Three-dimensional Metal Research Articles

Ionic liquid gating induced self-intercalation of transition metal chalcogenides

Ionic liquids provide versatile pathways for controlling the structures and properties of quantum materials. Previous studies have reported electrostatic gating of nanometer-thick flakes leading to emergent superconductivity, insertion or extraction of protons and oxygen ions in perovskite oxide films enabling the control of different phases and material properties, and intercalation of large-sized organic cations into layered crystals giving access to tailored superconductivity. Here, we report an ionic-liquid gating method to form three-dimensional transition metal monochalcogenides (TMMCs) by driving the metals dissolved from layered transition metal dichalcogenides (TMDCs) into the van der Waals gap. We demonstrate the successful self-intercalation of PdTe2 and NiTe2, turning them into high-quality PdTe and NiTe single crystals, respectively. Moreover, the monochalcogenides exhibit distinctive properties from dichalcogenides. For instance, the self-intercalation of PdTe2 leads to the emergence of superconductivity in PdTe. Our work provides a synthesis pathway for TMMCs by means of ionic liquid gating driven self-intercalation.

Non-Conjugated Poly(Diphenylene Phthalide)-New Electroactive Material.

In organic electronics, conjugated conductive polymers are most widely used. The scope of their application is currently very wide. Non-conjugated polymers are used much less in electronics and are usually used as insulation materials or materials for capacitors. However, the potential of non-conjugated polymers is much wider, due to the fact that new electronic materials with unique electronic properties can be created on the basis of non-conjugated polymers, as well as other inorganic dielectrics. This article demonstrates the possibilities of creating electrically conductive materials with unique electronic parameters based on non-conjugated polymers. The results of the study of the sensory properties of humidity are given as examples of the practical application of the structure. The abnormal electronic properties are realized along the interface of two polymer dielectrics with functional polar groups. The submicron films of polydiphenylenephthalide were used as a dielectric. It is shown that a quasi-two-dimensional electronic structure with abnormally large values of conductivity and mobility of charge carriers occurs along the interface. These structures are often called quasi-two-dimensional electron gas (Q2DEG). This article describes the manufacturing processes of multielectrode devices. Polymer films are deposited via the spin-coating method with polymer solutions in cyclohexanone. The metal electrodes were manufactured through thermal deposition in a vacuum. Three types of metal electrodes made of aluminum, copper and chromium were used. The influence of the electron work function of contacting metals on the electronic parameters of the structure was studied. It was established that the work function decrease leads to an increase in the conductivity and mobility of charge carriers. The charge carrier parameters were estimated based on the analysis of the current-voltage characteristics within the space-charge-limited current technique. The Richardson-Schottky thermionic emission model was used to evaluate values a potential barrier at metal/organic interfaces. It was established that the change in ambient humidity strongly affects the electronic transport properties along the polymer/polymer interface. It is demonstrated that the increase in conductivity with an increase in humidity occurs due to an increase in the mobility of charge carriers and a decrease in the height of the potential barrier at the three-dimensional metal contact with two-dimensional polymer interface. The potential barrier between the electrode and the bulk of the polymer film is significantly higher than between the electrode and the quasi-two-dimensional polymer structure.

Pines’ demon observed as a 3D acoustic plasmon in Sr2RuO4

The characteristic excitation of a metal is its plasmon, which is a quantized collective oscillation of its electron density. In 1956, David Pines predicted that a distinct type of plasmon, dubbed a ‘demon’, could exist in three-dimensional (3D) metals containing more than one species of charge carrier1. Consisting of out-of-phase movement of electrons in different bands, demons are acoustic, electrically neutral and do not couple to light, so have never been detected in an equilibrium, 3D metal. Nevertheless, demons are believed to be critical for diverse phenomena including phase transitions in mixed-valence semimetals2, optical properties of metal nanoparticles3, soundarons in Weyl semimetals4 and high-temperature superconductivity in, for example, metal hydrides3,5–7. Here, we present evidence for a demon in Sr2RuO4 from momentum-resolved electron energy-loss spectroscopy. Formed of electrons in the β and γ bands, the demon is gapless with critical momentum qc = 0.08 reciprocal lattice units and room-temperature velocity v = (1.065 ± 0.12) × 105 m s−1 that undergoes a 31% renormalization upon cooling to 30 K because of coupling to the particle–hole continuum. The momentum dependence of the intensity of the demon confirms its neutral character. Our study confirms a 67-year old prediction and indicates that demons may be a pervasive feature of multiband metals.

Printing Three-Dimensional Refractory Metal Patterns in Ambient Air: Toward High Temperature Sensors.

Refractory metals offer exceptional benefits for high temperature electronics including high-temperature resistance, corrosion resistance and excellent mechanical strength, while their high melting temperature and poor processibility poses challenges to manufacturing. Here this work reports a direct ink writing and tar-mediated laser sintering (DIW-TMLS) technique to fabricate three-dimensional (3D) refractory metal devices for high temperature applications. Metallic inks with high viscosity and enhanced light absorbance are designed by utilizing coal tar as binder. The printed patterns are sintered into oxidation-free porous metallic structures using a low-power (<10W) laser in ambient environment, and 3D freestanding architectures can be rapidly fabricated by one step. Several applications are presented, including a fractal pattern-based strain gauge, an electrically small antenna (ESA) patterned on a hemisphere, and a wireless temperature sensor that can work up to 350°C and withstand burning flames. The DIW-TMLS technique paves a viable route for rapid patterning of various metal materials with wide applicability, high flexibility, and 3D conformability, expanding the possibilities of harsh environment sensors.

Three-dimensional composite Li metal anode by simple mechanical modification for high-energy batteries

Three-dimensional composite Li metal anode by simple mechanical modification for high-energy batteries

Three-Dimensional WCoFe Ternary Metal Oxide Nanowire Network as a Carbon-Free Cathode Catalyst for High-Performance Li–O2 Batteries

Three-Dimensional WCoFe Ternary Metal Oxide Nanowire Network as a Carbon-Free Cathode Catalyst for High-Performance Li–O₂ Batteries

Superior strength–ductility synergy in three-dimensional heterogeneous-nanostructured metals

Heterogeneous microstructural design has been proven to be an effective strategy in breaking the strength–ductility dilemma in nanostructured metals. However, the precise control of heterogeneous microstructures to achieve strength–ductility synergy remains challenging. Here, we demonstrate a novel powder metallurgy approach for creating three-dimensional (3D) core–shell nanostructures with highly tunable shell thickness and grain size distributions. These 3D nanostructures enable superior strength–ductility synergy in pure copper, pushing the boundary of the Ashby map to unchartered territory. A combination of microstructural characterization, atomistic simulations and crystal plasticity modeling reveals that the generation and accumulation of geometrically necessary dislocations near the core–shell interface play a pivotal role in accommodating the strain gradient and sustaining a high strain-hardening rate during plastic deformation. Our work provides a viable approach for designing bulk nanostructured materials with 3D heterogeneous ingredients and demonstrates a promising pathway for the development of strong and ductile materials.

Continuous conducting architecture developed by supporting Prussian blue analogue on metal-organic framework derived carbon-doped manganese- oxide nanorods for high-performance sodium-ion batteries

Prussian blue analogues (PBA) are regarded as promising cathode materials for sodium-ion batteries (SIBs) owing to their open framework with large interstitial sites to accommodate Na+ ions. However, PBA suffer from low electronic conductivity and mechanical instability, which may be improved by their structural modification leading to enhanced kinetics. In this regard, we report an in-situ integration of ultra-small PBA cubes into three-dimensional metal organic framework (MOF) derived carbon-doped manganese oxide nanorods (C-Mn2O3), which form a continuous conductive architecture with intimate PBA/C-Mn2O3 contact. The C-Mn2O3 nanorods provide nucleation sites for the growth of PBA cubes and further act as the electronic pathway to improve electrode reaction kinetics. This hierarchical configuration effectively buffers the lattice expansion, which improve the structural stability of NiCoPBA. Consequently, the composite exhibits promising performance in aqueous Na+ batteries. Specifically, it delivers a high capacity of 97 mAh/g within a narrow potential window of and retained 82% capacity for 1000 cycles in aqueous electrolyte. It shows even higher capacity of 136 mAh/g and similar capacity retention (76% after 1000 cycles) in non-aqueous electrolytes. The promising performance of developed materials demonstrates the significant impact decreasing the size of PBA cubes has on the capacity by reducing the diffusion pathways and thus facilitating intercalation/deintercalation within the cubes. This study offers new insights of exploiting redox-active substrates to modify and stabilize PBA materials for energy storage applications.

Three-Dimensional Neodymium Metal–Organic Framework for Catalyzing the Cyanosilylation of Aldehyde and the Synthesis of 2,3-Dihydroquinazolin-4(1H)-one Derivatives

In this work, a novel 3D lanthanide metal–organic framework (Ln-MOF) Nd-cdip (H4cdip = 5,5′-carbonyldiisophthalic acid) was successfully synthesized, which could be used as an efficient heterogeneous catalyst for cyanosilylation and the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives at room temperature based on the Lewis acid sites in the channels of the MOF. Moreover, Nd-cdip had an excellent turnover number (500) for catalyzing cyanosilylation in no solvent condition. Nd-cdip could be reused in both of the above-mentioned reactions at least five times without a significant decrease in yield. The possible mechanism of cyanosilylation catalyzed by Nd-cdip was studied by using the luminescence properties of Tb-cdip, which has the same structure and functions as Nd-cdip. Furthermore, both reactions catalyzed by Nd-cdip were fitted to zero-order dynamics.

Novel sulfonated rGOHfO2/PVDF hybrid nanocomposite ultrafiltration membrane towards direct potable reuse water production

Using wastewater to produce safe and reliable reclamation water is a sustainable means of reducing water scarcity. Membrane technology can be a viable path for producing advanced treated water from wastewater. Numerous three-dimensional metal oxide nanoparticles with graphene oxide (GO) have been evaluated in membrane fabrication. On the other hand, there are no reports on the use of GO combined with hafnium oxide (HfO2) for the fabrication of ultrafiltration (UF) membranes to produce direct potable reuse (DPR) water. In this study, rGOHfO2 (reduced GOHfO2) was synthesized using a microwave method. A novel sulfonated rGOHfO2 (SrGOHfO2) nanocomposite was fabricated and added to the polyvinylidene fluoride (PVDF) to develop advanced nanohybrid UF membranes toward the production of DPR water and improve dispersibility and hydrophilicity. The incorporation of SrGOHfO2 into PVDF membranes had very positive effects on hydrophilicity, MWCO, and morphology. The P-SGOHf-2 membrane (0.2 wt % SrGOHfO2) exhibited excellent pure water flux of approximately 301 ± 3% and 133.3 ± 2% than PVDF and P-GOHf membrane, respectively. The P-SGOHf-2 membrane showed high separation efficiency up to 94 ± 1% and 98 ± 04% towards humic acid (HA) and bovine serum albumin (BSA), respectively. The superior antifouling properties were observed in the SrGOHfO2 incorporated membranes compared to the P-GOHf and PVDF membranes, with a 2.9% irreversible fouling ratio (Rir) and a 97.1% flux recovery ratio (FRR) for the P-SGOHf-2 membrane. The excellent performance of the P-SGOHf-2 membrane was attributed to the larger number of sulfonic acid groups (-SO3H) in the SrGOHfO2 nanocomposite. In the tertiary UF membrane filtration mode operation using the secondary effluent of the field-scale wastewater treatment plant, the P-SGOHf-2 membrane performed high flux with reliable effluent quality (154 ± 5L m−2 h−1, 0.26 ± 0.03 NTU, no pathogens), while it exhibited lower membrane resistances during filtration. These advanced nanohybrid membranes can be a sustainable, viable alternative technology compared to the traditional tertiary treatment processes that utilize expensive and complex multi-step processes to produce DPR water.

THE PROBLEM OF FORECASTING THE ROD STRUCTURES SURVIVABILITY

Purpose. Methods of metal structures calculation which would take into account sudden changes of the design scheme and its elements destruction as a result, are not perfect enough and are often fragmentary. The research of survivability of multi-element bar structures affected by negative factors will improve the efficiency of the such structures calculation with the prospect of further expanding the possibilities of forecasting the survivability of metal structures depending on its operation conditions. As a research object three-dimensional metal bar structures are considered, which are characterized by a high degree of production significance and responsibility during the operation. Methodology. The considered normative documents do not have a single approach regarding the identification of the problem and technique of generating possible solutions, but they combine all the listed standards. Approaches and methods for assessing the degree of a structure damage or serviceability are somewhat different: in some documents the area of damaged floor structures is limited; in others, the state of structures that have not gone out of work is assessed; as well as the economic forecast of a new building construction or restoring an old one. If we group the normative documents’ provisions of the different countries, we can single out two established approaches on "progressive destruction" protection. According to the first approach, it is necessary to use indirect protection measures, according to the second one, it is necessary to use the ability of key (bearing) elements to perceive damaging effects, the ability of structure to redistribute loads in case of some elements’ failures. Results. To increase the stability of building structures to progressive destruction, metal ones particularly, it is necessary to consider the possibility of local destruction already at the stage of building design. Its increase is facilitated by a decrease in the number of hinged joints, in some cases the use of integral structural elements, the use of building materials affected by plastic deformation, as well as the identification of building structure elements which under normal operating conditions do not perform bearing functions, but perform them in the case of the local destruction appearance. Scientific novelty. The analyses of the regulatory base and the researchers’ works in a number of countries including Ukraine regarding the progressive destruction is performed. The necessity to improve the concept of designing construction objects is justified. The basis of this concept should consist of both theoretical research and experimental confirmation of the accepted assumptions. Practical value. The necessity of forming a unified approach for determining the problem of survivability and durability of structures, redistribution of loads on undamaged structural elements is substantiated. Directions for the development of measures and design solutions regarding the prevention of the progressive destruction of multi-element bar structures are proposed.

Two Cu-Based Phosphonate Metal–Organic Frameworks as Efficient Water-Splitting Photocatalysts

Two novel three-dimensional metal–organic frameworks (MOFs) based on the photoactive pyrene tetraphosphonate ligand and copper (denoted as IEF-8 and IEF-9) have been hydrothermally synthesized and fully characterized (XRD, FTIR, TGA, SEM, XPS, etc.). Their crystal structures were unveiled by single-crystal X-ray diffraction. Remarkably, these materials exhibit coordinatively unsaturated copper (II) sites, free −PO3H2 and −PO3H acidic groups, and good thermal and chemical stability. Further, their optoelectronic characterization evidenced a photoresponse suitable for photocatalysis. In this sense, the photocatalytic activity of pyrene phosphonate MOFs was evaluated for the first time for the challenging hydrogen evolution reaction. In particular, IEF-8 exhibited a catalytic efficiency higher than that of the benchmarked Ti carboxylate photocatalyst MIL-125(Ti)–NH2, producing 1800 μmol·g–1 after 22 h under UV–vis irradiation in the absence of any co-catalyst. Furthermore, this material presented good reusability (at least up to 4 cycles), preserving its activity and structural integrity.

Ultra-Thick Cathodes for High-Energy Lithium-Ion Batteries Based on Aluminium Foams—Microstructural Evolution during Densification and Its Impact on the Electrochemical Properties

Using three-dimensional (3D) metal foams as current collectors is considered to be a promising approach to improve the areal specific capacity and meet the demand for increased energy density of lithium-ion batteries. Electrodes with an open-porous metal foam as current collector exhibit a 3D connected electronic network within the active mass, shortening the electron transport pathways and lowering the electrodes’ intrinsic electronic resistance. In this study, NMC622 cathodes using an aluminium foam as current collector with a measured areal capacity of up to 7.6 mAh cm−2 were investigated. To this end, the infiltrated foams were densified to various thicknesses between 200 µm and 400 µm corresponding to an electrode porosity between 65% and 30%. The microstructural analysis reveals (i) the elimination of shrinking cavities and a decrease in the porosity of the infiltrated active mass, (ii) an improved contact of active mass to the current collector structure and (iii) a pronounced clogging of the surface pores. The electrochemical properties such as capacity and rate capability are correlated to the electrode’s microstructure, demonstrating that densification is necessary to improve active material utilization and volumetric capacity. However, strong densification impairs the rate capability caused by increased pore resistance and hindered electrolyte accessibility.

Intrinsic optical absorption in Dirac metals

A Dirac metal is a doped (gated) Dirac material with the Fermi energy (EF) lying either in the conduction or valence bands. In the non-interacting picture, optical absorption in gapless Dirac metals occurs only if the frequency of incident photons (Ω) exceeds the direct (Pauli) frequency threshold, equal to 2EF. In this work, we study, both analytically and numerically, the role of electron–electron (ee) and electron–hole (eh) interactions in optical absorption of two-dimensional (2D) and three-dimensional (3D) Dirac metals in the entire interval of frequencies below 2EF. We show that, for Ω≪EF, the optical conductivity, ℜσ(Ω), arising from the combination of ee and certain eh scattering processes, scales as Ω2lnΩ in 2D and as Ω2 in 3D, respectively, both for short-range (Hubbard) and long-range (screened Coulomb) interactions. Another type of eh processes, similar to Auger–Meitner (AM) processes in atomic physics, starts to contribute for Ω above the direct threshold, equal to EF. Similar to the case of doped semiconductors with parabolic bands studied in prior literature, the AM contribution to ℜσ(Ω) in Dirac metals is manifested by a threshold singularity, ℜσ(Ω)∝(Ω−EF)d+2, where d is the spatial dimensionality and 0<Ω−EF≪EF. In contrast to doped semiconductors, however, the AM contribution in Dirac metals is completely overshadowed by the ee and other eh contributions. Numerically, ℜσ(Ω) happens to be small in almost the entire range of Ω<2EF. This finding may have important consequences for collective modes in Dirac metals lying below 2EF.

A Generalized Ductile Phase Field Model for Fracture Behavior of Three-Dimensional Metal Structures

The commercial finite element software is usually used to analyze the failure modes of metal structures. In this work, we present a generalized ductile phase field model to solve the fracture problems of three-dimensional metal structures. This model can be easily implemented in Abaqus software. The isotropic hardening model and exponential hardening law were used to describe plastic behavior of metals. The different element types were introduced to mesh the structures conveniently. The ductile phase field governing equations were given and solved by the Broyden–Fletcher–Goldfarb–Shanno (BFGS) quasi-Newton monolithic algorithm. Moreover, an efficient and accurate adaptive analytic method of the third-order real symmetric matrix was proposed to implement the tension–compression decomposition. Some typical specimens commonly used in engineering were designed and manufactured. The corresponding static and fatigue tests were carried out, and the simulation results were compared with the experimental ones. The proposed model can predict the crack initiation and propagation of arbitrary three-dimensional metal structures under tensile, shear, torsional and fatigue loading.

Quinoid-Based Three-Dimensional Metal–Organic Framework Fe2(dhbq)3: Porosity, Electrical Conductivity, and Solid-State Redox Properties

We report the synthesis, characterization, and electronic properties of the quinoid-based three-dimensional metal-organic framework [Fe2(dhbq)3]. The MOF was synthesized without using cations as a template, unlike other reported X2dhbq3-based coordination polymers, and the crystal structure was determined by using single-crystal X-ray diffraction. The crystal structure was entirely different from the other reported [Fe2(X2dhbq3)]2-; three independent 3D polymers were interpenetrated to give the overall structure. The absence of cations led to a microporous structure, investigated by N2 adsorption isotherms. Temperature dependence of electrical conductivity data revealed that it exhibited a relatively high electrical conductivity of 1.2 × 10-2 S cm-1 (Ea = 212 meV) due to extended d-π conjugation in a three-dimensional network. Thermoelectromotive force measurement revealed that it is an n-type semiconductor with electrons as the majority of charge carriers. Structural characterization and spectroscopic analyses, including SXRD, Mössbauer, UV-vis-NIR, IR, and XANES measurements, evidenced the occurrence of no mixed valency based on the metal and the ligand. [Fe2(dhbq)3] upon incorporating as a cathode material for lithium-ion batteries engendered an initial discharge capacity of 322 mAh/g.

A three-dimensional terbium metal − organic framework fluorescent sensor for efficient detection of chloroquine phosphate in serum

A novel three-dimensional (3D) anionic anhydrous metal − organic framework (MOF), {[NH2(CH3)2]·[Tb(pdca)2]}n (Tb-MOF; H2pdca = 2,5-pyridinedicarboxylic acid) has been triumphantly fabricated and structurally characterized. The obtained Tb-MOF displays good stability in some common solvent systems and high temperature environments. The luminescence properties of Tb-MOF are investigated by fluorescence spectra, and the results exhibit superb characteristic emission of Tb3+ ions, which lay a foundation for exploring the fluorescence sensing application of the material. More importantly, based on competitive absorption and dynamic quenching, Tb-MOF can be applied to detect chloroquine phosphate (CQ) used for the treatment of COVID-19 and malaria, showing high sensitivity and fast response speed in the sensing process. Notably, the specific quenchingeffect between Tb-MOF and CQ in the serum system without interference from other components, demonstrating the practical application potential of Tb-MOF.

Magnetic quantum phase transition in a metallic Kondo heterostructure

We consider a two-dimensional quantum spin system described by a Heisenberg model that is embedded in a three-dimensional metal. The two systems couple via an antiferromagnetic Kondo interaction. In such a setup, the ground state generically remains metallic down to the lowest temperatures and allows us to study magnetic quantum phase transitions in metallic environments. From the symmetry point of view, translation symmetry is present in two out of three lattice directions such that crystal momentum is only partially conserved. Importantly, the construction provides a route to study, with negative-sign-free auxiliary-field quantum Monte Carlo methods, the physics of local moments in metallic environments. Our large-scale numerical simulations show that as a function of the Kondo coupling, the system has two metallic phases. In the limit of strong Kondo coupling, a paramagnetic heavy-fermion phase emerges. Here, the spin degree of freedom is screened by means of the formation of a composite quasiparticle that participates in the Luttinger count. At weak Kondo coupling, magnetic order is present. This phase is characterized by Landau-damped Goldstone modes. Furthermore, the aforementioned composite quasiparticle remains intact across the quantum phase transition.

Advancements in Laser Wire-Feed Metal Additive Manufacturing: A Brief Review

Laser Wire-Feed Metal Additive Manufacturing (LWAM) is a process that utilizes a laser to heat and melt a metallic alloy wire, which is then precisely positioned on a substrate, or previous layer, to build a three-dimensional metal part. LWAM technology offers several advantages, such as high speed, cost effectiveness, precision control, and the ability to create complex geometries with near-net shape features and improved metallurgical properties. However, the technology is still in its early stages of development, and its integration into the industry is ongoing. To provide a comprehensive understanding of the LWAM technology, this review article emphasizes the importance of key aspects of LWAM, including parametric modeling, monitoring systems, control algorithms, and path-planning approaches. The study aims to identify potential gaps in the existing literature and highlight future research opportunities in the field of LWAM, with the goal of advancing its industrial application.

High-Performance CMOS Inverter Array with Monolithic 3D Architecture Based on CVD-Grown n-MoS2 and p-MoTe2.

In thiswork, monolithic three-dimensional complementary metal oxide semiconductor (CMOS) inverter array has been fabricated, based on large-scale n-MoS2 and p-MoTe2 grown by the chemical vapor deposition method. In the CMOS device, the n- and p-channel field-effect transistors (FETs) stack vertically and share the same gate electrode. High k HfO2 is used as the gate dielectric. An Al2 O3 seed layer is used to protect the MoS2 from heavily n-doping in the later-on atomic layer deposition process. P-MoTe2 FET is intentionally designed as the upper layer. Because p-doping of MoTe2 results from oxygen and water in the air, this design can guarantee a higher hole density of MoTe2 . An HfO2 capping layer is employed to further balance the transfer curves of n- and p-channel FETs and improve the performance of the inverter. The typical gain and power consumption of the CMOS devices are about 4.2 and 0.11 nW, respectively, at VDD of 1V. The statistical results show that the CMOS array is with high device yield (60%) and an average voltage gain value of about 3.6 at VDD of 1 V. This work demonstrates the advantage of two-dimensional semi-conductive transition metal dichalcogenides in fabricating high-density integrated circuits.