Search Results (596)

Chromium-doped diamond-like carbon (DLC-Cr) nanocomposite films were successfully deposited using a high-power impulse magnetron sputtering (HiPIMS) system. The Cr content in the films was controlled by adjusting the Cr target powers. The influence of Cr content on the microstructure, mechanical properties, tribological performance, and wettability of the films was systematically investigated. The results show that the Cr content and deposition rate of the films increased with increases in the target power. The surface topography of the films evolved from smooth to rough as the Cr target increased from 10 W to 70 W. At low Cr doping rates, the film mainly exhibited an amorphous structure, whereas the nanocomposite structure was formed at proper Cr doping rates. Raman and XPS analyses revealed that Cr incorporation altered the I_D/I_G ratio and promoted the formation of Cr-C bonds, leading to a more graphitic and nanocomposite-like structure. The nanoindentation results show that an optimal Cr content enhances both hardness and elastic modulus, while higher Cr concentrations lead to a decline in mechanical strength due to more graphitization and decreasing stress. Tribological tests exhibited a significant reduction in the friction coefficient (0.21) and wear rate (0.63 × 10⁻¹⁴ m³/N·m) at a moderate Cr level. Additionally, the surface wettability evolved toward enhanced hydrophilicity with increasing Cr power, as evidenced by reduced water contact angles and increased surface energy. These findings demonstrate that controlled Cr incorporation effectively tailors the structure, stress state, and surface chemistry of DLC films, offering a tunable pathway to achieving optimal mechanical performance and tribological stability for advanced engineering applications. 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

Herein, we propose a simple and cost-effective method for fabricating moderate-sensitivity surface-enhanced Raman scattering (SERS) substrates using Cu-plasma polymer fluorocarbon (Cu-PPFC) nanocomposite films fabricated through RF sputtering. The use of a composite target composed of carbon nanotube (CNT), Cu, and polytetrafluoroethylene (PTFE) powders (5:60–80:35–15 wt%) offers the advantage of the simple fabrication of moderate-sensitivity SERS substrates with a single cathode compared to co-sputtering. X-ray photoelectron spectroscopy (XPS) revealed that the film surface was partially composed of metallic Cu with Cu-F bonds and Cu–O bonds, confirming the coexistence of the conducting and plasmon-active domains. UV-VIS spectroscopy revealed a distinct absorption peak at approximately 680 nm, indicating the excitation of localized surface plasmon resonances in the Cu nanoclusters embedded in the plasma polymer fluorocarbon (PPFC) matrix. Atomic force microscopy and grazing incidence small-angle X-ray scattering analyses confirmed that the Cu nanoparticles were uniformly distributed with interparticle distances of 20–35 nm. The Cu-PPFC nanocomposite film with the highest Cu content (80 wt%) exhibited a Raman enhancement factor of 2.18 × 10⁴ for rhodamine 6G, demonstrating its potential as a moderate-sensitivity SERS substrate. Finite-difference time-domain (FDTD) simulations confirmed the strong electromagnetic field localization at the Cu-Cu nanogaps separated by the PPFC matrix, corroborating the experimentally observed SERS enhancement. These results suggest that a Cu-PPFC nanocomposite film, easily fabricated using a composite target, provides an efficient and scalable route for fabricating reproducible, inexpensive, and moderate-sensitivity SERS substrates suitable for practical sensing applications. Full article

This study aimed to examine the influence of sputtering temperature on the bonding structure and properties of non-hydrogenated chromium/nickel co-doped diamond-like carbon (DLC) films synthesized via direct current magnetron sputtering. The Cr/Ni doping levels in the coatings were regulated by varying the shield opening above a chromium-nickel (20/80 at.%) target, resulting in a total metal co-doping concentration ranging from 6.1 to 8.9 at.%. The thickness of the Cr/Ni-DLC films ranged from 160 to 180 nm. Meanwhile, the deposition temperatures of 185 °C and 235 °C were achieved by adjusting the substrate-to-target distance. The XPS and Raman spectroscopy results indicated enhanced graphitization of the Cr/Ni-DLC films with a decrease in the synthesis temperature. XPS results indicated the formation of carbon-oxide and metal-oxide bonds, with no evidence of metal carbide formation in the doped DLC films. Furthermore, both the nanohardness and Young’s modulus demonstrated significant improvement, while the friction coefficient was reduced more than twice as the deposition temperature increased. These findings provide valuable insights into the influence of deposition temperature on Cr/Ni co-doped DLC films, highlighting their potential as advanced functional coatings. Full article

Volatile organic compounds (VOCs) released from automotive interior materials and exchanged with external air seriously compromise cabin air quality and pose health risks to occupants. Electronic noses (E-noses) based on metal oxide semiconductor (MOS) micro-electro-mechanical system (MEMS) sensor arrays provide an efficient, real-time solution for in-vehicle gas monitoring. This review examines the use of SnO₂-, ZnO-, and TiO₂-based MEMS sensor arrays for this purpose. The sensing mechanisms, performance characteristics, and current limitations of these core materials are critically analyzed. Key MEMS fabrication techniques, including magnetron sputtering, chemical vapor deposition, and atomic layer deposition, are presented. Commonly employed pattern recognition algorithms—principal component analysis (PCA), support vector machines (SVM), and artificial neural networks (ANN)—are evaluated in terms of principle and effectiveness. Recent advances in low-power, portable E-nose systems for detecting formaldehyde, benzene, toluene, and other target analytes inside vehicles are highlighted. Future directions, including circuit–algorithm co-optimization, enhanced portability, and neuromorphic computing integration, are discussed. MOS MEMS E-noses effectively overcome the drawbacks of conventional analytical methods and are poised for widespread adoption in automotive air-quality management. 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

To address the challenge of achieving uniform coating on large-aperture substrates with significant sagittal height differences, this study employs a conventional-sized movable sputtering target combined with substrate rotation to realize high-uniformity control. The research establishes a geometric deposition model for the spatial thickness distribution of thin films on large-aperture, high-sagittal-height substrates and develops a precise control method for the deposition distribution on the substrate surface. Using the gradient descent algorithm, an optimal velocity modulation curve is calculated, and the spatial thickness distribution under this curve is determined. Compared with traditional least-squares optimization, this method effectively overcomes the issues of slow computation speed and poor convergence in large-scale numerical calculations, enabling rapid and uniform spatial control of large-aperture substrates. Calculation results demonstrate that the proposed method reduces the film non-uniformity from over 60% to a final value of 2.66%, with a corresponding PV value of 2.61%, across the 6550 mm aperture, showcasing its high precision. Full article

The performance of ultra-high-purity copper sputtering targets is critical for nanoscale integrated circuit fabrication, yet challenges such as dynamic recovery and recrystallization hinder grain refinement and texture control. In the present work, cryogenic deformation was introduced to address these issues. Through electron backscatter diffraction (EBSD), X-ray diffraction (XRD), and mechanical testing, the microstructure, texture, and mechanical properties of 6N ultra-high-purity copper processed by room-temperature rolling (RTR) and cryorolling (CR) were comparatively investigated. Results reveal that RTR deformation is dominated by slip mechanisms; the RTR sample with 90% reduction exhibits obvious dynamic recrystallization (DRX) and forms a bimodal structure dominated by Copper ({112}⟨111⟩) and S ({123}⟨634⟩) textures. In contrast, CR suppresses thermal activation processes, enabling deformation mechanisms suggestive of twinning activity, leading to ultrafine fibrous structures, while shifting texture components toward Brass ({110}⟨112⟩) and S. Compared to RTR-processed samples, CR-processed samples possess superior mechanical performance. The CR sample with 90% reduction exhibits: a microhardness of 164.60 HV, a yield strength of 385.61 MPa, and a tensile strength of 648.02 MPa, which are, respectively, 33.2%, 91.7%, and 84.6% higher than those of RTR counterparts. Williamson–Hall analysis confirms that the CR sample with 90% reduction achieves finer substructure sizes (~133 nm) and higher stored energy (~22 J·mol⁻¹) by suppressing dynamic recovery, providing a robust driving force for subsequent annealing. This work demonstrates that cryorolling optimizes microstructure and texture through twin-dislocation synergy, providing a fundamental basis for the development of advanced sputtering targets. Full article

TiO_xN_y coatings are known for their good biocompatibility and corrosion resistance and have been previously explored for biomedical applications, including cardiovascular stents. In this work, emphasis is placed on a systematic investigation of the effect of substrate bias voltage on the structural, morphological, and mechanical properties of TiO_xN_y films deposited by reactive magnetron sputtering. TiO_xN_y coatings were deposited on 316L stainless steel substrates using a pure titanium target (99.99%) in an Ar–N₂–O₂ gas mixture at various substrate bias voltages (0 to −150 V). The influence of substrate bias on the deposition rate, structure, and mechanical properties of the films was investigated. X-ray diffraction (XRD) analysis revealed the sequential phase evolution from cubic TiN to oxynitride TiON and further to TiO₂ (anatase/rutile) with increasing negative substrate bias, indicating that ion bombardment energy plays a decisive role in determining the crystallinity and phase composition of the coatings. The coating deposited at −50 V exhibited the highest hardness (~430 HV) and good adhesion strength (critical load 20–25 N). Contact angle measurements confirmed the hydrophilic behavior of the coatings, which is favorable for biomedical applications. Full article

Tantalum nitride (TaN) coatings are valued for their hardness, chemical inertness, and biocompatibility; however, they lack intrinsic antibacterial properties, which limits their application in biomedical environments. Introducing copper (Cu) into the TaN matrix offers a potential solution by combining TaN’s mechanical and chemical durability with Cu’s well-documented antimicrobial action. This study explores how varying copper incorporation affects the structural, electrical, photocatalytic, and antibacterial characteristics of TaCuN multilayer films synthesized via reactive magnetron sputtering. Three thin TaCuN films were fabricated using a high-power reactive magnetron co-sputtering system, varying the Cu target power to control the composition. Structural and morphological analysis was performed using X-ray diffraction (XRD), scanning/transmission electron microscopy (STEM/TEM), and energy-dispersive X-ray spectroscopy (EDS). Electrical conductivity was studied along and across the film surfaces at temperatures ranging from 20 to 375 K using AC impedance spectroscopy. Optical and photocatalytic properties were assessed using UV–Vis spectroscopy and methylene blue degradation tests. Antibacterial activity against Staphylococcus aureus was analyzed under visible light using CFU reduction tests. XRD and TEM analyses revealed a multilayered four-zone architecture with alternating Ta-, Cu-, and N-rich phases and a dominant cubic δ-TaN pattern. The layers exhibited pronounced conductivity anisotropy, with in-plane conductivity (~10³ Ω⁻¹ cm⁻¹) exceeding cross-plane conductivity by ~10⁷ times, attributed to the formation of a metallic conduction channel in the mid-layer. Optical spectra indicated limited light absorption above 300 nm and negligible photocatalytic activity. Increasing the Cu content substantially enhanced antibacterial efficiency, with the highest-Cu sample achieving 95.6 % bacterial growth reduction. Morphological evaluation indicated that smooth film surfaces (Ra < 0.2 μm) effectively minimized bacterial adhesion. Reactive magnetron sputtering enables the precise engineering of TaCuN multilayers, combining high electrical anisotropy with robust antibacterial functionality. The optimized TaCuN coating offers promising potential in biomedical and protective applications where both conductivity and microbial resistance are required. Full article

Yttrium oxide (Y₂O₃) films have been widely used as protective layers in plasma etching equipment, but achieving stoichiometric films with high deposition rates remains a challenge. In this study, Y₂O₃ films were fabricated by a medium-frequency reactive magnetron sputtering (MF-RMS) technique. The oxygen flow and target control voltage were regulated through a closed-loop feedback control system, which effectively solved the problem. The microstructure, mechanical, optical, and plasma etching properties were systematically investigated. The results showed that near-stoichiometric films can achieve a relatively high deposition rate. Increasing the deposition temperature induced a structural transition in the Y₂O₃ film from a predominantly cubic phase to a mixture of cubic and monoclinic phases. For Y₂O₃ films deposited at room temperature, increasing the bias voltage increased the deposition rate but reduced hardness and elastic modulus. The Y₂O₃ film deposited at 300 °C in the near-metallic mode exhibited the highest hardness and elastic modulus, reaching 13.3 GPa and 222.0 GPa, respectively. All Y₂O₃ films exhibited excellent transmittance and resistance to plasma etching. This study provides an effective protective strategy for semiconductor etching chambers. Full article

In this study, we investigate the role of film thickness in modulating the properties of Cu films deposited on BaTiO₃ ceramic substrates using direct current magnetron sputtering (DCMS) and high-power pulsed magnetron sputtering (HiPIMS). While HiPIMS is known for producing dense films, and the thickness-dependent properties of sputtered Cu films are well-documented, this work uniquely explores the synergistic interplay between deposition technique and thickness on BaTiO₃ ceramic substrates, revealing novel insights into stress evolution and property optimization for advanced microelectronic and coating applications. Cu films of 300 nm, 1000 nm, and 1700 nm were systematically compared for their microstructures, surface morphologies, and electrical and mechanical properties, elucidating the critical role of thickness in densification, stress state, and overall performance. The results indicate that the target current and voltage waveforms of HiPIMS are similar to square waves, and the ionization rate is significantly higher than that of DCMS. Still, the deposition rate at the same power of 180 W is only 44.6% of that of DCMS. The films obtained by both processes present a strong (111) orientation; the crystallite size of the DCMS film grows with increasing thickness, while the HiPIMS film shows increasing and then decreasing, and its residual stress is overall lower than that of DCMS. In terms of surface morphology, DCMS films appeared porous and rough, whereas HiPIMS films were denser and smoother. In terms of properties, the resistivity of HiPIMS films is significantly lower than that of DCMS, especially at 1000 nm thickness. The binding force is also better than that of DCMS, especially at thicknesses less than 1000 nm, which is mainly attributed to the compressive stresses introduced by the energetic ion bombardment at the early deposition stage. These findings provide new mechanistic insights into thickness-dependent stress and property modulation, offering a reference for tailoring high-performance Cu films through process optimization. Full article

TiW thin films with superior surface properties were deposited at room temperature using RF magnetron sputtering under low-temperature process conditions. The correlation between bulk plasma characteristics and thin-film properties was investigated as a function of applied RF power (200–600 W) and process pressure (1–10 mTorr). Plasma potential and ion density were measured using a Langmuir probe, while deposition rate, surface roughness, sheet resistance, and crystallinity were evaluated. Increasing the applied RF power simultaneously increased plasma potential and ion density, enhancing ion bombardment energy at both the target and substrate, which improved sputtering efficiency and deposition rate. Under low-temperature deposition, thermal stress induced by differences in thermal expansion between the film and substrate was minimal. However, limited surface diffusion of adatoms caused incomplete coalescence of nucleation islands, adversely affecting film crystallinity. Refractory metals such as tungsten exhibit strong dependence of residual stress and microstructure on deposition conditions, highlighting the importance of plasma and process parameters on TiW film properties. When RF power was increased, the enhancement in deposition rate outweighed the effect of increased ion energy, leading to tensile stress from void formation dominating over compressive stress induced by high-energy ions. This also contributed to increased grain size and reduced sheet resistance. In contrast, variations in process pressure had minor effects on plasma characteristics, resulting in limited changes in the deposited film properties. Full article

Two low-cost optical–chemical sensors based on plastic optical fibers (POFs) and molecularly imprinted polymers (MIPs) are developed and tested for the detection of 4-chloro-2-methylphenoxyacetic acid (MCPA), a herbicide of great interest in environmental monitoring. The first sensor is based on an optical splitter composed of two modified POFs coupled with an MIP for measuring MCPA. The second type of sensor is based on a surface plasmon resonance (SPR) D-shaped POF platform combined with the same MIP receptor for MCPA. The two proposed polymer-based sensors, exploiting different optical phenomena, were tested using similar equipment, consisting of white light sources and spectrometers. The experimental results show that both MCPA sensors present high selectivity for the target analyte and similar performances in terms of detection limits (LODs) of 3 nM and detection ranges (between 3 nM and 500 nM) by exploiting the MIP’s sites with a similar affinity constant. The polymer-based sensors exhibited better performances than those achieved by the electrochemical technique combined with the same MIP presented in the literature. Then, tests performed on real samples demonstrated good recovery values (between 82% and 116%), assessing the applicability of both sensors in real-world scenarios. Moreover, the POF-MIP splitter sensor configuration can be fabricated without expensive fabrication steps, such as spinning and sputtering processes. Full article

This study investigates the influence of multilayer architecture on the mechanical, corrosion, and tribological properties of Ti/TiN coatings deposited on biomedical Ti-6Al-4V alloy. Nine multilayer configurations were prepared by DC/RF magnetron sputtering using metallic Ti and ceramic TiN targets, with a fixed TiN/Ti ratio of 3:1 and varying total numbers of layers (3, 5, and 7) and deposition times (30, 60, and 120 min). A strict application of the 10% indentation depth rule was implemented to eliminate substrate effects, which revealed significantly higher intrinsic hardness values (540–740 HV) and indentation moduli (124–143 GPa) compared to the substrate (353 HV; 114 GPa). In contrast, conventional higher-load testing underestimated coating performance due to substrate dominance. Among the investigated architectures, the Ti/TiN-7 configuration exhibited the best balance of properties, combining high hardness (~690 HV), modulus (~137 GPa), improved corrosion resistance (Ecorr up to −0.13 V, Icorr reduced by an order of magnitude), and stable abrasive wear behavior. These findings demonstrate that both bilayer number and deposition time critically determine the mechanical and functional response of Ti/TiN multilayers. The results provide practical guidelines for the reliable characterization and design of multilayer coatings for biomedical and aerospace applications. Full article