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Nonpolar (100), polar (002), semipolar (101), and nonpolar (110) preferred oriented ZnO films were synthesized by regulated growth using the chemical bath deposition method. The crystallinity, surface morphology, and optical properties of ZnO films with different preferred orientations after annealing in different atmospheres were systematically investigated. The experimental results show an increase in crystallinity and a decrease in surface roughness of the films after annealing; in particular, the optical transmittance of semipolar (101) preferred oriented ZnO films was significantly higher than that of the other samples. XPS and PL spectra confirmed that annealing in argon effectively increased donor defects, whereas annealing in oxygen and ozone reduced donor defects in the films, and that ozone annealing was best suited to enhance acceptor defects in nonpolar (110) preferred oriented ZnO films. Argon annealing is the best for the enhancement of donor defects in polar (002) preferred oriented ZnO films. This work achieves modulation of optical properties and defects of ZnO films by annealing in different atmospheres, which provides new ideas for the application of ZnO materials. [ABSTRACT FROM AUTHOR]

Recently, deep-ultraviolet (DUV) light-emitting devices have attracted attention for various applications. GaN/AlN superlattices have emerged as a promising alternative for achieving high-efficiency DUV emission. To fabricate superlattices with high crystal quality and abrupt interfaces, we have utilized face-to-face-annealed sputter-deposited AlN template substrates characterized by a flat surface and low dislocation density. Furthermore, radio-frequency plasma-assisted molecular beam epitaxy with in situ reflection high-energy electron diffraction monitoring was employed for the growth process. The growth of the superlattices follows a specific sequence. Step 1: AlN growth, Step 2: conversion of Al droplets to AlN, Step 3: GaN growth, and Step 4: evaporation of Ga droplets. This study explored the impact of GaN thickness on the GaN/AlN superlattice. The GaN thickness was linearly controlled by changing the duration of Step 3. This approach allowed for the growth of a flat GaN layer up to 1 monolayer (ML) and achieved superlattices with abrupt interfaces. Single-peak cathodoluminescence (CL) emission at 240–245 nm was observed from the superlattices, with the peak shift toward longer wavelengths as the GaN thickness increased. In contrast, quantum dot-like GaN islands were generated with a thickness of over 1 ML, induced by compressive strain. Superlattices with thicker GaN exhibited broad CL emission with multiple peaks. However, the AlN barrier layer reduced the surface roughness and maintained abrupt interfaces within the superlattices. Therefore, to obtain sharp single-peak UV emission from GaN/AlN superlattices, the growth sequence should be controlled to obtain flat GaN layers without dots. [ABSTRACT FROM AUTHOR]

Achieving high material perfection in aluminum (Al) films and their associated Al/AlOx heterostructures is essential for enhancing the coherence time in superconducting quantum circuits. We grew Al films with thicknesses ranging from 3 to 30 nanometers (nm) epitaxially on sapphire substrates using molecular beam epitaxy (MBE). An integral aspect of our work involved electron-beam (e-beam) evaporation to directly deposit aluminum oxide (Al2O3) films on the freshly grown ultrathin epitaxial Al films in an ultra-high-vacuum (UHV) environment. This in situ oxide deposition is critical for preventing the oxidation of parts of the Al films, avoiding the formation of undesired native oxides, and thereby preserving the nm-thick Al films in their pristine conditions. The thicknesses of our Al films in the study were accurately determined; for example, coherence lengths of 3.0 and 20.2 nm were measured in the nominal 3.0 and 20 nm thick Al films, respectively. These Al films were epitaxially grown on sapphire substrates, showing an orientational relationship, denoted as Al (111) ⟨ 2 1 ¯ 1 ¯ ⟩ ∥ sapphire (0001) [ 2 1 ¯ 1 ¯ 0 ]. The Al/sapphire interface was atomically ordered without any interfacial layers, as confirmed by in situ reflection high-energy electron diffraction (RHEED) and cross-sectional scanning transmission electron microscopy (STEM). All sample surfaces exhibited smoothness with a roughness in the range of 0.1–0.2 nm. The Al films are superconducting with critical temperatures ranging from 1.23 to around 2 K, depending on the film thickness. [ABSTRACT FROM AUTHOR]

This study investigates the interface between ice and organic solvents using atomic force microscopy (AFM). Atomically flat ice surfaces were prepared and observed by AFM in 1-octanol, 1-hexanol, and 1-butanol. The results show differences in surface roughness influenced by the interaction of ice and alcohols. Young's modulus of ice was analyzed by force curve measurements, providing valuable insights into the properties of ice in liquid environments. The results showed the characteristics of the ice surface in different solvents, suggesting potential applications in understanding surface and interface phenomena associated with ice under realistic conditions. [ABSTRACT FROM AUTHOR]

We present diamond-like carbon (DLC) conversion surfaces to detect particles with energy below 2 keV. Conversion surfaces have been widely applied in measurements of low-energy particles by instruments onboard planetary and heliophysics missions. Their effectiveness is characterized by the efficiency in changing the charge state of the incident particles while maintaining a narrow angular distribution for the reflected particles. DLC as a conversion surface coating material has high conversion efficiency. We developed a conversion surface production process that provides ultra-smooth and ultra-thin DLC conversion surfaces. The process includes substrate preparation through precision cleaning, plasma immersion ion deposition of the DLC film, and diagnostics of the film parameters. The latter includes the measurement of the coating thickness, surface roughness, and the conversion efficiency for ion beams with energy below 2 keV. The process we developed provides the DLC conversion surface coating of repeatable parameters with a mean surface roughness of 3.4 ± 0.2 Å and a mean film thickness of 46.7 ± 0.8 nm uniform across the sample area. Ion beam measurements showed a negative ion yield of 1%–2% for hydrogen atoms and 8%–15% for oxygen atoms with an angular scatter distribution of 10°–20° at full width of half maximum. These results agree with those of other conversion surface coatings in the literature. The DLC conversion surfaces presented here are implemented in the conversion surface subsystem of the Interstellar Mapping and Acceleration Probe (IMAP)-Lo instrument of the IMAP mission scheduled for launch in 2025. [ABSTRACT FROM AUTHOR]

Coarse-grained (CG) molecular models greatly reduce the computational cost of simulations allowing for longer and larger simulations, but come with an artificially increased acceleration of the dynamics when compared to the parent atomistic (AA) simulation. This impedes their use for the quantitative study of dynamical properties. During coarse-graining, grouping several atoms into one CG bead not only reduces the number of degrees of freedom but also reduces the roughness on the molecular surfaces, leading to the acceleration of dynamics. The RoughMob approach [M. K. Meinel and F. Müller-Plathe, J. Phys. Chem. B 126(20), 3737–3747 (2022)] quantifies this change in geometry and correlates it to the acceleration by making use of four so-called roughness volumes. This method was developed using simple one-bead CG models of a set of hydrocarbon liquids. Potentials for pure components are derived by the structure-based iterative Boltzmann inversion. In this paper, we find that, for binary mixtures of simple hydrocarbons, it is sufficient to use simple averaging rules to calculate the roughness volumes in mixtures from the roughness volumes of pure components and add a correction term quadratic in the concentration without the need to perform any calculation on AA or CG trajectories of the mixtures themselves. The acceleration factors of binary diffusion coefficients and both self-diffusion coefficients show a large dependence on the overall acceleration of the system and can be predicted a priori without the need for any AA simulations within a percentage error margin, which is comparable to routine measurement accuracies. Only if a qualitatively accurate description of the concentration dependence of the binary diffusion coefficient is desired, very few additional simulations of the pure components and the equimolar mixture are required. [ABSTRACT FROM AUTHOR]

Copper (Cu) interconnections have been widely used in advanced electronic packaging due to their outstanding thermal and electric properties. Preparing a smooth and uniform Cu seed thin layer is one of the critical processes to obtain high-reliability Cu interconnections. The barrier layer between Cu and silicon (Si) devices is necessary to prevent the inter-diffusion between Cu and Si. However, little work has been done on the surface roughness analysis of the Cu seed layer deposited on the diffusion barrier layer. In this paper, the influences of deposition thickness, incident energy, barrier layer temperature, and surface morphology on the surface roughness of the Cu seed layer deposited on α-titanium (α-Ti) barrier layer were studied in detail by the molecular dynamics (MD). The simulation results indicated that appropriate parameters have a beneficial effect on reducing the surface roughness, and the surface morphology of the Cu seed layer strongly connects with that of the barrier layer. These results provided a foundation for optimizing the quality of the Cu seed layer. [ABSTRACT FROM AUTHOR]

We have measured the absolute doubly differential angular sputtering yield for 20 keV Kr+ impacting a polycrystalline Cu slab at an incidence angle of θi = 45° relative to the surface normal. Sputtered Cu atoms were captured using collectors mounted on a half dome above the sample, and the sputtering distribution was measured as a function of the sputtering polar, θs, and azimuthal, ϕs, angles. Absolute results of the sputtering yield were determined from the mass gain of each collector, the ion dose, and the solid angle subtended, after irradiation to a total fluence of ∼1 × 1018 ions/cm2. Our approach overcomes shortcomings of commonly used methods that only provide relative yields as a function of θs in the incidence plane (defined by the ion velocity and the surface normal). Our experimental results display an azimuthal variation that increases with increasing θs and is clearly discrepant with simulations using binary collision theory. We attribute the observed azimuthal anisotropy to ion-induced formation of micro- and nano-scale surface features that suppress the sputtering yield through shadowing and redeposition effects, neither of which are accounted for in the simulations. Our experimental results demonstrate the importance of doubly differential angular sputtering studies to probe ion sputtering processes at a fundamental level and to explore the effect of ion-beam-generated surface roughness. [ABSTRACT FROM AUTHOR]

Hydrophobicity has proven fundamental in an inexhaustible amount of everyday applications. Material hydrophobicity is determined by chemical composition and geometrical characteristics of its macroscopic surface. Surface roughness or texturing enhances intrinsic hydrophilic or hydrophobic characteristics of a material. Here we consider crystalline surfaces presenting molecular-scale texturing typical of crystalline porous materials, e.g., metal-organic frameworks. In particular, we investigate one such material with remarkable hydrophobic qualities, ZIF-8. We show that ZIF-8 hydrophobicity is driven not only by its chemical composition but also its sub-nanoscale surface corrugations, a physical enhancement rare amongst hydrophobes. Studying ZIF-8's hydrophobic properties is challenging as experimentally it is difficult to distinguish between the materials' and the macroscopic corrugations' contributions to the hydrophobicity. The computational contact angle determination is also difficult as the standard "geometric" technique of liquid nanodroplet deposition is prone to many artifacts. Here, we characterise ZIF-8 hydrophobicity via: (i) the "geometric" approach and (ii) the "energetic" method, utilising the Young–Dupré formula and computationally determining the liquid–solid adhesion energy. Both approaches reveal nanoscale Wenzel-like bathing of the corrugated surface. Moreover, we illustrate the importance of surface linker termination in ZIF-8 hydrophobicity, which reduces when varied from sp3 N to sp2 N termination. We also consider halogenated analogues of the methyl-imidazole linker, which promote the transition from nanoWenzel-like to nanoCassie–Baxter-like states, further enhancing surface hydrophobicity. Present results reveal the complex interface physics and chemistry between water and complex porous, molecular crystalline surfaces, providing a hint to tune their hydrophobicity. [ABSTRACT FROM AUTHOR]

Epitaxial Mn-doped indium tin oxide (ITO) films were deposited on single-crystal yttria stabilized zirconia (YSZ) substrates with (111), (110), and (100) crystal plane orientations using RF magnetron sputtering. The epitaxial relationship between the Mn-doped ITO films and the YSZ substrates was studied using x-ray diffraction (XRD) patterns in the ω–2θ scan mode and XRD pole figures. The Mn-doped ITO films on the YSZ(111) and YSZ(110) substrates exhibited a higher degree of crystallinity than the film on the YSZ(100) substrate as per the x-ray rocking curves. Fluctuations in the crystalline alignment were found to significantly influence the electrical properties of Mn-doped ITO films. Ferromagnetic hysteresis loops were observed at room temperature for all the epitaxial Mn-doped ITO films, irrespective of their crystallographic orientation. The magnetic properties of the epitaxial Mn-doped ITO films suggest that a combination of delocalized charge carrier-mediated interaction and bound magnetic polaron-driven interaction is required to explain the origin of ferromagnetism in these films. The Mn-doped ITO film on the YSZ(111) substrate exhibited the most desirable characteristics in terms of crystallinity, surface smoothness, electrical conductivity, and magnetic properties. [ABSTRACT FROM AUTHOR]

This study examines the impact of dimensionless roughness on flow separation structures and flow characteristics through a combination of experimental and numerical simulation methods. The findings indicate that a specific dimensionless roughness k + exists for the fixed airfoil that minimizes cascade loss. Furthermore, increasing surface dimensionless roughness can alter the flow separation structure and effectively prevent flow separation. The numerical simulation results indicate that as dimensionless roughness increases, the impact of open separation and separation bubbles on the flow state over the blade surface is reduced or eliminated. In cases where separation occurs in the cascade, increasing dimensionless roughness results in a reduction in the boundary layer thickness and the width of the wake jet, thereby leading to a smoother outlet angle and improved efficiency. Conversely, when there is no separation, increasing dimensionless roughness leads to the accumulation of low-energy fluid at the trailing edge of the cascade. This results in an increase in the boundary layer thickness and the width of the wake loss, a larger outlet angle of the blade, and a decrease in the efficiency of the cascade. By analyzing the influence of dimensionless roughness on flow separation in cascades, engineers can quickly identify the geometric roughness height to suppress flow separation. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of planning methods—pushing and pulling—on the surface topographic characteristics of Cedrela sinensis and Korean Paulownia wood boards according to ISO 25178 standards. Surface roughness was assessed using a stylus profilometer (Mitutoyo SJ301) and a 3D Optical Profilometer (VR-6000, Keyence). The parameters measured included arithmetical mean height (Ra and Sa), root mean square roughness (Rq), average maximum height of the surface (Rz and Sz), texture aspect ratio (Str), the spatial parameter of the surface (Spc), and developed interfacial area ratio (Sdr). These parameters collectively provide a comprehensive description of a surface's texture, aiding in assessing its roughness, directionality, and functional characteristics. On average, Cedrela sinensis push-finished surfaces showed Ra of 16.78 μm, while pull-finished surfaces showed Ra of 11.22 μm. For Paulownia, push-finished surfaces had Ra of 6.04 μm, while pull-finished surfaces had Ra of 5.83 μm. Statistical t-test results showed no significant differences between push and pull planning methods (p > 0.05). The surface roughness analysis reveals that Cedrela sinensis surfaces exhibit higher roughness, more significant height variations, and more complex textures than Paulownia. These findings are valuable for the woodworking industry, offering insights into optimizing planning methods for specific wood species and applications. [ABSTRACT FROM AUTHOR]

The primary goal of this study is to elucidate the structural and electrical characteristics, alongside potential applications, of ceramic-polymeric composites. These composites are achieved by incorporating lithium-lanthanum titanates (Li 3x La 2/3−x TiO 3 - LLTO) into a polyvinyl alcohol polymeric matrix (PVA). The synthesis of lithium-lanthanum titanates occurred through high-energy ball milling method. Then, three types of composites were produced using the solvent casting method: a sample of pure Poly (vinyl alcohol) polymer (PVA), a second PVA composite with the addition of La 0 · 59 Li 0 · 24 TiO 3 (Li-0.24) and a third sample with La0· 56 Li 0 · 33 TiO 3 (Li-0.33). SEM and AFM analyzes revealed notable changes in the morphology and 3D spatial patterns of the films upon incorporating lithium-lanthanum titanates into the PVA matrix. The PVA film presents a topography featuring a more evenly distributed range of topographic heights, indicating a smoother surface structure. With varying LLTO content, the morphology of the PVA composite underwent changes. The lower roughness of the PVA surface is evident from its measured average roughness value (Ra = 1.9 ± 0.5 nm). Upon incorporating LLTO, the surfaces displayed increased roughness, measuring specifically at 40.1 ± 7.3 nm (Li-0.24) and 22.7 ± 5.5 nm (Li-0.33). Notably, there was an approximately 43 % reduction in the average roughness value from Li-0.24 to Li-0.33. The analysis by Raman allowed the identification of functional groups of the PVA polymeric chain, in addition to the presence of some vibrational modes related to the structure of lithium-lanthanum titanates for the sample with the highest content of Li+ ions (Li-0.33). Finally, the sample Li-0.33 showed the lowest value of electrical resistance (67 kΩ) and of phase angle (16°), compared to the PVA (100 MΩ and 90°). These results show that the presence of the LLTO changed the insulating behavior of the PVA matrix changed and improved potential to electronic applications. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA), a commonly used material for bone repair, can enhance its biological properties through the modulation of its crystallinity. Exploring the variations in physicochemical and biological properties associated with different degrees of crystallinity is crucial for advancing the applications of HA. In this study, stoichiometric nano-apatite precursors were initially synthesized using chemical precipitation. Subsequently, four groups of HA ceramics with varying degrees of crystallinity (24 %, 42 %, 72 %, 100 %) were produced by adjusting the calcination temperature, as confirmed through comprehensive characterizations. A systematic investigation was then conducted to examine the impact of crystallinity on the physicochemical, cytological, and in vivo osteogenic properties of HA ceramics, elucidating the influence of crystallinity on the osteogenic potential of HA. Results indicated that higher crystallinity in HA ceramics enhanced mechanical strength and hardness while reducing surface roughness, hydrophilicity, and protein affinity. Cytological studies revealed that decreased crystallinity led to lower cell proliferation rates but facilitated cell adhesion, spreading, and increased expression of osteogenic genes. Moreover, cell experiments with extracts further supported the significant role of surface properties of HA ceramics in modulating cell behavior. In vivo osteogenic assays demonstrated that reduced crystallinity notably stimulated new bone formation. Overall, by integrating the results of in vitro and in vivo experiments, it can be concluded that reducing the crystallinity of HA ceramics, the biological properties of HA ceramics can be significantly enhanced while maintaining a certain level of mechanical strength, such as HA2 group (42 % crystallinity). This study highlights the substantial impact of crystallinity and surface characteristics of HA ceramics on cell behavior, offering valuable insights and strategies for enhancing and optimizing bone repair materials in future applications. [ABSTRACT FROM AUTHOR]

Understanding the role of surface morphology and molecular structure interface thermal transport is essential for designing thermal management materials. In the present work, models of solid–liquid interfaces were created by placing liquid n-alkane between two platinum crystals. The effect of different levels of crystal surface roughness–flat, small, and large-scale grooves–and polymer chain lengths, under varying solid–liquid affinity, on the interface thermal resistance (ITR) were assessed using non-equilibrium molecular dynamics simulations. The overall trend confirmed that grooved surfaces have higher ITR than flat surfaces at low affinity, and lower ITR values were observed at high affinity. Large grooves enabled more favourable polymer orientations than those of small grooves, resulting in a smaller ITR. However, long chains did not facilitate heat transfer normal to the interface because they preferentially aligned parallel to it. For efficient heat transfer, a balance between the roughness scale and polymer length must be considered. [ABSTRACT FROM AUTHOR]

As a typical 3D printing process, fused filament fabrication still has disadvantages when operating on manufacturing lines due to the non-uniform textures of the oriented surfaces of the 3D-printed components. This work investigates the effects of structural parameters, i.e., orientations angle, ABS and PLA materials, three different layer thicknesses, three different perimeters, and three different infill rates utilizing a balanced modified Taguchi experimental design and 63 different parametric combinations to characterize the surface roughness parameters: average Ra, mean roughness depth Rz, root mean square Rq, skewness Rsk, and kurtosis Rku. The analysis of the experimental results, i.e., the levels mean values analysis plots and linear residual analysis of variances, showed that the layer thickness strongly influences all surface parameters and interacts considerably with all orientations. In contrast, material type, number of perimeters, and infill rate had insignificant impacts on surface roughness parameters. Finally, the additive linear modelling approach was utilized and validated for proper predictions, making it helpful for surface engineering applications. [ABSTRACT FROM AUTHOR]

In this paper, a novel double-disc straight groove lapping (DDSGL) method is proposed to reduce roundness error and improve surface roughness of tapered rollers. According to the conjugate surface principle and the kinematic characteristics of the tapered roller, the theoretical contour of the grinding tool working surface was designed. The contact relationship between the rollers and the working surface of the grinding tool is established. The relative motion between the tapered rollers and the grinding tool is discussed in detail, and the lapping trajectory on the rolling surface of tapered rollers is calculated and analyzed. The impact of the system's structural parameters (i.e., eccentric circular groove radius, eccentricity, and upper disc circular groove radius) as well as the kinematic parameters (lower disc rotational speed) on the uniformity of the lapping trajectory in the lapping process was explored. The structural parameters of the DDSGL equipment were determined using the standard deviation of the lapping trajectory distributed on the tapered roller rolling surface. Finally, the lapping experiments of tapered rollers were carried out in a homemade equipment, and the results show that the newly proposed method can effectively improve the roundness and reduce the surface roughness of the tapered rollers. [ABSTRACT FROM AUTHOR]

Ultrasonic rolling extrusion process (UREP) is the newly arisen surface strengthening technology, which can effectively reduce the surface roughness of the workpiece and improve the residual compressive stress at the certain depth on the surface so that it has great adaptability to the enhancement of the surface properties of the bearing ring. Through theoretical analysis, finite element simulation, and experiment method, the surface mechanical properties and the surface roughness of UREP strengthening when applied to the material of the wind power bearing ring are studied. Firstly, the strengthening principle of UREP is illustrated. Secondly, according to the motion trajectory of the rolling ball during UREP, the kinematic model of UREP is established. The forming principle of the surface micromorphology during UREP is explored. Thirdly, based on the contact characteristics between the rolling ball and the surface of the workpiece, the contact mechanics model of UREP is established. Based on Hertz contact theory, elastoplastic mechanics theory, and contact mechanics theory, the mechanical properties of the contact area between the rolling ball and the surface of the workpiece during UREP are analyzed. Finally, the simulation and experiment of 42CrMo steel cylindrical workpiece during UREP are carried out, and the variation trends in the simulation values are found to be consistent with those observed in the experimental results. The results show that the residual compressive stress generated in the surface of 42CrMo cylindrical workpiece after UREP gradually increases with the increase of the layer depth and then decreases and transforms into the residual tensile stress. Moreover, the surface roughness first decreases and then increases with the rise of the amplitude and the static pressure. Similarly, it gradually improves when the feed rate and rotational speed rises. The established UREP simulation is useful for imitating the actual machining process of 42CrMo steel during UREP, which extends the effective way for UREP parameter optimization. [ABSTRACT FROM AUTHOR]

The Ti-6Al-4V alloy is an important material used in many high-end devices, such as medical, aerospace, petrochemical, and sports equipment. Thus, the feasibility of producing Ti-6Al-4V with mirror surface quality through magnetic polishing was assessed in this study. One of the extremely challenging aspects of magnetic polishing for Ti-6Al-4V alloys is the generation of a magnetic field suitable for surface-quality finishing. Moreover, machined material residue cannot be completely removed, the alloy has limited application, and uniform surface quality on a large workpiece surface cannot be achieved because generating strong and suitable magnetic field is currently infeasible. To create a polishing process with a highly efficient magnetic field source for improving material removal rate and surface quality, a linear variable magnetic field array was proposed by Halbach. Finite element simulation processes combined with experimental validation provide an efficient polishing model with high field area and intensity generated by an improved Halbach magnet array. The magnetic force generated by the improved Halbach array and the force distribution process on the Fe3O4 magnetic particle were analyzed. Thus, material removal and the distribution and pressure of abrasive SiO2 particles acting on the polished surface were examined. The influences of technological factors on surface quality and material removal ability were systematically studied. The proposed chemical–magnetorheological finishing model showed a considerably increased magnetic field generation compared with the previous model (1.7 times that of the conventional Halbach array), thereby efficiently removing materials. Polishing models established for Ti-6Al-4V alloy markedly improved surface quality after 80 min of treatment, and an ultrafine workpiece surface showed an Ra of 1 nm, which had an initial roughness of approximately 500 nm. [ABSTRACT FROM AUTHOR]

This research studied the effect of rice husk ash (RHA) during the turning of AlSi10Mg aluminum alloy. Stir casting was the chosen fabrication technique for this investigation. The combined effects of the following turning process parameters including cutting speed (s), feed (f), depth of cut (d), and weight fraction of reinforcement ( w t ) on the responses; that is the tool wear and surface roughness were studied. Taguchi L 16 orthogonal array was adopted to determine the experimental runs. The analysis of variance (ANOVA) for the tool wear and the surface roughness showed that the feed and the cutting speed were the most significant factors influencing the tool wear and surface roughness, respectively. Using single objective optimization also affirmed the feed and cutting speed as the most influencing parameters for the tool wear and surface roughness, respectively. The predicted model for tool wear and surface roughness obtained from the regression equation shows a good correlation with the experimental results. A correlation of 95% and 94% of tool wear and surface roughness was determined between the predicted and corresponding experimental results. [ABSTRACT FROM AUTHOR]

The present research aims to improve the surface quality of laser powder bed fusion (LPBF) built cobalt chrome alloy (CoCr) by pulse laser remelting. The laser power, overlap percentage, and spot diameter are varied to determine the best parameters for laser polishing. The microhardness and microstructural changes associated with pulse laser remelting are described. Surface morphology and surface roughness parameters are reported for various laser remelting parameters. Among the three different spot diameters, 1, 2, and 3 mm, the maximum (> 50%) reduction in surface roughness was obtained for 2 mm with 1J laser energy and 50% X and 20% Y as well as 20% X and 50% Y overlaps. A DoE- and RSM-based approach has been utilized for parametric optimization of the surface roughness. The squared laser power is identified as a critical parameter by ANOVA. A Pareto chart confirms the significance of squared laser power across spot diameters. Optimization suggests that a 2-mm spot diameter works best with specific parameters to produce a better surface finish. However, the nanosecond order laser pulses have a limitation on the depth of surface modification without severe ablation and thereby on the reduction in the surface roughness. [ABSTRACT FROM AUTHOR]

This study focuses on the relationship between porosity, surface roughness, microstructure, strength, and thermal properties, as well as their effect on the bioactivity and biodegradability of fabricated akermanite (AK; Ca 2 MgSi 2 O 7) bioceramic scaffolds. Firstly, we prepared the AK nanopowders using the mechanical activation method, mixed them with varying proportions of space-holder agent (NaCl), specifically 15, 20, 30, 40, and 50 vol%, and sintered them at 1200 °C to create porous scaffolds. We investigated the physical properties and microstructure using the Archimedes method and field emission scanning electron microscopy (FE-SEM), respectively. The mechanical properties in terms of microhardness, compressive strength, longitudinal modulus, Young's modulus, bulk modulus, and shear modulus were measured. The bioactivity and biodegradability of prepared scaffolds were assessed after soaking in simulated body fluid (SBF) for 10 days by FE-SEM and inductively coupled plasma-atomic emission spectroscopy (ICP-AES), respectively. The results revealed that porous scaffolds with suitable mechanical properties, bioactivity, and biodegradability were prepared. The porosity had a significant impact on the mechanical and biodegradability of the investigated scaffolds. It reduced mechanical properties slightly while improving bioactivity and biodegradability. The microstructure study displayed that all scaffolds formed apatite layer on their surfaces. This is because of good bioactivity and the suitable porosity level of AK. The obtained findings provide promising prospects for the future use of AK in bone tissue engineering. [ABSTRACT FROM AUTHOR]

In this study, alumino-borate glass was manufactured to fabricate glass with excellent corrosion resistance to plasma, and the Y 2 O 3 was substituted with YF 3. The basic properties of the glass were analyzed DTA, density, hardness, and transmittance. Plasma corrosion resistance is evaluated by the etch rate, surface roughness, and XPS of the glasses via CF 4 plasma etching. The results revealed that all glasses had superior plasma resistance than the reference material, quartz. As the amount of Y 2 O 3 increased, the etch rate decreased, and the YF 3 -containing glasses exhibited the highest plasma resistance by an etch rate of 22.17 nm/min. • Alumino-borate glass containing the Yttrium element was used as a plasma-resistant material. • When YF 3 fluoride was added, it showed the lowest etching rate and showed 11 times better plasma resistance than quartz. • The plasma resistance properties of Y 2 O 3 –Al 2 O 3 –B 2 O 3 -YF 3 glass are affected by the residual fluoride layer. [ABSTRACT FROM AUTHOR]

The cleaning of traditional ceramics consumes much water and detergents. It is valuable to consider how to endow the ceramics with self-cleaning character. In this paper, titanic-based-crystallites (CaTi(SiO 5) or TiO 2) superhydrophilic glazes with superior self-cleaning properties were in situ prepared by a simple one-time firing method. There is no any extra treatment involved in the preparation process. It was found that the precipitation of titanic-based crystallites in the glaze could be adjusted by controlling the cooling system. The transformation mechanism of the phase was analyzed based on the phase separation state. Stress conditions of a dirt cell on surfaces with different roughness were discussed. The correlation between geometric structure and self-cleaning performance demonstrated that the multi-level structure is vital for self-cleaning performance. The self-cleaning mechanism of the superhydrophilic glaze was proposed. The titanic-based crystallite glazes possess superhydrophilic characteristics (<8.0 °), high hardness (642.44–707.85 kgf·mm−2), and excellent self-cleaning performance to oily ink stamps and relatively good performance to human fecal simulacrum, the miso sauce, due to the multi-level structure with nano-scale surface roughness, showing a good application potential on the self-cleaning domain, i.e. glass and traditional ceramic, etc. [ABSTRACT FROM AUTHOR]

A superhydrophobic surface is defined as having a contact angle exceeding 150 °C, indicating a remarkable ability to repel water. Generally, superhydrophobicity originates from the utilization of low‐surface‐energy materials with unique micro‐ and nanostructures. Superhydrophobic surfaces have gained considerable recognition and are widely employed in diverse areas for anti‐icing, oil‐water separation, anticorrosion, self‐cleaning, blood‐repellent, and antibacterial applications. These surfaces can greatly enhance industrial processes by yielding significant performance improvements. In this review, we introduce the basic theories that provide a foundation for understanding the hydrophobic properties of superhydrophobic surfaces. We then discuss current techniques for fabricating superhydrophobic coatings, critically analyzing their strengths and limitations. Furthermore, we provide an overview of recent progress in the application of superhydrophobic materials. Finally, we summarize the challenges in developing superhydrophobic materials and future trends in this field. The insights provided by this review can help researchers understand the basic knowledge of superhydrophobic surfaces and obtain the latest progress and challenges in the application of superhydrophobic surfaces. It provides help for further research and practical application of superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

Rutile germanium dioxide (r-GeO2) has been identified as an ultrawide bandgap semiconductor recently, featuring a bandgap of 4.68 eV—comparable to Ga2O3—but offering bipolar dopability, higher electron mobility, higher thermal conductivity, and higher Baliga figure of merit (BFOM). These superior properties position GeO2 as a promising material for various semiconductor applications. However, the epitaxial growth of r-GeO2, particularly in its most advantageous rutile polymorph, is still at an early stage. This work explores the growth of r-GeO2 using metal-organic chemical vapor deposition (MOCVD) on an r-TiO2 (001) substrate, utilizing tetraethyl germane as the precursor. Our investigations reveal that higher growth temperatures significantly enhance crystalline quality, achieving a full width at half maximum of 0.181° at 925 °C, compared to 0.54° at 840 °C and amorphous structures at 725 °C. Additionally, we found that longer growth durations increase surface roughness due to the formation of faceted crystals. Meanwhile, adjusting the susceptor rotation speed from 300 to 170 RPM plays a crucial role in optimizing crystalline quality, effectively reducing surface roughness by approximately 15 times. This study offers a foundational guide for optimizing MOCVD growth conditions of r-GeO2 films, emphasizing the crucial need for precise control over deposition temperature and rotation speed to enhance adatom mobility and effectively minimize the boundary layer thickness. [ABSTRACT FROM AUTHOR]

In recent years, there has been growing interest in using polymer nanocomposite membranes as a more advanced method for removing pollutants from water and treating wastewater for various purposes. In this study, thin‐film nanocomposite (TFN) membranes of polycarbonate/polyvinyl alcohol–titanium dioxide thin‐film (PC/PVA–TiO2) were fabricated by dip‐coating a PC substrate in a PVA/TiO2 solution. Various methods, including attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectroscopy, field emission scanning electron microscopy (FE‐SEM), atomic force microscopy (AFM), and water contact angle were utilized to assess the structural characteristics of the produced membranes. The PC/PVA thin‐film composite (TFC) and PC/PVA–TiO2 TFN membranes were then examined in a submerged membrane system to evaluate their effectiveness in filtering humic acid (HA) under various vacuum transmembrane pressure (0.3 and 0.6 bar) condition. The FTIR‐ATR results confirmed the formation of the active layer of PVA/TiO2 nanoparticles (NPs). It was observed that adding 1 wt.% of TiO2 NPs to the active layer of PVA/TiO2 significantly enhanced the water contact angle from 77.5° for PC support to 55.3° for PC/PVA–TiO2 (0.1) TFN membranes. Furthermore, the FE‐SEM results confirmed the formation of an active layer of PVA/TiO2 with a thickness of 237.87 nm. The pure water flux increased from 101.64 L/m2h for the PC/PVA TFC membrane to 144.02 L/m2h and 199.09 L/m2h for the PC/PVA–TiO2 (0.05) and PC/PVA–TiO2 (0.1) TFN membranes, respectively. Also, the results revealed that at lower transmembrane pressure, all membranes showed higher value in HA removal as compared to when higher transmembrane pressure was used. [ABSTRACT FROM AUTHOR]

This study aims to produce cadmium selenium (CdSe) thin films with a hexagonal structure using the chemical bath deposition (CBD) method. In this study, 0.075 g of cadmium chloride (CdCl2) is used as a Cd source, 0.06 g of etilendiamin tetra acetic acid [(EDTA), (C10H16N2O8)] as a complexing agent, and 0.1 g of selenourea [CSe(NH2)2] as a selenium source. Ammonia (NH3) is employed to adjust the pH value of the solutions and varying amounts of Na2SO3 (from 0.1 to 1.6 g) are used as a reducing agent. This chemical combination has been used for the first time to produce CdSe thin films. X‐ray diffraction (XRD) results confirm that CdSe thin films exhibit a hexagonal structure without requiring annealing. The energy band gap values calculated via absorption graphs range from 1.76 to 1.91 eV. The surface morphologies are examined using scanning electron microscope (SEM) images. SEM images show that there are no voids, cracks, or pinholes. The software named ImageJ is used to determine surface roughness, showing range from 6 to 8 nm. The photographs of the samples show that some films adhere homogeneously to the surfaces of substrates, depending on the amount of Na2SO3 used. [ABSTRACT FROM AUTHOR]

ABSTRACT The high tensile strength and high resistance of nickel‐based superalloy 686 against high temperatures and corrosion rates have made it a widely used in important applications such as the aerospace industry, high pollution‐ and corrosion‐resistance equipment manufacturing and petrochemical industry. Therefore, the machining of this advanced alloy with its unique properties is extremely important and can be challenging. Significant increase in input parameters levels, reduction of machining costs, improvement of surface and subsurface properties and clean production are among the issues that should be considered in dealing with Inconel 686 turning operations. Simultaneous application of advanced tools such as polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN) and optimised minimum quantity lubrication (MQL) method and evaluating the results obtained with a wide range of output parameters related to machining process performance and tribological properties can be proposed as an innovation and a solution to this problem in this article. This study analyses several output parameters with different speeds and feeds to evaluate the effect of cutting insert type on machining process performance and tribological properties. The output parameters include tool wear, residual stress, cutting zone temperature, surface smoothness, machining forces and workpiece surface defects. The results indicated that using the optimised MQL method reduces the size of lubricant droplets and increases the surface covered by cooling. With these changes, the performance of the machining process and the parameters related to the surface integrity increase significantly. Among the parameters associated with the performance of the machining process, the PCD tool reduces the cutting zone temperature by 23%, the tool wear by 19% and the machining forces by 18% compared to the PCBN tool. In the parameters related to surface integrity, this method reduces the residual stress by 19% and the surface roughness by 9% compared to the PCBN tool. From the production index perspective, the PCD tool can significantly increase the cutting speed and feed rate, reducing production time and costs. [ABSTRACT FROM AUTHOR]

Through Silicon Via (TSV), a kind of 3D packaging technique, can improve chip integration based on "More than Moore" scheme. The larger copper area ratio at the TSV barrier layer interface requires strong adjustability of the removal rate selection ratio of copper, tantalum and TEOS–SiO2, and stronger surface defect control and surface profile correction capabilities. In this paper, the effects of guanidine hydrochloride (GH) and 2,2′-[[(Methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol (TT-LYK) system on the tunability of Ta and Cu removal rate in chemical mechanical polishing (CMP) of TSV wafer barrier material were studied. GH can complex TaO 4 3 - , while TT-LYK can form a protective film on the surface of Cu, thereby achieving rate regulation. The results showed that when the concentration of GH increased from 0 to 2 wt%, the removal rate selectivity ratio of Ta and Cu raised from 1.02:1 to 1.26:1. When the concentration of TT-LYK increased from 2.5 to 10 mmol/L, the removal rate selectivity ratio of Ta and Cu increased from 1.33:1 to 1.79:1, which verified that the GH and TT-LYK systems can efficiently regulate the rate and rate selection ratio of Ta and Cu. Surface roughness for both metals decreased from pre-polishing values of 5.03 nm to post-polishing values of 0.37 nm for Ta, from pre-polishing values of 5.33 nm to post-polishing values of 1.26 nm for Cu indicating that GH and TT-LYK systems significantly improved the surface quality. [ABSTRACT FROM AUTHOR]

This paper reports a new nondestructive noncontact method of sensing surface roughness, particularly the surface undulation produced in the plowing stage of wear. This method involves inductance measurement. It is fast, provides global information and is suitable for real-time monitoring, but it is limited to electrical conductors. This amounts to structural self-sensing. Ultramild abrasive wear primarily in the plowing regime, with areal weight loss ≤ 0.075 g/cm2 and ≤ 0.040 g/cm2 for steel and aluminum, respectively (i.e., thickness loss ≤ 0.30 mm and ≤ 0.48 mm for steel and aluminum, respectively), is effectively sensed by this method. The inductance measurement involves two electrical contacts (clips) and an LCR meter (2 kHz). The inductance increases monotonically with increasing degree of wear primarily in the plowing regime, beyond which it does not increase further. This is due to the sensitivity of the inductance to the surface undulation, as expected from Faraday's law. Longitudinal wear (wear performed in the inductance measurement direction, i.e., direction along the metal bar length) and transverse wear (wear performed along the direction perpendicular to the inductance measurement direction) give similar weight loss. However, the fractional increase in inductance due to wear is greater for transverse wear than longitudinal wear, as expected from Faraday's law. Hence, the inductance method can discern the surface undulation direction, i.e., the wear direction, but the weight loss method cannot. The fractional increase in inductance due to wear is greater for steel (magnetic) than aluminum (not magnetic). However, magnetic character is not required for the sensing. [ABSTRACT FROM AUTHOR]

Thin films of FePtCo ternary alloy with 100 nm thickness have been deposited on an Si substrate using a DC magnetron sputtering system by co-sputtering of Co metal target and Fe40Pt60 alloy target in three different conditions, i.e. as-deposited at room temperature, annealed at 400 °C ${}_{}^ \circ C$ ∘ C , and deposited on the seed- layer. The effects of target sputtering power, leading to different compositions and various deposition conditions on surface roughness of films and magnetic properties, were studied. The average surface roughness of the as-deposited films decreases with the increase in the sputtering power of the Co target. For the annealed and seed-layered films, an increase in Co sputtering power resulted in an increased in roughness. Moreover, the annealed films possess smallerlower roughness due to an increase in the surface mobility. On the other hand, the Cu seed- layer decreases the roughness by preventing the diffusion of the film into the substrate. The room -temperature M-H measurement shows that the films exhibit soft ferromagnetism with coercivity in the order of ${10^3}$ 10 3 A/m and large saturation magnetizationmagnetisation of the order ${10^6}$ 10 6 A/m. The saturation magnetizationmagnetisation decreases with the increase in the sputtering power and is not influenced by the film surface roughness. On the other hand, riseincrease in surface roughness leads to decrease in coercivity of the films. HIGHLIGHTS: Thin films of FePtCo ternary alloy have been deposited by co-sputtering of Co metal target and Fe40Pt60 alloy target. The effects of surface roughness of films on magnetic properties were studied. The room-temperature M-H measurement shows that the films exhibit soft ferromagnetism. The saturation magnetisation decreases with sputtering power and is not influenced by the film surface roughness. On the other hand, increase in surface roughness leads to decrease in coercivity of the films. [ABSTRACT FROM AUTHOR]

The effect of surface roughness on the interfacial contact resistance (ICR) and the corrosion behavior of 446 stainless steel in simulated anode environments for proton exchange membrane fuel cell (PEMFC) (i.e., 0.5 mol L−1 H2SO4 + 2 ppm F− and 5 × 10−4 mol L−1 H2SO4 + 0.1 ppm F− bubbled with hydrogen gas at 80 °C) was investigated by means of atomic force microscopy, potentiodynamic polarization, electrochemical impedance spectroscopy and ICR test. The surface roughness (Ra) produced by mechanical grinding increases noticeably with the decrease of sandpaper grit size from 1000# to 240#. 446 stainless steel shows the active state under free corrosion conditions in the two test solutions and the passive state at the typical anode working potential of PEMFC after the activation-passivation transition. The corrosion resistance decreases with the increase of roughness in both solutions. The corrosion product films formed in the solution with lower acidity are more protective, leading to the appearance of the diffusion process. The enlargement of surface roughness results in the gradual reduction of ICR, but the acceleration of active and passive dissolutions. [ABSTRACT FROM AUTHOR]

A set of direct shear tests was conducted to investigate the effects of sand mean grain size and geomembrane surface roughness on the shear behaviour of the sand–geomembrane interface. Four types of sands with different mean grain sizes were used and the interfaces included a smooth geomembrane (SGM) and four textured ones with different asperity characteristics. The samples were prepared in a direct shear box at five sedimentation angles. The experimental results showed that the peak friction angle of the soil–textured geomembrane interface was dependent on the mean grain size, inherent anisotropy and surface roughness of the geomembrane. The shear strength of sand–textured geomembranes was two to three times larger than that of the sand–SGM interface. The peak and residual friction angles of sand-SGM interface occurred at sedimentation angle of 72° while it was 108° for sand-TGM interfaces. An increase in mean grain size increased the shear strength of the sand–textured geomembrane interface; while a reverse condition occurred for the sand–SGM interface. The shear strength occurred at larger horizontal displacement as mean particle size increased and the effect of relative roughness on peak friction angle increased with increase in mean grain size. [ABSTRACT FROM AUTHOR]

This research paper explores the impact of electrical discharge machining process parameters, including current, pulse‐on time (Ton), and pulse‐off time (Toff), on the material removal rate (MRR) and surface roughness (SR) during the fabrication of aluminum silicon dioxide (Al7075–SiO2) composites. The Al7075–SiO2 composites were produced through stir casting, incorporating 10% by weight of SiO2 reinforcements with an average particle size of 54 µm. To systematically investigate the process parameters' effects, Taguchi's L9 orthogonal array was implemented in the design of experiments. Subsequently, the experimental data underwent analysis of variance (ANOVA) for thorough analysis. The response table for MRR and SR demonstrated that the current significantly influenced both responses (MRR and SR). The ANOVA results provided valuable insights into the percentage contribution of each parameter to the responses. Through the analysis, the optimal control variable settings for achieving the highest MRR were identified as a current of 3 A, a pulse‐on time of 1500 µs, and a pulse‐off time of 1 µs. Conversely, to attain the lowest SR, the ideal control variable settings were determined to be a current of 1 A, a pulse‐on time of 500 µs, and a pulse‐off time of 1 µs. Results also suggest that the error was within admissible range of 5% and the percentage contribution of the current (70.19%) had the largest effect on MRR. [ABSTRACT FROM AUTHOR]

When traffic flows pass through existing bridges, the dynamic effect of the vehicle loads increases due to the local surface damage rather than the entire roughness level of the bridge deck. This study presents a method for evaluating a dynamic impact factor (IM) from a bridge dynamic response under a traffic flow considering the local surface damage. The random axle loads of traffic vehicles under the deteriorated roughness conditions are presented using an input load time-history applied to each discretized deck node of a finite element bridge model. The amplification ratios of the root mean square of the simulated acceleration under nominal road surface conditions with respect to the specified IMs in the design stage are calculated. The relationship between the ratios and IMs is determined to evaluate the dynamic impact factors under any surface roughness condition. The method is validated by applying it to two existing bridges with different road surface damage and traffic conditions. The results show that the IMs depend on both the traffic loading and bridge surface roughness conditions. Under the same traffic flow conditions, the values increase when the road surface damage increases. However, the increases in the IMs vary according to the location of the surface roughness deterioration in both of the target bridges. [ABSTRACT FROM AUTHOR]