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Shock experiments are widely used to understand the mechanical and electronic properties of matter under extreme conditions. However, after shock loading to a Hugoniot state, a clear description of the post-shock thermal state and its impacts on materials is still lacking. We used diffraction patterns from 100-fs x-ray pulses to investigate the temperature evolution of laser-shocked Al–Zr metal film composites at time delays ranging from 5 to 75 ns driven by a 120-ps short-pulse laser. We found significant heating of both Al and Zr after shock release, which can be attributed to heat generated by inelastic deformation. A conventional hydrodynamic model that employs (i) typical descriptions of Al and Zr mechanical strength and (ii) elevated strength responses (which might be attributed to an unknown strain rate dependence) did not fully account for the measured temperature increase, which suggests that other strength-related mechanisms (such as fine-scale void growth) could play an important role in thermal responses under shock wave loading/unloading cycles. Our results suggest that a significant portion of the total shock energy delivered by lasers becomes heat due to defect-facilitated plastic work, leaving less converted to kinetic energy. This heating effect may be common in laser-shocked experiments but has not been well acknowledged. High post-shock temperatures may induce phase transformation of materials during shock release. Another implication for the study is the preservability of magnetic records from planetary surfaces that have a shock history from frequent impact events. [ABSTRACT FROM AUTHOR]

Ti-doped In 2 O 3 thin films with varying Ti contents are prepared by partial reactive co-sputtering using ceramic In 2 O 3 and metallic Ti targets and characterized by in situ x-ray photoelectron spectroscopy, electrical conductivity, and Hall-effect measurements. For a substrate temperature of 400 ° C , the carrier concentration increases faster than the Ti content and saturates at ≈ 7.4 × 10 20 c m − 3 . Based on these results, it is suggested that Ti does not directly act as donor in In 2 O 3 but is rather forming TiO 2 precipitates and that the related scavenging of oxygen generates oxygen vacancies in In 2 O 3 as origin of doping. Neutralization of oxygen vacancies is, therefore, suggested to be origin of the limitation of the carrier concentration in Ti-doped In 2 O 3 films. [ABSTRACT FROM AUTHOR]

We have studied the epitaxial growth of Si thin films on the Cd(0001) surface using low-temperature scanning tunneling microscopy. When deposited at low temperatures (100 K), Si atoms form dendritic islands with triangular shapes, indicating the existence of anisotropic edge diffusion in the process of Si film growth. After annealing to elevated temperatures, the triangular dendritic Si islands become hexagonal compact islands. Moreover, the 2D Si islands located on two different substrate terraces exhibit different heights due to the influence of quantum-well states in Cd(0001) films. Based on high-resolution scanning tunneling microscopy images, it is observed that the first, second, and third Si layers show the pseudomorphic 1 × 1 structure. In particular, the first and second layer islands reveal the opposite triangles, indicating the hexagonal close-packed stacking of Si atoms. These results provide important information for the growth of pristine Si films on metal substrates and the understanding of Si–metal interaction. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR) is a key technique in developing sensor platforms for clinical diagnostics, drug discovery, food quality, and environmental monitoring applications. While prism‐coupled (Kretschmann) SPR remains a “gold‐standard” for laboratory work‐flows due to easier fabrication, handling and high through put, other configurations such as grating‐coupled SPR (GC‐SPR) and wave‐guide mode SPR are yet to fulfil their technology potential. This work evaluates the technical aspects influencing the performance of GC‐SPR and reviews recent progress in the fabrication of such platforms. In principle, the GC‐SPR involves the illumination of the plasmonic metal film with periodic gratings to excite the surface plasmons (SP) via diffraction‐based phase matching. The real performance of the GC‐SPR is, however, heavily influenced by the topography of the grating structures produced via top‐down lithography techniques. This review discusses latest in approaches to achieve consistent plasmonic gratings with uniform features and periodicity over a large scale and explores the choice of plasmon‐active and substrate material for enhanced performance. The review also provides insights into the different GC‐SPR measurement configurations and highlights on opportunities with their potential applications as biosensors with translational capabilities. [ABSTRACT FROM AUTHOR]

By incorporating the dual ceramic elements TiB 2 /B 4 C, we investigated their impact on the mechanical properties, thermal properties, and friction performance of copper-based powder metallurgy materials, and elucidated the friction wear mechanism. Additionally, machine learning algorithms were employed to predict the friction coefficient and stability coefficient. The conclusions are as follows:With the increase in the TiB 2 /B 4 C ratio, the trend of mechanical properties initially increases and then decreases, with the optimum ratio being 5:3 for TiB 2 and B 4 C, exhibiting superior mechanical properties. Moreover, B 4 C enhances the thermal conductivity of copper-based friction materials more effectively than TiB 2. In terms of overall friction performance, the ratio of TiB 2 to B 4 C at 5:3 yields better frictional properties. The primary components of the friction surface friction film are CuO, Cu 2 O, Fe 2 O 3 , and B 2 O 3 , transitioning from a ceramic film to a metallic film as the TiB 2 /B 4 C ratio increases. The friction wear mechanism shifts from abrasive wear to severe fatigue wear as the TiB 2 /B 4 C ratio increases, accompanied by oxidative wear. Furthermore, an AdaBoost algorithm model was developed to effectively predict the friction coefficient and stability coefficient, with accuracies of 0.9993 and 0.8739, respectively. [ABSTRACT FROM AUTHOR]

In this perspective we discuss the progress made in the mechanistic studies of the surface chemistry associated with the atomic layer deposition (ALD) of metal films and the usefulness of that knowledge for the optimization of existing film growth processes and for the design of new ones. Our focus is on the deposition of late transition metals. We start by introducing some of the main surface-sensitive techniques and approaches used in this research. We comment on the general nature of the metallorganic complexes used as precursors for these depositions, and the uniqueness that solid surfaces and the absence of liquid solvents bring to the ALD chemistry and differentiate it from what is known from metalorganic chemistry in solution. We then delve into the adsorption and thermal chemistry of those precursors, highlighting the complex and stepwise nature of the decomposition of the organic ligands that usually ensued upon their thermal activation. We discuss the criteria relevant for the selection of co-reactants to be used on the second half of the ALD cycle, with emphasis on the redox chemistry often associated with the growth of metallic films starting from complexes with metal cations. Additional considerations include the nature of the substrate and the final structural and chemical properties of the growing films, which we indicate rarely retain the homogeneous 2D structure often aimed for. We end with some general conclusions and personal thoughts about the future of this field. [ABSTRACT FROM AUTHOR]

The van der Waals (vdW) contact, characterized by its bondless interactions, opens up exciting possibilities in cutting‐edge mask technology. It enables incredibly close proximity to samples at the atomic level while facilitating non‐destructive engineering. In this study, the concept of a vdW metal mask using the template striped ultra‐flat Ag/Au film is introduced. The probe tip‐assisted metal film transfer under an optical microscope is employed to showcase all‐solid and residue‐free engineering on 2D materials. The robust nature of the vdW metal mask allows for various treatments, including gas, liquid, solid, plasma, and light, making it a universal tool for fabricating 2D material‐based devices and samples with sub‐1 µm resolution, all without the need for lithography technologies. With the superiority in simple sample fabrication, ultra‐clean surfaces, and robustness under harsh conditions, the technique is believed to flourish in the 2D material research field. [ABSTRACT FROM AUTHOR]

Ellipsometry is an optical analytical method in which desired reflecting or transmitting surface parameters are related to measurements by mathematical models. Recent work has shown that using artificial intelligence (AI), methods can result in predicting reflecting surface parameters faster and more easily than by using iterative methods. This prior AI work used artificial neural networks applied to a growing absorbing film on a known substrate. Each different substrate required a set of separately trained networks across the wavelength spectrum, thus necessitating training a new set of networks for each new substrate. The work presented here does not require substrate optical property data. Thus, one set of spectroscopic networks can serve a large number of different substrates. This becomes possible by increasing the number of measurements per wavelength from two to three. For now, we consider transparent substrates for which the extinction coefficient of the substrate (k2) is zero or near zero. As before, the noniterative, stable, and fast performance lends itself to real-time, in situ monitoring of thin film growth. Examples for such growth of an absorbing metal film, chromium, will be given using two different substrates. The multilayer perceptron configuration consists of six input and six output neurons with two hidden layers of 80 neurons each. Solutions are performed at each wavelength independently and do not rely on fitting functions for optical properties. [ABSTRACT FROM AUTHOR]

We have developed and optimized a method to grow ruthenium films of unprecedented quality. Our three-step process is reminiscent of solid-phase epitaxy. First, c-cut sapphire substrates are terminated at their Al-rich √31 × √31R ± 9° reconstruction by in situ annealing. Second, 3D structured epitaxial Ru films are deposited at low temperatures by laser evaporation of Ru rods. Third, the films, thus, obtained are epitaxially transformed by high-temperature annealing. X-ray diffraction studies reveal good crystallinity of the obtained 15–60 nm-thick films: peak widths of the rocking curve are one order of magnitude smaller than those of the best published films. Scanning transmission electron microscopy and electron energy loss studies show that the interface between the sapphire substrates and the flat Ru films is atomically sharp with very limited intermixing. These results demonstrate the usefulness of postanneal processes for producing high-quality epitaxial films of elemental metals on insulating substrates. [ABSTRACT FROM AUTHOR]

Resonant nanostructures have emerged as versatile photonic platforms for boosting optical nonlinear responses on a subwavelength scale for their ability to confine intense electromagnetic fields while relaxing the phase-matching requirements. Recent significant advances in this field are associated with the utilization of non-radiative eigenmodes above the light cone, termed bound states in the continuum (BICs), which provide a unique mechanism for light trapping to realize excitation of ultrahigh quality (Q) factor resonances. Nevertheless, the current studies on BICs predominantly focus on symmetry-protected BICs (SP-BICs), whose excitation requires symmetry breaking, and Q factors are limited by fabrication imperfections. Here, we demonstrate a simple and feasible scheme for creating degenerate pairs of mirror-coupled super-BICs by harnessing magnetic dipole resonances coupled to their mirror images in adjacent metal films. Unlike trivial SP-BICs, mirror-coupled BICs showcases the huge enhancement of Q factors and are resilient against fabrication imperfections. By combining mirror-coupled resonance with the engineered radiative loss, we obtain a perfect absorber with near-unity absorption and ultra-narrow bandwidth at a critical coupling condition. Finally, we numerically demonstrate the terahertz (THz) regime, polarization-insensitive highly efficient third-harmonic generation benefiting from the maximum field enhancement localized within the perfect absorber. Our work not only paves the way toward unlocking the full potential of BIC resonance but also promise valuable insights for developing efficient THz optoelectronic devices and metadevices across a wide range of fields. [ABSTRACT FROM AUTHOR]

Scanning tunneling microscopy shows that copper deposited at room temperature onto a freshly exfoliated MoS2 surface forms Cu(111) clusters with periodic preferred heights of 5, 8, and 11 atomic layers. These height intervals correlate with Fermi nesting regions along the necks of the bulk Cu Fermi surface, indicating a connection between physical and electronic structures. Density functional theory calculations of freestanding Cu(111) films support this as well, predicting a lower density of states at the Fermi level for these preferred heights. This is consistent with other noble metals deposited on MoS2 that exhibit electronic growth, in which the metal films self-assemble as nanostructures minimizing quantum electronic energies. Here, we have discovered that it is critical for the metal deposition to begin on a clean MoS2 surface. If copper is deposited onto an already Cu coated surface, even if the original film displays electronic growth, the resulting Cu film lacks quantization. Instead, the preferred heights of the Cu clusters simply increase linearly with the amount of Cu deposited upon the surface. We believe this is due to different bonding conditions during the initial stages of growth. Newly deposited copper would bond strongly to the already present copper clusters, rather than the weak bonding, which exists to the van der Waals terminated surface of MoS2. The stronger bonding with previously deposited clusters hinders additional Cu atoms from reaching their lowest quantum energy state. The interface characteristics of the van der Waals surface enable surface engineering of self-assembled structures to achieve different applications. [ABSTRACT FROM AUTHOR]

Scanning tunneling microscopy shows that copper deposited at room temperature onto a freshly exfoliated MoS2 surface forms Cu(111) clusters with periodic preferred heights of 5, 8, and 11 atomic layers. These height intervals correlate with Fermi nesting regions along the necks of the bulk Cu Fermi surface, indicating a connection between physical and electronic structures. Density functional theory calculations of freestanding Cu(111) films support this as well, predicting a lower density of states at the Fermi level for these preferred heights. This is consistent with other noble metals deposited on MoS2 that exhibit electronic growth, in which the metal films self-assemble as nanostructures minimizing quantum electronic energies. Here, we have discovered that it is critical for the metal deposition to begin on a clean MoS2 surface. If copper is deposited onto an already Cu coated surface, even if the original film displays electronic growth, the resulting Cu film lacks quantization. Instead, the preferred heights of the Cu clusters simply increase linearly with the amount of Cu deposited upon the surface. We believe this is due to different bonding conditions during the initial stages of growth. Newly deposited copper would bond strongly to the already present copper clusters, rather than the weak bonding, which exists to the van der Waals terminated surface of MoS2. The stronger bonding with previously deposited clusters hinders additional Cu atoms from reaching their lowest quantum energy state. The interface characteristics of the van der Waals surface enable surface engineering of self-assembled structures to achieve different applications. [ABSTRACT FROM AUTHOR]

Metal oxide films are essential in most electronic devices, yet they are typically deposited at elevated temperatures by using slow, vacuum-based processes. We printed native oxide films over large areas at ambient conditions by moving a molten metal meniscus across a target substrate. The oxide gently separates from the metal through fluid instabilities that occur in the meniscus, leading to uniform films free of liquid residue. The printed oxide has a metallic interlayer that renders the films highly conductive. The metallic character of the printed films promotes wetting of trace amounts of evaporated gold that would otherwise form disconnected islands on conventional oxide surfaces. The resulting ultrathin (<10 nanometers) conductors can be patterned into flexible circuits that are transparent, mechanically robust, and electrically stable, even at elevated temperatures. [ABSTRACT FROM AUTHOR]

Hundreds of nanometer-thick metal layers are used as electrical conductors in various technologies and research fields. The intensity of the radiation transmitted by such devices is a small fraction and is often neglected. Here, it is shown that intense terahertz time-domain spectroscopy can probe the absolute electro-optical properties of a 100 nm thick gold sample in transmission geometry without the need to apply electrical contacts or handle wires. The terahertz conductivity of the metal film agrees with that obtained from standard contact measurements of the static component within the error bars. This experimental approach can help to quantify the electrical properties of opaque and conductive materials such as the composite electrodes used in photovoltaic or electrochemical applications, and in the quality control of metal films. [ABSTRACT FROM AUTHOR]

As a layered material with single/multi-atom thickness, two-dimensional transition metal sulfide WS2 has attracted extensive attention in the field of science for its excellent physical, chemical, optical, and electrical properties. The photoelectric properties of WS2 are even more promising than graphene. However, there are many existing preparation methods for WS2, but few reports on its direct growth on tungsten films. Therefore, this paper studies its preparation method and proposes an innovative two-dimensional material preparation method to grow large-sized WS2 with higher quality on metal film. In this experiment, it was found that the reaction temperature could regulate the growth direction of WS2. When the temperature was below 950 °C, the film showed horizontal growth, while when the temperature was above 1000 °C, the film showed vertical growth. At the same time, through Raman and band gap measurements, it is found that the different thicknesses of precursor film will lead to a difference in the number of layers of WS2. The number of layers of WS2 can be controlled by adjusting the thickness of the precursor. [ABSTRACT FROM AUTHOR]

Supramolecular chemistry–mediated synthesis has thus far been employed for the design of ordered mesoporous structures surrounded by various metal oxides that are helpful as nanometer-scaled unique reaction containers with high specific surface area, large pore volume and uniform mesopores useful for the storage and mass transport of large-sized molecules. The evaporation-induced self-assembly (EISA) process is very powerful for fabricating mesoporous metal oxide films with the rapid evaporation of solvents. Although a similar EISA process is also applied to synthesize mesoporous metal oxide powders using the room-temperature drying process with slow evaporation of solvents, the control of the evaporation rate should be quantified for the complete reproduction of high-quality metal oxide powders. In this feature article, I introduce our recent challenge in synthesizing highly porous metal oxides in powder form with the smart optimization of synthetic conditions by combining several EISA processes to eliminate the mismatch of the rate of solvent evaporation, inducing the self-assembly of amphiphilic organic molecules. [ABSTRACT FROM AUTHOR]

Bioresorbable electrochemical sensors remain mostly unexplored despite their ability to provide continuous in situ measurements of critical biomarkers. The primary challenge arises from the direct exposure of the electrodes' thin metal films to biofluids, which poses difficulties in ensuring both proper operational lifetimes and sensing performance. Molybdenum (Mo) presents itself as a promising biometal due to its uniquely gradual dissolution in biofluids, facilitated by the formation of a slower‐dissolving MoOx surface layer. Consequently, carefully engineered MoOx films can endow transient electrochemical sensors with unparalleled stability during extended operational lifetimes. Herein an unprecedented sensor architecture achieved via the unique pairing of sputtered Mo and MoOx thin films, probed as a pH and dissolved oxygen sensor is reported. Compared to a bare Mo electrode, a bilayer Mo+MoOx electrode subjected to post‐deposition annealing (400 °C, 60 min, N2 environment) displayed a largely improved stability (>24 h) in solution and demonstrated predictable functionality during ongoing film dissolution at 37 °C. Collectively, this work establishes a pioneering strategy for the fabrication of reliable and clinically relevant implantable electrochemical sensors. [ABSTRACT FROM AUTHOR]

The current study presents a fundamental understanding of the behavior of different-sized hydrogen bubbles rising in a new slag – metal system featured with a thick upper slag layer and ever-changing slag thickness and slag physical properties in the H2-based smelting process, based on newly developed CLSVOF model simulations. The evolution of bubble shape, bubble rising velocity, and the formation, collapse and detachment of metal liquid film wrapped on the bubble are predicted. The results show that decreasing the slag layer thickness or the slag viscosity delays the detachment of the metal liquid film from the bubble, increases the bubble rising velocity in the metal layer, but make no difference to the bubble terminal rising velocity in the slag layer. As a result, the bubble has shorter rising time in the bath with a higher slag viscosity. The resistance of the slag – metal interface to the bubble decreases with the increase of the bubble diameter, and small bubble therefore passes through the interface more slowly than the large one. In addition, the bubble shape evolution and bubble breakup in the slag layer are complicated with the increase of the slag thickness, bubble diameter and slag viscosity. [ABSTRACT FROM AUTHOR]

The traditional and modified structures are simulated by the finite element method (FEM). In the modified structure, ten well-known add layers with complex refractive indexes (MgF2, SiO2, ITO, Si, ZnO, PLZT, GaAs, LNO, PZT, and TiN) are proposed over a thin film of gold metal. Due to the addition of the add layer, the stability of the proposed structure increases and also manipulates the performance parameters of the considered structure. Therefore, we investigated theoretically that the reflectance spectrum is a function of the incidence angle, and surface plasmon waves at the resonance angle were obtained. From the reflectance spectra, we obtained the maximum shift, i.e., 2.369° in Si, and the minimum shift, i.e., 1.484° for MgF2, from the considered add layer. Moreover, the full beam width is minimum, i.e., 5.1140°; the figure of merit is high, i.e., 27.109 a.u./RIU; detection accuracy is maximum, i.e., 0.292; and the quality factor is also high, i.e., 27.563 RIU−1 for the traditional SPR sensor among all considered structure. In addition, if we keep the complex refractive index (n + ik) of considered add layer remain constant and varying the thickness of considered add layer then the resonance angle shifts towards right angle, minimum reflectance value shift upwards, width of reflectance curve becomes broader, and penetration depth decreases. After that, the same observation is found if we keep thickness and imaginary part of complex refractive index remain constant but only real part of complex refractive index increases of considered add layer. But, when we keep the thickness of add layer and real part of complex refractive index remain constant and varying the imaginary part complex refractive index of the considered add layer then the resonance angle shifts towards right angle, minimum reflectance value decreases, and penetration depth (PD) value increases. After that, we calculated the performance parameters, i.e., field intensity at different interfaces (metal-sensing medium (M-S), metal-dielectric (M-D), and dielectric-sensing medium (D-S)), shift in resonance angle (∆θr), full beam width (FBW), sensitivity (S), detection accuracy (DA), quality factor (Q), figure of merit (FoM), and penetration depth (PD) for all the considered structures. From the obtained result, we have observed that the PD is maximum for MgF2, i.e., 2.96 nm, and minimum for GaAs, i.e., 0.26 nm, among all the structures considered. This comparative study will help to choose an add layer with a complex refractive index over a metal thin film in a SPR sensor for the detection of analytes or molecules present in the sensing medium. [ABSTRACT FROM AUTHOR]

This manuscript presents a Kretschmann configured long-range surface plasmon resonance (LRSPR) imaging sensor (structure: 2S2G prism-MgF2-Ag-PtSe2-BlueP/MoS2-SM) demonstrating ultrahigh imaging sensitivity, SImg. (23,250 RIU−1); detection accuracy, DA (50 Deg.−1); angular figure of merit, FoMAng. (1930.87 RIU−1); imaging figure of merit, FoMImg. (1,162,500 Deg.−1 RIU−1); and better penetration depth, PD (1129.4 nm), for sensing of biomolecules. The MATLAB and COMSOL simulation software are used for numerical analysis of the results. The effect of different dielectric buffer layers, DBLs (MgF2, LiF, Cytop & Teflon), and Ag/Au thin metal films on sensor performance has been substantiated to find the best suited DBL and metal film. The use of PtSe2 leads to further enhance sensor performance due to its high carrier mobility, tunable bandgap, chemical stability, and immunity to toxicity. Heterostructure of BlueP/MoS2 plays an important role in attachment of biomolecules due to larger surface area and higher optical adsorption efficiency (5%), quantum confinement effect of MoS2. Furthermore, heterostructure of BlueP/MoS2 leads to improve the sensor performance parameters due to high charge carrier transfer efficiency. Overall, larger PD of proposed LRSPR sensor is suitable to detect larger size biomolecules. Hence, the proposed sensor performance paves a way for its efficient use in field of biological molecule sensing. [ABSTRACT FROM AUTHOR]

Haptic perception of softness is a unique feature of the human skin that relies on the concurrent measurements of the lateral deformation and compression of the skin during object manipulation. This is challenging to implement in robotics because of combined requirements in sensing modalities, skin format, robotic structures, and synthetic materials. A soft sensory skin supporting distributed and bimodal mechanical sensing over large surface area and suitable for robotic hand manipulation is reported. Resistive pressure and strain sensors are prepared with spray‐coated liquid metal films embedded in a silicone matrix. Object softness is computed through a calibrated model based on both sensor response curves and the stiffness of the carrier robot. The soft sensory skin enables localization and discrimination of softness that promise interesting future implementation for robotic palpation or precise teleoperation. [ABSTRACT FROM AUTHOR]

Evaluating the output of emitters and calibrating detectors using absolute power sensors is critical for public use. In free-space thermal power sensors, the measurement accuracy and sensitivity depend on the absorption characteristics of the absorber, and the response time relates to its intrinsic thermal time constant. A response time of a few seconds is useful in practical scenarios where factors such as power variations caused by changes in the current–voltage characteristics of the emitter are monitored. At the minimum, an intrinsic thermal time constant of a few tens of second is required to achieve a few-second measurement time because the actual time can be enhanced by the control method of the sensors. However, in the sub-terahertz region, conventional broadband absorbers must be adequately thick for high absorption, increasing thermal capacity. Thus, achieving high absorption and a good thermal response remains challenging. In this study, an absorber featuring a resin-hollow pyramidal structure covered with a metal film thinner than the skin depth was devised. To realize the proposed absorber, we used resin 3D printing and Ni–P electroless plating. A comparison with conventional absorbers demonstrated that the thermal time constant was comparable to that of a planar absorber, known for its suitable response but low absorption below 1 THz, while maintaining over 98.6% absorptance in the 0.1- to 0.3-THz range. These results can aid in the construction of a sub-terahertz power sensor with high accuracy, high sensitivity, and a few-second response time. [ABSTRACT FROM AUTHOR]

[Display omitted] Compared with layered materials such as graphite and transition metal disulfide compounds with highly anisotropic in-plane covalent bonds, it is inherently more challenging to obtain independent metallic two-dimensional films with atomic thickness. In this study, PtNi layered metallene nanobowls (LMBs) with multilayer atomic-scale nanosheets and bowl-like structures have been synthesized in one step using structural and electronic effects. The material has the advantage of catalyzing pH-universal hydrogen evolution reaction (HER). Compared with Pt/C, PtNi LMBs exhibited excellent HER activity and stability under all pH conditions. The overpotentials of 10 mA cm−2 at 0.5 M H 2 SO 4 , 1.0 M phosphate buffer and 1.0 M KOH were 14.8, 20.3, and 34.0 mV, respectively. Under acidic, neutral and alkaline conditions, the HER Faraday efficiencies reach 98.97%, 98.85%, and 99.04%, respectively. This study provides an example for the preparation of unique multilayer nanobowls, and also provides a basic research platform for the development of special HER materials. [ABSTRACT FROM AUTHOR]

This manuscript presents a Kretschmann configured long-range surface plasmon resonance (LRSPR) imaging sensor (structure: 2S2G prism-MgF2-Ag-PtSe2-BlueP/MoS2-SM) demonstrating ultrahigh imaging sensitivity, SImg. (23,250 RIU−1); detection accuracy, DA (50 Deg.−1); angular figure of merit, FoMAng. (1930.87 RIU−1); imaging figure of merit, FoMImg. (1,162,500 Deg.−1 RIU−1); and better penetration depth, PD (1129.4 nm), for sensing of biomolecules. The MATLAB and COMSOL simulation software are used for numerical analysis of the results. The effect of different dielectric buffer layers, DBLs (MgF2, LiF, Cytop & Teflon), and Ag/Au thin metal films on sensor performance has been substantiated to find the best suited DBL and metal film. The use of PtSe2 leads to further enhance sensor performance due to its high carrier mobility, tunable bandgap, chemical stability, and immunity to toxicity. Heterostructure of BlueP/MoS2 plays an important role in attachment of biomolecules due to larger surface area and higher optical adsorption efficiency (5%), quantum confinement effect of MoS2. Furthermore, heterostructure of BlueP/MoS2 leads to improve the sensor performance parameters due to high charge carrier transfer efficiency. Overall, larger PD of proposed LRSPR sensor is suitable to detect larger size biomolecules. Hence, the proposed sensor performance paves a way for its efficient use in field of biological molecule sensing. [ABSTRACT FROM AUTHOR]

There is a growing need for precise and rapid detection methods in fields such as biomedical diagnostics, environmental monitoring, and chemical analysis. Surface plasmon resonance (SPR) sensors have been used for the detection and quantification of a wide range of analytes, including biomolecules, chemicals, and gases, in real-time. Despite the promising capabilities of SPR sensors, there remains a gap in creating a balance between having a large enough area to capture a significant number of analytes for detection and being small enough to ensure high sensitivity. This research aims to explore the design of a D-shaped SPR-based optical fiber sensor, focusing on the use of copper, gold, and silver thin films at optimized width and thickness of 10 µm and 45 nm, respectively, to improve the sensor's performance. Employing a computational approach, this study examines the influence of the optimized width and refractive indices of metallic films on the sensor's characteristics. The 10 µm width of the metallic thin film has been found to produce an optimal balance between the sensitivity and the dynamic range of the sensor. Leveraging on the ratio of the real and imaginary parts of the dielectric constant of the thin film metal provides insight into the optical properties and sensitivity at certain wavelengths. Within an analyte refractive index range of 1.37–1.42 and a wavelength range of 650–1200 nm, results indicate that silver outperforms gold and copper at the optimized width with a wavelength sensitivity, and detection accuracy of 12,300 nmRIU−1, and 3.075, respectively. By optimizing the width of the metal thin film at 10 µm, a highly sensitive D-SPR is designed, allowing for enhanced sensor detection capabilities for a wide range of bioanalytes. [ABSTRACT FROM AUTHOR]

Cost-effective, versatile, and rapid deposition of single-crystal metal films is crucial to a wide spectrum of applications ranging from catalysis, plasmonics, electrochemistry, and optoelectronics to templating, epitaxial substrates, and integrated nanomanufacturing. High crystal quality typically implies low growth rates, which makes it challenging to achieve thicknesses in excess of 1 µm with conventional approaches. We show facile close-space sublimation of epitaxial single-crystal Au, Ag, and Cu films on MgO substrates. We demonstrate 10 μm thickness in less than 1 h while maintaining sub-5 nm rms surface roughness for a range of low- and high-index crystal film orientations. We show that the results can be captured by a simple model based on "line-of-sight" sublimation, which serves as a predictive tool and provides a basis to discuss broader potential as well as the limitations of this approach. [ABSTRACT FROM AUTHOR]

An arrayed nanocavity-shaped architecture consisting of the key GdFe film and SiO2 dielectric layer is constructed, leading to an efficient infrared (IR) absorption metasurface. By carefully designing and optimizing the film system configuration and the surface layout with needed geometry, a desirable IR radiation absorption according to the spatial magnetic plasmon modes is realized experimentally. The simulations and measurements demonstrate that GdFe-based nanocavity-shaped metasurfaces can be used to achieve an average IR absorption of ~81% in a wide wavelength range of 3–14 μm. A type of the patterned GdFe-based nanocavity-shaped metasurface is further proposed for exciting relatively strong spatial electromagnetic wavefields confined by a patterned nanocavity array based on the joint action of the surface oscillated net charges over the charged metallic films and the surface conductive currents including equivalent eddy currents surrounding the layered GdFe and SiO2 materials. Intensive IR absorption can be attributed to a spatial electromagnetic wavefield excitation and resonant accumulation or memory residence according to the GdFe-based nanocavity-shaped array formed. Our research provides a potential clue for efficiently responding and manipulating and storing incident IR radiation mainly based on the excitation and resonant accumulation of spatial magnetic plasmons. [ABSTRACT FROM AUTHOR]

Na2S is a key material in sodium‐sulfur batteries and its single‐monolayer film may also be a new 2D material. Herein, the results are first reported by STM, XPS, and DFT simulation that the Na2S single‐monolayer film shows different atomic structures depending on the underlying metals, and these structures can be changed by thermal annealing. All structures are well supported by DFT simulation on corresponding Na2S up, down, and standing models, as well as the NaS in‐plane model. Further, a wide bandgap of Na2S single‐monolayer film is measured, which decreases from Au(111) to Ag(111) and Cu(111) due to the different Na2S interactions with metal substrates. Finally, it is demonstrated that dibenzo 18‐crown‐6‐ether molecules can grow on phase VI of Na2S film at room temperature, as compared with preferred metal surfaces and Na2S phase III structure. [ABSTRACT FROM AUTHOR]

A liquid helium-free cryostat for radio frequency (RF) test of the superconducting cavity is designed and constructed. Gifford-Mcmahon (G-M) cryocoolers are used to provide cooling capacity, and the heat leakage at 4 K is less than 0.02 W. Vertical and horizontal tests of two Nb3Sn cavities are carried out in the cryostat with different surface treatments outside the cavities. Both of the cavities achieve stable continuous wave (CW) operation. A novel treatment, which cold-sprayed a 3.5 mm thick Cu layer onto the outside of the cavity, enables the maintenance of an average temperature of 5.5 K in the cavity at a RF loss of 10 W, implying that the thermal stability and uniformity of the cavity has been significantly improved. Through the synergistic control of four metal film resistors, a cooling rate of 0.06 K/min near 18 K is realized, and the cavity temperature gradient is reduced to 0.17 K/m, which effectively improves the RF performance of the cavity. The maximum E a c c of the cavity reaches 3.42 MV/m, and the Q 0 is 1.1 × 109. An electromagnetic–thermal coupling simulation model for the superconducting cavity is established and is in good agreement with the experimental results. The simulation results show that the cavity with a Cu-spraying treatment and the thermal links of 5N Al can satisfy the E a c c of 10 MV/m under conduction cooling. [ABSTRACT FROM AUTHOR]

The contact resistivity originating from the metal–semiconductor interface is a crucial factor for conversion efficiency of thermoelectric films devices. Due to anisotropic nature of state‐of‐art Bi2Te3 films, the contact resistivity also needs to match with the different orientations in/out‐plane film configurations. Here, a series of bismuth telluride (Bi2Te3) films with different orientations are deposited, and the contact resistivity between Ti/Cr/Cu and Bi2Te3‐based films is studied in detail. The increased (00l) orientation can effectively reduce the contact resistivity mainly due to the enhanced Tunneling effect. Finally, a low contact resistivity of 0.84 µΩ cm2 is observed in highly (00l)‐orientated Bi2Te3 film in contact with Cr. This work provides an effective method to control contact resistivity by adjusting the orientation of film, and also provides guidance on how to further improve the performance of thin film‐TEDs with different configurations. [ABSTRACT FROM AUTHOR]

A high‐performance self‐powered deep ultraviolet (DUV) photodetector based on the NiO/β‐Ga2O3 heterojunction is fabricated and analyzed. The NiO/β‐Ga2O3 heterojunction photodetectors are fabricated both with and without a post‐annealing process following NiO film deposition. Each photodetector structure is investigated through technology computer‐aided design simulations, including energy band diagram, trap density, and carrier concentration. The pristine self‐powered NiO/β‐Ga2O3 photodetector, lacking a post‐annealing process, exhibits partial Schottky contact formation between metal and NiO film, leading to performance degradation, including reduced responsivity, detectivity, and response time. On the other hand, the post‐annealed self‐powered NiO/β‐Ga2O3 photodetector demonstrates high performance such as a responsivity of 592.0 mA W−1, a detectivity of 4.30 × 1012 Jones, and response times of 30.93 ms and 72.32 ms, respectively. Therefore, the fabricated NiO/β‐Ga2O3 photodetector shows a promising potential for various applications requiring DUV detection without an external voltage bias. [ABSTRACT FROM AUTHOR]

A fully biodegradable, ultra‐sensitive, and soft strain sensor is pivotal for temporary, real‐time monitoring of microdeformations, crucial in disease diagnosis, surgical precision, and prognosis of muscular, and vascular conditions. Nevertheless, the strain sensitivity of previous biodegradable sensors, denoted by gauge factor (GF) up to ≈100, falls short of requirements for complex biomedical monitoring scenarios, specifically monitoring cardio‐cerebrovascular diseases with microscale variations in vascular surface strain. Here, a fully biodegradable, ultra‐sensitive crack‐based flexible strain sensor is introduced achieving GF of 1355 at 1.5% strain through integration of molybdenum (Mo) film, molybdenum trioxide (MoO3) adhesion layer, and polycaprolactone (PCL) substrate. Analysis of crack morphology of biodegradable thin‐film metals, including Mo, tungsten (W), and magnesium (Mg), reveals material‐dependent sensitivity and repeatability of crack‐based strain sensors. The effect of the adhesion layer and polymer substrate is also investigated. Overall morphological studies on the sensor present a comprehensive understanding of metal film cracking behavior and corresponding performance characterization, showing significant potential for highly sensitive sensors. A hybrid membrane composed of candelilla wax (Cw), beeswax (Bw), and polybutylene adipate‐co‐terephthalate (PBAT) is introduced to provide hydrophobic, yet flexible encapsulation. In vivo, short‐term (≈3 days) monitoring of vascular pulsatility underscores the potential of the sensing tool for rapid, accurate, and temporal disease diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Atomic sawtooth surfaces have emerged as a versatile platform for growth of single-crystal van der Waals layered materials. However, the mechanism governing the formation of single-crystal atomic sawtooth metal (copper or gold) films on hard substrates (tungsten or molybdenum) remains a puzzle. In this study, we aim to elucidate the formation mechanism of atomic sawtooth metal films during melting–solidification process. Utilizing molecular dynamics, we unveil that the solidification of the liquid copper initiates at a high-index tungsten facet with higher interfacial energy. Subsequent tungsten facets follow energetically favourable pathways of forming single-crystal atomic sawtooth copper film during the solidification process near melting temperature. Formation of atomic sawtooth copper film is guaranteed with a film thickness exceeding the grain size of polycrystalline tungsten substrate. We further demonstrate the successful growth of centimeter-scale single-crystal monolayer hexagonal boron nitride films on atomic sawtooth copper films and explore their potential as efficient oxygen barrier. Although single-crystal (SC) 2D materials can be grown on atomic sawtooth metal surfaces, the formation mechanism during the melting-solidification process remains unclear. Here authors reveal that solidification starts at high-index facets and spreads, forming a SC atomic sawtooth surface. [ABSTRACT FROM AUTHOR]

The multimode optoelectronic operation in a single component device is an attractive design strategy for future optoelectronics, which demands unique and complex multifunction. Here, a novel dual‐mode optoelectronic device with both memory and switching functionalities by utilizing alternating metallic stripe domain regime‐induced controllable hysteresis of two dimensional (2D)‐crystalline VO2 films is reported. It is found that the formation and disappearance of tensile strain‐induced metallic stripe domain arrays are susceptible to temperature‐induced thermal energy, allowing controllable hysteresis in electric field‐induced metal‐insulator transition (E‐MIT) by tuning the total region of aligned metallic stripe domains within the VO2 films through current flow‐induced thermal energy. Based on the tunable hysteresis in E‐MIT, the 2D‐crystalline VO2 film‐based device exhibits successful multimode optoelectronic memory and switching operations. The device with a large hysteresis width exhibits high‐performance optoelectronic memory behavior with a high on/off ratio of up to ≈55% and a long retention time over 5000 s response to a light pulse optically triggering MIT. On the other hand, the 2D‐crystalline VO2 film device with a narrow hysteresis width exhibits high performance of photodetection with a responsivity of 316 mA W−1 and response times of ≈1.2 and ≈2 µs at rise and fall, respectively. [ABSTRACT FROM AUTHOR]

In this paper, nickel chloride was selected as metal ions and 2,2′-bipyridine (bipy) and benzoic acid (ba) as ligands to synthesize Ni-bipy-ba ternary complex. Its corrosion inhibition effects on the corrosion of P110 carbon steel in 0.5 M HCl were evaluated by weight loss test, electrochemical measurements, surface analyses, and theoretical calculations. The results show that the Ni-bipy-ba ternary complex exhibits excellent corrosion inhibition properties compared with the two ligands, especially at high temperatures, which is supported by the calculation of thermodynamic parameters. Surface analyses indicate that Ni-bipy-ba ternary complex can inhibit corrosion by forming adsorption film on the metal surface. Theoretical calculations show a good correlation with the experimental results. The best corrosion inhibition efficiency of Ni-bipy-ba ternary complex could be ascribed to the synergistic effect of metal ligands and the complex structure with larger dimension and molecular mass. [ABSTRACT FROM AUTHOR]

The accuracy of the signal within a driving chain for the rate-integrating hemispherical resonator gyro (RI-HRG) plays a crucial role in the overall performance of the gyro. In this paper, a notable and effective method is proposed to realize the identification and compensation of the unbalanced error in the driving chain for the RI-HRG that improved the performance of the multi-loop control applied in the RI-HRG. Firstly, the assembly inclination and eccentricity error of the hemispherical resonator, the inconsistent metal conductive film layer resistance error of the resonator, the coupling error of the driving chain, and the parameter inconsistency error of the circuit components were considered, and the impact of these errors on the multi-loop control applied in the RI-HRG were analyzed. On this basis, the impact was further summarized as the unbalanced error in the driving chain, which included the unbalanced gain error, equivalent misalignment angle, and unbalanced equivalent misalignment angle error. Then, a model between the unbalanced error in the driving chain and a non-ideal precession angular rate was established, which was applicable to both single channel asynchronous control and dual channel synchronous control of the RI-HRG. Further, an unbalanced error identification and compensation method is proposed by utilizing the RI-HRG output with the virtual precession control. Finally, the effectiveness of the proposed method was verified through simulation and experiments in kind. After error compensation, the zero-bias instability of the RI-HRG was improved from 3.0950°/h to 0.0511°/h. The results of experiments in kind demonstrated that the proposed method can effectively suppress the non-ideal angular rate output caused by the unbalanced error in the driving chain for the RI-HRG, thereby further improving the overall performance of the RI-HRG. [ABSTRACT FROM AUTHOR]

Nanofilms of zinc, aluminum, lead, silver, and copper have been obtained by the laser-plasma method. The conditions of deposition of such films on substrates, providing the absence of metal particles on their surface, were determined. The threshold power densities of the laser radiation acting on a metal target, at which an intense evaporation of its material begins, were found experimentally. It is shown that the boiling temperature of the material of a target influences the surface relief of the metal nanofilms obtained. The conditions of obtaining fi lm coatings with small particles of the target material on their surface, which can be used for the realization of the giant Raman scattering, were determined. [ABSTRACT FROM AUTHOR]

The stress distribution in sealing glass is one of the most concerning issues for glass‐to‐metal (GtM) seals. In this study, photoluminescence spectroscopy was applied by exploiting the piezospectroscopic effect of Cr‐doped α‐Al2O3 (ruby), and the overall stress distribution along the radius of a concentric seal was detected and analyzed. It was discovered that the compressive stress first increased and then decreased at the edge of the seal. The maximum compressive stress of 91 MPa was detected at ∼20 µm from the interface and was ascribed to the interaction between the glass and surface oxide film of the metal. Stress distributions in pore regions were also investigated and obvious stress fluctuations were observed clustering around pores. A circle of compressive stress was observed around the pores in a single glass without a metal housing; for the pores in the center of the concentric seal, the stress distribution was dominated by the inner contraction of the metal housing; and for the pores near the edge of the seal, the concentration of tensile stress located perpendicular to that of the compressive stress. This study demonstrates a high‐resolved and nondestructive method to detect the stress field and explores the potential for future tailorability of stress distribution in GtM seals. [ABSTRACT FROM AUTHOR]

Thin films of crystalline solids with substantial free volume built from organic chromophores and metal secondary building units (SBUs) are promising for engineering new optoelectronic properties through control of interchromophore coupling. Zn‐based SBUs are especially relevant in this case because they avoid quenching the chromophore's luminescence. We find that layer‐by‐layer spin‐coating using Zn acetate dihydrate and benzene‐1,4‐dicarboxylic acid (H2BDC) and biphenyl‐4,4'‐dicarboxylic acid (H2BPDC) linkers readily produces crystalline thin films. However, analysis of the grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) data reveals the structures of these films vary significantly with the linker, and with the metal‐to‐linker molar ratio used for fabrication. Under equimolar conditions, H2BPDC creates a type of structure like that proposed for SURMOF‐2, whereas H2BDC generates a different metal‐hydroxide‐organic framework. Large excess of Zn2+ ions causes the growth of layered zinc hydroxides, irrespective of the linker used. Density functional theory (DFT) calculations provide structural models with minimum total energy that are consistent with the experimentally observed diffractograms. In the broader sense, this work illustrates the importance in this field of careful structure determination, e. g., by utilizing GIWAXS and DFT simulations to determine the structure of the obtained crystalline metal‐organic thin films, such that properties can be rationally engineered and explained. [ABSTRACT FROM AUTHOR]

This paper portrays the effect of growth rate on the structural, magnetic, and electrical properties of sputtered Ni thin films. Seventy-five nanometer thick Ni films were grown on Si <100> substrates at room temperature by high power impulse magnetron sputtering with varying growth rates such as 0.27, 0.57, 1.01, 2.18, and 2.65 Å/s. All the films crystallized in a single FCC type structure devoid of any impurity phase. With an increase in the growth rate, the density of the Ni films was found to increase. The surface roughness and the stresses developed in Ni films were found to decrease with an increase in the growth rate. Microstructural investigations indicated an island of surface morphology for all the films. An increase in growth rate was also found to affect the magnetic properties of Ni thin films considerably. Saturation magnetization increased with an increase in growth rate both along the in-plane and out-of-direction owing to the increase in the density of the film and reduction in stresses and surface roughness. Further, the in-plane magnetization studies also showed an increase in in-plane magnetic anisotropy in Ni films with an increase in growth rate. Evidences for improvement in the in-plane magnetic anisotropy were derived from the increase in the in-plane coercivity and remanence. Temperature variation of electrical resistivity in Ni films indicated a metallic behavior. Films grown at higher growth rates exhibited high-temperature co-efficient of resistance suitable for resistance temperature detector applications. [ABSTRACT FROM AUTHOR]

New features of light propagation in nonmagnetic lossless medium with weak nonlocal nonlinear response are described. The function of nonlinear response in a weak nonlocal approximation included in the dielectric permittivity is proposed. Stationary self-consistent wave equation in the term of the average of the field intensity is formulated. The procedure allowing to find the spectrum of stationary states of such an equation in relation to the metal-film covered waveguide is indicated. Dispersion equation determining the propagation constant as a function of the waveguide system parameters in general form of the waveguide region is obtained. The proposed theory is applied to calculate the eigenmode spectrum of metal-film covered circular fiber. Exact solution to the self-consistent wave equation describing the radial symmetric distribution of the electric field in a fiber cross section is found. Explicit equation determining the discrete spectrum of the propagation constant is obtained. It is shown that each mode corresponds to a set of the propagation constant values, which are generated by the zeros of the Bessel functions. Discrete spectrum of the propagation constant is linearly shifted by a value proportional to the coefficient of nonlinearity. Varying the value of the nonlinearity coefficient is effectively used to adjust the fiber diameter, which optimizes the characteristics of the waveguide. [ABSTRACT FROM AUTHOR]

Metallic films, which are thin layers of metal deposited on surfaces, have a wide range of uses in many sectors. Metallic films are usually produced by sputtering or chemical vapor deposition and serve an important role in electronics, optics and coatings. Their fundamental conductivity, reflective qualities and adaptability makes important for the development of innovative materials and systems. Investigations are conducted on the rigidity, optical reflecting power, temperature conductivity and power mobility of metallic films. These attributes are affected by layer thickness, composition and deposition processes. Understanding the complexities of these physical features is critical for modifying metallic films to particular applications, which drives technological and material science innovation. In this research, the physical characteristics of metallic films, which are thinner than 20 – 200 nm were evaluated. The suggested methods for determining the Cu, and Al films temperature-dependent coefficients of resistance, thermal conductivity properties, particular heat and thermal diffusivity. The rapid amount of heating that is observed in a brief period allows the thermal characteristics of the metallic layer to be primarily evaluated without impacting the substrate. [ABSTRACT FROM AUTHOR]

The arbitrarily formed golden cluster systems were created in the gas state which has strong Resistive Switching (RS) behavior around ambient temperatures and makes these attractive candidates for the creation of electronics geared toward neuron categorization along with information analysis. The cluster-assembled nanotechnology coatings that are fully linked have an irregular shape that includes neuromorphic crystallographic flaws, interactions and frontiers of grains, highlighting the complex interaction among electromagnetic in mechanical elements. In this analysis, we conduct a thorough investigation of the electroforming procedure that is utilized in the creation of film that was the cluster assembled. The present research sheds light regarding the electroforming procedure's substantial influence on the complex relations among nanopores and the mesoscale layer formations and underlying neurological properties of resistance switches activities that ensure. The findings provide insight into a methodical oversight of electroforming operation and reveal its function in building distinct patterns at various sizes in films of cluster assembled. The discovery not only improves our understanding of the intricate relationships among architectural and electrical parts but it provides opportunities for designing neurological structures that are randomly constructed and customized over multiple information-handling applications. [ABSTRACT FROM AUTHOR]

Regulation of the surface film characteristics of Li‐metal is a pivotal strategy for augmenting the electrochemical performance of Li‐metal batteries. This investigation elucidates a straightforward approach to surface film modification, namely, pre‐treatment via a CO2 gas reaction, and its subsequent impact on the electrochemical attributes of Li‐metal electrodes. Analysis of the topography and composition of the Li metal surfaces revealed the transformation of the surface film into a more uniform layer enriched with inorganic compounds, including Li2CO3 and Li2O, by pre‐treatment. This pre‐treatment process significantly enhances the electrochemical properties, such as cyclability and overpotential, in Li/Li symmetric cells, primarily because of the formation of an improved solid‐electrolyte interphase (SEI) derived from the altered surface film on Li metal electrodes. The reformed SEI significantly increases the mobility of Li ions through the interphase, thereby attenuating the impedance associated with Li‐ion migration within the SEI. This resistance attenuation is instrumental in alleviating the overpotentials, thereby significantly refining the electrochemical plating and stripping dynamics of Li metal electrodes. [ABSTRACT FROM AUTHOR]

Surface Plasmon Resonance (SPR) serves as a crucial optical technique in the realm of chemical sensing. Under specific conditions, the reflectivity of a thin metal film exhibits an exceptional sensitivity to optical changes in the medium on one side. In this investigation, we propose and simulate a plasmonic sensor incorporating a silicon nitride grating with Ag layers for the detection of solution and gas at an optical communication wavelength of 1550 nm. In both cases of the surface diffraction-grating, there is a notable enhancement in angular sensitivity compared to conventional prism-coupled configurations. Simulations, employing rigorous coupled wave analysis (RCWA), highlight that the suggested sensor, optimized in design parameters, offers notably superior sensitivity, a lower detection limit, and a higher figure of merit (FOM) than existing grating-based SPR sensors. This implies the potential realization of refractive index sensors with a high figure of merit through such streamlined and compact configurations. [ABSTRACT FROM AUTHOR]

The rapid increase in the resistivity of thin metal films as their thickness decreases to sub-10 nm, known as the resistivity size effect, is an important issue that must be addressed to ensure device performance in ultraminiaturized semiconductor devices. Molybdenum carbide (MoCx) has been studied as a candidate for emerging interconnection materials because it can maintain a low resistivity even at a low thickness. However, reports on stable precursors with guaranteed reactivity for atomic layer deposition (ALD) remain limited; moreover, the process of forming low-resistance MoCx thin films must be studied. In this study, we propose a new route to form low-resistivity MoCx thin films by thermal ALD with partial ligand dissociation by controlling the process pressure to enhance the reactivity of the Mo precursor with reactants. Following the proposed deposition process and subsequent annealing, uniform and continuous thin films were formed (even at a sub-5 nm thickness), with an extremely low resistivity of approximately 130 μΩ cm. Therefore, the proposed method can be applied as a next-generation interconnect process; notably, high-quality thin films can be formed through pressure-assisted decomposition, even with a lack of thermal energy during the ALD process. [ABSTRACT FROM AUTHOR]

The excitation of sound by a femtosecond laser pulse in a metal layer on a dielectric substrate has been studied. The modulations of the reflection coefficient of the metal, which arise due to the propagation of sound in it, are described in detail. It is shown that, in addition to oscillations corresponding to odd harmonics of sound waves, oscillations corresponding to even harmonics can be present on the profile of the Fourier image of the reflection coefficient change. The efficiency of even harmonic generation depends on the substrate material and the metal film thickness. The dependence of the reflection coefficient change on time has been studied. It has been established that if the electron heat flux reaches the metal–dielectric interface before the energy of the electrons is transferred to the lattice, then modulations are present both due to sound that occurs at the metal–vacuum interface and at the metal–dielectric interface. The wavelength of probe radiation also affects the reflection coefficient change. If real and imaginary parts of the permittivity at the wavelength of probing radiation are comparable in magnitude, then the Fourier image of the reflection coefficient change contains a smaller number of maxima, and the change in the reflection coefficient over time is accompanied by splitting of peaks. [ABSTRACT FROM AUTHOR]

Type I and type II silicon clathrates are guest–host structures made of silicon polyhedral cages large enough to contain atoms that can be either inserted or evacuated with only a slight volume change of the structure. This feature is of interest not only for batteries or storage applications but also for tuning the properties of the silicon clathrate films. The thermal decomposition process can be tuned to obtain Na8Si46 and Na2