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We investigated the effect of Cr thin film deposition on the thermal stability and corrosion resistance of hot-dip aluminized steel. A high-quality Cr thin film was deposited on the surface of the Al-9 wt. % Si-coated steel sheets by physical vapor deposition. When the Al-Si coated steel sheets were exposed to a high temperature of 500℃, Fe from the steel substrate diffused into the Al-Si coating layer resulting in discoloration. However, the highly heat-resistant Cr thin film deposited on the Al-Si coating prevented diffusion and surface exposure of Fe, improving the heat and corrosion resistances of the Al-Si alloy coated steel sheet.

Group IIIA metal chalcogenides are an auspicious material system due to their variability of properties and hence the multitude of application options, for example, in the fields of optoelectronic, thermoelectric, piezo‐, and ferroelectric devices. Indium and gallium selenide films are innovatively grown in a sequential PVD (physical vapor deposition) process starting from metal precursor layers of various thicknesses, which are then subject to chalcogenization in different selenium contents. The resulting thin films are investigated for structural and optical properties by Raman, XRD (X‐ray diffraction), and UV–Vis–NIR spectrometry, revealing that all the compounds In2Se3, InSe, In4Se3, Ga2Se3, and GaSe as well as different polytypes can be achieved depending on the metal/chalcogen ratio. Results from Raman and XRD spectroscopy are highly consistent, and also from the optical measurements changes in absorption characteristics can be correlated. The results indicate, that by fine‐tuning the selenium content, deliberately growing ultra‐thin layers of the different indium and gallium phases will be possible, thus opening up a promising route for 2D material fabrication. Given the scalability of the fabrication method, it is highly promising for large‐scale deployment of the materials. [ABSTRACT FROM AUTHOR]

The optical synaptic device is a novel nonvolatile memory device that combines optical sensing function with synaptic plasticity to simulate the basic biomimetic behaviors of the human visual system. It shows a great potential application in artificial vision. However, most of the current optical synaptic devices are either structurally special or complex, which are quite difficult to prepare especially for mass production. In this work, a submillimeter single‐crystal Bi2O2Se flake with selenium vacancies (Bi2O2Se‐VSe) grown by physical vapor deposition is presented. Upon the Bi2O2Se‐VSe flake, an optical synaptic device is designed with the persistent photoconductivity (PPC) effect induced by selenium vacancies. The device can simulate the biological synapses with an obvious synaptic plasticity. Moreover, an artificial vision system consisting of a 3 × 4 array of optical synaptic devices has been fabricated. The intensity of the image pattern can keep at a high memory level of 54.64% and 19.31% for 532 and 1060 nm waiting for 400 s after illumination of 100 s, which demonstrates the devices exhibit excellent image sensing, learning, and memory storage. This work opens up a new route for fabricating the optical synaptic device with a simple structure and provides new ideas for studying artificial vision systems. [ABSTRACT FROM AUTHOR]

Engineering the spectral response of materials in infrared (IR) wavelength range can enable effective radiative cooling. Current configurations of IR emitters usually adopt complicated photonic designs and engineered structures because pure/singular materials such as dielectrics and polymers can hardly realize broadband and spectrally selective emissivity simultaneously. Herein, we propose single-layer silicon oxynitride (SiON) coatings with visible transparency and outstanding broadband spectral emissivity of 0.8–0.9 in the wavelength range of 8–14 μm. The single layered composite coating has a thickness below 2 μm, and its mid-IR broadband absorption characteristics can be tuned by adjusting the chemical intermixing of SiO2 and SiN as well as proportion of the Si–O and Si–N bonds during the physical and chemical vapor deposition processes, respectively. When deposited on solar reflective substrate, the composite coating with highest selective emissivity of 0.9 shows a promising net cooling power of ≥ 120 W m−2, when the ambient temperature is 27 °C. In an outdoor experiment, the selective emitter exhibits 4.5–5 °C lower temperature when compared to the ambient temperature inside the chamber, thus achieving the sub-ambient daytime cooling. Therefore, absorption bandwidth extension of single material provides a feasible cooling solution for many applications, including solar cells, and building and automobile windows. [ABSTRACT FROM AUTHOR]

The present study aims to extend the life of tungsten carbide (WC) cutting tools utilized in face milling operations of Ti-6Al-4V by applying hard protective coatings developed using the cathodic-arc physical vapor deposition (CAPVD) technique. Box-Behnken design with 15 experimental runs and response surface methodology were used to mathematically model the relationships between input parameters and output responses to determine the optimal cutting parameters resulting in maximum material removal rate and minimum tool wear. Additionally, the performance of uncoated and coated carbide tools was assessed under dry and wet conditions to identify the best machining conditions. Intriguingly, the tool life of an uncoated WC tool in dry conditions was up to threefold more than that in wet conditions. The tool life of the coated tools was 33% to 166% longer than that of their uncoated counterparts. An analysis of their performance revealed an inverse relationship between the amount of Al in the coating and the tool life. The results from sliding wear tests suggest that Al-deficient coatings have a low coefficient of friction. This study sheds light on the effectiveness of CAPVD-coated carbide tools for improving the tool life during face milling of Ti-6Al-4V. [ABSTRACT FROM AUTHOR]

BACKGROUND: This investigation was conducted to encapsulate 316L SS with a Ti-based alloy coating. OBJECTIVE: The aim was to fabricate a coating using TiN, TiO2, and TiCoCr powders on 316L SS through the physical vapor deposition (PVD) sputtering process. METHODS: The powders were consecutively coated on 316L SS through the PVD sputtering process with coating durations of 30, 60, and 90 min. Further microhardness, surface roughness, microabrasion, and adhesion strength tests were also carried out. RESULTS: A 60% improvement in abrasion resistance was observed in TiCoCr-coated samples compared to the uncoated substrate. The X-ray diffraction results confirmed the optimal formation of Ti alloy coatings with corresponding orientation over the SS substrates. Moreover, TiCoCr with a 90 min coating duration had much better surface characteristics than TiO2 and TiN. CONCLUSION: The 90 min coating duration should be optimal for coating in steel for bio-implants. [ABSTRACT FROM AUTHOR]

Surface modification techniques play an important role in adjusting the physicochemical properties of titanium and its alloys. To reduce the penetration of alloying element ions into the body, various types of oxide coatings are used to protect it from the corrosive environment. Another important issue related to the surface layer requirement is ensuring an appropriate set of mechanical properties. Accordingly, in this study, the mechanical and electrochemical properties of the silicon dioxide layers formed by the deposition of nano physical vapor deposition on the surface of titanium and titanium 13‐niobium 13‐zirconium alloy samples were investigated. To evaluate the mechanical properties of the layers produced by this method, hardness tests were carried out, as well as tests on the adhesion of these layers to the metal substrate. On the other hand, electrochemical properties were studied using potentiodynamic measurements to assess the resistance to pitting corrosion, followed by impedance measurements to interpret the processes and phenomena occurring at the silicon dioxide layer/electrolyte interface. The data obtained showed different mechanical and electrochemical properties of the silicon dioxide layers generated with varying process parameters. [ABSTRACT FROM AUTHOR]

Graphene, a two-dimensional material of carbon atoms in a honeycomb lattice, with many extraordinary properties is used to make nano and microelectronic devices. In this study, electrical properties of extensive monolayer graphene area (1.6 × 10–2 m2) produced by chemical vapor deposition was investigated. Electrical contacts were formed by bottom-up patterning of Cr on Si3N4 insulating substrates using a wire cut stencil mask in a physical vapor deposition setup. The graphene sheet was then transferred over the electrical contacts. Surface characterization with AFM, Raman spectroscopy, TEM and electron diffraction have been effective in identifying the defects, holes, wrinkles, and the number of layers. Current–voltage and resistance characterizations were performed with an I–V measurement setup and a four-point probe system. The results show that monolayer graphene with linear/ohmic behavior is well insulated from the flat substrate regardless of the holes, wrinkles and impurities induced due to the wet transfer. The currents achieved here with Si3N4 and stencil mask, are one to two orders of magnitude larger than those obtained with SiO2 and lithographic methods presented in the literature. These signify that exploiting flatter substrates and cleaner electrode deposition methods clearly enhances electrical properties of graphene-based devices. [ABSTRACT FROM AUTHOR]

The effect of vacuum ultraviolet (VUV) radiation during ionized physical vapor deposition (IPVD) of tantalum barriers on various porous organosilicate glass low‐k SiCOH films is studied using advanced diagnostics and quantum chemical calculations. VUV photons break the Si–C bonds, releasing hydrocarbon radicals from the pore surfaces. These radicals, trapped in pores that are partially sealed by tantalum deposition, can either react with tantalum to form carbide‐like compounds, TaCx, or be redeposited in the pores as CHx polymers. This is evidenced by a decrease in CH3 groups that correlates with an increase in TaCx. The formation of TaCx poses a significant challenge in the back end of line (BEOL) technology when reducing the barrier thickness. [ABSTRACT FROM AUTHOR]

In this study, we present the manufacture and characterisation of a novel thin film photodiode based on a GaN/MoS2 composite. The purpose of this research is to explore the potential of this composite material for applications in fast response photodetection. The photodiodes were fabricated using physical vapor deposition technique. The investigation of the surface topology and structural characteristics of the nanostructured GaN/MoS2 thin films was conducted using scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction techniques. The electrical performance of the fabricated photodiodes was investigated by measuring their current–voltage (I–V) characteristics within a bias voltage range from − 2 to + 2 V. The external quantum efficiency of the photodiodes were measured to be up to 11.86% and 8.26% for the pn-photodiode and Schottky photodiode, respectively. On the other hand, the internal quantum efficiency of the fabricated photodiodes were measured to be up to 13.78% and 10.02% for the pn-photodiode and Schottky photodiode, respectively. Also, a response time of 800 µs and 18.23 ms for Schottky-photodiode and pn-photodiodes respectively. These results demonstrate the potential of GaN/MoS2 composite photodiodes for fast response photodetection applications. [ABSTRACT FROM AUTHOR]

The rapid growth of portable electronic devices, electric vehicles, and grid-scale energy storage systems has accelerated the demand for enhancing existing materials and innovating new materials in rechargeable battery technologies. Li-ion batteries have dominated the energy storage field among the various battery systems. Na-ion batteries have emerged as promising candidates due to their similarities to Li-ion battery chemistry, low cost, and environmental sustainability. This study explores the potential advantages of synthesizing the binder-free Cu 1.9 Bi 0.1 Se@SWCNT heterostructure directly on the copper collector surface. A crucial aspect of this research is the intentional use of nanostructuring during synthesis. This technique capitalizes on the benefits of greater surface area, enhanced electron transport, and superior ionic conductivity. The synthesis method not only ensures excellent electrical and mechanical contact with the collector but also omits the need for a binder, offering a potential for improved overall performance in Li-ion and Na-ion batteries. The electrodes were synthesized using a simple and cost-effective physical vapor deposition method. The structural, morphological, and electrochemical properties of the electrodes were characterized. The binder-free Cu 1.9 Bi 0.1 Se@SWCNT electrode with 25 % SWCNT content exhibits excellent performance in Li-ion half cells, maintaining a high energy capacity of 556 mAh g−1 at 0.1 A g−1 over 100 cycles and 244 mAh g−1 at 0.5 A g−1 over 750 cycles. However, in the Na-ion battery system, the performance is notably poorer, revealing challenges and limitations. Most likely, the larger size of sodium ions posed difficulties in intercalation within the anode material structure. [ABSTRACT FROM AUTHOR]

The rising levels of water pollution and climate change contribute to water shortages. These factors influence the loss of the environment's biodiversity and threaten human health. Toxic dye pigments from industries are a significant source of pollution. In this article, we present the synthesis method, characteristics, and photocatalytic properties of the CuO-ZnO nanocomposite, which may affect the degree of decomposition of dyes found in water. The nanocomposite consisting of copper oxide nanowires with zinc oxide nanostructures (CuO-ZnO nanocomposite) was prepared by physical vapor deposition and thermal oxidation methods. The crystalline structure, surface topographies and morphologies, elemental composition, and optical properties of the obtained samples were studied with various techniques such as x-ray diffraction analysis, high-resolution transmission electron microscopy, field emission scanning electron microscopy, energy dispersive x-ray analysis, and UV-vis spectroscopy. The photocatalytic activity of the nanocomposite was measured by testing the degradation of methylene blue under visible irradiation. An increase in the photocatalytic activity of the nanocomposite was observed compared to pure CuO and ZnO. The CuO-ZnO nanocomposite demonstrated a high dye degradation of about 94% during 120 min. [ABSTRACT FROM AUTHOR]

In hard coating materials, Titanium Nitride (TiN) is widely used as a surface coating material due to its excellent properties. In machining processes, it is crucial to optimize the coating process for better parameter selection. This optimization could enhance the performance of cutting tools. In this paper, TiN is coated on tungsten carbide tools using the Physical Vapor Deposition (PVD) method. Coating surface thickness is investigated as an output function that primarily depends on the Nitrogen gas pressure, Argon gas pressure, and turntable speed. The Particle Swarm Optimization algorithm (PSO) is utilized as an efficient metaheuristic technique for optimization purposes. PSO is integrated with Response Surface Methodology (RSM), which functions as a modeling method to generate the objective function for coating thickness. RSM also analyzes the effect of input parameters on the produced film thickness. Finally, Prediction Interval (PI) and Residual Error (e) are used to validate the RSM model. The results show that the actual value of film thickness falls within 95% accuracy and exhibits very low error. While PSO is found to be a powerful technique for optimizing coating thickness, it has reduced the ratio of the average experimental value by 75%. [ABSTRACT FROM AUTHOR]

Titanium-based physical vapor deposition (PVD) coatings, such as titanium nitride (TiN) and titanium niobium nitride (TiNbN), are common solutions for surface modifications in medical applications. Ex vivo studies of retrieved knee implants indicate the demand for increased scratch and abrasion resistance of PVD coatings in clinical applications. Based on the promising mechanical performance of titanium aluminum nitride (TiAlN) as a coating for tools, the aim of this study was to evaluate the impact of the chemical composition of titanium-based nitride coatings with aluminum (Al) and niobium (Nb). Nine titanium aluminum niobium nitride (Ti1−x−yAlxNbyN) coatings with 0.4 ≤ x < 0.7 and 0 ≤ y ≤ 0.18, as well as commercial TiN and TiNbN, were coated in an industrial scale arc PVD process, following a randomized, multifactorial response surface design. The deposition rate, the scratch resistance, and the hardness were measured following standardized protocols. The microstructure of the coating was analyzed by SEM and XRD. In addition, the surface roughness was determined by laser scanning microscopy. A quadratic regression was performed to determine the impact of the chemical composition on coating properties. Experimental results and regression analyses revealed the significant impact of the chemical composition of Ti1−x−yAlxNbyN on the coating microstructure, mechanics, and morphology. Scratch resistance for initial crack formation and cohesive failure could be increased decisively, compared to TiN. [ABSTRACT FROM AUTHOR]

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Within the nanoscale, methodically reconfiguring interface charges, and leveraging this newly structured interface to modify the energy-momentum dynamics of heterojunction energy bands, hold profound implications for microwave electronics because of the intensified interaction between external microwaves and interfaces of materials. Mastering the orderly reconstruction of interface charges, contingent upon precise control over composition, orientation, and electronic structure remains a challenge at this scale. Herein, an in situ hierarchical assembly approach is used to successively deposit layers of Cu2S, C, and MoS2 on a hollow cubic framework with a thickness of 20 nm. Additionally, by harnessing the quasi-graphitic characteristics and elevated work function of graphitized carbon in the middle layer, its inherent charge is steered toward both the outer and inner layers, establishing a structured configuration for the crafted Cu2S@C and C@MoS2 interfaces. Employing advanced off-axis electron holography, microwave dielectric measurements, and first-principle calculations, the dynamic reconstruction of interface charges and the resulting microwave response is ascertained. The synergistic effect revealed that the Cu2S@C@MoS2 materials exhibited exceptional microwave absorption, with an effective absorption band covering 7.03 GHz at 2.0 mm thickness. Furthermore, the orderly reconstruction of nano-interfaces paves the way for research into novel electromagnetic protection materials and their unique electronic behaviors. [ABSTRACT FROM AUTHOR]

Calcia-Magnesia-Alumino Silicate (CMAS) is a form of molten siliceous residue generated at elevated temperatures within aeroengines. CMAS adheres to the surface of thermal barrier coatings (TBCs) and has the potential to cause significant damage to engine components, resulting in TBC failures. The aviation industry has long recognized CMAS as a substantial threat to aircraft engines, and this threat persists today. A substantial amount of research has been carried out, primarily focusing on gaining a fundamental understanding of the degradation mechanism of traditional TBCs manufactured using air plasma spraying (APS) and electron beam physical vapor deposition (EB-PVD) technologies after CMAS attack. A thorough understanding of why CMAS forms, its role in causing severe spallation, and how to prevent it is of significant concern both academically and industrially. This review article provides a detailed examination of the chemistry of CMAS and the resulting degradation mechanisms that the TBC may encounter throughout the aeroengine service life. This article also explores recent research, incorporating case studies, on the impact of CMAS attack on the resulting chemical and structural modifications of the ceramic topcoats. Current strategies designed to mitigate CMAS infiltration and perspectives for enhanced mitigation are discussed. [ABSTRACT FROM AUTHOR]

This paper reports the deposition of Zn on glass substrates using the physical vapor deposition (PVD) method, followed by an annealing process to grow ZnO for gas-sensing applications. Surface morphologies were characterized using scanning electron microscopy, which revealed nanowire shape. The diameter of the wire was about 35 nm. In addition, X-ray diffraction analysis demonstrated that the ZnO nanowire possessed a wurtzite structure with an orientation of (002). Three types of resistive gas sensors with a spiral-square and two-comb electrode geometries were designed, fabricated, and tested for their ethanol vapor-sensing properties. The experimental results show that the sensor with square-spiral electrode has the sensitivity of 43% for 2,000 ppm of ethanol vapor at 200°C, while the sensor with a comb electrode shows the sensitivity of 32% at the same conditions. Also, two sensors with different dimensions of comb-shaped electrodes showed the same sensitivity, as both the width and the distance between the fingers change simultaneously in the larger comb-shaped electrode. The response time for the comb electrode is shorter than the square-spiral type, and the recovery time is almost independent of the electrode geometry. Therefore, the optimal structure should be selected based on the application. [ABSTRACT FROM AUTHOR]

The mid‐infrared (mid‐IR) region is attractive for spectroscopy because this range has molecular fingerprint information. Existing FTIR‐based systems are limited by their complex optical systems, highlighting the ongoing necessity to advance miniaturization and simplify these systems. Here, a compact mid‐IR spectroscopy is introduced in the mid‐IR range, utilizing a continuously variable mid‐IR filter. This filter is made from Germanium (Ge) and BaF2 and is produced using physical vapor deposition. Continuously varying wavelengths of mid‐IR light are transmitted from different areas of the filter. These different wavelengths of light enter each pixel of the microbolometer array. Calibration is conducted using a sample material to match each pixel of the microbolometer array to its corresponding wavelength. Additionally, a deconvolution algorithm is applied to sharpen the acquired spectrum. This results in acquisition of high signal‐to‐noise ratio mid‐IR spectra in the LWIR region. Using this technology, mid‐IR spectroscopy for several types of samples like polymer film, and gas molecules is possible. In addition, by adopting total internal reflection, it is possible to measure non‐uniform thickness samples, such as liquid droplets. [ABSTRACT FROM AUTHOR]

A polycrystalline nanostructured thin film of zinc cadmium sulfide was meticulously fabricated on a glass substrate using the thermal evaporation method physical vapor deposition within a vacuum chamber. Different doping concentrations were introduced by varying the cadmium (Cd) content, resulting in Zn1- x Cd x S films with Cd concentrations ranging from x = 0.00–0.20 wt %. The impact of Cd doping on the third-order nonlinear optical (TONLO) properties of these films was thoroughly studied using the Z -scan method, employing a diode-pumped solid-state continuous-wave laser. To gain insight into the structural characteristics, the Zn1- x Cd x S thin films underwent analysis through x-ray diffraction. Optical studies confirmed the tunability of the optical band gap (Eg) in the Zn1- x Cd x S films, ranging from 3.88 eV for undoped ZnS to 2.80 eV for the film fabricated with 20 wt. % of Cd-content. This significant reduction in 'Eg' renders the films highly suitable for use as absorbing layers in applications such as solar cells and optoelectronics. Surface morphology analysis, performed via field emission scanning electron microscopy, revealed noticeable alterations with increased Cd doping. Significantly, the doped films exhibited a substantial redshift in the band edge and an increase in transmittance within the visible and near-infrared regions. The investigation of TONLO properties, including the nonlinear absorption coefficient (β), nonlinear refractive index (n 2) and susceptibility χ (3), yielded values ranging from 3.15 × 10−3 to 8.16 × 10−3 (cm W−1), 1.65 × 10−8 to 7.45 x 10–8 (cm2 W−1), and 3.12 × 10−5 to 7.86 × 10−5 (esu), respectively. These results indicate the presence of self-defocusing nonlinearity in the films. Overall, the outcomes underscore the potential of Cd-doped ZnS nanostructures in modifying surface morphology and enhancing NLO characteristics. Zn1- x Cd x S thin films exhibit promise for applications in nonlinear optical devices, as evidenced by these encouraging findings. [ABSTRACT FROM AUTHOR]

Silver and gold are the most used plasmonic metals for surface-enhanced Raman spectroscopy (SERS), accounting for the vast majority of the published literature in this field. These two metals are preferred due to their excellent plasmonic enhancement, stability, and relative ease of synthesis and functionalization of their associated nanostructures. However, both silver and gold face earth abundance limitations, and so alternatives should be sought, particularly for large-scale plasmonic applications such as plasmon-enhanced photovoltaics or optical cloaking. In this work, a method to produce effective and scalable copper-based substrates for electrochemical SERS (EC-SERS) is introduced, utilizing commercially available carbon screen-printed electrodes (SPE) and physical vapor deposition (PVD). The carbon black particles present on the working electrode of the SPE serve as an efficient scaffold for the fabrication of copper nanostructures. Several test molecules were used to illustrate the performance of these sensors in the SERS analysis. This work also highlights the first reported formation of an electrochemically generated N-heterocyclic carbene (NHC) self-assembled monolayer (SAM) on a nanostructured copper surface under potential control in an aqueous electrolyte. [ABSTRACT FROM AUTHOR]

Microscope projection photolithography (MPP) offers a versatile method of prototyping microscale devices. The benefits of MPP include the ability to create features at a variety of dimensions, the ability to work outside of a clean room, and the ability to use robotic microscope stage controls to adjust the positions of features easily and accurately. This makes MPP a precise, yet flexible technique ideal for manufacturing contact pads that can be used to investigate the properties of individual nanowires. An enormous breadth of research has been dedicated to the synthesis and characterization of nanowires. The properties of individual nanowires can, however, vary greatly between syntheses or within a batch. Characterization of individual nanowires remains an important step in the scale-up of these materials. Their characterization does, however, often require complex and highly sensitive self-assembly techniques to arrange nanowires on substrates with proper placement of electrical contacts. Some work has been done on techniques for the selective characterization of individual nanowires, but those methods rely on using focused electron-beam writing techniques to connect nanowires to pre-existing electrical contacts. The study of nanowires would benefit from a rapid, flexible approach to fabricating contacts for individual nanowires. This study demonstrates a system for fabricating electrical contacts with minimum feature sizes of ∼0.9 μm on individual nanowires (e.g., diameters from <75 to >125 nm) that are positioned randomly on a small substrate (e.g., <1 cm2). Designs for double and quadruple contact pads have been shown to enable the effective measurement of the electrical properties of individual nanowires. The techniques provided herein can provide a rapid, simple, and customizable method of studying individual nanowires. [ABSTRACT FROM AUTHOR]

Flexible electronics have gained a lot of attention in recent years due to their compatibility with soft robotics, artificial arms, and many other applications. Meanwhile, the detection of acoustic frequencies is a very useful tool for applications ranging from voice recognition to machine condition monitoring. In this work, the dynamic response of Pt nanoparticles (Pt NPs)-based strain sensors on flexible substrates is investigated. the nanoparticles were grown in a vacuum by magnetron-sputtering inert-gas condensation. Nanoparticle sensors made on cracked alumina deposited by atomic layer deposition on the flexible substrate and reference nanoparticle sensors, without the alumina layer, were first characterized by their response to strain. The sensors were then characterized by their dynamic response to acoustic frequency vibrations between 20 Hz and 6250 Hz. The results show that alumina sensors outperformed the reference sensors in terms of voltage amplitude. Sensors on the alumina layer could accurately detect frequencies up to 6250 Hz, compared with the reference sensors, which were sensitive to frequencies up to 4250 Hz, while they could distinguish between two neighboring frequencies with a difference of no more than 2 Hz. [ABSTRACT FROM AUTHOR]

With the proliferation of electronics and wireless devices, managing disruptive electromagnetic interference (EMI) has become imperative. This review examines recent advancements in magnetic nanocomposite materials for EMI shielding applications. Fundamentally, these multifunctional nanocomposites leverage the synergy between magnetic and conductive components to facilitate exceptional microwave absorption and reflection capabilities. The analysis begins by elucidating the physics of EMI shielding mechanisms, including reflection, absorption, and multiple internal reflections. Building on electromagnetic principles, the magnetic properties of nanocomposite constituents are discussed, emphasizing their role in enabling magnetic loss, dielectric loss, and eddy current induction within materials. The review then extensively explores common synthesis techniques for magnetic nanocomposites, such as co-precipitation, sol–gel, and hydrothermal methods. A detailed examination of the resulting nanocomposite characteristics and EMI shielding performance provides useful insights into composition-structure–property relationships. Moreover, innovative fabrication strategies based on physical vapor deposition are highlighted for their precision in controlling nanostructure morphology. Subsequently, the review dives into the nuanced interplay between dielectric, conductive, and magnetic nanocomposite components and their synergistic influence on EMI shielding. Current challenges are also discussed, encompassing issues like nanoparticle agglomeration and environmental durability. Finally, scalable production methods are reviewed as a crucial step towards real-world applications. This all-encompassing review synthesizes the frontiers of magnetic nanocomposite engineering, design, and fabrication for next-generation EMI shielding materials with tailored, application-specific shielding capabilities. [ABSTRACT FROM AUTHOR]

Due to their superior corrosion resistance at high temperatures, stainless steels have a wide range of applications in numerous industries (including chemistry, the petrochemical industry, the paper industry, and nuclear engineering), it is also utilized in the medical industry as an implant material. To enhance the outstanding qualities of stainless steel such as high temperature corrosion, surface coating methods are also used. Boronizing, nitriding, thermal spray coating, physical vapor deposition, chemical vapor deposition, and electro-spark deposition procedures are used to apply these coating processes to steel surfaces. The electro-spark deposition (ESD) coating technology is one of the most promising approaches in this area. Using high-frequency and high-current electric pulses, the ESD micro-welding procedure bonds electrode material to the surface of a metallic substrate. In this study, AISI 304 and AISI 316L stainless steels were coated with FeAl and NiAl intermetallics using the ESD method. First, suitable experimental parameters for ESD coating were established. Second, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the microstructures and phases that formed on the coated surfaces. Then, the surface hardness of the resulting layers was determined. Finally, the corrosion properties of intermetallic-coated stainless steels were determined using electrochemical methods and compared with each other. As a result, both the hardness values and corrosion resistances of both stainless steel sheets have increased with intermetallic coatings. [ABSTRACT FROM AUTHOR]

We summarize the current knowledge on crystal structures, synthesis, applications, and Raman spectroscopy of Wadsley phases of vanadium oxide, including VO2 (B), V6O13, V4O9, V3O7, and V2O5. While these oxides have garnered significant attention for potential energy storage applications and have been studied for decades, there remains inconsistency in data regarding their characteristic Raman spectra. To address this, we synthesized a series of Wadsley phases by physical vapor deposition of amorphous vanadium oxide films and subsequent annealing in a controlled environment. X‐ray diffraction studies confirmed the formation of VO2 (B), V6O13, V4O9, and V3O7. We meticulously measured the room‐temperature Raman spectra of these phases, offering robust reference data for the easy identification of vanadium oxides in unknown samples. Finally, we studied low‐temperature phase transitions in VO2 (B) and V6O13. [ABSTRACT FROM AUTHOR]

The paper brings to the attention of researchers the morphological changes of metal oxides, which appear as a result of the process of physical solar vapor deposition (SPVD) based on experiments carried out at the CNRS-PROMES laboratory, UPR 8521, belonging to the French National Centre for Scientific Research (CNRS). The SPVD process is an innovative tool who has been developed in 2 kW solar furnaces at Odeillo-Font Romeu, France, to synthesis pure and doped nanoparticles, such as: ZnO, CeO2, ZrO2, BiO2, SiO. A variety of metal oxides nanoparticles have been obtained by focusing solar energy on pellets of commercial powders through the controlled process of vaporization followed by condensation directed on a cooper tube or on nanoporous filter. After the micrograph analysis the change of shape and dimension can be observed depending on the type of oxide and the process parameters. It is noticed the appearance of new morphologies, not found in other synthesis methods. The paper brings new information about morphological and dimensional changes after synthesis by physical process which can be essential for researchers, in the choice of methods for the elaboration of nanomaterials. [ABSTRACT FROM AUTHOR]

CrAlN and CrAlBN coatings were prepared on the surface of high-speed steel and shaper cutter by physical vapor deposition (PVD) technique using arc ion source. In the process of coating preparation, the adhesive layers were deposited by low bias voltage (−40 V) and the working layers are deposited by high bias voltage (−130 V). The effects of the addition of B element on the microstructure, hardness, elastic modulus and wear resistance of CrAlBN coating were studied. The results show that B element and its compounds exist in amorphous form in the coating, resulting in lattice distortion of the coating, increase of coating hardness to 37.1 GPa, and decrease of elastic modulus to 406.2 GPa. The addition of B element increases the uniformity of the columnar structure distribution and decreases the width of the columnar structure and grain size. The resistance to elastic deformation and plastic deformation of CrAlBN coating is improved, the wear resistance is improved. The performance of CrAlN and CrAlBN coatings on shaper cutter was studied. It was found that the main failure mode of shaper cutters is boundary wear and the wear mechanism of coatings had changed obviously. CrAlBN coating is mainly due to fatigue induced failure, accompanied by some diffusion wear. The addition of B element makes the CrAlBN coating have excellent resistance to oxidative wear, abrasive wear and diffusion wear during cutting. The results show that the addition of B element can improve the microstructure and mechanical properties of CrAlN coating, and the preparation of CrAlBN coating on the surface of the shaper cutter can significantly improve the service life of the coated shaper cutter, which has significance for the development of the shaper cutter industry. [ABSTRACT FROM AUTHOR]

Multiple advantages, such as good formability, high specific strength, excellent thermal conductivity, and high corrosion resistance, enable aluminum alloy wide application in various fields; however, low surface hardness and poor wear resistance limit its further development. In this study, three surface modification coatings were successfully prepared on the surface of 7A04 aluminum alloy by microarc oxidation (MAO) and a combination of hard anodizing treatment (HA) and physical vapor deposition (PVD), named MAO, HA+W+DLC, and HA+Ti+ta-C, respectively. The microstructure, hardness, and tribological properties of the three coatings and the 7A04 aluminum alloy substrate were studied. The results show that the surface quality and hardness of the coated samples were higher than those of the 7A04 aluminum alloy and that the HA+Ti+ta-C coating possessed the highest hardness of 34.23 GPa. Moreover, the wear resistance of the two multilayer coatings was significantly improved during the ring-block wear tests under oil lubrication, exhibiting a wear rate of 1.51 × 10−7 mm3/N·m for HA+W+DLC and 1.36 × 10−7 mm3/N·m for HA+Ti+ta-C. [ABSTRACT FROM AUTHOR]

ZrN-Cu coatings containing two different amounts of Cu (~11 at.% and ~25 at.%) were deposited using an industrial physical vapor deposition (PVD) system. The as-deposited coatings exhibited 100% bactericidal efficiency against Escherichia coli CCM 3988 for an exposure time of 40 min. Subsequently, the samples were attached onto our faculty's door handles for six months to study the coatings' long-term effectiveness and durability under actual operational conditions. The samples were periodically evaluated and it was observed that the coatings with 25 at.% Cu performed better than the ones with 11 at.% Cu. For example, following 15 days of being touched, the bactericidal effectiveness of the sample containing 25 at.% Cu dropped to 65% while it fell to 42% for the sample containing 11 at.%. After 6 months, however, both samples showed bactericidal efficiency of ~16–20%. The bactericidal efficiency of the samples touched for 6 months was successfully restored by polishing them. Furthermore, a group of samples was kept untouched and was also evaluated. The untouched samples with Cu content of ~25 at.% did not show any drop in their bactericidal properties after 6 months. ZrN-Cu coatings were concluded to be promising materials for self-sanitizing application on high-touch surfaces. [ABSTRACT FROM AUTHOR]

CuO-loaded TiO2 nanomaterials have applications in pollutant degradation via photocatalysis. However, the existing methods of fabricating these nanomaterials involve liquid-phase processes, which require several steps and typically generate liquid waste. In this study, TiO2 and TiO2–CuO nanoparticulate thin films were successfully fabricated through a one-step gas-phase approach involving a combination of plasma-enhanced chemical vapor deposition and physical vapor deposition. The resulting films consisted of small, spherical TiO2 nanoparticles with observable CuO on the TiO2 surface. Upon annealing in air, the TiO2 nanoparticles were crystallized, and CuO was completely oxidized. The photocatalytic activity of TiO2–CuO/H2O2, when introduced into the rhodamine 6G degradation system, was substantially enhanced under both ultraviolet and visible light irradiation. Moreover, this study highlights the influence of pH on the photocatalytic activity; TiO2–CuO/H2O2 exhibited the highest photocatalytic activity at pH 13, with a reaction rate constant of 0.99 h−1 cm−2 after 180 min of visible light irradiation. These findings could facilitate the development of nanoparticulate thin films for enhanced pollutant degradation in wastewater treatment. [ABSTRACT FROM AUTHOR]

This perspective outlines the research directions of ferroelastic rare‐earth (RE) tantalates (RETaO4), which have been studied as multifunctional thermal/environmental barrier coatings (T/EBCs) with working temperatures above 1600°C. Ferroelastic RETaO4 ceramics exhibit several distinct features, including the reversible second‐order ferroelastic phase transition, high toughness, low thermal conductivity, low oxygen ion conductivity, and adjustable thermal expansion coefficients. This perspective provides a concise summary of the research progress on tantalate coatings synthesized via air plasma spraying and electron beam physical vapor deposition. The service performance of tantalate coatings is typically evaluated through thermal fatigue and shock measurements. Uncovering the failure mechanisms and understanding influencing factors are key aspects for future studies. In this regard, establishing the synthesis‐structure‐property relationship of RETaO4 coatings is essential. This brief perspective can serve as a guide for future work on RETaO4 coatings and further advancements in their applications across various fields, including aviation engines and gas turbines. [ABSTRACT FROM AUTHOR]

In the quest for advanced materials suitable for next-generation electronic and optoelectronic applications, tungsten disulfide (WS2) ultrathin films have emerged as promising candidates due to their unique properties. However, obtaining WS2 directly on the desired substrate, eliminating the need for transfer, which produces additional defects, poses many challenges. This paper aims to explore the synthesis of WS2 ultrathin films via physical vapor deposition (PVD) followed by sulfurization in a confined space, addressing the challenge of film formation for practical applications. Precursor layers of tungsten and WS2 were deposited by RF magnetron sputtering. Subsequent sulfurization treatments were conducted in a small, closed, graphite box to produce WS2 films. The physical and chemical properties of these precursor and sulfurized layers were thoroughly characterized using techniques such as X-ray reflectometry (XRR), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The findings reveal notable distinctions in film thickness, structural orientation, and chemical composition, attributable to the different precursor used. Particularly, the sulfurized layers from the tungsten precursor exhibited a preferred orientation of WS2 crystallites with their (00L) planes parallel to the substrate surface, along with a deviation from parallelism in a small angular range. This study highlights the necessity of precise control over deposition and sulfurization parameters to tailor the properties of WS2 films for specific technological applications. [ABSTRACT FROM AUTHOR]

Polymethines containing an allyl group have been synthesized. Their films are produced by physical vapor deposition (PVD) on glass, silicon (Si), gold (Au), polytetrafluoroethylene (PTFE), and nanostructured plastic substrates. Optical spectra recorded during the deposition showed no decomposition of molecules. The influence of dye structure and substrate on the morphology of the deposits is studied using atomic force microscopy (AFM). Depending on the dye structure and the substrate material, various nanostructures are grown. Dichroic nanowires (NWs) are formed by self‐assembly on Au and Si substrates. On the Si surface, NWs grow between the edges of neighboring Au stripes. Several methods are used for the selective opening of the allyl group. Smooth films are produced with optical spectra similar to those deposited by PVD. The morphology of the films is dependent on the activation conditions. The thermal stability of the films exceeds the stability of those deposited via PVD. [ABSTRACT FROM AUTHOR]

Ultra-thin flexible glass with thicknesses of 100 μm or below is a substrate in the fields of optics, electronics, and semiconductors. Its brittleness is challenging in production processes like physical vapor deposition processes, especially in roll-to-roll production. In many cases, multiple geometric deformations take place and each step, like coating or cutting, influences the glass strength. By now, the relation between the strength of ultra-thin glass under quasi-static conditions and its strength under cyclic load has not been studied. Moreover, the effect of coatings has not been investigated. Both aspects are crucial to design reliable production processes. Therefore, the strength of ultra-thin glass under cyclic load was studied for uncoated and coated substrates. Two coating types were investigated: a single indium tin oxide film and a seven-layer antireflective layer stack. The coatings significantly influence the strength of the underlying glass in both test modes. The barrier properties, thin film stress, and the morphology/crystalline structure are identified as the major characteristics influencing the strength. [ABSTRACT FROM AUTHOR]

The 2,4,5-Triphenyl Imidazole (TPI) C21H16N2 samples were deposited as thin film by means of the physical vapor deposition (PVD) on glass and silicon substrates. As well as, three solutions with different concentrations using dimethyl sulfoxide (DMSO) solvent. The physical properties of all samples were investigated using different techniques. The thin film's morphology was examined using atomic force microscopy (AFM) of the sample on silicon substrates, revealing a highly rough surface. The optical characteristics of both the thin film on glass substrate, the solutions, and the powder were studied through transmittance and absorbance measurements, which helped determine a value of the band gap of 3.45 eV. Photoluminescence and thermal photoluminescence spectroscopy showed the high emission of the material in its different aspects. Theoretical simulations of the HOMO–LUMO gap and electronic absorption spectra were obtained using the density functional theory (DFT) approach. [ABSTRACT FROM AUTHOR]

The present study investigates the influence of substrate bias on edge-rounding of TiAlN-coated drill bits arising out of coating deposition and the resulting cutting performance while machining Inconel 718. Tungsten carbide (WC) drill bits were deposited with TiAlN coating through a cathodic arc physical vapor deposition (CAPVD) system. Five different substrate bias voltages varying from −20 V to −60 V were employed for the deposition. The hardness, adhesion strength, and residual stress were significantly influenced by substrate bias. The sharp edges of coated drill bits exhibited significant edge-rounding at relatively higher levels of substrate bias. The reason for such edge-rounding is the re-sputtering and residual stress-induced micro-chipping of the previously formed coating layer during the deposition. The edge-rounding of drill bits was in the order of: 20 V <30 V <40 V <50 V <60 V. The drill bits deposited at −50 V substrate bias exhibited the best tool life owing to optimum edge radius (resulting in better edge stability) and coating properties. The present study helps identify an optimum level of substrate bias, which results in a favorable edge radius and the best tool life of the coated drill bits. [ABSTRACT FROM AUTHOR]

This study explored the development of an optimal effective solar absorber by leveraging recent advancements in artificial intelligence and nanotechnology. A predictive computational approach for designing a multilayer metal-dielectric thin film solar selective absorber, specifically the SiO2/Cr/SiO2/Cr/SiO2/Cu structure was proposed. The adopted approach integrates the transfer matrix method (TMM) as a predictive electromagnetic tool and combines it with the swarm-based heuristic algorithm grey wolf optimization (GWO) linked to machine learning algorithms, specifically the artificial neural network (ANN). Through dynamic modeling and rigorous testing against multiple static versions, the adopted approach demonstrates exceptional predictive performance with an value of 0.999. The results obtained using this novel GWO-ANN approach reveal near-perfect broadband absorption of 0.996534 and low emission of 0.194170594 for the designed thin film structure. These outcomes represent a significant advancement in photo-to-thermal conversion efficiency, particularly for a working temperature of 500 °C and a solar concentration of 100 suns, showcasing its potential for practical applications across various fields. Additionally, the designed structure meets the stringent thermal stability requirements necessary for current Concentrated solar power (CSP) projects. This emphasizes its suitability for integration into existing CSP systems and highlights its potential to contribute to advancements in solar energy technology. [ABSTRACT FROM AUTHOR]

Chalcogen vacancy has long been recognized as a detrimental deep‐level defect that can induce severe charge recombination and diminish the quasi‐Fermi‐level splitting in Sb2S3 and Sb2Se3, especially when they are prepared by physical vapor deposition in vacuum. In order to counter this limitation, a sulfur‐supplemented vapor transport deposition technique is proposed, which intentionally introduces low pressure sulfur vapor and can thus afford low‐defect‐density antimony chalcogenide films. The resultant photocathodes modified with conformal TiO2 protection layer and Pt cocatalyst demonstrate a photocurrent as high as 20 mA cm−2 along with a much improved fill factor and onset potential, achieving an applied bias photoconversion efficiency above 1%. This work highlights the importance of the vacancy defect passivation and the preferential crystalline orientation in the film in promoting the photocathode performance. [ABSTRACT FROM AUTHOR]

Undoped and In‐doped ZnSb thin films are deposited on rigid glass and flexible polyimide (Kapton) by physical vapor deposition. Detailed structural and chemical characterization is performed along with measurement of electrical and optical properties. These properties are very similar for films on glass and Kapton. Flexible ZnSb films show remarkable stability of electrical and optical properties, which are unchanged after 104 cycles of linear bending with surface strain 0.18%. Only severe flexing after this treatment (torsional bending with surface strain 1.7%) causes progressive degradation of conductivity over tens to hundreds of cycles. The ZnSb optical direct gap is determined to be 0.89 ± 0.05 eV. The optical direct gap of β Zn4Sb3 was 1.07 ± 0.05 eV. Other absorption features in the films, including smaller indirect gaps, are discussed. [ABSTRACT FROM AUTHOR]

Radiative cooling in smart windows using VO2 – a dynamic thermal management material, is of potential interest for enhancing energy savings in buildings due to its both solar and emittance tuneability in response to changing temperatures. However, studies related to the effects of VO2 thin film microstructure in a multilayer system on emissivity regulation are currently lacking. The present study addresses the thermochromic and emissivity performance of VO2/ZnSe/ITO/Glass Fabry−Perot (F–P) cavity thin film system, by manipulating the porosity in VO2 thin film. The device is fabricated by commercially feasible physical vapor deposition methods such as sputtering and thermal evaporation, most suitable for mass production. The optimized sample with porous VO2 delivers an enhanced long-wave infrared (LWIR) emissivity contrast of ΔɛLWIR ≥ 0.4 preserving a high visible transparency Tlum(avg) of ∼41 % compared to dense VO2. Then finite difference time domain (FDTD) simulation is performed to further understand the effects of varying VO2 porosity and ZnSe thickness on the F–P cavity properties. The reduced low-temperature ɛLWIR (0.1–0.2) gives this film better energy saving in regions where warming demand is dominant as simulated by EnergyPlus. [ABSTRACT FROM AUTHOR]

In this paper, the authors investigated the impact of DLC coatings doped with tungsten (a-C:H:W) coatings obtained using plasma-assisted physical vapor deposition (PVD) on the properties of the 100Cr6 steel. The results of the 100Cr6 steel specimens with and without the coating were compared. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis were used to observe the morphology of the coating surfaces and cross-sections and identify the elements in the coating composition. The contact angle of the investigated surfaces was measured with a tensiometer. Additionally, the effect of the coatings on the tribological properties of lubricated friction pairs was evaluated. Friction tests were performed on a ball-on-disc tribometer under lubrication with cutting fluid. The surface texture of the samples before and after the tribological tests was measured using a confocal profilometer. The results obtained from the tests and analysis allow for the conclusion that the use of DLC coatings a-C:H:W increases the hardness of 100Cr6 steel by three times. The values of the contact angles were indicative of surface hydrophilic characteristics. The tungsten-doped diamond-like coating under friction conditions reduced the coefficient of friction and wear. DLC coatings a-C:H:W lubricated with the cutting fluid improve the mechanical and tribological properties of 100Cr6 steel sliding surfaces under friction. [ABSTRACT FROM AUTHOR]

Abstract Equipping otherwise passive surfaces with electronic functionality enables advanced interactive robotics, consumer products, sensor skins, and structural health monitoring. Concurrently, the rapidly growing number of electronic devices fuels the search for sustainable materials and processes that aid in reducing electronic waste. Wood is CO2‐neutral, omnipresent in the construction industry, in furniture, musical instruments, or packaging, yet so far, its potential for direct integration with electronics remains largely unexplored. Complications arise as traditional methods of equipping wood with electronics often compromise structural integrity and thus limit applications requiring load‐bearing capabilities. Here, seamless fabrication methods that allow the direct enhancement of wooden surfaces with electrically conducting structures, sensors, and microelectronic components based on screen printing of conducting inks or physical vapor deposition of thin metal films in conjunction with laser engraving are presented. Such electronic circuits imperceptibly operate on the surface of structural elements or as parts of decorative wooden furniture. These types of electronic wooden surfaces enable touch‐sensing applications, monitoring temperature, or the curing of varnishes without compromising functionality and mechanical stability. This multidisciplinary approach opens up new avenues for the development of smart wooden structures with embedded electronics, revolutionizing the way it is monitored, controlled, and interacted with wood‐based constructions.

In recent years, researchers have been exploring Janus particles, a unique type of colloidal system, which has gained enormous attention across diverse fields, from soft matter physics to biology. These particles, possessing an asymmetric surface, can be manipulated in the fluid using external energy sources. This versatility makes them suitable for mimicking biological systems and applications like cargo transportation, drug delivery, biosensing, and environmental cleanup. The study focuses on the response of metal-dielectric (Ti-PMMA) Janus spheres in the AC field, created through the Physical Vapor Deposition (PVD) technique. When subjected to a uniform AC electric field, these particles exhibit different dynamic behaviors at various frequency ranges. The particles show diverse responses from induced-charge electrophoresis (ICEP: 500 Hz-80 kHz) to reversed motion (r: ICEP:100 kHz-1 MHz) and linear chain formation (1 MHz). Additionally, they randomly cluster near the lower characteristic frequency (800 Hz) of the ICEP, whereas they exhibit the 3D motion at frequencies (100 Hz) below this lower characteristic value. The mechanisms behind these dynamic phenomena could be explained by considering the concept of electric double layer (EDL), self-dielectrophoresis (sDEP), dipolar interactions, hydrodynamic interactions, and electrothermal effects. These active Janus Colloids are further leveraged to manipulate 1 µm diameter PMMA passive microparticles and E. coli bacteria at 1 kHz, showcasing their potential applications in cargo delivery under various microfluidic research areas. The manipulation of payloads could be explained based on dielectrophoretic trapping due to locally generated field gradients around the surface of the Janus sphere. Therefore, the present work offers an unprecedented opportunity to study such out-of-equilibrium complex active matter systems and create novel functional materials. Moreover, it could also be extended as a fuel-free microrobotics system for various biomedical applications such as sensing and on-demand drug or cargo delivery inside the microfluidics chamber.

Two-dimensional van der Waals ferroelectric semiconductors have attracted extensive research interest in both theoretical investigation and device applications due to their ferroelectricity and semiconducting nature. However, it is still not well understood how the ferroelectric phase is able to coexist with the semiconducting phase in this emerging material class. In this work, mm-scale continuous films of In2Se3 with a thickness of ∼3 nm were synthesized successfully by physical vapor deposition. Furthermore, we fabricated asymmetric ferroelectric semiconductor junctions (a-FSJs) from thick exfoliated and PVD-grown ultrathin In2Se3 films. A high read current density of ∼100 A/cm2 and a distinction ratio of over 102 at VRead = 0.5 V are achieved in devices fabricated by a 3 nm-thick In2Se3 film toward ultrahigh-density memory integration. Notably, the coercive voltage is constant, with In2Se3 film thickness decreasing from 200 to 3 nm. A qualitative model is proposed to elucidate the anomalous film-thickness-independent coercive voltage in this ultrathin a-FSJ, which can also be generalized to other emerging two-dimensional ferroelectric semiconductors. [ABSTRACT FROM AUTHOR]