction angles. Characteristic quantities are identified to reduce the parameter space which in turn allows a systematic comparison of simulations and analytical results. Various multiphase-field (MPF) formulations are compared which approximate the sharp interface problem in terms of a diffuse regularization. An interfacial thickness convergence study reveals that the model error is largely dependent on the ratio of bulk to interfacial stabilizing force as well as the underlying model formulation. An additional grid convergence study highlights the efficiency of a more advanced discretization scheme. The results can be used to guide the selection of appropriate models and to estimate the interface thickness and spatial resolution required to achieve a given accuracy target. The post-processing framework consists of a fully automated determination of well-defined metrics from the phase field simulation data, eliminating human bias and facilitating reproducibility. The corresponding code is made openly available to assist the materials science and engineering community in validating MPF, multi-order parameter and similar model developments. We believe that this work provides a reliable benchmark procedure to better understand the potentials and limitations of current MPF models as well as alternative approaches. [ABSTRACT FROM AUTHOR]

We present a method using Zernike moments for quantifying rotational and reflectional symmetries in scanning transmission electron microscopy (STEM) images, aimed at improving structural analysis of materials at the atomic scale. This technique is effective against common imaging noises and is potentially suited for low-dose imaging and identifying quantum defects. We showcase its utility in the unsupervised segmentation of polytypes in a twisted bilayer TaS2, enabling accurate differentiation of structural phases and monitoring transitions caused by electron beam effects. This approach enhances the analysis of structural variations in crystalline materials, marking a notable advancement in the characterization of structures in materials science. [ABSTRACT FROM AUTHOR]

Recent advances in materials science, device designs and advanced fabrication technologies have enabled the rapid development of transient electronics, which represents a class of devices or systems that their functionalities and constitutions can be partially/completely degraded via chemical reaction or physical disintegration over a stable operation. Therefore, numerous potentials, including zero/reduced waste electronics, bioresorbable electronic implants, hardware security, and others, are expected. In particular, transient electronics with biocompatible and bioresorbable properties could completely eliminate the secondary retrieval surgical procedure after their in-body operation, thus offering significant potentials for biomedical applications. In terms of material strategies for the manufacturing of transient electronics, silicon nanomembranes (SiNMs) are of great interest because of their good physical/chemical properties, modest mechanical flexibility (depending on their dimensions), robust and outstanding device performances, and state-of-the-art manufacturing technologies. As a result, continuous efforts have been made to develop silicon-based transient electronics, mainly focusing on designing manufacturing strategies, fabricating various devices with different functionalities, investigating degradation or failure mechanisms, and exploring their applications. In this review, we will summarize the recent progresses of silicon-based transient electronics, with an emphasis on the manufacturing of SiNMs, devices, as well as their applications. After a brief introduction, strategies and basics for utilizing SiNMs for transient electronics will be discussed. Then, various silicon-based transient electronic devices with different functionalities are described. After that, several examples regarding on the applications, with an emphasis on the biomedical engineering, of silicon-based transient electronics are presented. Finally, summary and perspectives on transient electronics are exhibited. [ABSTRACT FROM AUTHOR]

This article explores the principles and applications of electrochemical gas separations for green energy integration. It discusses the inefficiencies of traditional gas phase separation methods and highlights the advantages of electrochemical separations, such as high energy efficiency and simultaneous separation and compression of purified gas. The article focuses on three specific electrochemical gas separations: hydrogen pump, ammonia compression, and carbon dioxide separation. It discusses the challenges and potential solutions for each technology, emphasizing the need for material development and optimal operating conditions. The text also discusses the use of electrochemical gas separations for carbon capture and reduction of greenhouse gas emissions, highlighting the importance of developing diverse technologies to address different application conditions. The article concludes by stating that further research and development are necessary to fully harness the potential of electrochemical gas separations. [Extracted from the article]

Reservoir computing has been considered as a promising intelligent computing paradigm for effectively processing complex temporal information. Exploiting tunable and reproducible dynamics in the single electronic device have been desired to implement the "reservoir" and the "readout" layer of reservoir computing system. Two-dimensional moiré materials, with an artificial lattice constant many times larger than the atomic length scale, are one type of most studied artificial quantum materials in community of material science and condensed-matter physics over the past years. These materials are featured with gate-tunable periodic potential and electronic correlation, thus varying the electric field allows the electrons in the moiré potential per unit cell to exhibit distinct and reproducible dynamics, showing great promise in robust reservoir computing. Here, we report that a moiré synaptic transistor can be used to implement the reservoir computing system with a homogeneous reservoir-readout architecture. The synaptic transistor is fabricated based on an h-BN/bilayer graphene/h-BN moiré heterostructure, exhibiting ferroelectricity-like hysteretic gate voltage dependence of resistance. Varying the magnitude of the gate voltage enables the moiré transistor to switch between long-term memory and short-term memory with nonlinear dynamics. By employing the short- and long-term memories as the reservoir nodes and weights of the readout layer, respectively, we construct a full-moiré physical neural network and demonstrate that the classification accuracy of 90.8% can be achieved for the MNIST (Modified National Institute of Standards and Technology) handwritten digits database. Our work would pave the way towards the development of neuromorphic computing based on moiré materials. [ABSTRACT FROM AUTHOR]

Solid state compounds exhibiting multiple and coupled macroscopic orders, named multiferroics, represent a challenge for both theoretical and experimental modern condensed-matter physics. Spins and the electric polarisation in conventional magnetic and ferroelectric materials can be manipulated on their fundamental timescales, by means of femtosecond laser pulses. In view of the resounding success and popularity of the all-optical approach, it is only natural to wonder about the application of this scheme to study the intrinsic coupling between spins and charges in multiferroics. Deeply fundamental questions arise: can ultrashort laser pulses deterministically activate, enhance or suppress the magnetoelectric coupling on the femtosecond timescale? Can these processes be triggered in a fully coherent fashion, thus being unrestrained by any thermal load? Which mechanism of spin-charge coupling is most favourable to overcome these overarching and daunting challenges? This problem is interdisciplinary in nature, requiring contributions from materials science and condensed matter physics from both theoretical and experimental perspectives. High-quality materials suitable for optical investigations have to be identified, synthetized and characterised. General and valid models offer then a guide to the plethora of possible light-induced processes, resulting in the desired ultrafast multiferroic manipulations. Finally, healthy experimental schemes, able to unambiguously track the ultrafast dynamics of either the ferroelectric or the magnetic order parameter have to be developed and implemented. Our motivation to write this review is to lay a broad and multidisciplinary foundation, which may be employed as a starting point for non-equilibrium approaches to the manipulation of the multiferroicity on the femtosecond timescale. This was also one of the main goals of the COST Action MAGNETOFON, whose network constitutes the core of the authors of this review. The present work thus represents a part of the scientific legacy of MAGNETOFON itself. [ABSTRACT FROM AUTHOR]

Atom manufacturing has become a blooming frontier direction in the field of material and chemical science in recent years, focusing on the fabrication of functional materials and devices with individual atoms or with atomic precision. Framework nucleic acids (FNAs) refer to nanoscale nucleic acid framework structures with novel properties distinct from those of conventional nucleic acids. Due to their ability to be precisely positioned and assembled at the nanometer or even atomic scale, FNAs are ideal materials for atom manufacturing. They hold great promise for the bottom-up construction of electronic devices by precisely arranging and integrating building blocks with atomic or near-atomic precision. In this review, we summarize the progress of atom manufacturing based on FNAs. We begin by introducing the atomic-precision construction of FNAs and the intrinsic electrical properties of DNA molecules. Then, we describe various approaches for the fabrication of FNAs templated materials and devices, which are classified as conducting, insulating, or semiconducting based on their electrical properties. We highlight the role of FNAs in the fabrication of functional electronic devices with atomic precision, as well as the challenges and opportunities for atom manufacturing with FNAs. [ABSTRACT FROM AUTHOR]

Leveraging generative Artificial Intelligence (AI), we have transformed a dataset comprising 1000 scientific papers focused on biological materials into a comprehensive ontological knowledge graph. Through an in-depth structural analysis of this graph, we have calculated node degrees, identified communities along with their connectivities, and evaluated clustering coefficients and betweenness centrality of pivotal nodes, uncovering fascinating knowledge architectures. We find that the graph has an inherently scale-free nature, shows a high level of connectedness, and can be used as a rich source for downstream graph reasoning by taking advantage of transitive and isomorphic properties to reveal insights into unprecedented interdisciplinary relationships that can be used to answer queries, identify gaps in knowledge, propose never-before-seen material designs, and predict material behaviors. Using a large language embedding model we compute deep node representations and use combinatorial node similarity ranking to develop a path sampling strategy that allows us to link dissimilar concepts that have previously not been related. One comparison revealed detailed structural parallels between biological materials and Beethoven’s 9th Symphony, highlighting shared patterns of complexity through isomorphic mapping. In another example, the algorithm proposed an innovative hierarchical mycelium-based composite based on integrating path sampling with principles extracted from Kandinsky’s ‘Composition VII’ painting. The resulting material integrates an innovative set of concepts that include a balance of chaos and order, adjustable porosity, mechanical strength, and complex patterned chemical functionalization. We uncover other isomorphisms across science, technology and art, revealing a nuanced ontology of immanence that reveal a context-dependent heterarchical interplay of constituents. Because our method transcends established disciplinary boundaries through diverse data modalities (graphs, images, text, numerical data, etc), graph-based generative AI achieves a far higher degree of novelty, explorative capacity, and technical detail, than conventional approaches and establishes a widely useful framework for innovation by revealing hidden connections.

The adsorption dynamics of double-stranded DNA (dsDNA) molecules on a graphene oxide (GO) surface are important for applications of DNA/GO functional structures in biosensors, biomedicine and materials science. In this work, molecular dynamics simulations were used to examine the adsorption of different length dsDNA molecules (from 4 bp to 24 bp) on the GO surface. The dsDNA molecules could be adsorbed on the GO surface through the terminal bases and stand on the GO surface. For short dsDNA (4 bp) molecules, the double-helix structure was partially or totally broken and the adsorption dynamics was affected by the structural fluctuation of short dsDNA and the distribution of the oxidized groups on the GO surface. For long dsDNA molecules (from 8 bp to 24 bp) adsorption is stable. By nonlinear fitting of the contact angle between the axis of the dsDNA molecule and the GO surface, we found that a dsDNA molecule adsorbed on a GO surface has the chance of orienting parallel to the GO surface if the length of the dsDNA molecule is longer than 54 bp. We attributed this behavior to the flexibility of dsDNA molecules. With increasing length, the flexibility of dsDNA molecules also increases, and this increasing flexibility gives an adsorbed dsDNA molecule more chance of reaching the GO surface with the free terminal. This work provides a whole picture of adsorption of dsDNA molecules on the GO surface and should be of benefit for the design of DNA/GO based biosensors. [ABSTRACT FROM AUTHOR]

Photons with variable energy, high coherency, and switchable polarization provide an ideal tool-kits for exploring the cutting-edge scientific questions in the condensed matter physics and material sciences. Over decades, extensive researches in the sample fabrication and excitation have employed the photon as one of the important means to synthesize and explore the low-dimensional quantum materials. In this review, we firstly summarize the recent progresses of the state-of-the-art thin-film deposition methods using excimer pulsed laser, by which syntactic oxides with atomic-unit-cell-thick layers and extremely high crystalline quality can be programmatically fabricated. We demonstrate that the artificially engineered oxide quantum heterostructures exhibit the unexpected physical properties which are absent in their parent forms. Secondly, we highlight the recent work on probing the symmetry breaking at the surface/interface/interior and weak couplings among nanoscale ferroelectric domains using optical second harmonic generation. We clarify the current challenges in the in-situ characterizations under the external fields and large-scale imaging using optical second harmonic generation. The improvements in the sample quality and the non-contact detection technique further promote the understanding of the mechanism of the novel properties emerged at the interface and inspire the potential applications, such as the ferroelectric resistive memory and ultrahigh energy storage capacitors. [ABSTRACT FROM AUTHOR]

Micro-nano particle manipulation methods in liquid environments have been widely used in the fields such as medicine, biology and material science. Nevertheless, the methods usually rely on pre-prepared physical microfluidic channels. In this work, virtual electrodes based on the optically induced dielectrophoresis (ODEP) method were used as virtual microchannels instead of traditional physical microfluidic channels. Virtual microchannels with different shapes were implemented by the designs of projected light patterns, which made the virtual microchannels have great flexibility and controllability. The theory of ODEP was verified by simulation and analysis of electric field distributions. The relationship between the manipulation force and the alternating current (AC) voltage or the AC frequency exerted on the cells was assessed. The experimental results indicated that the manipulation force was increased with the increase of the AC voltage, and it was reduced with the increase of the AC frequency. Moreover, different virtual microchannels were designed to carry out the transportation, aggregation and sorting of yeast cells and rat basophilic leukemia cells (RBL-2H3 cells) and the survival rate of the cells was evaluated. This work shows that the virtual microchannels can be flexibly realized by ODEP in liquid environments. [ABSTRACT FROM AUTHOR]

In the past couple of years, there are critical developments and advances in chemistry and potential applications of 2 dimensional materials (2D). 2D materials have went ahead for novel areas of research in material science after the development of graphene. As a consequence, another group of 2D materials, MXene was developed and transforming this field of study. MXene’s have been synthesized and reported in 2011 which explored more potential applications of these materials in all fields of science and technology. This review was written to highlight the on-going progress in the synthesis, characterization tools, biotechnological and biomedical uses of MXenes which are 2D carbides, nitrides, and carbonitrides of transition metals. We have taken examples of MXene to discuss how it can be analysed by using X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Nuclear Magnetic Resonance (NMR). These methods could be utilized to acknowledge if the precursor (MAX phase) is appropriate for MXene synthesis and authenticate efficacious synthesis of MXene along with its arrangement, physical features and properties. We have also highlighted the wide scope of bio-imaging, biotechnological, biomedical, and environmental uses of MXenes, their derivatives, and MXene-based composites. In addition, various characterization techniques used for MXene analysis have been briefly discussed. We underline that utilization of MXenes, in present day’s biotechnology research, is still very much in its early stages, therefore scientific processes must be standardized and improved. [ABSTRACT FROM AUTHOR]

Para- and ortho-isomers of water have different chemical and physical properties. Excitations by magnetic field, laser emission or hydrodynamic cavitation are reported to change energetic levels and spin configurations of water molecules that in turn change macroscopically measurable properties of aqueous solutions. Similar scheme is also explored for dissolved molecular oxygen, where physical excitations form singlet oxygen with different spin configurations and generate a long chain of ionic and freeradical reactions. This work utilizes electrochemical impedance spectroscopy (EIS) to characterize ionic dynamics of proposed spin conversion methods applied to dissolving of carbon dioxide CO2 and hydrogen peroxide H2O2 in pure water excited by fluctuating weak magnetic field in μT range. Measurement results demonstrate different ionic reactivities and surface tension effects triggered by excitations at 10−8 J/mL. The CO2- and O2-related reaction pathways are well distinguishable by EIS. Control experiments without CO2/H2O2 input show no significant effects. Dynamics of electrochemical impedances and temperature of fluids indicates anomalous quasi-periodical fluctuations pointing to possible carbonate-induced cyclic reactions or cyclical spin conversion processes. This approach can underlie the development of affordable electrochemical sensors operating with spin conversion technologies with applications in quantum biology, biophysics, and material science. [ABSTRACT FROM AUTHOR]

Plasma-based positron sources are attracting significant attention from the research community, thanks to their rather unique characteristics, which include broad energy tuneability and ultra-short duration, obtainable in a compact and relatively inexpensive setup. Here, we show a detailed numerical study of the positron beam characteristics obtainable at the dedicated user target areas proposed for the EuPRAXIA facility, the first plasma-based particle accelerator to be built as a user facility for applications. It will be shown that MeV-scale positron beams with unique properties for industrial and material science applications can be produced, alongside with GeV-scale positron beams suitable for fundamental science and accelerator physics. [ABSTRACT FROM AUTHOR]

We outline the basic theory behind white light interferometry and the workings of a typical light interferometer microscope. We study WLI images obtained for rough and smooth chrome steel spheres to illustrate the principle that curved rough surfaces can be imaged with such a device as long as the surface roughness is kept within certain limits. [ABSTRACT FROM AUTHOR]

Carbon nanofibers (CNFs) exhibit the advantages of high mechanical strength, good conductivity, easy production, and low cost, which have shown wide applications in the fields of materials science, nanotechnology, biomedicine, tissue engineering, sensors, wearable electronics, and other aspects. To promote the applications of CNF-based nanomaterials in wearable devices, the flexibility, electronic conductivity, thickness, weight, and bio-safety of CNF-based films/membranes are crucial. In this review, we present recent advances in the fabrication of CNF-based composite nanomaterials for flexible wearable devices. For this aim, firstly we introduce the synthesis and functionalization of CNFs, which promote the optimization of physical, chemical, and biological properties of CNFs. Then, the fabrication of two-dimensional and three-dimensional CNF-based materials are demonstrated. In addition, enhanced electric, mechanical, optical, magnetic, and biological properties of CNFs through the hybridization with other functional nanomaterials by synergistic effects are presented and discussed. Finally, wearable applications of CNF-based materials for flexible batteries, supercapacitors, strain/piezoresistive sensors, bio-signal detectors, and electromagnetic interference shielding devices are introduced and discussed in detail. We believe that this work will be beneficial for readers and researchers to understand both structural and functional tailoring of CNFs, and to design and fabricate novel CNF-based flexible and wearable devices for advanced applications. [ABSTRACT FROM AUTHOR]

The rapid expansion of nanotechnology and material science prompts two-dimensional (2D) materials to be extensively used in biomedicine, optoelectronic devices, and ultrafast photonics. Owing to the broadband operation, ultrafast recovery time, and saturable absorption properties, 2D materials become the promising candidates for being saturable absorbers in ultrafast pulsed lasers. In recent years, the novel 2D MXene materials have occupied the forefront due to their superior optical and electronic, as well as mechanical and chemical properties. Herein, we introduce the fabrication methods of MXenes, incorporation methods of combining 2D materials with laser cavities, and applications of ultrafast pulsed lasers based on MXenes. Firstly, top-down and bottom-up approaches are two types of fabrication methods, where top-down way mainly contains acid etching and the chief way of bottom-up method is chemical vapor deposition. In addition to these two typical ones, other methods are also discussed. Then we summarize the advantages and drawbacks of these approaches. Besides, commonly used incorporation methods, such as sandwich structure, optical deposition, as well as coupling with D-shaped, tapered, and photonic crystal fibers are reviewed. We also discuss their merits, defects, and conditions of selecting different methods. Moreover, we introduce the state of the art of ultrafast pulsed lasers based on MXenes at different wavelengths and highlight some excellent output performance. Ultimately, the outlook for improving fabrication methods and applications of MXene-based ultrafast lasers is presented. [ABSTRACT FROM AUTHOR]

The approaching end of Moore's law scaling has significantly accelerated multiple fields of research including neuromorphic-, quantum-, and photonic computing, each of which possesses unique benefits unobtained through conventional binary computers. One of the most compelling arguments for neuromorphic computing systems is power consumption, noting that computations made in the human brain are approximately 106 times more efficient than conventional CMOS logic. This review article focuses on the materials science and physical mechanisms found in metal chalcogenides that are currently being explored for use in neuromorphic applications. We begin by reviewing the key biological signal generation and transduction mechanisms within neuronal components of mammalian brains and subsequently compare with observed experimental measurements in chalcogenides. With robustness and energy efficiency in mind, we will focus on short-range mechanisms such as structural phase changes and correlated electron systems that can be driven by low-energy stimuli, such as temperature or electric field. We aim to highlight fundamental materials research and existing gaps that need to be overcome to enable further integration or advancement of metal chalcogenides for neuromorphic systems. [ABSTRACT FROM AUTHOR]

The neutron Bragg-edge imaging is expected to be a new non-destructive energy-resolved neutron imaging technique for quantitatively two-dimensional or three-dimensional visualizing crystallographic information in a bulk material, which could be benefited from pulsed neutron source. Here we build a Bragg-edge imaging system on the General Purpose Powder Diffractometer at the China Spallation Neutron Source. The residual strain mapping of a bent Q235 ferrite steel sample has been achieved with a spectral resolution of 0.15% by the time-of-flight neutron Bragg-edge imaging on this system. The results show its great potential applications in materials science and engineering. [ABSTRACT FROM AUTHOR]

With recent developments in direct imaging techniques using x-ray and neutron imaging, there is an increasing need for efficient test setups to study the mechanical and/or transport behavior of porous rocks. Bespoke designs from commercial suppliers are expensive and often difficult to modify. This paper presents a novel design of a portable triaxial cell for imaging deformation (and a suggested adaptation to introduce fluid transport) through rocks/sand/soil under the triaxial states of stress representative of those encountered in the case of groundwater aquifers or subsurface hydrocarbon reservoirs. The design philosophy and the parameters are detailed so that interested researchers can use this experimental setup as a template to design and modify triaxial cells to suit their own experimental requirements. The design has been used in two imaging beamlines: Imaging and Material Science & Engineering (IMAT), ISIS facility, Harwell, Oxfordshire, UK, and BT2 of the National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, MD, USA. The mass attenuation coefficients extracted from the 2D radiograms of the triaxial cell were compared with those reported in the literature. Further suggestions for the adaptation of the triaxial cells for studying the mechanics of deformation and fracture in rocks are included. [ABSTRACT FROM AUTHOR]

We report on the direct generation of optical vortex lattice (OVL) modes from a diode-pumped Pr3+:LiYF4 (Pr:YLF) laser achieved by employing off-axis (transverse) and defocused (longitudinal) pumping geometries in the laser medium. OVL modes with more than 40 phase singularities are generated. The experimentally observed OVL modes are well supported by a theoretical analysis based on the superposition of Hermite-Gaussian modes. We also discuss the intracavity frequency doubling of the OVL modes. The proposed OVL mode laser system can be applied to fundamental optical science and advanced material engineering. [ABSTRACT FROM AUTHOR]

Searching for new carbon allotropes with superior properties has been a longstanding interest in material sciences and condensed matter physics. Here we identify a novel superhard carbon phase with an 18-atom trigonal unit cell in a full-sp3 bonding network, termed tri-C18 carbon, by first-principles calculations. Its structural stability has been verified by total energy, phonon spectra, elastic constants, and molecular dynamics simulations. Furthermore, tri-C18 carbon has a high bulk modulus of 400 GPa and Vickers hardness of 79.0 GPa, comparable to those of diamond. Meanwhile, the simulated x-ray diffraction pattern of tri-C18 carbon matches well with the previously unexplained diffraction peaks found in chimney soot, indicating the possible presence of tri-C18 carbon. Remarkably, electronic band structure calculations reveal that tri-C18 carbon has a wide indirect bandgap of 6.32 eV, larger than that of cubic diamond, indicating its great potential in electronic or optoelectronic devices working in the deep ultraviolet region. [ABSTRACT FROM AUTHOR]

Diamond, cubic boron nitride (c-BN), silicon (Si), and germanium (Ge), as examples of typical strong covalent materials, have been extensively investigated in recent decades, owing to their fundamental importance in material science and industry. However, an in-depth analysis of the character of these materials' mechanical behaviors under harsh service environments, such as high pressure, has yet to be conducted. Based on several mechanical criteria, the effect of pressure on the mechanical properties of these materials is comprehensively investigated. It is demonstrated that, with respect to their intrinsic brittleness/ductile nature, all these materials exhibit ubiquitous pressure-enhanced ductility. By analyzing the strength variation under uniform deformation, together with the corresponding electronic structures, we reveal for the first time that the pressure-induced mechanical softening/weakening exhibits distinct characteristics between diamond and c-BN, owing to the differences in their abnormal charge-depletion evolution under applied strain, whereas a monotonous weakening phenomenon is observed in Si and Ge. Further investigation into dislocation-mediated plastic resistance indicates that the pressure-induced shuffle-set plane softening in diamond (c-BN), and weakening in Si (Ge), can be attributed to the reduction of antibonding states below the Fermi level, and an enhanced metallization, corresponding to the weakening of the bonds around the slipped plane with increasing pressure, respectively. These findings not only reveal the physical mechanism of pressure-induced softening/weakening in covalent materials, but also highlights the necessity of exploring strain-tunable electronic structures to emphasize the mechanical response in such covalent materials. [ABSTRACT FROM AUTHOR]

Due to the concern about the health damage caused by the consumption of food and water contaminated by highly toxic heavy metals, the quantification of these chemical species has led research fields, such as material science and electrochemistry, to develop new analytical methodologies for the determination of these contaminants even at trace levels. In this sense, the use of ionimprinted polymers for the surface modification of electrodes has improved the sensitivity and selectivity of methodologies for the electrochemical detection of metals due to the specific molecular recognition capability of the polymer. This strategy allows the design of low-cost, sensitive, precise, and accurate electroanalytical methodologies with excellent selectivity when used in the analysis of complex samples. This review discusses recent advances in the development of electroanalytical methodologies based on ion-imprinted polymers for their application in the determination of heavy metals in food and drinking water samples. Topics about the monomers used for the synthesis of the ion-imprinted polymers, their influence on the polymer characteristics, the electrode modification procedure, the electrode composition, and the electrochemical analysis conditions used are addressed. [ABSTRACT FROM AUTHOR]

Accelerating materials discovery crucially relies on strategies that efficiently sample the search space to label a pool of unlabeled data. This is important if the available labeled data sets are relatively small compared to the unlabeled data pool. Active learning with efficient sampling methods provides the means to guide the decision making to minimize the number of experiments or iterations required to find targeted properties. We review here different sampling strategies and show how they are utilized within an active learning loop in materials science. [ABSTRACT FROM AUTHOR]

Phase decomposition in binary Fe1−xCux is studied using Monte Carlo simulations. Initially, density functional theory calculations are utilized to determine reference energies of various Fe–Cu compounds that serve as input for a temperature and composition-dependent cluster expansion. On this basis, the thermodynamic properties of the bcc Fe–Cu system are predicted and used to simulate the equilibrium constitution of bcc Cu-rich precipitates in an Fe-rich solid solution at various temperatures and supersaturations. Complementarily, computationally efficient pair potentials are developed in the local chemical environment approach that are calibrated on the first principles-cluster expansion results. These are then utilized in large-scale simulations for analysis of the multi-particle precipitate evolution. It is concluded that both approaches provide comparable information in terms of the precipitate radius as well as interface constitution. Whereas the cluster expansion ('full-information') path is especially useful in predicting energies of various ground state configurations for small systems, the local chemical environment approach ('fast-computation') path is particularly useful in evaluation of cluster formation kinetics and evolution statistics. [ABSTRACT FROM AUTHOR]

An educational-grade experimental strategy is presented for the microscale 3D topographical reconstruction of a surface, based on a simple optical microscope and the use of free image-processing software. The experimental procedure, appropriate for an undergraduate lab, allows students to familiarise themselves with the basic principles underlying many tomographic imaging techniques relevant in a broad range of contexts, from material sciences, to life sciences, to medical sciences. [ABSTRACT FROM AUTHOR]

We present a moment-based alternative approach to retrieve multiple scattering contrasts from x-ray analyzer-based imaging. By use of the properties of moments of convolutions, the multiple-image radiography approach is theoretically validated. Furthermore, higher order moments of the object scattering distribution, inaccessible in multiple-image radiography, are simultaneously provided by this alternative approach. It is experimentally demonstrated that the skew and kurtosis information related to the distribution of sub-pixel features within the object can be obtained from those complementary contrasts. Finally, the sensitivity of the retrieved multiple scattering contrasts is investigated experimentally. The finding that the sensitivity is inversely proportional to the square root of the detected photon number essentially indicates that the retrieval of moments with an order higher than two can be achieved without increasing exposure time or dose. The presented alternative approach provides an access to the exploitation of multiple scattering contrasts, which is expected to be useful in biomedical research, materials science, security screening, etc. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks, a class of highly crystalline porous materials, have gained intense research interest in material science in the last decade due to its intriguing chemistry and unique properties which lead to diverse applications. There are different methods for the development of MOF thin film in lab scale and its fabrication in electronic devices. However, the harsh reaction conditions, prolonged synthesis time, complex experimental setup etc. limit its application. Here, the electrochemical synthesis offers the advantages of mild reaction conditions, real time tuning of applied potential, short reaction time etc. which make the selective deposition of MOF on various conducting substrates facile. In this review, we focus on the direct electrochemical synthesis of MOF with emphasis on anodic and cathodic electrodeposition. The two different synthetic methods are explained in detail with a detailed review on its progress since its development. The electrosynthesis of MOF is still in its infancy stage and therefore the challenges and future perspectives associated with it are also discussed. [ABSTRACT FROM AUTHOR]

Phase-shifting interferometry (PSI) has been widely applied in the field of accurate optical methodology. However, the fluctuation of background and amplitude intensities due to the instability of laser source, and phase-shifting error or vibration are significant problems for the PSI. In this study, the spatiotemporal phase-shifting method (ST-PSM) (Ri S et al 2019 J. Opt. 21 095702), which is a highly accurate and robust phase analysis method using spatial and temporal intensities information simultaneously, is first applied to laser interferometry to achieve a stable measurement. Through several simulations, three effects of fluctuations in background and amplitude intensities, phase-shifting error were investigated. As a result, we clarified that the periodic phase error with fundamental or second harmonic frequencies occurs in the conventional PSM method, whereas no periodic error occurs in the ST-PSM. Besides, the ST-PSM is also robust to the noise either for uniform or distorted interference fringe images. In the Michelson laser interferometer experiment, the ST-PSM realizes a much more stable measurement of phase and phase gradient distributions than the PSM. We have revealed the excellent performance and the striking advantage that ST-PSM is entirely free of periodic errors in a similar manner to the simulations. Therefore, laser interferometry using the ST-PSM can be expected to apply to various applications, including the extremely accurate non-contact shape and deformation measurement, as well as thickness measurement of transparent materials in life and material sciences. [ABSTRACT FROM AUTHOR]

Traditional materials discovery is in 'trial-and-error' mode, leading to the issues of low-efficiency, high-cost, and unsustainability in materials design. Meanwhile, numerous experimental and computational trials accumulate enormous quantities of data with multi-dimensionality and complexity, which might bury critical 'structure–properties' rules yet unfortunately not well explored. Machine learning (ML), as a burgeoning approach in materials science, may dig out the hidden structure–properties relationship from materials bigdata, therefore, has recently garnered much attention in materials science. In this review, we try to shortly summarize recent research progress in this field, following the ML paradigm: (i) data acquisition → (ii) feature engineering → (iii) algorithm → (iv) ML model → (v) model evaluation → (vi) application. In section of application, we summarize recent work by following the 'material science tetrahedron': (i) structure and composition → (ii) property → (iii) synthesis → (iv) characterization, in order to reveal the quantitative structure–property relationship and provide inverse design countermeasures. In addition, the concurrent challenges encompassing data quality and quantity, model interpretability and generalizability, have also been discussed. This review intends to provide a preliminary overview of ML from basic algorithms to applications. [ABSTRACT FROM AUTHOR]

The plasmonic properties of individual metallic nanostructures are of great importance for application in surface science, materials science, and nanophotonics. Herein, being facilitated with a home-made flow device and pulsed laser irradiation, we proposed a batch preparation protocol towards spherical Au nanoparticles (Au NPs) and cage shell entrapped spherical core nanoparticles (Au@cAu NPs) with highly uniform morphology and a tunable size distribution. The Fano resonance behavior exhibited by the effective interaction between spherical Au NPs and the silicon surface has great potential for the design of ultrasensitive optical sensing devices. In comparison with the spherical Au NP, the individual Au@cAu NP displayed not only a red-shifted and broadened localized surface plasmon resonance (LSPR) scattering peak, but also a higher electromagnetic field enhancement. Therefore, the Au@cAu NPs offer a better choice for plasmonic enhancement-based applications in the red and near-infrared region. In general, the current work provides a new and easy method for the large-scale preparation of gold-based uniform nanostructures, and offers an avenue to understand the interference of different plasmon modes in plasmonic systems, which has potential applications in surface science. [ABSTRACT FROM AUTHOR]

Silica, SiO2, has attracted significant interest as one of the most important compounds in the fields of condensed-matter physics, materials science, and geoscience etc. Here, we theoretically investigate crystal structural characteristics and elastic properties of coesite and its high-pressure polymorph coesite-II at high pressures, which is critical to improve the understanding of densification mechanism of silica at high pressure. The driving mechanism for the pressure-induced transition pathways of coesite comes from both structural features and elastic effect. The phase transition of coesite to cosite-II is triggered by the shortening of Si1–O1 bond distance, and accompanied by elastic instability from a combination of softening elastic constants C44 and C46. The structural modulation of coesite-II along the b-axis direction, as proposed experimentally, results from, on the one hand, the bending of Si2–O15–Si3 angles and shortening of Si5–O4 and Si7–O4 distance with increasing pressure and, on the other hand, elastic softening associated with phonon instability. These results provide key insights into the densification mechanism of silica under high pressure. [ABSTRACT FROM AUTHOR]

Composites based on candle wax and pencil graphite were fabricated with different concentrations of graphite in the range 0% w/w to 70% w/w. These composites were fabricated ('ironed') into a sandwich structure with kitchen aluminum foil serving as electrodes. The composites' electrical resistance was measured and it was found that the composite with 15% w/w of graphite was the best choice for further investigation according to the percolation theory of electrical conductivity thresholds. The wax–graphite composites were subjected to impact forces from a basketball, measured by the school's PASCO equipment. A calibration curve of the specific electrical resistance versus the force of impact was constructed. Following the standards of the International Basketball Federation (FIBA), the quality of the basketball was evaluated in terms of the bounce height of a free-falling ball and the force acting on the ball during the impact with the floor. The wax–graphite composite with a threshold concentration of 15% w/w graphite proved to be a sensitive sensor for measuring the impact force, even when small forces were under investigation. The project as presented here could be used as a laboratory topic for advanced level high school physics or undergraduate lab work in materials science or applied physics. [ABSTRACT FROM AUTHOR]

Harmonic motion is a significant topic in undergraduate lectures for university physics students. A typical example, presented in lectures around the globe, is the motion of a mass at the end of a spring. It should be emphasized that the harmonic motion in the aforementioned case is just an approximation for small displacements. However, the value of this example for teaching purposes is undeniable, if used properly. Its significance is connected to the adoption of an analytical way of thinking by the students that can help them to not only memorize isolated fragments but to really understand the topic in depth. As a result, the students should be able to apply a similar analysis to new and unsolved problems and explore unknown physical systems using basic theoretical tools. To move in the right direction, a new example is presented in this paper: the motion of a rigid sphere on an elastic half space. This phenomenon is extremely complicated. However, in this paper it is shown that for a specific range of values, this motion can be approximated to harmonic motion. This fact will significantly help students to learn how to resolve unknown problems and tasks using their knowledge. In addition, the analysis provided by this paper can be used as an alternative and simpler solution for data processing in nanoindentation experiments. As a result, it can be used as a valuable tool not only for undergraduate physics students but also for young researchers in the fields of nanotechnology and materials science. [ABSTRACT FROM AUTHOR]

Electromagnetic (EM) wave absorbing materials have been a research hotspot in materials science and related technical fields in recent years. Finding lightweight, efficient, and broadband electromagnetic wave absorbing materials has always been a very challenging subject. Herein, we successfully prepared Co3O4-WS2 hybrid nanosheets with heterostructures, which excellent combine the advantages of magnetic property of Co3O4 and dielectric property of WS2. By the electromagnetic synergy effect, maximum RL is up to −61.1 dB at 1.9 mm, and the bandwidth exceeds 5 GHz. Such highly efficient microwave absorption is attributed to not only the electromagnetic synergy effect, but the dipole polarization as well as conduction loss. These results show that the obtained Co3O4-WS2 is an excellent EM wave absorbing material and can be used as a candidate for advanced EM wave absorbing materials in the fields such as commerce, military and aerospace in future. [ABSTRACT FROM AUTHOR]