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In this study, we compare the performance of ferroelectric memristor devices based on the fabrication method for the top electrode, focusing on atomic layer deposition (ALD) and physical vapor deposition techniques. We investigate the effects of these methods on the formation of the orthorhombic phase (o-phase) in HfAlOx (HAO) ferroelectric films, which is crucial for ferroelectric properties. The devices were fabricated with HAO films doped with 3.4% aluminum, followed by rapid thermal annealing at 700 °C. Our results demonstrate that the atomic layer deposition process forms a TiOxNy capping layer at the interface between the HAO film and the TiN top electrode, which promotes the o-phase formation. This capping layer effect leads to enhanced polarization characteristics, as evidenced by higher remnant polarization and tunneling electroresistance (TER) in the ALD-fabricated devices. The ALD method also results in a better interfacial layer condition, confirmed by a lower interfacial non-ferroelectric capacitance (Ci). Characterization techniques, including transmission electron microscopy, energy dispersive x-ray spectroscopy, and x-ray diffraction. These structural advantages contribute to enhanced electrical performance, demonstrating neuromorphic applications. Here, our study highlights the significant impact of the ALD deposition method on enhancing the ferroelectric properties and overall performance of ferroelectric memristor devices, making it a promising approach for advanced memory and neuromorphic computing applications. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) molybdenum disulfide (MoS2) holds immense promise for next-generation electronic applications. However, the role of contact deposition at the metal/semiconductor interface remains a critical factor influencing device performance. This study investigates the impact of different metal deposition techniques, specifically electron-beam evaporation and sputtering, for depositing Cu, Pd, Bi, Sn, Pt, and In. Utilizing Raman spectroscopy with backside illumination, we observe changes at the buried metal/1L MoS2 interface after metal deposition. Sputter deposition causes more damage to monolayer MoS2 than electron-beam evaporation, as indicated by partial or complete disappearance of first-order E′(Γ)α and A′1(Γ)α Raman modes post-deposition. We correlated the degree of damage from sputtered atoms to the cohesive energies of the sputtered material. Through fabrication and testing of field-effect transistors, we demonstrate that electron-beam evaporated Sn/Au contacts exhibit superior performance including reduced contact resistance (~12×), enhanced mobility (~4.3×), and lower subthreshold slope (~0.6×) compared to their sputtered counterparts. Our findings underscore the importance of contact fabrication methods for optimizing the performance of 2D MoS2 devices and the value of Raman spectroscopy with backside illumination for gaining insight into contact performance. [ABSTRACT FROM AUTHOR]

Physical vapor deposition can prepare organic glasses with high kinetic stability. When heated, these glassy solids slowly transform into supercooled liquid in a process known as rejuvenation. In this study, we anneal vapor-deposited glasses of methyl-m-toluate for 6 h at 0.98Tg to observe rejuvenation using dielectric spectroscopy. Glasses of moderate stability exhibited partial or full rejuvenation in 6 h. For highly stable glasses, prepared at substrate temperatures of 0.85Tg and 0.80Tg, the 6 h annealing time is ∼2% of the estimated transformation time, and no change in the onset temperature for the α relaxation process was observed, as expected. Surprisingly, for these highly stable glasses, annealing resulted in significant increases in the storage component of the dielectric susceptibility, without corresponding increases in the loss component. These changes are interpreted to indicate that short-term annealing rejuvenates a high frequency relaxation (e.g., the boson peak) within the stable glass. We compare these results to computer simulations of the rejuvenation of highly stable glasses generated by using the swap Monte Carlo algorithm. The in silico glasses, in contrast to the experiment, show no evidence of rejuvenation within the stable glass at times shorter than the alpha relaxation process. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) molybdenum disulfide (MoS2) holds immense promise for next-generation electronic applications. However, the role of contact deposition at the metal/semiconductor interface remains a critical factor influencing device performance. This study investigates the impact of different metal deposition techniques, specifically electron-beam evaporation and sputtering, for depositing Cu, Pd, Bi, Sn, Pt, and In. Utilizing Raman spectroscopy with backside illumination, we observe changes at the buried metal/1L MoS2 interface after metal deposition. Sputter deposition causes more damage to monolayer MoS2 than electron-beam evaporation, as indicated by partial or complete disappearance of first-order E′(Γ)α and A′1(Γ)α Raman modes post-deposition. We correlated the degree of damage from sputtered atoms to the cohesive energies of the sputtered material. Through fabrication and testing of field-effect transistors, we demonstrate that electron-beam evaporated Sn/Au contacts exhibit superior performance including reduced contact resistance (~12×), enhanced mobility (~4.3×), and lower subthreshold slope (~0.6×) compared to their sputtered counterparts. Our findings underscore the importance of contact fabrication methods for optimizing the performance of 2D MoS2 devices and the value of Raman spectroscopy with backside illumination for gaining insight into contact performance. [ABSTRACT FROM AUTHOR]

The structural relaxation dynamics of conventionally prepared bulk glass of N,N′-bis(3-methylphenyl)-N,N′-diphenyl-benzidine (TPD) was measured by differential scanning calorimetry. The calorimetric data were quantitatively described in terms of the Tool–Narayanaswamy–Moynihan (TNM) model. The TNM parameters were evaluated using a combination of linearization and non-linear optimization methodologies: h*/R = 109.5 kK, ln(A/s) = −321, β = 0.37, x = 0.64. In addition, the TNM phenomenology was used to describe recently reported normalized thickness data of stable and aged thin TPD films measured by ellipsometry. The structural relaxation was found to proceed at a markedly higher rate in these thin films prepared by the physical vapor deposition compared to that of conventional bulk glass. This feature appears to be associated with the significantly narrower distribution of relaxation times (β ≅ 0.8) observed for stable thin film in "as-deposited" form with uniquely dense molecular packing. Interestingly, very similar attributes of the relaxation kinetics were also found in the aged thin film with a previously erased thermal history associated with the deposition. [ABSTRACT FROM AUTHOR]

Deposition of epitaxial oxide semiconductor films using physical vapor deposition methods requires a detailed understanding of the role of energetic particles to control and optimize the film properties. In the present study, Ga 2 O 3 thin films are heteroepitaxially grown on Al 2 O 3 (0001) substrates using oxygen ion beam sputter deposition. The influence of the following relevant process parameters on the properties of the thin films is investigated: substrate temperature, oxygen background pressure, energy of primary ions, ion beam current, and sputtering geometry. The kinetic energy distributions of ions in the film-forming flux are measured using an energy-selective mass spectrometer, and the resulting films are characterized regarding crystalline structure, microstructure, surface roughness, mass density, and growth rate. The energetic impact of film-forming particles on the thin film structure is analyzed, and a noticeable decrease in crystalline quality is observed above the average energy of film-forming Ga + ions around 40 eV for the films grown at a substrate temperature of 725 ° C. [ABSTRACT FROM AUTHOR]

Photosensitization of semiconductors by excitation of chiral plasmonic metallic nanostructures has attracted much attention, not only for the analysis and detection of circularly polarized light but also for its potential applications in chiral photosynthesis. Although there have been reports on the detection of semiconductor-sensitized current in chiral nanostructures precisely fabricated by physical vapor deposition and/or lithography techniques, there have been no studies using plasmonic metal nanocolloids synthesized by chemical processes. In this study, we report the establishment of a fabrication method for large-area chiral photoelectrodes and the semiconductor photosensitization phenomenon realized using chiral plasmonic nanoparticles. Chiral plasmonic Au nanoparticles prepared by previously reported colloidal methods were immobilized onto a TiO2 thin film electrode by electrophoresis. When TiO2 electrodes loaded with chiral Au nanoparticles synthesized using L-cysteine were irradiated with circularly polarized light, left circularly polarized light irradiation at a wavelength of 500–600 nm generated a larger anodic photocurrent than right circularly polarized light irradiation at the same wavelength. This trend was reversed for TiO2 electrodes immobilized with colloidal Au nanoparticles synthesized with D-cysteine. From these results, we conclude that the efficiency of photocurrent generation by chiral plasmon excitation can be controlled by the polarization direction of the incident light. [ABSTRACT FROM AUTHOR]

Purpose: AISI 4140 is a versatile, low alloy steel often used in various applications in mechanical systems and manufacturing processes. To mention a few in processes such as friction stir welding tooling and in engine components, temperatures above 700°C coupled with wear. Despite its versatility, it is still susceptible to wear and corrosion. A common method to address this shortcoming is physical vapor deposition (PVD) coating. This study aims to experimentally investigate the wear performance of AISI 4140 PVD coated with titanium nitride (TiN) and titanium aluminum nitride (TiAlN) at room and elevated temperatures. Design/methodology/approach: Two sets of three samples were prepared. Where one sample was uncoated AISI 4140, TiN and TiAlN PVD coated, one set was tested at room temperature and the other set at 780°C for comparison purposes. The average coating thicknesses were measured, and the adhesion properties were assessed using a scratch test. Their tribological wear scars were further characterized using scanning electron microscope (SEM) energy-dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD), Raman and confocal microscopy, and the results were furnished in the paper. Findings: With the scratch test, the first critical load (Lc) on the TiAlN coating was 15% higher than that of the TiN coating. At room temperature, TiN had the highest coefficient at 0.61, while TiAlN was 0.39. After 1,500 s, samples showed run-in and stability. At elevated temperatures, TiAlN started with the highest friction but stabilized later than TiN and uncoated samples, which stabilized after 200 s due to titanium oxide formation. This was due to the formation of an oxidation layer caused by the thermal environment. Hence, the opposite is observed at room temperature. The findings were supported by the Raman, XRD, SEM EDS and areal topography analysis. Originality/value: The results presented in the study are valuable to design engineers and researchers anticipating wear in high temperature applications. Therefore, with these results, reasonable, informed decisions can be made about specific design requirements. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2024-0354/ [ABSTRACT FROM AUTHOR]

This research aims to examine flank wear and material removal rates (MRRs) while finish hard turning work material of Inconel 718 with physical vapor deposition involving the process of cathodic arc evaporation TiAlN/TiCN-coated cermet CNC cutting tool insert. The L27Taguchi orthogonal design array is used for designing the experiments. The aim of this research is to optimize the process key parameters, such as cutting speed, rate of feed, depth of cut, and tool tip radius, in order to reduce flank wear and significantly improve MRR during the dry turning processes. This study examines the critical conditions of cutting parameters that were investigated by using analysis of variance (ANOVA), while the parameters which affect the flank wear and MRRs were optimized using response surface methodology according to the Design of the Taguchi orthogonal test. Mathematical models for both response parameters were derived using regression analysis, namely flank wear and MRR. The generated models achieved an accuracy of roughly 92% and 93% for estimating the flank wear and MRR values, respectively. The study revealed that cutting speed accounted for 34.28% of the most effective parameters in reducing flank wear, subsequently, the depth of cut reached 17.71%. In terms of MRR, the depth of cut accounted for 68.43% of the effectiveness, with a cutting speed of 12.94%. The optimal values for cutting speed, feed, cut depth and tool tip radius, in order to minimize wear, were determined to be 700m/min, 0.15mm/rev, 1.0mm, and 0.4mm, respectively. The optimal values for achieving the maximum MRR are 800m/min for cutting speed, 0.15m/min for rate feed, 2mm for cut depth, and 1.2mm for tool tip radius. Regression theory is used to construct correlation models, which have been shown to be statistically significant at the 0.05 level. An experimental approach is studied to investigate the coating defects and flaws of worn TiAlN/TiCN-coated cermet inserts using atomic force microscopy (AFM), optical and scanning electron microscope (SEM). Lastly, the creation of chips under optimal conditions has been shown. [ABSTRACT FROM AUTHOR]

Conductive sponge sensors based on crack structure have attracted widespread attention in the field of wearable electronics for their excellent compressibility. However, the conventional preparation methods such as primary-coating and single-layer crack structure tend to result in poor stability and sensitivity of conductive sponge sensors. Therefore, a high-performance sensor of conductive nickel@polyurethane sponge prepared by secondary coating based on the double-layer crack structure is proposed in this study. A uniform conductive Ni-layer was coated on polyurethane sponge by secondary-coating metal nickel via physical vapor deposition (PVD) and electroless deposition (ELD), and a double-layer crack structure was designed by using the cyclic compression method to construct cracks in the primary and secondary-coated Ni layers, respectively. The sensor exhibited excellent stability due to the secondary-coating method, and the double-layer crack structure improved the sensitivity of the sensor to detect small deformations (< 10%) (GF = 99.33), which was nearly 3.8 times higher than that of the secondary-coated conductive sponge sensor with single-layer crack structure. Meanwhile, the sensor possessed an ultra-wide sensing range, low resistance relaxation time, and fast response time of 122 ms, as well as excellent reproducibility, and showed excellent sensitivity and application potential of application detection in areas such as speech recognition, human motion monitoring, and physiological signal monitoring. [ABSTRACT FROM AUTHOR]

[Display omitted] Two-dimensional (2D) layered group-IV monochalcogenides with large surface-to-volume ratio and high surface activity make that their structural and optoelectronic properties are sensitive to air oxidation. Here, we report the utilization of oxidation-induced gradient doping to modulate electronic structures and optoelectronic properties of 2D group-IV monochalcogenides by using SnS nanoplates grown by physical vapor deposition as a model system. By a precise control of oxidation time and temperature, the structural transition from SnS to SnSO x could be driven by the layer-by-layer oxygen doping and intercalation. The resulting SnSO x with a graded narrowing bandgap exhibits the enhanced optical absorption and photocurrent, leading to the fabricated SnSO x photodetector with remarkable photoresponsivity and fast response speed (<64 μs) at a broadband spectrum range of 520–1550 nm. The peak responsivity (7294 A/W) and detectivity (9.54 × 109 Jones) of SnSO x device are at least two orders of magnitude larger than those of SnS photodetector. Moreover, its photodetection performance can be competed with state-of-the-art of 2D materials-based photodetectors. This work suggests that the air oxidation could be utilized as an efficient strategy to engineer the electronic and optical properties of SnS and other 2D group-IV monochalcogenides for the development of high-performance broadband photodetectors. [ABSTRACT FROM AUTHOR]

Background/Objectives: The increasing demand for total hip arthroplasty (THA), due to aging populations and active lifestyles, necessitates advancements in implant materials and design. This review evaluates the role of surface coatings in enhancing the performance, biocompatibility, and longevity of hip implants. It addresses challenges like wear, corrosion, and infection, focusing on innovative surface engineering solutions. Methods: The review analyzes various surface modification techniques, including physical vapor deposition (PVD), chemical vapor deposition (CVD), electrophoretic deposition (EPD), plasma spraying, and ion implantation. It also examines their effectiveness in improving tribological properties, biocompatibility, and resistance to infection. Computational methods such as finite element analysis (FEA) are discussed for predicting potential coating failures. Results: The findings underscore the challenges posed by wear debris and corrosion in common configurations, like metal-on-metal (MoM) and metal-on-polyethylene (MoP). Innovative coatings, such as diamond-like carbon (DLC) films and hydroxyapatite (HA) layers, demonstrate enhanced performance by reducing friction, wear, and bacterial adhesion, while promoting osteogenic cell attachment. Surface textures and optimized tribological properties further improve implant functionality. Multifunctional coatings exhibit potential in balancing biocompatibility and infection resistance. Conclusions: Surface engineering plays a critical role in advancing next-generation hip implants. The integration of advanced coatings and surface modifications enhances implant durability, reduces complications, and improves patient outcomes. Future research should focus on combining innovative materials and computational modeling to refine coating strategies for long-term success in THA. [ABSTRACT FROM AUTHOR]

Recently, various methods have been developed for synthesizing zinc oxide (ZnO) nanostructures, including physical and chemical vapor deposition, as well as wet chemistry. These common methods require either high temperature, high vacuum, or toxic chemicals. In this study, we report the growth of zinc oxide ZnO nanowires by a new hot water deposition (HWD) method on various types of substrates, including copper plates, foams, and meshes, as well as on indium tin oxide (ITO)-coated glasses (ITO/glass). HWD is derived from the hot water treatment (HWT) method, which involves immersing piece(s) of metal and substrate(s) in hot deionized water and does not require any additives or catalysts. Metal acts as the source of metal oxide molecules that migrate in water and deposit on the substrate surface to form metal oxide nanostructures (MONSTRs). The morphological and crystallographic analyses of the source-metals and substrates revealed the presence of uniformly crystalline ZnO nanorods after the HWD. In addition, the growth mechanism of ZnO nanowires using HWD is discussed. This process is simple, inexpensive, low temperature, scalable, and eco-friendly. Moreover, HWD can be used to deposit a large variety of MONSTRs on almost any type of substrate material or geometry. [ABSTRACT FROM AUTHOR]

During the synthesis of tellurium (Te) crystals, the coexistence of multiple crystalline phases (α-Te, β-Te, and γ-Te) with diverse structures commonly occurs, leading to instability and complexity in the performance of Te-based optoelectronic devices. This study employs physical vapor deposition to synthesize Te crystals of various sizes and morphologies, followed by spatially and temperature-dependent evaluation using Raman mapping and infrared photoluminescence (PL) spectroscopy. Spatially resolved results reveal that the size and morphology of Te crystals significantly influence the energy and peak profiles of Raman and PL spectra. Statistical analysis of spatially random sampling indicates the PL peak energies of Te crystals follow a lognormal distribution in terms of their occurrence frequencies, reflecting the complex interplay of multiple factors during crystal growth. This results in the coexistence of α-Te and β-Te phases, forming α/β-Te heterophase homojunction (HPHJ). Meanwhile, temperature-dependent PL results, obtained for the range of 3–290 K, reveal multi-peak competitive behavior in the PL spectra, accompanied by S-shaped shifts in peak energy. These features can be rationally explained by an interface transition-recombination mechanism based on the I-type α/β-Te HPHJ model. It also confirms infrared PL spectroscopy is an effective method for identifying the crystalline phase composition of Te crystals. [ABSTRACT FROM AUTHOR]

Bis (8-hydroxyquinoline) copper (CuQ2) is an important organometallic complex based on a central metal cation coordinated to quinolate ligands. However, CuQ2 exhibits limitations such as low fluorescence intensity, short fluorescence lifetime, and low efficiency of visible light absorption. In this study, density functional theory (DFT) calculations were performed to investigate the frontier molecular orbitals of CuQ2, revealing its potential for excellent luminescence properties. Subsequently, CuQ2 was synthesized using physical vapor deposition (PVD), yielding micron-sized CuQ2 particles. CuQ2 micron particles were characterized using scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), ultraviolet visible spectroscopy (UV–Vis), photoluminescence and fluorescence lifetime. The results demonstrate that the deposition temperature significantly influences the morphology, thermal stability and fluorescence properties of CuQ2. At a deposition temperature of 200 °C, the CuQ2-C sample forms spherical micron particles with uniform morphology, enhanced thermal stability, optimal visible light absorption efficiency, and highest fluorescence intensity. The CuQ2-C sample exhibits a maximum emission wavelength of 660 nm, a maximum excitation wavelength of 333 nm, and a fluorescence lifetime of 10.646 μs. [ABSTRACT FROM AUTHOR]

Recent advancements in organic materials based sensor technology created a prospective field in designing sensors that are both cost‐effective and environment friendly. In view of that an electronic material system has been prepared depositing a uniform layer of graphite‐infused Polyaniline (PANI) onto the sponge framework using a straightforward physical vapor deposition technique. The prepared active materials were studied for the composition, morphology, optical properties, and charge transport characteristics. In the current context of rapidly growing sensor technology, this works describes an innovative approach of improving the response of the prepared electronic system of PANI/Gr composites, integrated into porous PU sponge substrates. Incorporation of graphite in PANI improved the electrical conductivity of the composite and porous structure of PU increased the interaction surface area. The performance of the prepared materials in humidity detection was evaluated by studying their resistive response under varying humidity levels, which was measured through current‐voltage (I‐V) characteristics. The higher interaction sites of the reported active sensing system leads to inspiring humidity sensitivity of 0.522–26.22 kΩ/% RH with reasonable response and recovery time of 572 and 416 sec respectively. Additionally, the reported sensor system consisting of degradable materials will offer a useful way of reducing electronic garbage. [ABSTRACT FROM AUTHOR]

The tribological performance of the tungsten carbide substrate (WC‐Co), improved by ceramic coatings, is still being reported in new studies that have been carried out to date. It has become a hot research topic that are widely applied in hard material research, especially in the tools manufacturing fields. This study was conducted to investigate the wear characteristics of a commercial cemented carbide tool (WC‐Co) coated with a physical vapor deposition chromium‐vanadium nitride film (CrVN), followed by a boriding process as a final thermochemical treatment. Tested in dry sliding contact against an alumina ball as a static partner, the tribological responses of the specimen were analyzed and compared with an uncoated specimen. Friction coefficients, calculated from volume loss, were around.58 for all specimens except the uncoated specimen at 10 N of applied load. Wear scar analyses revealed the occurrence of several wear mechanisms that is polishing, oxidation, wear debris formation, surface binder removal, grain fragmenting, and grain pull‐out. [ABSTRACT FROM AUTHOR]

Soldering (sticking) to and erosion of steel die materials are common problems in commercial aluminum die casting operations. One approach for minimizing both of these issues is to place physical vapor deposition (PVD) coatings onto the surfaces of the die components. An alternate approach is the use of higher thermal conductivity die materials, such as tungsten-based alloys. While PVD coatings are becoming relatively widely used, there is little rigorous data to identify the best coating conditions to maximize life of the coatings. There is also little information on the life of alternate nonferrous die materials. This paper reports on a laboratory study that examined the effect of PVD coating conditions and alternate die materials on die component life. The test involves rotating pins fabricated from different die materials and PVD coated H13 tool steel in a crucible of molten aluminum alloy held at a temperature of 680±10 °C. The pins were periodically removed from the melt (typically every 1–2 h) to observe their condition. The effect of two aluminum alloy composition were evaluated, A380 and a binary Al–11%Si alloy. The results showing rates of dissolution of the pins are presented. Examination of failed pins showed that the molten aluminum did not appear to attack or dissolve the PVD coatings, but the coatings failed when the molten aluminum penetrated the coating though cracks, and dissolved the steel substrate, causing the cracked coating to flake off. Once the coatings were breached by the liquid aluminum, the samples quickly failed. A mechanism describing factors controlling chemical soldering of the aluminum to die casting dies is presented. [ABSTRACT FROM AUTHOR]

This study examined the influence of substrate temperature and the ratio of iron and copper vapor flow on the structural state of Fe–Cu vacuum condensates. XRD patterns of the condensates deposited under specific electron beam physical vapor deposition process parameters revealed peaks corresponding to either bcc or bcc+fcc phases. Analysis of the lattice parameter of the single bcc structure indicates that only a portion of the copper atoms dissolve in the bcc-Fe lattice, while undissolved copper atoms form bcc-Cu inclusions that are coherent with the bcc-Fe lattice. A model for the formation of the bcc-Cu structure as an adaptive phase is proposed. The formation of the adaptive phase in vacuum condensates is driven by the bcc-Cu epitaxy on the surface of bcc-Fe crystallites and excess vacancies in the condensate structure. As the copper concentration in the isostructural Fe–Cu composite increases, the level of microstrain in its bcc crystal lattice also increases. The transformation of bcc-Cu particles into fcc-Cu via a shear mechanism occurs when heated above 400 °C. It was found that increasing the deposition temperature reduces the concentration range for the formation of the isostructural composite. It is suggested that higher deposition temperatures and increased copper concentration lead to larger copper particle sizes and reduced excess vacancy concentration, which disrupts their coherence with the bcc-Fe matrix. As a result, a composite with a eutectic-like microstructure consisting of bcc-Fe and fcc-Cu phases forms directly during vapor phase condensation. [ABSTRACT FROM AUTHOR]

Gas turbine blades and disks undergo wear at high temperatures at dovetail joints where tolerances are very small. Thin hard coatings are known to enhance the wear resistance of the superalloy components minimally influencing the tolerance levels. However, fundamental understanding of the coating's wear mechanisms operating in these harsh conditions is not well understood. In this study, wear tests are performed to understand the wear mechanisms that operate in the temperature range from RT up to 800 °C for thin hard TiAlN coating using simple wear geometry eliminating any influence of wear debris. It is challenging to measure wear of thin hard coatings especially at elevated temperatures but important nevertheless. A coated ball on disk geometry with rough alumina as counterface is used for wear studies to understand exclusively the influence of humidity and temperature coating wear behavior. Cathodic arc evaporation, a physical vapor deposition technique is used to deposit TiAlN coatings on heat-treated IN718 substrates and characterized with, XRD, EPMA, TEM, SEM, nanoindentation, and FIB. The wear at room temperature shows scatter which has been ascribed to seasonal fluctuations in relative humidity. Further, wear results are shown to correlate with Young's equation for capillary condensation. Wear below 50 pct RH is essentially dry and constant up to 600 °C above which wear increases marginally upto 800 °C. The coefficient of friction shows a maximum at 400 °C, below which friction reduces due to increased adsorption of water vapor, while above 400 °C, TiO2 forms on the surface to reduce the friction. The wear rate at 3 N load in the range of 50–800 °C is ~ 1 × 10−6 mm3/m/N. For 5 N load, the wear rate is same as for 3 N load upto 600 °C but doubles above 700 °C. The average contact pressure through the test is ~ 550 and 650 MPa which is almost twice the design contact pressure. The wear debris gets richer in Ti with increase in temperatures. The Al-rich TiAlN coatings deposited by cathodic arc evaporation (CAE) technique show a low and constant wear behavior over a wide range of temperatures and are ideally suited for the protecting the dovetail joints in gas turbines. [ABSTRACT FROM AUTHOR]

Li-ion batteries are at risk of explosions caused by fires, primarily because of the high energy density of Li ions, which raises the temperature. Battery cases are typically made of plastic, aluminum, or SAF30400. Although plastic and aluminum aid weight reduction, their strength and melting points are low. SAF30400 offers excellent strength and corrosion resistance but suffers from work hardening and low high-temperature strength at 700 °C. Additionally, Ni used for plating has a low current density of 25% international copper alloy standard (ICAS). SAF2507 is suitable for use as a Li-ion battery case material because of its excellent strength and corrosion resistance. However, the heterogeneous microstructure of SAF2507 after casting and processing decreases the corrosion resistance, so it requires solution heat treatment. To address these issues, in this study, SAF2507 (780 MPa, 30%) is solution heat-treated at 1100 °C after casting and coated with Ag (ICAS 108.4%) using physical vapor deposition (PVD). Ag is applied at five different thicknesses: 0.5, 1.0, 1.5, 2.0, and 2.5 μm. The surface conditions and electrochemical properties are then examined for each coating thickness. The results indicate that the PVD-coated surface forms a uniform Ag layer, with electrical conductivity increasing from 1.9% ICAS to 72.3% ICAS depending on the Ag coating thickness. This enhancement in conductivity can improve Li-ion battery safety on charge and use. This result is expected to aid the development of advanced Li-ion battery systems in the future. [ABSTRACT FROM AUTHOR]

We used high-power impulse magnetron sputtering (HiPIMS) to deposit tungsten carbide films for superior wear protection in abrasive environments. In order to sample different W-to-C ratios more efficiently, a combinatorial approach was chosen. A single sputter target with two equal segments was used, consisting of an upper tungsten and lower graphite segment. This allowed us to vertically sample various elemental compositions in just one deposition run without creating graphitic nano-layers by rotating the substrate holder. The substrate bias voltage, being one of the most effective process parameters in physical vapor deposition (PVD), was applied in both constant and pulsed modes (the latter synchronized to the target pulse). A direct comparison of the different modes has not been performed so far for HiPIMS W-C (separated W and C targets). The resulting coating properties were mainly analyzed by nano-hardness testing and X-ray diffraction. In general, the W2C phase prevailed in tungsten-rich coatings with pulsed bias, leading to slightly higher tungsten contents. Hardness reached maximum values of up to 35 GPa in the center region between the two segments, where a mix of W2C and WC1-x phases occurs. With pulsed bias, voltage hardnesses are slightly higher, especially for tungsten-rich films. In those cases, compressive stress was also found to be higher when compared to constant bias. Erosive wear testing by blasting with alumina grit showed that the material removal rate followed basically the coating's hardness but surprisingly reached minimum wear loss for W2C single-phase films just before maximum hardness. In contrast to previous findings, low friction that requires higher carbon contents of at least 50 at. % is not favorable for this type of wear. [ABSTRACT FROM AUTHOR]

In this paper, the ceramic coating of thermal barrier coatings (TBCs) was prepared on the surface of the tube specimens by Electron Beam Physical Vapor Deposition (EB-PVD) process. Subsequently, a service simulation was conducted using a simulation device to analyze the failure behavior of the TBCs. The effects of high-temperature sintering and CaO-MgO-Al2O3-SiO2 (CMAS) corrosion on the microstructural evolution, phase structural changes, and insulation performance of the thermal barrier coatings were investigated. The results indicated that with increasing high-temperature sintering time, the "feather" structures at the boundaries of the columnar grains evolve into the "tentacle" structure that facilitates the fusion of adjacent columnar grains, resulting in increased grain diameter and wider gaps. No transformation from t'-ZrO2 to the monoclinic phase m-ZrO2 occurred during the high-temperature sintering process. Over time, CMAS wets the coating surface and infiltrates the interior of the coating, causing corrosion to the Yttria-stabilised zirconia (YSZ) and accelerating sintering. A new phase, ZrSiO4, was formed after corrosion without inducing the transition. [ABSTRACT FROM AUTHOR]

Ionized metal physical vapor deposition (IMPVD), which is operated at a very low pressure to take advantage of the metal sputtering effect on the target surface, has unique properties compared with conventional DC magnetron sputtering. In this study, we investigated the effect of the rotating magnetic field on the plasma formation of IMPVD to enhance the deposition uniformity. This was accomplished through a multi-step simulation, which enabled plasma analysis, sputtered particle and chemical reaction analysis, and deposition profile analysis. A two-dimensional particle-in-cell Monte Carlo simulation utilizes the exact cross-section data of the Cu ion collisions and calculates the particle trajectories under specific magnetic field profiles. This new methodology gives guidance for the design of the magnetic field profiles of IMPVD and an understanding of the physical mechanism. [ABSTRACT FROM AUTHOR]

The punching of holes or recesses on computer numerical control coordinate presses occurs in sheets at high speeds (up to 1200 strokes/min) with an accuracy of ~0.05 mm. One of the most effective approaches to the wear rate reduction of stamping tools is the use of solid lubricants, such as wear-resistant coatings, where the bulk properties of the tool are combined with high microhardness and lubricating ability to eliminate waste disposal and remove oil contaminants from liquid lubricants. This work describes the efficiency of complex CrAlSiN/DLC:Si coatings deposited using a hybrid unit combining physical vapor deposition and plasma-assisted chemical vapor deposition technologies to increase the wear resistance of a punch tool made of X165CrMoV12 die steel during coordinate punching of 4.0 mm thick 41Cr4 carbon structural steel sheets. The antifriction layer of DLC:Si allows for minimizing the wear under thermal exposure of 200 °C. The wear criterion of the lateral surface was 250 μm. The tribological tests allow us to consider the CrAlSiN/DLC:Si coatings as effective in increasing the wear resistance of stamping tools (21,000 strokes for the uncoated tool and 48,000 strokes for the coated one) when solving a wide range of technological problems in sheet stamping of structural steels. [ABSTRACT FROM AUTHOR]

Physical vapor deposition (PVD) provides a route to prepare highly stable and anisotropic organic glasses that are utilized in multi-layer structures such as organic light-emitting devices. While previous work has demonstrated that anisotropic glasses with uniaxial symmetry can be prepared by PVD, here, we prepare biaxially aligned glasses in which molecular orientation has a preferred in-plane direction. With the collective effect of the surface equilibration mechanism and template growth on an aligned substrate, macroscopic biaxial alignment is achieved in depositions as much as 180 K below the clearing point TLC−iso (and 50 K below the glass transition temperature Tg) with single-component disk-like (phenanthroperylene ester) and rod-like (itraconazole) mesogens. The preparation of biaxially aligned organic semiconductors adds a new dimension of structural control for vapor-deposited glasses and may enable polarized emission and in-plane control of charge mobility. [ABSTRACT FROM AUTHOR]

Using colloids effectively confined in two dimensions by a cell with a thickness comparable to the particle size, we investigate the nucleation and growth of crystallites induced by locally heating the solvent with a near-infrared laser beam. The particles, which are "thermophilic," move towards the laser spot solely because of thermophoresis with no convection effects, forming dense clusters whose structure is monitored using two order parameters that gauge the local density and the orientational ordering. We find that ordering takes place when the cluster reaches an average surface density that is still below the upper equilibrium limit for the fluid phase of hard disks, meaning that we do not detect any sign of a proper "two-stage" nucleation from a glass or a polymorphic crystal structure. The crystal obtained at late growth stage displays a remarkable uniformity with a negligible amount of defects, arguably because the incoming particles diffuse, bounce, and displace other particles before settling at the crystal interface. This "fluidization" of the outer crystal edge may resemble the surface enhanced mobility giving rise to ultra-stable glasses by physical vapor deposition. [ABSTRACT FROM AUTHOR]

As a promising in-situ hydrogen generation material, magnesium (Mg) has been seeking a promotion in its hydrogen generation property. Increasing the specific surface area, for example, replacing the Mg bulk using Mg powder, can greatly increase the hydrogen generation property, but it brings a high explosion risk, a difficulty in controlling the hydrogen generation, and an oxidation problem. In this work, we prepare a novel Mg@Ni foam material with Mg deposits on Ni foam by a physical vapor deposition method. The Ni foam not only increases the hydrolysis reaction areas of Mg by improving its specific surface area, but also kinetically accelerates the hydrolysis reaction rate of Mg by forming a uniform Mg-Ni galvanic cell. As a result, the Mg@Ni foam material realizes a near-theoretical hydrogen generation amount of Mg and a hydrogen generation rate significantly higher than those realized by the bulk Mg-based materials. The Mg@Ni foam material with the excellent hydrogen generation property is also free from explosion risk, easy to be controlled, and resistible to oxidation. A hydrogen fuel cell powered by the hydrogen generated by the Mg@Ni foam material can yield a steady voltage and run a small car for a long distance.

Rechargeable lithium batteries (LBs) are considered the most promising electrochemical energy storage systems for utilizing renewable energies like solar and wind, ushering society into an electric era. However, the development of LBs faces challenges due to interfacial issues caused by side reactions between existing electrode and electrolyte materials. Magnetron sputtering (MS), a type of physical vapor deposition technology, offers solutions with its wide material selection, gentle deposition process, high uniformity of nano/micro‐scale thin films, and strong thin‐film adhesion. This review outlines the main operating principles of MS technology and explores its advanced applications in interfacial modification of various cathodes, anodes, separators, solid‐state electrolytes, and thin‐film LBs integrated with other microelectronic devices. Furthermore, the review discusses the potential of MS technology to accelerate scientific research and industrial progress toward higher‐performance LBs, advancing human society. [ABSTRACT FROM AUTHOR]

Polycrystalline silicon (poly‐Si) has been and still is a pivotal material, particularly in the electronics and solar energy industries. Controlling crystallization is one of the challenges, e.g., in producing poly‐Si films for radio frequency applications. Since film growth by deposition is a random process, producing a specific grain size distribution for poly‐Si is challenging. By combining molecular dynamics simulation data with surface diffusion physics, novel transparent models are constructed that shed light on the physics behind the deposition of poly‐Si thin films and assist the selection of simulation parameters. Both probabilistic and geometric approaches are used to find relevant simulation parameters and their bounds to describe the complex grain–grain boundary interactions in the growth of poly‐Si thin films. Poly‐Si growth simulations provide valuable information to better understand the features of optimal growth conditions. The constructed parameterized deposition model is fitted to the simulation data. In addition to further refining the simulation of customized poly‐Si films, the presented modeling concept can also be used more generally in the analysis of physical vapor deposition. [ABSTRACT FROM AUTHOR]

Supramolecular additives are an established class of nucleating agents to modify and control the solid‐state morphology of semi‐crystalline polymers, in particular isotactic polypropylene (iPP). A widely used reinforcement material for iPP is glass fibers (GFs), which significantly improve the mechanical properties. Here, these two types of materials are combined by creating defined hierarchical superstructures composed of glass microfiber nonwovens and supramolecular nanofibers based on selected 1,3,5‐benzetrisamides (BTA). The supramolecular nanofibers are prepared by physical vapor deposition (PVD), a straightforward solvent‐free process. By systematically varying PVD process parameters, it is shown that supramolecular BTA nanofibers can be reproducibly prepared on flat substrates. The morphology of the supramolecular nanofibers can be controlled by substrate temperature, evaporation time, and evaporation rate. The use of GF nonwovens enables the fabrication of hierarchical superstructures with a bottlebrush morphology comprising supramolecular nanofibers of defined length. These hierarchical superstructures are capable of nucleating iPP and thus promote transcrystallization of the iPP from the decorated GFs surface, which ultimately improves the adhesion between the GFs and the iPP. Laminating decorated GF nonwovens between two iPP films clearly increases the mechanical properties of the composites in contrast to composites without nucleating agents. [ABSTRACT FROM AUTHOR]

Nowadays, polycrystalline lead telluride is one of the premier substances for thermoelectric devices while remaining a hopeful competitor to current semiconductor materials used in mid-infrared photonic applications. Notwithstanding that, the development of reliable and reproducible routes for the synthesis of PbTe thin films has not yet been accomplished. As an effort toward this aim, the present article reports progress in the growth of polycrystalline indium-doped PbTe films and their study. The introduction foregoing the main text presents an overview of studies in these and closely related research fields for seven decades. The main text reports on the electron-beam-assisted physical vapor deposition of n-type indium-doped PbTe films on two different amorphous substrates. This doping of PbTe is unique since it sets electron density uniform over grains due to pinning the Fermi level. In-house optimized parameters of the deposition process are presented. The films are structurally characterized by a set of techniques. The transport properties of the films are measured with the original setups described in detail. The infrared transmission spectra are measured and simulated with the original optical-multilayer modeling tool described in the appendix. Conclusions of films' quality in terms of these properties altogether are drawn. [ABSTRACT FROM AUTHOR]

It is always a hot and difficult problem of how to realize multi-bit data storage by preparing multi-resistance memristors by a simple process compatible with standard CMOS processes. In this work, a tristable TaO x -based memristor with tunable oxygen vacancies is fabricated by physical vapor deposition, consisting of a high-resistance state and two low-resistance states. Its set and reset voltages are low −1.1V, −2.1V, and -1V, 3.3V, respectively. The XPS characterization demonstrates the presence of three valence states within the TaO x film. It has been suggested that different barriers lead to different switching voltages during the transition of the trivalent state, resulting in the formation of stable states. Interestingly, when increasing the concentration of oxygen during preparation to decrease the concentration of oxygen vacancies in TaO x film, the volt-ampere properties of memristor change from tristable to bistable, which further proves the above point. This work provides a viable strategy for switching between bistable and tristable states in memristors prepared from transition metal oxides. [ABSTRACT FROM AUTHOR]