Search Results (265)

Biocompatible thin films are essential for advancing biomedical devices, as they enhance integration with biological tissues, improve device longevity, and reduce complications. The rapid evolution of both medical needs and materials science has led to a diverse array of deposition techniques, each offering unique advantages and challenges for tailoring surface properties without compromising the bulk characteristics of implants and sensors. While laser-based methods—such as pulsed laser deposition (PLD) and Matrix-Assisted Pulsed Laser Evaporation (MAPLE)—are renowned for their precision, ability to preserve complex material stoichiometry, and suitability for low-temperature processing, the broader landscape includes several other important approaches. Physical Vapor Deposition (PVD) techniques, including magnetron sputtering and pulsed electron deposition, are widely used for their ability to create uniform, adherent coatings with controlled thickness and composition, making them suitable for both hard and soft biomedical substrates. Chemical Vapor Deposition (CVD) and its plasma-enhanced variant (PECVD) offer conformal coatings and excellent control over film chemistry, which is particularly valuable for functional polymer and ceramic films. Other methods, such as sol–gel processing, ion beam deposition, and electrophoretic deposition, provide additional flexibility in terms of coating composition, adhesion, and processing temperature, allowing for the fabrication of films with tailored mechanical, chemical, and biological properties. Despite these advances, the field faces ongoing challenges in optimizing film properties for specific clinical applications, ensuring reproducibility, and scaling up production for widespread use. The necessity of this review lies in its comprehensive comparison of laser-based techniques with alternative deposition methods, providing critical insights into their respective strengths, limitations, and suitability for different biomedical scenarios. By synthesizing recent developments and highlighting current gaps, this review aims to guide researchers and clinicians in selecting the most appropriate thin-film deposition strategies to meet the evolving demands of next-generation biomedical devices. Full article

Metal surfaces exposed to air environments invariably undergo various surface modifications, altering their secondary electron emission coefficient (SEEC). However, the physical mechanisms underlying these surface modifications differ across metals, yielding distinct effects on SEEC. To investigate the SEEC properties of silver oxide and the impact of surface oxidation on the SEEC of silver, silver oxide and silver coatings were prepared by sputtering, followed by studies of their physical properties and SEEC. Results indicate that under conditions where preparation, storage, and testing were kept as consistent as possible, the SEEC of oxidized silver surfaces is not much different from that of silver-coated surfaces. The SEEC maximum values of silver oxide and silver coatings are 1.7 and 1.6, and the values decreased to 1.5 and 1.4 after ion-sputtering treatment. To validate the impact of surface oxidation on the SEEC of silver, various surface states were achieved on silver substrates. Elemental analysis revealed that vacuum heating effectively removes contaminants from silver coating surfaces, resulting in a significant reduction in SEEC values. Ion sputtering removed contaminants, etched the oxidation layer, and modified the morphology of the silver surface effectively. After 5 min of ion sputtering, the SEEC maximum of the original silver sample decreased from 2.6 to 1.73, and after 15 min of ion sputtering, it further decreased to 1.7. This result indicates that surface oxidation contributes minimally to the SEEC variation of silver exposed to air. The findings revealed in this work hold engineering significance for understanding alterations in the SEEC properties of silver surfaces under different surface conditions. Full article

Externally applied electric fields are widely employed during thin-film deposition to improve film uniformity, texture and densification. Despite extensive experimental evidence, the physical mechanisms by which such fields influence nucleation, surface diffusion, island coalescence and interface stability remain theoretically fragmented. Classical thin-film growth models assume a field-free energetic landscape and therefore provide limited predictive guidance for field-assisted manufacturing strategies. In this work, we introduce the Field-Driven Growth Model (FDGM), a unified theoretical framework that incorporates field–matter interactions directly into the free-energy functional governing thin-film growth. By explicitly accounting for effective dipolar coupling arising from field-induced polarization of surface species, predominantly quadratic in the field amplitude and consistent with linear-response polarization, the model consistently modifies the fundamental processes of nucleation, surface diffusion and coalescence. At the continuum scale, the FDGM predicts a field-induced stabilization mechanism that suppresses long-wavelength roughening modes and defines a field-controlled morphological crossover wavelength (field-controlled cutoff). The FDGM demonstrates that field-assisted nucleation bias, anisotropic surface diffusion, field-biased coalescence pathways and morphological stabilization are not independent phenomena, but multiscale manifestations of a single energy-minimization principle acting on a field-modified energy landscape. By providing analytical stability criteria and explicit links between external field parameters and morphological outcomes, the model establishes a predictive foundation for the manufacturing of thin films with improved uniformity in advanced thin-film-based devices. The framework is broadly applicable to deposition techniques such as sputtering, pulsed-laser deposition, chemical vapor deposition and atomic layer deposition. Full article

Machine learning (ML) offers a powerful paradigm for accelerating performance prediction of high-entropy alloys (HEAs). The present study proposed an ML framework based on the ridge regression algorithm for predicting the hardness of MoNbTaW HEA films. By comparing various feature-screening strategies, an optimized feature set comprising three features, namely δG, Λ, and Ω, was selected from 20 candidate physical features. The model based on this feature set exhibited strong predictive performance. In 10-fold cross-validation, R² was 0.86, RMSE was 0.41 GPa and MAE was 0.31 GPa. On the reserved validation set, R² was 0.88, RMSE was 0.37 GPa, and MAE was 0.31 GPa. The model further revealed the influence trends of constituent elements and key features on hardness. By using ML to mine useful information from a dataset of HEA film samples prepared via magnetron sputtering, this work provides an approach for rapid and cost-effective design of HEAs. Full article

Due to its very high theoretical specific capacity, lithium is still considered a promising anode material for innovative next-generation battery cells. The aim is to produce thin lithium metal anodes (LMAs) that are sufficient for the battery cell due to the lithium already present in the cathode and thus additionally increase the energy density of the cell. The production of thin lithium layers (<10 µm) is challenging with most processes, and very costly with decreasing thickness. In this study, the use of magnetron sputtering to deposit thin layers of lithium for the production of LMAs is tested. An innovative process—the deposition of lithium from a liquid phase via Hot Target Sputtering—will be presented that has the potential to overcome the previous limitations in the deposition rate, and enables the potential for industrial application. The process was successfully tested in terms of general process control, stability and reproducibility and used to produce lithium metal anodes. These were then successfully integrated in All-Solid-State-Battery (ASSB) cells and compared with a lithium reference foil in a C-rate test with regard to their electrochemical performance reaching ≈ 110 mAh g⁻¹ at a 1C discharge rate. Full article

Antibacterial thin-film coatings are of increasing interest for enhancing hygiene in controlled environments such as commercial greenhouses. Phytopathogens including Pseudomonas syringae, and human pathogens such as Escherichia coli, Micrococcus luteus, and Staphylococcus aureus, frequently contaminate greenhouse environments. The present study aimed to develop and evaluate multifunctional magnetron-sputtered glass coatings with strong antimicrobial performance, deposited by physical vapor deposition to achieve precise control of film composition and uniform coverage of large substrates (≥0.25 m²), ensuring industrial-scale applicability. Thin films were fabricated by magnetron sputtering using multi-alloy targets composed of Cu, Sn, Zn, Al, Ni, Fe, Ti, Mn, Nb, or Co. Fourteen distinct coating compositions were characterized using high-resolution transmission electron microscopy, scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Antibacterial performance was evaluated against the following strains: E. coli (PCM 2560), M. luteus (PCM 525), S. aureus (PCM 2602), and P. syringae pv. tomato (IOR2146). Coatings prepared from 90%Cu-10%Sn, 90%Cu-10%Zn, and 80%Cu-20%Ti targets exhibited one of the highest antibacterial efficiencies. These coatings also showed strong mechanical durability and corrosion resistance. Our results indicate that coatings obtained from Cu-based multi-alloy targets by magnetron sputtering are promising candidates for use as durable, antimicrobial inner glass surfaces in future greenhouse applications. Full article

This study investigates the development of multilayer Cr/CrC coatings as a sustainable alternative to cadmium (Cd) for corrosion protection in aerospace components exposed to aggressive environments. The coatings were deposited on AISI 4130 steel and silicon (100) substrates using unbalanced magnetron sputtering, a physical vapor deposition (PVD) technique. Advanced characterization was performed using SEM, AFM, XRD, and TEM, revealing the formation of nanocomposite structures whose characteristics depend on the carbon content and the deposition conditions. The electrochemical performance of the coatings was evaluated through electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution, and the results showed a significant improvement in corrosion resistance, particularly when a Cr anchor layer was incorporated. These findings confirm that Cr/CrC coatings represent a viable and environmentally friendly alternative to cadmium for aerospace applications. Full article

Zinc oxide (ZnO) nanostructures have been intensively investigated for applications in sensing, photocatalysis, and optoelectronic devices, where functional performance is strongly governed by morphology, crystallinity, and defect structure. Conventional wet-chemical and vapor-phase growth methods often require long processing times or complex chemistries and face reproducibility and compatibility challenges when applied to thin, flexible, or curved metallic substrates. Pulsed high-energy techniques—such as pulsed laser deposition (PLD), high-power impulse magnetron sputtering (HiPIMS), and pulsed laser or plasma processing—offer a versatile alternative, enabling rapid and localized synthesis both from and on Zn-bearing thin shells. These methods create transient nonequilibrium conditions that accelerate oxidation and promote spatially controlled nanostructure formation. This review highlights the emerging integration of artificial intelligence (AI) with pulsed ZnO synthesis on thin metallic substrates, emphasizing standardized data reporting, Bayesian optimization and active learning for efficient parameter exploration, physics-informed and graph-based neural networks for predictive modeling, and reinforcement learning for adaptive process control. By connecting synthesis dynamics with data-driven modeling, the review outlines a path toward predictive and autonomous control of ZnO nanostructure formation. Future perspectives include autonomous experimental workflows, machine-vision-assisted diagnostics, and the extension of AI-guided pulsed synthesis strategies to other functional metal oxide systems. Full article

With continuous breakthroughs in electrochromic technology, tungsten trioxide (WO₃) thin films, as a core material in this field, are rapidly expanding their applications in smart windows, anti-glare automotive rearview mirrors, and adaptive optical lenses. Owing to its excellent electrochromic properties—including high optical modulation, short switching times, and high coloration efficiency—WO₃ has become a research focus in the field of electrochromic devices. This review takes WO₃ thin films as the research subject. It begins by introducing the crystal structure of WO₃ and the ion/electron co-intercalation-based electrochromic mechanism and explains two key performance parameters for evaluating electrochromic properties: optical modulation amplitude and coloration efficiency. Subsequently, it provides a detailed review of recent advances in the preparation of WO₃ thin films via physical methods (including sputtering deposition, evaporative deposition, and pulsed laser deposition) and chemical methods (including hydrothermal, sol–gel, and electrodeposition methods). A systematic comparison is made of the microstructure and electrochromic performance (optical modulation amplitude and coloration efficiency) of films prepared by different methods, and the interaction between WO₃ film morphology and device structure is analyzed. Finally, the advantages and challenges of physical and chemical methods in tuning film properties are summarized, and the outlook of their application prospects in high-performance electrochromic devices is given. This review aims to provide guidance for the selection and process optimization of WO₃ thin films with enhanced performance for applications such as smart windows, anti-glare rearview mirrors, and adaptive optical systems. Full article

This study presents the Raman spectral characteristics and selected electrical parameter measurements of WS₂ films deposited by magnetron sputtering on sapphire and subsequently sulfurized. The analysis of the Raman spectra focuses on the positions and shifts of the E¹_2g and A_1g vibrational modes. The effects of different sputtering times on WS₂ films and the corresponding activation energy values were also investigated. From both physical and experimental perspectives, the Raman spectral features of WS₂ films were found to depend on the laser excitation wavelengths (532 nm and 632.8 nm) as well as on possible crystallographic defects and variations in the excitation point position. These defects have a significant influence on both the Raman spectra and the activation energies of the studied samples. The calculated activation energies (~ 0.15–0.19 eV) of the conduction charge carriers correlate with shallow defect-related energy levels indicated by the Raman characteristics. Full article

Fiber Bragg Grating (FBG) sensors facilitate compact, multiplexed, and electromagnetic interference-immune monitoring in embedded and harsh environments. The removal of the polymer jacket, a measure taken to withstand elevated temperatures or facilitate integration, exposes the fragile glass. This underscores the necessity of functional coatings, which are critical for enhancing durability, calibrating sensitivity, and improving compatibility with host materials. This review methodically compares coating materials and deposition routes for FBGs, encompassing a range of techniques including top-down physical-vapor deposition (sputtering, thermal/e-beam evaporation, cathodic arc), bottom-up chemical vapor deposition (CVD)/atomic layer deposition (ALD), wet-chemical methods (sensitization/activation, electroless plating (EL), electrodeposition (ED)), fusion-based processes (casting and melt coating), and hybrid stacks (e.g., physical vapor deposition (PVD) seed → electrodeposition; gradient interlayers). The consolidation of surface-preparation best practices and quantitative trends reveals a comprehensive understanding of the interrelationships between coating material/stack, thickness/microstructure, adhesion, and sensitivity across a range of temperatures, extending from approximately 300 K to cryogenic regimes. Practical process windows and design rules are distilled to guide method selection and reliable operation across cryogenic and high-temperature regimes. Full article

Gold thin films were deposited on quartz substrates by DC magnetron sputtering to fabricate electrodes for electrochemical and resistive sensing applications. The influence of sputtering parameters on film thickness, structure, and electrical properties was systematically investigated. XRD analysis revealed a predominant (111) crystallographic orientation. Microstrain values, determined via Williamson–Hall (W–H) analysis, were low (below 0.013) and closely correlated with surface roughness trends. AFM measurements showed that the surface roughness increased with film thickness. Electrical resistivity decreased linearly with increasing thickness and exhibited a critical grain size of approximately 25 nm, beyond which conductivity improved markedly. These results demonstrate the strong dependence of Au thin-film morphology and performance on deposition conditions, offering practical guidelines for optimizing their application in functional sensing devices. Full article

Phase-change memory (PCM) is a promising candidate for in-memory computation and neuromorphic computing due to its high endurance, low cycle-to-cycle variability, and low read noise. However, among other factors, its performance strongly depends on the post-lithography fabrication steps. This study examines the impact of reactive ion etching (RIE) on PCM device performance by evaluating different etching gas mixtures, CHF₃:O₂, H₂:Ar, and Ar, and determining their impact on key device characteristics, particularly initial resistance and cycling stability. The present study demonstrates that a two-step etching approach in which the capping layer is first removed using H₂:Ar and the underlying GST layer is subsequently etched using physical Ar sputtering ensures stable and reliable PCM operation. In contrast, chemically reactive gases negatively impact the initial resistance, cycling stability, and device lifetime, likely due to alterations in the material composition. For the cycling stability evaluation, an advanced measurement algorithm utilizing the aixMATRIX setup by aixACCT Systems is employed. This algorithm enables automated testing, dynamically adjusting biasing parameters based on cell responses, ensuring a stable ON/OFF ratio and high-throughput characterization. Full article

In view of the need to increase the durability of working tools exposed to intense friction, this study analysed hybrid coatings (TiAlCN, AlTiCN, AlCrTiN, TiN, CrN) with a DLC (Diamond-Like Carbon) layer, deposited using PVD (Physical Vapour Deposition) methods (arc evaporation and magnetron sputtering). The structural characteristics of the coatings were determined using SEM (Scanning Electron Microscope) and AFM (Atomic Force Microscope) microscopy, as well as Raman spectroscopy, which confirmed the compact structure and amorphous nature of the DLC layer. Tribological tests were performed using a ball-on-disc test, revealing that DLC hybrid coatings significantly reduce the coefficient of friction (stabilisation in the range of 0.10 to 0.14 due to DLC graphitisation), limiting tool wear even under increased load. The SEM-EDS (Scanning Electron Microscope-Energy Dispersive Spectroscopy) microscopic examination revealed that the dominant wear mechanisms are abrasive and adhesive damage, and the AlCrTiN/DLC system is characterised by low wear and high adhesion (L_c = 10⁵ N), making it the optimal configuration for the given loads. Microhardness tests showed that high hardness does not always automatically translate into increased wear resistance (e.g., the AlTiCN coating with 4220 HV showed the highest wear), while coating systems with moderate hardness (TiAlCN/DLC, CrN/DLC) achieved very low wear values (~0.17 × 10⁻⁵ mm³/Nm), which highlights the importance of synergy between the hardness of the sublayer and the low friction of DLC in the design of protective coatings. Full article

In this study, SiO₂ thin films were sputtered from a Si target using reactive HiPIMS (high-power impulse magnetron sputtering) in an argon–oxygen process gas. In order to understand the behavior of HiPIMS, the deposition process was studied by systematically varying the sputtering parameters and monitoring the current waveforms. A decaying transient was observed at the leading edge of the pulse, caused by the L-C term of the HiPIMS generator, the cable, and the target. To investigate the periodic transient, we used, to the best of our knowledge, for the first time, a standing wave ratio meter (SWR). In order to be able to deposit films with the desired properties, the target voltage and its associated current characteristics were also investigated. The formation of a distinct step-like shape in the current–voltage characteristics is observed during reactive sputtering. A simple physical model was used to determine the position and length of the plateau. The appearance of hysteresis, which is typical of reactive sputtering, was also observed. These findings may help us to better understand the mechanism of reactive HiPIMS deposition of SiO₂. Full article