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Deep levels in the whole bandgap of 4H-SiC generated by reactive ion etching (RIE) are investigated with both n- and p-type SiC Schottky barrier diodes by deep-level transient spectroscopy (DLTS). Depth profiles of the observed deep levels were analyzed using the DLTS peak intensities at various bias voltages and numerical calculations. The major electron traps detected after RIE and subsequent annealing at 1300 ° C include the Z 1 / 2 (E C − 0.66 eV), ON1 (E C − 0.88 eV), ON2 (E C − 0.95 eV), and EH 6 / 7 (E C − 1.50 eV) centers, and the major hole traps include the UK1 (E V + 0.51 eV), UK2 (E V + 0.72 eV), HK0 (E V + 0.77 eV), HK2 (E V + 0.79 eV), and HK3 (E V + 1.31 eV) centers, where E C and E V denote the conduction and valence band edges, respectively. Most of the traps were localized near the surface (<0.5 μ m) with a maximum density of about 1 × 10 15 cm − 3 , but several traps such as the ON1 and HK0 centers penetrate deep into the bulk region (>2 μ m). By annealing at 1400 ° C, most of the hole traps were eliminated, but several electron traps remained. From these results, the origins of these defects are discussed. [ABSTRACT FROM AUTHOR]

Vibrational sum frequency spectra provide information about interfaces that is sensitive to the orientation of molecules, their electronic environment, and the local electric fields. Here, we use molecular dynamics simulations in order to study a surfactant, para-cyanophenol, at the air–water interface. The volume fractions of water and the organic surfactant are considered at various points over the nanometer-scale region in a Lorentz–Lorenz model. We find that the calculated ratios of nonlinear susceptibility tensor elements are in agreement with experimental data only when this depth profile was considered. We also use these data to evaluate the ratio of the C–N hyperpolarizability tensor elements in the interfacial region. [ABSTRACT FROM AUTHOR]

The authors implanted P atoms at 50 and 140-keV energies with respective fluences of 1 × 10 14 and 2 × 10 14 /cm 2 into diamond thin films synthesized by chemical vapor deposition on the type-Ib diamond substrate formed by high-pressure and high-temperature conditions. The occupational sites of implanted P atoms were determined in each processing stage of P implantation, ion-beam-induced epitaxial crystallization (IBIEC) annealing by 3-MeV-Ne 2 + ion irradiation at 750 ° C, and thermal annealing at 850 ° C in vacuum, by quantitatively comparing the random and channeling yields in Rutherford backscattering (RBS) measurements. In the analysis of RBS spectra, simulated distributions were fitted to the experimentally obtained spectra and we quantitatively identified the occupational sites and ratio of implanted P atoms. In addition, we investigated the diffusion phenomenon of implanted P atoms during annealing processes from the depth profile of scattered He ions. Consequently, the averaged occupational ratio in the substitutional lattice site was stably recorded around 50%. From the depth profile in the RBS spectra, thermal diffusion of implanted P atoms was clearly observed during the last thermal annealing after MeV-IBIEC annealing. We finally discuss the potentials of the MeV-IBIEC irradiation at relatively low temperatures applying to useful and credible annealing methods for electrical activation as well as recovery of damaged crystallinity. [ABSTRACT FROM AUTHOR]

In this work, we have performed a detailed study of the defects created in the bulk of 4H-SiC after thermal oxidation and post oxidation annealing using deep level transient spectroscopy and minority carrier transient spectroscopy (MCTS). The study reveals the formation of several shallow and deep level majority carrier traps in the bandgap. The ON1 (E C − 0.85 eV), ON2a (E C − 1.05 eV), and ON2b (E c − 1.17 eV) levels are the most dominant and are observed across all the samples (E C denotes the conduction band edge). Three shallow levels Ti(k) (E C − 0.17 eV), E 0.23 (E C − 0.23 eV), and C 1 / 2 (E C − 0.36 / 0.39 eV) are observed in the samples. For most of the majority carrier defects, the highest concentration is observed after an NO anneal at 1300 ° C. This behavior is sustained in the depth profile measurements where the defect concentration after the NO anneal at 1300 ° C is significantly higher than for the rest of the samples. The origin of most of the majority carrier defects has been attributed to C interstitial injection from the interface during thermal oxidation and annealing. MCTS measurements reveal two prominent minority carrier traps, labeled O 0.17 (E V + 0.17 eV) and B (E V + 0.28 eV), where the concentration of O 0.17 is independent of annealing parameters while the concentration of the B level increases after the NO anneal (E V denotes the valence band edge). Furthermore, the depth profiles of the defects are used to evaluate their diffusion parameters by solving the diffusion equation to fit the experimental profiles. The defect concentrations decay exponentially with depth, which evidences that the defects were created at or near the SiO 2 –SiC interface and migrate toward the bulk during oxidation and post-oxidation annealing. [ABSTRACT FROM AUTHOR]

We generalize a native Nb 2 O 5 dissolution model [G. Ciovati, Appl. Phys. Lett. 89, 022507 (2006)] to sequential overlayer dissolutions, multilayer dissolution, and realistic temperature profiles, which may be applicable to other materials. The model is applied to secondary ion mass spectrometry depth profile measurements for varying temperature profiles and two-step oxide dissolution in Nb and found to agree well. In the context of the Meissner screening response due to impurity profiles on the length scale of the London penetration depth, the shallow diffusion of O impurities results in a substantial decrease in the peak supercurrent density near the surface. In this framework, oxide dissolution and oxygen diffusion can account for a rise in peak supportable magnetic field in SRF cavities with baking time and a suppression after the optimal baking time is reached, in good agreement with peak-field baking temperatures and times as well as recent quench field measurements. [ABSTRACT FROM AUTHOR]

We show that the micro-scale variations in the relaxation state of amorphous silicon (a-Si) can be well-identified by Raman mapping over hundreds or thousands of μm2 in 1–2 h. Pure and relaxed a-Si is obtained by self-implantation in crystalline silicon (c-Si) followed by anneal at 500 °C. It is then locally re-implanted over micro-sized patterns to produce unrelaxed a-Si zones. Raman mappings are obtained by pointwise confocal μ-Raman and hyperspectral Raman imaging. We also measure the depth profiles of the relaxation state in re-implanted a-Si by scanning the edge of a re-implanted sample. We infer from the depth profiles that the minimal damage dose to fully de-relax a-Si is 0.04 displacements per atoms, which is an order of magnitude smaller than the fluence needed to fully amorphize c-Si. [ABSTRACT FROM AUTHOR]

Positron annihilation was used to probe vacancy-type defects in electrodeposited Cu films after nanosecond pulse laser annealing. For the as-deposited Cu film, we identified the coexistence of two different vacancy-type defects, vacancy clusters (such as V16) and monovacancy-type defects, coupled with impurities. An enlargement in the vacancy size was observed after the laser annealing process. The size of these defects was estimated to be close to V30, and such defects could not be formed by conventional furnace annealing. After furnace annealing at 400 °C, the size of the larger vacancy clusters decreased, but that of the smaller vacancies increased. The observed change in the sizes of vacancies is considered to be related to interactions between vacancies and impurities. The depth profile of the defects varied by changing the laser energy density and the number of laser shots. The impact of laser annealing on the vacancy-type defects was observed even after furnace annealing at 800 °C. Because the presence of point defects in electroplated Cu directly correlates with electromigration and grain growth, the ability of laser annealing to introduce large vacancy clusters in the localized region shows the potential of nanosecond laser annealing as a low-thermal budget process tool for back-end-of-line materials. [ABSTRACT FROM AUTHOR]

In this study, we investigate the diffusion of Si donors in AlN. Amorphous S i 1 − x N x sputtered on the surface of bulk AlN with low dislocation density is used as a Si source. The diffusion experiments are conducted through isochronal and isothermal annealing in a protective N2 atmosphere at temperatures between 1500 and 1700 °C. The Si depth profiles measured by secondary ion mass spectrometry exhibit a convex box-like shape with a steep diffusion front. These concentration profiles are best described with a diffusion coefficient that depends on the square of local Si concentration. From the characteristic box-shaped Si profiles, we conclude that diffusion of Si in AlN is mediated by singly negatively charged dopant–vacancy pairs S i Al V Al −. The strong concentration dependence of Si diffusion is due to the electric field associated with the incorporation of Si donors ( Si Al + 1 ) on substitutional Al lattice sites and reflects that Si is fully electrically active at diffusion temperature. The experimentally obtained extrinsic Si diffusion coefficient is reduced to intrinsic doping conditions. The temperature dependence of Si diffusion for intrinsic conditions is described by an activation enthalpy of (10.34 ± 0.32) eV and a pre-exponential factor of 235 − 203 + 1485 c m 2 s − 1 . The migration enthalpy of the donor–vacancy pair S i Al V Al − is estimated to be around 3.5 eV. This estimation is based on the activation enthalpy of the transport capacity of S i Al V Al − and theoretical results concerning the formation energy of negatively charged vacancies on Al-sites in AlN. [ABSTRACT FROM AUTHOR]

In a recent paper, Mandelis et al. [J. Appl. Phys. 133, 055102 (2023)] describe a photothermal methodology and a new inversion technique which, when applied to a heterogeneous material, is claimed to allow a simultaneous reconstruction of the depth profiles of thermal conductivity and density (assuming that the specific heat is a known constant). In this Comment we recall that, for the thermophysical configuration considered, the thermal conductivity and volumetric heat capacity profiles cannot be identified simultaneously because they are fully correlated. The exposed problem exhibits unconditional non-identifiability leading to the non-uniqueness of the solution. The apparent success of the inversion tests does not preclude the fact that, for any (apparently) optimal solution, an infinite multiplicity of equally satisfactory pairs of conjugate profiles can be built. The simultaneous identification of the density and thermal conductivity profiles is here an unsolvable inverse problem. [ABSTRACT FROM AUTHOR]

Most organic carbon delivered to the seafloor is degraded within the bioturbated layer. Theory and empirical evidence have shown that organic carbon reactivity relates to the age of a particle. However, due to particle mixing, the age‐depth linear relation induced by sediment accretion is obfuscated. Here we combine a Lagrangian particle tracking model that resolves the age distribution of particles in the bioturbated zone and couple it to age‐dependent organic carbon degradation. Depth profiles for organic carbon concentration, reactivity and degradation rate are presented for sediments receiving low and high reactivity organic carbon in coastal, continental slope and deep‐sea environments. Our results show that a simple first‐order kinetics model suffices for well‐mixed sediments and systems receiving pre‐processed materials. A reactive continuum approach is needed for poorly mixed sediments receiving highly reactive organic carbon and for sediments below the bioturbated layer. Plain Language Summary: Animals inhabiting marine sediments mix particles and impact organic carbon degradation kinetics and degradation rates. Experiments and theory have shown that organic carbon reactivity declines as degradation progresses with time. However, most studies employ a constant reactivity. Here we couple an individual particle mixing model with age‐dependent reactivity and show that a constant reactivity model is adequate for well‐mixed sediments and for sediments receiving organic carbon that has already been degraded elsewhere. An age‐dependent reactivity model is needed for poorly mixed sediments receiving highly reactive organic carbon. Key Points: Age‐dependent organic carbon kinetics is coupled to a Lagrangian particle tracking modelOrganic carbon concentrations, reactivities and degradation rates in the bioturbated zone are presentedA simple first‐order (one‐G) model suffices for well‐mixed sediments and sediments receiving pre‐processed organic carbon [ABSTRACT FROM AUTHOR]

Introduction: Timber harvesting on steep terrain is a challenge in terms of economic viability, safety, and environmental performance. Felling with chainsaws and use of yarders seems optimal in this environment. However, using mobile traction winches allows for the safe work of ground-based technologies even in these challenging conditions. Methods: Our study assessed the impact of winch-assisted cut-to-length harvesting on soil disturbance in young forest stands (up to 40 years old) across slopes of 14.9°-27.4° (27-52%). Utilizing 78 measurement points (i.e., 234 measurements), we analyzed soil samples from trail ruts, between ruts, and undisturbed areas for soil bulk density (g.cm-3) and soil moisture content (%), simultaneously measuring penetration resistance (MPa), penetration depth (cm) and rut depth (cm). Results: The results highlighted that areas without winch assistance experienced the most significant increases in soil bulk density (up to 22.35%) and penetration resistance (up to 26.8%), though these differences were not statistically significant. Linear mixed effects models did not confirm a significant effect (p > 0.05) of a traction winch on the soil bulk density (g cm-3) and penetration resistance (MPa) in the ruts of the forwarding trails. Mean forwarding trail profile depths ranged from 4.63 to 7.28cm, with the maximum depths between 10.86 and 17.25cm, showing deeper ruts in non-assisted areas. Moreover, the presence of the traction winch (p<0.05) significantly affected themaximal depth of the forwarding trail rut. Conclusion: The findings suggest that winch-assisted harvesting may mitigate soil disturbance (rut depths) on steep slopes, offering a sustainable option for utilizing ground-based machinery with reduced environmental impact. [ABSTRACT FROM AUTHOR]

Vapor phase infiltration (VPI) has emerged as a promising tool for fabrication of novel hybrid materials. In the field of polymeric gas separation membranes, a beneficial impact on stability and membrane performance is known for several polymers with differing functional groups. This study for the first time investigates VPI of trimethylaluminum (TMA) into poly(1‐trimethylsilyl‐1‐propyne) (PTMSP), featuring a carbon–carbon double bond as functional group. Saturation of the precursor inside the polymer is already attained after 60 s infiltration time leading to significant densification of the material. Depth profiling proves accumulation of aluminum in the polymer itself, but a significantly increased accumulation is visible in the gradient layer between polymer and SiO2 substrate. A reaction pathway is proposed and supplemented by density‐functional theory (DFT) calculations. Infrared spectra derived from both experiments and simulation support the presented reaction pathway. In terms of permeance, a favorable impact on selectivity is observed for infiltration times up to 1 s. Longer infiltration times yield greatly reduced permeance values close or even below the detection limit of the measurement device. The present results of this study set a strong basis for the application of VPI on polymers for gas‐barrier and membrane applications in the future. [ABSTRACT FROM AUTHOR]

Background: Radiobiological effectiveness of radiation in cancer treatment can be studied at different scales (molecular till organ scale) and different time post irradiation. The production of free radicals and reactive oxygen species during water radiolysis is particularly relevant to understand the fundamental mechanisms playing a role in observed biological outcomes. The development and validation of Monte Carlo tools integrating the simulation of physical, physico‐chemical and chemical stages after radiation is very important to maintain with experiments. Purpose: Therefore, in this study, we propose to validate a new Geant4‐DNA chemistry module through the simulation of water radiolysis and Fricke dosimetry experiments on a proton preclinical beam line. Material and methods: In this study, we used the GATE Monte Carlo simulation platform (version 9.3) to simulate a 67.5 MeV proton beam produced with the ARRONAX isochronous cyclotron (IBA Cyclone 70XP) at conventional dose rate (0.2 Gy/s) to simulate the irradiation of ultra‐pure liquid water samples and Fricke dosimeter. We compared the depth dose profile with measurements performed with a plane parallel Advanced PTW 34045 Markus ionization chamber. Then, a new Geant4‐DNA chemistry application proposed from Geant4 version 11.2 has been used to assess the evolution of HO•${\mathrm{HO}}^ \bullet $, eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $, H3O+${{\mathrm{H}}}_3{{\mathrm{O}}}^ + $, H2O2${{\mathrm{H}}}_2{{\mathrm{O}}}_2$, H2${{\mathrm{H}}}_2$, HO2•${\mathrm{HO}}_2^ \bullet $, HO2−,O2•−${\mathrm{HO}}_2^ - ,{\mathrm{\ O}}_2^{ \bullet - }$ and HO−${\mathrm{HO}}^ - $ reactive species along time until 1‐h post‐irradiation. In particular, the effect of oxygen and pH has been investigated through comparisons with experimental measurements of radiolytic yields for H2O2${{\mathrm{H}}}_2{{\mathrm{O}}}_2$ and Fe3+. Results: GATE simulations reproduced, within 4%, the depth dose profile in liquid water. With Geant4‐DNA, we were able to reproduce experimental H2O2${{\mathrm{H}}}_2{{\mathrm{O}}}_2$ radiolytic yields 1‐h post‐irradiation in aerated and deaerated conditions, showing the impact of small changes in oxygen concentrations on species evolution along time. For the Fricke dosimeter, simulated G(Fe3+) is 15.97 ± 0.2 molecules/100 eV which is 11% higher than the measured value (14.4 ± 04 molecules/100 eV). Conclusions: These results aim to be consolidated by new comparisons involving other radiolytic species, such as eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $ or ,O2•−$,{\mathrm{\ O}}_2^{ \bullet - }$ to further study the mechanisms underlying the FLASH effect observed at ultra‐high dose rates (UHDR). [ABSTRACT FROM AUTHOR]

The conducting two‐dimensional electron gas (2DEG) behavior in LaAlO3 (LAO)/SrTiO3 (STO) and their associated mechanisms from various aspects have brought tremendous attention in the concerned area of research. To correlate the 2DEG behavior with their compositions, we have performed time of flight secondary ion mass spectrometry (TOF‐SIMS) depth profile analysis of thin films of Cr‐doped LAO/STO system as LaAl1‐xCrxO3 (x = 0, 0.2, 0.6 and 1) deposited over TiO2 terminated STO substrate, which includes two parent compounds LAO/STO (metallic) and LCO/STO (insulating). The uniform decrease of La and Al concentration at the interface of LAO/STO (metallic) system and in the contrary the nonuniformity of La and Cr concentration in LCO/STO (insulating) system have been highlighted. The uniform variation of ionic concentration at the interface of LAO/STO may increase the career concentrations to make the system metallic. The upward and downward diffusion at the interfaces of intermediate compositions varies differently from their parent ones due to the mixing of Al and Cr. Our results may help to understand the conducting nature of LAO/STO system for future developments and applications in such system. [ABSTRACT FROM AUTHOR]

In contrast to traditional X‐ray photoelectron spectroscopy (XPS), hard X‐ray photoelectron spectroscopy (HAXPES) can provide information from deeper within a sample while maintaining chemical resolution. However, working with higher energy X‐rays introduces a series of new or different issues ranging from energy calibration to factors associated with quantitative analysis. As part of the efforts to identify and increase community awareness about these issues, a workshop was held to review HAXPES metrology challenges with the perspective of converting it into a quantitative technique. A summary is hereby given of this workshop, which was entitled "What New Challenges Come with the Capabilities of HAXPES?" It was held in Portland, OR, USA, on November 7, 2023, and was primarily sponsored by the ASTM E42 Committee and the Applied Surface Science Division of the American Vacuum Society. This report contains summaries of the presentations and discussions at this workshop regarding the current open problems in HAXPES metrology. There were 20 participants at the workshop. [ABSTRACT FROM AUTHOR]

As a remote and in situ diagnostic technique for the first wall of tokamaks, laser-induced breakdown spectroscopy (LIBS) has shown promising potential for depth profile analysis of deposition layers on plasma-facing components (PFCs). However, due to the complexity of the interface of deposition layers and the limitations of laser profiles, achieving an accurate deposition layer thickness is often more difficult for an in situ LIBS system in tokamaks. In previous studies, a Laser Profile & Interface Roughness model (LPIR model), which considers the laser beam profile and interface roughness factors, has been developed to identify the interface of deposition layers. In this study, the effect of ablation rates from different materials in the deposited layers on the accuracy of their thickness has been investigated. The depth profiling of a Ni-Cu-Ni-Cu multilayer sample, which has a four-layer structure, has been carried out using the LIBS technique under different focusing conditions as well as various laser pulse energies, with the pressure maintained at 10-5 mbar. The LPIR model was used to reconstruct the depth distribution profile of the Ni-Cu-Ni-Cu multilayer sample and quantify the interfacial positions of the deposited layers. A layer thickness correction method for multilayer sample is proposed based on the dependence of the ablation rates of different layers on laser fluence. The correction ability has been evaluated based on the relative errors between the calculated and the scanning electron microscope (SEM) values for different layer thicknesses. The relative errors of the corrected layer thicknesses are all significantly improved, and the accuracy of the layer thicknesses has been substantially improved. The proposed method will not only help us better understand the LIBS depth profiling of multilayer samples under different laser fluence conditions, but it will also further improve the accuracy of the layer thickness analysis of multilayer samples. This result is of positive significance for the application of in situ LIBS diagnostics in plasma-wall interaction (PWI) studies. [ABSTRACT FROM AUTHOR]

The current research work involves the fabrication and tribological properties analysis of constant basalt filler reinforced (30 wt %) bio-based polypropylene (PP) and high density polyethylene (HDPE) thermoplastic composites. Compression molding technique is used after an internal mixing process in order to produce composite samples. The physical and hardness properties have been evaluated for both neat polymers and composite samples. In order to study the coefficient of friction (COF) and specific wear rate (SWR) of PP and HDPE composite samples, the Taguchi and Analysis of Variance (ANOVA) methodologies were applied. For PP samples, the optimum parameters in response to COF are found to be 0 wt% basalt (rank 3), 9 N load (rank 1), 200 r/min speed (rank 4), and 100 m distance (rank 2); for the SWR output, the optimum parameters are 30 wt% basalt (rank 1), 6 N load (rank 4), 100 r/min speed (rank 2), and 200 m distance (rank 3). For HDPE samples, the optimum parameters in response to COF are 0 wt% basalt (rank 1), 6 N load (rank 3), 100 r/min speed (rank 4), and 100 m distance (rank 2); for the SWR output, the optimum parameters are 30 wt% basalt (rank 1), 6 N load (rank 3), 100 r/min speed (rank 4), and 150 m distance (rank 2). Consistently, it has been shown that incorporating basalt fillers to PP and HDPE composites has more dramatically decreased SWR than COF. The depth of wear constantly rises according to increasing load, irrespective of the processing variables, as shown in 2D depth profiles. It is discovered that the confirmation tests carried out for the optimum parameters are within statistically acceptable bounds. The depth profile plots revealed that the worn track edges are found with polymer bumps because of deep grooves and softened polymer debris, which commonly observed more with HDPE samples due to low softening temperature. Moreover, the worn surfaces of the composites have plowed lines and cracks that are brought about by the micro-cutting and micro-plowing activity of the erosive asperities counterface. In addition to surface characteristics, the transfer films created during sliding also significantly influenced the mode of sample wear. [ABSTRACT FROM AUTHOR]

Accurate prediction of the embedment depth of surface-laid pipelines is fundamental to determine in-service performance, which is closely related to the resistance the seabed provides during pipe-lay. The presence of a surficial crust overlying normally consolidated seabeds increases difficulties in accurately assessing the variation in penetration resistance with depth. In an attempt to address these difficulties, this paper presents results from a series of large-deformation finite-element analyses of a pipeline vertically penetrating crusty seabeds under undrained conditions. A detailed parametric study was carried out to examine the effects of crust strength geometry (strength ratio, crust thickness, and strength gradient) and softening properties (soil sensitivity and ductility) on the penetration response and the evolution of soil flow mechanisms. A surficial crust leads to higher penetration resistance relative to a normally consolidated seabed without a crust. The numerical analyses revealed the transition in failure mechanism as the pipe penetrates through the crust into the underlying clay. Separate mechanisms identified at various transition points allowed for a mechanism-based empirical approach that produces a depth profile of penetration resistance for crusts of varying strength characteristics and thicknesses. The accuracy of this simplified calculation method typically is within 10% of the numerical results, and is suitable for use in engineering practice providing an evidence-based approach for the calculation of pipeline penetration in seabeds with surficial crusts. [ABSTRACT FROM AUTHOR]

The present study investigates the impact of varying process parameters on the mechanical properties of friction stir spot welding (FSSW) joints involving Al 5754 and Al 6111. Taguchi's L16 design of experiment approach was employed to conduct experiments and optimize the process parameters. Key parameters, including tool pin profile, dwell time (5–30 sec), rotating speed (250–1400 rpm), and plunge depth (1.5–1.8 mm), were systematically considered. The results indicated that the optimized welding conditions for attaining higher tensile‐shear strength are a spindle speed of 1400 rpm, dwell time of 10 sec, plunge depth of 1.7 mm, and a tool pin profile of a triangular pyramid. As for bending strength, the optimal conditions are a spindle speed of 250 rpm, dwell time of 30 sec, plunge depth of 1.8 mm, and a tool pin profile of a square pyramid, representing higher bending strength. The analysis of variance technique revealed that the tool pin profile and plunge depth significantly influenced the tensile‐shear strength and bending strength of the developed FSSW joint, respectively. Regression analysis was employed to formulate mathematical models predicting tensile and bending strength, and the predicted values closely matched experimental results with 80% accuracy. [ABSTRACT FROM AUTHOR]

Multilayer films of diamond‐like carbon (DLC) on monocrystalline diamond substrates have been for the first time obtained by plasma‐chemical deposition. Their chemical composition and structural and morphological properties are studied. The DLC individual layers differ in their sp3 carbon content. The multilayer nature of the resulting coatings is confirmed by periodic density modulation on the small‐angle X‐ray reflectometry curve and modulations in the CsC8, CsC6, CsC4 lines on the crater depth profile of secondary ions of elements (secondary ion mass spectrometry). The dependence of the deposition rate of multilayer DLC films on diamond, their composition and properties on the argon additive to the reaction gas mixture, as well as on methane flow, pressure and growth time, are studied. [ABSTRACT FROM AUTHOR]

The complex permittivity of adobe is measured using a coaxial probe system verses frequency (500 MHz to 7 GHz) and water content (0% to 6%). Measurements are performed using adobe samples collected from abode bricks. The geotechnical properties of the compressed earth bricks are characterized by (1) percentage of gravel, sands, and fines; (2) Atterberg limits; and (3) grain-size distribution. The variation in adobe complex permittivity verses frequency is measured at discrete levels of water content using small adobe samples exposed to controlled levels of constant humidity in an environmental chamber. The typical water content profile verses depth for an adobe brick is also determined. [ABSTRACT FROM AUTHOR]

Motivated by the importance of mixing arising from dissipating internal waves (IWs), vertical profiles of internal‐wave dissipation from a high‐resolution regional ocean model are compared with finestructure estimates made from observations. A horizontal viscosity scheme restricted to only act on horizontally rotational modes (such as eddies) is introduced and tested. At lower resolutions with horizontal grid spacings of 2 km, the modeled IW dissipation from numerical model agrees reasonably well with observations in some cases when the restricted form of horizontal viscosity is used. This suggests the possibility that if restricted forms of horizontal viscosity are adopted by global models with similar resolutions, they could be used to diagnose and map IW dissipation distributions. At higher resolutions with horizontal grid spacings of ∼250 m, the dissipation from vertical shear and horizontal viscosity act much more strongly resulting in dissipation overestimates; however, the vertical‐shear dissipation itself is found to agree well with observations. Plain Language Summary: Oceanic mixing impacts circulation, stratification (layering by density), and the uptake and transport of heat and nutrients. Over most of the ocean, mixing is caused by the breaking (turnover) of internal waves lying on the interfaces of density layers. Most ocean models do not contain a resolved internal wavefield, and therefore must parameterize internal wave (IW) mixing based upon external information. Recently developed high‐resolution ocean models with credible representations of internal waves may make it possible to map and understand global IW mixing without use of external information. Here we compare vertical profiles (profiles in depth) of IW dissipation in a regional model, which can be used to understand sensitivities to numerical schemes and grid spacings. With grid spacings that are attainable in global models, modeled dissipation profiles lie somewhat close to observed profiles, as long as certain choices are made within the numerical schemes. One numerical dissipation scheme is designed to realistically remove energy from eddy fields, which are the non‐wavelike motions in the ocean, and we have adapted this scheme to act less strongly on internal waves. Using this modified scheme, we find that high‐resolution global models may already be able to map IW dissipation. Key Points: Vertical profiles of internal wave (IW) dissipation in high‐resolution regional ocean simulations are compared with observed profilesProfiles in runs with a restricted form of horizontal viscosity and resolutions attainable in global models are close to observationsResults suggest high‐resolution global models can be used to map IW dissipation after numerical sensitivities are tested in regional models [ABSTRACT FROM AUTHOR]

Aerobic anoxygenic phototrophic (AAP) bacteria are a common part of microbial communities in the sunlit ocean. They contain bacteriochlorophyll a (BChl a)‐based photosystems that harvest solar energy for their metabolism. Across different oceanic regions, AAP bacteria seem to be more abundant in eutrophic areas, associated with high chlorophyll concentrations. While most previous studies focused on surface samplings, there is limited information regarding their vertical distribution in euphotic zones of the major ocean basins. Here, we hypothesized that AAP bacteria will follow a similar structure to the chlorophyll depth profile across areas with different degrees of stratification. To test this hypothesis, we enumerated AAP cells and determined bulk water BChl a concentrations along the photic zone of a latitudinal transect in the South and Central Atlantic Ocean. Overall, the distribution of AAP bacteria was highly correlated to that of chlorophyll a and to the abundance of picophytoplankton across both vertical and horizontal gradients. Furthermore, estimated light energy captured across the water column showed that, while AAP bacteria share a common latitudinal pattern of light absorption with picophytoplankton, they display a unique vertical arrangement with highest photoheterotrophic activity in the top 50 m of the surface ocean. [ABSTRACT FROM AUTHOR]

ABSTRACT The multidisciplinary, noninvasive analysis of baroque amber artworks is part of a research project that deals with the most valuable objects from the Museum of Gdansk (Poland). The two most interesting objects will be presented here: a Baroque Gdansk wardrobe‐shaped amber cabinet (made by Johann Georg Zernebach, Gdansk, 1724) and a crucifix (Gdansk, 17th century). Macro‐ (UV, IR, and X‐radiography) and micro‐ (XRF and Raman spectroscopy) analytical methods were applied to reveal traces of old conservation treatments and uncover the techniques of the 17th and 18th century amber masters. UV photography shows the differences between the amber plates that are not so easily detected under visible light, while XRF spectrometry detects elements atypical for amber objects, suggesting previous conservation treatments. Confocal Raman measurements, especially Raman depth profiling, were performed for the amber artworks and allowed to detect areas of previous conservation treatments. Single‐point scans were collected from the surface (0 μm) to a depth of −200 μm, with a step of 50 μm. The results allowed us to identify three different types of zones: where the amber was preserved without any protective layer, places where the amber was covered with a thin layer of a protective substance, and places where amber elements were compensated for loss using a binding agent and filler. The presented project allowed the development of a comprehensive methodology for the analysis of amber objects, especially to optimize the capabilities of confocal Raman microscopy. The combination of macro‐ and microanalytical techniques made it possible to obtain a broad overview of such complex artworks while optimizing the time and effort spent on the investigations. [ABSTRACT FROM AUTHOR]

Aluminum, due to its high abundance, very attractive theoretical capacity, low cost, low (de−) lithiation potential, light weight, and effective suppression of dendrite growth, is considered as a promising anode candidate for lithium‐ion batteries (LIBs). However, its practical application is hindered due to multiple detrimental challenges, including the formation of an amorphous surface oxide layer, pulverization, and insufficient lithium diffusion kinetics in the α‐phase. These outstanding intrinsic challenges need to be addressed to facilitate the commercial production of Al‐based batteries. The native passivation layer, Al2O3, plays a critical role in the nucleation and reversibility of lithiating aluminum and is thoroughly investigated in this study using high precision electrochemical micro calorimetry. The enthalpy of crystallization of β‐LiAl is found to be 40.5 kJ mol−1, which is in a strong agreement with the value obtained by calculation using Nernst equation (40.04 kJ mol−1). Surface treatment of the active material by the addition of 25 nm of alumina increases the nucleation energy barrier by 83 % over the native oxide layer. After the initial nucleation, the added alumina does not negatively impact the reversibility at 0.1 C rate, suggesting the removal of alumina is not necessary for improving the cyclability of aluminum anode based lithium‐ion batteries. Moreover, the coulombic efficiencies are also found to be slightly higher in the alumina treated samples compared to the untreated ones. [ABSTRACT FROM AUTHOR]

Reported depth profiles of hydrogen in plasma‐exposed n‐Si samples can be fitted with a simple model of hydrogen transport by negative and neutral species (H− and H0) accompanied by a reversible formation of hydrogen–donor pairs (HD) and by an irreversible production of mobile dimers H2A—in particular by a bulk pairing reaction of the H− and H0 species. Contrary to a complicated behavior of hydrogen found in p‐Si (with multiple independent states for positive ions and passivated boron), the situation in n‐Si appears to be much simpler as only single states for H−, H0, and HD are sufficient for profile reproduction. The parameters deduced from the profiles are the diffusivity of H−, the characteristic electron concentration marking equal contributions of H− and H0 into hydrogen transport, and the diffusivity of H2A dimers (in the available temperature range 120–225 °C). [ABSTRACT FROM AUTHOR]

Thin buried magnetic layers ranging from thicknesses of a few atomic monolayers to several nanometers are omnipresent in the fields of magnetism and spintronics. For the functionality and fine tuning of devices build with such layers, exact knowledge of the depth dependent magnetic properties is essential. Especially the interfacial magnetic properties are important. Hence, understanding how magnetism is affected by structural variations, such as thickness or interface roughness, is mandatory. In this study, we use x-ray resonant magnetic reflectometry and magnetometry to study the high-resolution depth dependent magnetization profiles of thin magnetic transition metal layers sandwiched between an oxide and chromium layer. Compared to bulk materials, the room temperature saturation magnetization of these layers is reduced by up to 67%. These reductions are extremely sensitive to small structural variations. From the magnetic depth profiles, we disentangle different effects contributing to the magnetization reduction and the exact magnetic properties of the interface. [ABSTRACT FROM AUTHOR]

In situ age and trace element determinations of monazite, rutile and zircon grains from an ultrahigh temperature (UHT) metapelite‐hosted leucosome from the Napier Complex using laser split‐stream analysis reveal highly variable behaviour in both the U–Pb and trace element systematics that can be directly linked to the microstructural setting of individual grains. Monazite grains armoured by garnet and quartz retain two concordant ages 2.48 and 2.43 Ga that are consistent with the previously determined ages for peak UHT metamorphism in the Napier Complex. Yttrium in the armoured grains is unzoned with contents of ~700 ppm for the garnet‐hosted monazite and in the range 400–1,600 ppm for the monazite enclosed within quartz. A monazite grain hosted within mesoperthite records a spread of ages from 2.43 to 2.20 Ga and Y contents ranging between 400 and 1,700 ppm. This grain exhibits core to rim zoning in both Y and age, with the cores enriched in Y relative to the rim and younger ages in the core relative to the rim. A monazite grain that sits on a grain boundary between mesoperthite and garnet records the largest spread in ages—from 2.42 to 2.05 Ga. The youngest ages in this grain are within a linear feature that reaches the core and is connected to the grain boundary between the garnet and mesoperthite; the oldest ages are observed where monazite is in contact with garnet. Yttrium in the grain is enriched in the core and depleted at the rim with the strongest depletions where monazite is adjacent to grain boundaries between the silicate minerals or in contact with garnet. The unarmoured monazite grains have lower intercept ages of 1.85 Ga, which overlaps with the bulk of ages determined from the rutile and is coincident with a previously reported zircon age obtained through depth profiling from the Napier Complex. The age and chemical relationships outlined above illustrate decoupling between the geochemical and geochronological systems in monazite. Individual grains are suggestive of a range of processes that modify these systems, including volume diffusion, flux‐limited diffusion and fluid‐enhanced recrystallization, all operating at the scale of a single thin section and primarily controlled by host mineral microstructural setting. These findings illustrate how the development of simple partitioning coefficients (cf. garnet/zircon) and geospeedometry based on experimentally determined diffusion coefficients on grain separates may not be achievable. However, it highlights the utility of combining age and trace element concentrations from multiple accessory minerals with microstructural information when trying to build a complete history of tectonothermal events experienced by an ancient rock system that has undergone a prolonged history of thermal, deformational and fluid flow events. [ABSTRACT FROM AUTHOR]

This study investigated the colour and corrosion resistance of a commercial sulphate-based versus a chloride-based trivalent chromium electrodeposit, as well as the effects of post-treatment in a hexavalent chromium passivate solution. Surface composition and depth profiles were analysed using X-ray Photoelectron Spectroscopy (XPS). The factors influencing the appearance and corrosion performance in a Russian Mud Test are discussed. [ABSTRACT FROM AUTHOR]

Optical second-harmonic generation (SHG) is achieved using adsorbed gold nanoparticles (AuNPs) with an average diameter of 16 nm at the aqueous solution–air interface in reflection. A detailed analysis of the depth profile of the SHG intensity detected shows that two contributions appear in the overall signal, one arising from the aqueous solution–air interface that is sensitive to the AuNP surface excess and one arising from the bulk aqueous phase. The latter is an incoherent signal also known as hyper-Rayleigh scattering (HRS). The results agree with those of an analysis involving Gaussian beam propagation optics and a Langmuir-like isotherm. Discrepancies are revealed for the largest AuNP concentrations used and indicate a new route for the design of soft metasurfaces. [ABSTRACT FROM AUTHOR]

To unveil the charge storage mechanisms and interface properties of electrode materials is very challenging for Na‐ion storage. In this work, we report that the novel layered perovskite Bi2TiO4F2@reduced graphene oxides (BTOF@rGO) serves as a promising anode for Na‐ion storage in an ether‐based electrolyte, which exhibits much better electrochemical performance than in an ester‐based electrolyte. Interestingly, BTOF@rGO possesses a prominent specific capacity of 458.3–102 mAh g−1/0.02–1 A g−1 and a high initial coulombic efficiency (ICE) of 70.3%. Cross‐sectional morphology and depth profile surface chemistry indicate not only a denser reactive interfacial layer but also a superior solid electrolyte interface film containing a higher proportion of inorganic components, which accelerates Na+ migration and is an essential factor for the improvement of ICE and other electrochemical properties. Electrochemical tests and ex situ measurements demonstrate the triple hybridization Na‐ion storage mechanism of conversion, alloying, and intercalation for BTOF@rGO in the ether‐based electrolyte. Furthermore, the Na‐ion batteries assembled with the BTOF@rGO anode and the commercial Na3V2(PO4)2F3@C cathode exhibit remarkable energy densities and power densities. Overall, the work shows deep insights on developing advanced electrode materials for efficient Na‐ion storage. [ABSTRACT FROM AUTHOR]

OrbiSIMS is a secondary ion mass spectrometry method with dual mass analyzers: a time-of-flight (ToF) mass spectrometer for high-speed imaging and an Orbitrap™ for high mass resolving power and mass accuracy. Originally developed for biological imaging, there is now growing interest in the application to semiconductor materials to resolve peak interferences that obfuscate analysis in traditional SIMS depth profiling experiments. We use a new method to calibrate the Orbitrap intensity scale to true counts, which allows comparison of the useful yield and duty cycle with a magnetic sector instrument and a time-of-flight instrument using an Sb implant in the silicon sample. The useful yield of the Orbitrap and magnetic sector instruments (for one detected peak) are similar. However, since the magnetic sector instrument has serial mass detection, its useful yield reduces as more peaks are analyzed. While the ToF instrument has parallel detection, it has a low duty cycle and the useful yield is two orders of magnitude lower for 1000 eV Cs+ sputtering. The depth resolution was also compared from the measurement of the downslope from depth profiles of an Sb delta multilayer. For 1000 eV Cs+ sputtering, the downslopes are 3.9, 2.3, and 2.7 nm/decade for Orbitrap, magnetic sector, and ToF instruments, respectively. Ion trajectory simulation shows that the poorer depth resolution of the OrbiSIMS is in part due to ion beam distortion at low energy. [ABSTRACT FROM AUTHOR]

Ion beams are used in x-ray photoelectron spectroscopy (XPS) to clean samples and perform compositional sputter depth profiles. The purpose of this article is to compile good practice, recommendations, and useful information related to the use of argon ion sources for inexperienced users of XPS instrumentation. The most used type of ion source generates monoatomic argon ions at a range of energies from a fixed direction relative to the instrument. The angle and direction of the ion beam with respect to the surface are normally altered by manipulating the sample, and this may involve tilting the sample to change the angle of incidence or rotating the sample to change the azimuthal incidence angle. Atomic argon ion beams cause damage to the structure of the material surface, which may exhibit itself as a change in stoichiometry or topography as well as the implantation of argon atoms. Therefore, caution is required in the interpretation of XPS depth profiles. Gas cluster ion sources offer new possibilities and choices to XPS users. Gas cluster sources enable the sputtering of organic materials with high yield in comparison to inorganic materials and offer the potential for nearly damage-free depth profiling of delicate organic materials as well as low damage cleaning of inorganic materials. It may be possible to use argon clusters to reduce damage during the depth profiling of inorganic materials, but there is currently insufficient evidence to make any general recommendations. [ABSTRACT FROM AUTHOR]

Over the last twenty years, more research has been conducted on the application of nanolime as a consolidant. However, a limitation in consolidation with nanolime is the back-migration of the product to the absorption surface during the drying phase, resulting in insufficient product deposition in depth. In this paper, a solvent composition is adapted to the substrate properties to examine the theory that a nanolime with low kinetic stability should be applied to prevent back-migration to the absorption surface for a substrate with large pore size. The common solvent composition of 100% ethanol has a kinetic stability considered too high. Nanolime dispersions (CaLoSiL® E 20 g/L) with different ethanol:water (100:0, 95:5, 90:10, 80:20) ratios were tested on lime mortar samples. The treated samples were subjected to several test methods to evaluate the effectiveness of the consolidation treatment. After comparing the results, the theoretical propositions were substantiated: a back-migration was noticeable in samples treated with the nanolime containing 100% ethanol, while no back-migration was observed in the other solvent compositions. Samples treated with a nanolime dispersion with the addition of 10% deionised water showed promising results regarding mechanical strength, product deposition over the entire depth profile of the sample, and porosity properties. [ABSTRACT FROM AUTHOR]

This paper presents issues related to the assessment of the texture of aggregate concrete (EAC) surfaces using various methods for its verification. Microtexture was assessed using the British Pendulum Tester (BPT) and Dynamic Friction Tester (DFT). Two laser profilometers were used to assess macrotexture, circular texture meter (CTM) and stationary laser profilograph (SPL), as well as the commonly known volumetric method. Measurements were carried out on left and right tracks and in between them on five test sections of expressways. Based on the analyses performed, it was found that the results obtained by the DFT were less sensitive to changes in microtexture between individual tracks compared to the results obtained by the BPT. The BPN values in the left track were lower than those in the right track. However, the difference between the DFT20 results in these spots was insignificant. Both MPD and MTD values did not show significant differences between the right and left tracks. However, some differences were observed between the MPD parameters obtained using the CTM and SPL. This resulted from the different frequency and length of the scanned surface profile. However, the differences were at an acceptable level. A very high linear correlation was obtained in the case of BPN and DFT20 values (r − 0.719), and in the case of MPD and MTD values, the correlation was almost certain (r above 0.900). Based on a comparative analysis of the models estimating mean texture depth (MTD/ETD), a significant difference was observed between models based on EAC pavement results and those based on asphalt surfaces. [ABSTRACT FROM AUTHOR]

Soil organic matter (SOM) is one of the essential components of soil and moisture to interfere with the detection. The soil moisture content by mass ratio and spectral parameters are often utilized to classify the moisture levels. But previous studies on the prediction of SOM content have focused mostly on the surface soil without covering the profile of depth range. This study aims to explore the influence of soil moisture on the inversion accuracy of the SOM profile. This study analyzed previously obtained near-infrared spectra were collected from the samples of the soil core column in the surface layer to about 150 cm underground. Each core was divided into subsamples with a height of 10 or 20 cm. The samples were gradually moistened to 6 groups of levels of soil moisture. According to the index of moisture tension, the air-dry state was defined as 1.500, 0.330, 0.100, 0.033 MPa, and the saturated state in turn. The data was normalized and transformed to the absorbance. Each set of spectral data was processed by seven spectral preprocessing. Among them, the standard normal variate transformation (SNV) was achieved the best. Meanwhile, successive projection algorithms (SPA) and competitive adaptive reweighting-successive projection algorithms (CARS-SPA) were used to screen the characteristic wavelengths. The number of characteristic wavelengths was then reduced to 6-8 at each level of soil moisture. The inversion models of SOM were constructed to combine with SNV preprocessing using full spectrum and characteristic wavelengths. The results indicated that: 1) The model accuracies of the SPA-PLSR and CARS-SPA-PLSR models were better than that of the PLSR model at six levels of moisture. 2) The SNV preprocessing was also combined to determine the coefficient of determination in prediction (R²p ) and root mean square error of the prediction set (RMSEP). Under the saturated state, R²p values of the SNV-SPA-PLSR and SNVCARS-SPA-PLSR models were 0.664 and 0.651, respectively, while the RMSEP values were 1.095 and 1.131 g/kg, respectively. In the air-dry state, R²p values of the two models were 0.799 and 0.753, respectively, and RMSEP values were 0.759 and 0.848 g/kg, respectively, indicating the better prediction of the SNV-SPA-PLSR model. The SNV-CARS-SPA-PLSR model shared the higher accuracy of prediction when the moisture tension levels were 0.033, 0.100, 0.330, and 1.500 MPa. Specifically, R²p values increased from 0.699 to 0.846, whereas, the RMSEP values decreased from 1.013 to 0.620 g/kg. 3) However, it was difficult to guarantee the same soil moisture level at the same depth in different locations of the field. The SOM calibration model was applied to the characteristic wavelengths on different datasets. The SNV-CARS-SPA-PLSR model was selected at the moisture tension of 1.500 MPa. The best performance was achieved for the organic matter in the six groups of soil moisture levels and mixed samples. The models can be expected to estimate the SOM content of the profile at various moisture levels. The findings can also provide a strong reference to improve the applicability of near-infrared spectra inversion models for the organic matter content at different levels of soil moisture. [ABSTRACT FROM AUTHOR]

Li–Al–O materials are interesting for several applications. Herein, a Li–Al–O thin‐film materials library, deposited by inert magnetron sputtering and postdeposition annealing in O2 atmosphere, is used to study the effects of different annealing temperatures (300–850 °C) and durations (1 min to 7 h) on crystallinity and composition of the films. X‐ray photoelectron spectroscopy depth profiling reveals inhomogeneous compositional depth profiles of conventionally annealed films (300–650 °C, 3–7 h) with increased Li contents toward the film surface and increased Al contents toward the film–substrate interface, as confirmed by a combination of Rutherford backscattering spectrometry and deuteron‐induced nuclear reaction analysis. The minimum temperature for the formation of crystalline LiAlO2 in the otherwise amorphous films is 550 °C. The undesired inhomogeneous depth profiles are transformed into homogeneous ones by rapid thermal annealing (750–850 °C, 1–10 min), while simultaneously causing the formation of crystalline LiAlO2. Therefore, rapid thermal annealing is shown to be more suitable than conventional annealing for the thermal processing of Li–Al–O thin films. Moreover, this conclusion is expected to have broader relevance beyond Li–Al–O materials, as it is likely to apply to other Li metal oxides, of which there are many technologically relevant ones. [ABSTRACT FROM AUTHOR]

In spite of its superior chemical sensitivity, XPS depth profiling is rarely used because of the alteration introduced by the sputter removal process and the resulting inhomogeneous in-depth concentration distribution. Moreover, the application of XPS becomes increasingly challenging in the case of the analysis of thin layers, if the thickness is in the range of 2–3 inelastic mean free paths (IMFP) of the photoelectrons. In this paper we will show that even in these unfavorable cases the XPS depth profiling is applicable. Herein the XPS depth profiling of a model system tungsten-carbide-rich nano-layer of high hardness and corrosion resistance is presented. We will show that the problems arising because of the relatively high IMFP can be corrected by introducing a layer model for the calculation of the observed XPS intensities, while the alteration, e.g. ion mixing, compound formation and similar artefact, introduced by the sputter removal process can be handled by TRIDYN simulation. The method presented here overcomes the limitation of XPS depth profiling. [ABSTRACT FROM AUTHOR]

A good understanding of the interplay between the cutting tool edge radius, elastic recovery, friction, and contact pressure is essential for better modeling of ploughing forces during micro-scale cutting. This study conducts plunging tests on an ultra-precision CNC with engineered tungsten carbide cutting tools on commercially pure titanium alloy. The cutting tool edge radius is prepared to be around 3.5–4 μm, which resembles those cutting tools used in micro scale machining. During plunging tests, the micro cutting tool is given a sinusoidal movement with an amplitude close to edge radius of the tool as the work material is rotated at a constant speed. The residual depth profiles of the webs corresponding to the commanded depths were investigated in detail to identify elastic recovery rate. The cutting and thrust force measurements during plunging experiments together with identified elastic recovery rate was employed in an analytical model of micro scale machining to obtain the variations of contact pressure and coefficient of friction as a function of commanded depth. Due to the scale of the experiments that were performed, the effects of surface topography of the cutting tool and possible alignment errors are also considered in the analytical model. A linear relationship between the contact pressure and elastic recovery has been identified during ploughing-dominated machining conditions for the work material and the cutting tool pair considered in this study. The proposed experimental technique is shown to be promising in terms of modeling ploughing forces during micro-scale cutting. • Plunging tests reveal the influence of edge radius on elastic recovery. • A linear relationship between contact pressure and elastic recovery. • Coefficient of friction remains almost constant during ploughing. [ABSTRACT FROM AUTHOR]

This document is a compilation of articles that discuss the field of laser materials processing and its applications in various industries. It emphasizes Europe's role in this field and provides an overview of a symposium held during the 2023 Spring Meeting of the European Materials Research Society. The articles cover topics such as laser nanostructuring, up-scaling processing rates, laser direct writing, laser texturing, and surface engineering. The authors provide detailed experimental observations and analysis of their findings, and their biographies highlight their expertise in laser processing. [Extracted from the article]

Recently discovered double gamma/beta (γ/β) polymorph Ga2O3 structures constitute a class of novel materials providing an option to modulate functional properties across interfaces without changing the chemical compositions of materials, in contrast to that in conventional heterostructures. In this work, for the first time, we investigate thermal transport in such homo-interface structures as an example of their physical properties. In particular, the cross-plane thermal conductivity (k) was measured by femtosecond laser-based time-domain thermoreflectance with MHz modulation rates, effectively obtaining depth profiles of the thermal conductivity across the γ-/β-Ga2O3 structures. In this way, the thermal conductivity of γ-Ga2O3 ranging from 1.84 to 2.11 W m−1 K−1 was found to be independent of the initial β-substrates orientations, in accordance with the cubic spinel structure of the γ-phase and consistently with the molecular dynamics simulation data. In turn, the thermal conductivity of monoclinic β-Ga2O3 showed a distinct anisotropy, with values ranging from 10 W m−1 K−1 for [−201] to 20 Wm−1 K−1 for [010] orientations. Thus, for double γ-/β-Ga2O3 polymorph structures formed on [010] β-substrates, there is an order of magnitude difference in thermal conductivity across the γ/β interface, which can potentially be exploited in thermal energy conversion applications. [ABSTRACT FROM AUTHOR]

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The nature and type of defects formed due to heavy-ion irradiation in tungsten foils are analyzed using transmission electron microscopy. The recrystallized tungsten foils were irradiated by 80 MeV gold ions at room temperature for a fluence of 1.3 × 10 14 ions/cm 2 that amounts to a net displacement per atom (dpa) of 0.22. The defect structures were analyzed using bright-field and weak-beam dark field imaging at two different depths to understand the depth profile of the defects. It is found that the defect clusters formed during the irradiation, both at the near-surface and at 2 μ m depth are of vacancy type that is confirmed by the local strain analysis and supports the findings of vacancy clusters in positron lifetime measurements. The analysis also shows that the dislocation-lines were of pure edge, pure screw and mixed. The fraction of mixed dislocation is found to increase during irradiation at the expense of pure edge and screw dislocations. [ABSTRACT FROM AUTHOR]

We investigate terahertz time-domain spectroscopy (THz-TDS) as a non-destructive and non-contact technique for depth profiling of dopants in semiconductors. THz temporal waveforms transmitted through silicon-ion-implanted semi-insulating gallium arsenide substrates, as-implanted or post-annealed by rapid thermal annealing, were analyzed by assuming a multi-layered Gaussian refractive index profile in the ∼sub-micrometer-thick implantation region. The implantation energy and dosages in this work were 200 KeV, 1014, 5 × 1014, and 1015 ions/cm2, respectively. The average values of real (n) and imaginary (κ) parts of refractive indices of an as-implanted sample in the depth range of 0–800 nm are 5.8 and 0.7, respectively, at 0.5 THz and are 6.2 and 0.2, respectively, at 1 THz. On the other hand, the refractive index profile of the post-annealed samples displays a prominent Gaussian-like form, and peak refractive indices (n ∼ 25 and κ ∼ 32.7 at 0.5 THz and n, κ ∼17 at 1 THz) were found to be at the depth of 210 nm. Reconstructed dopant profiles in as-implanted, implanted, and post-annealed substrates were found to be in good agreement with measurements by secondary ion mass spectroscopy as well as simulation by the Monte Carlo method. We were also able to determine accurately the projected range (Rp), straggle (Rs), and concentration of dopants by the analysis of THz-TDS data. The spatial resolution, along the depth direction, of the THz-TDS technique for depth profiling of dopants was estimated to be as small as 8-nm. This work suggests the feasibility of using THz-TDS for nondestructive and non-contact diagnostics for profiling dopants in semiconductors. [ABSTRACT FROM AUTHOR]

The formulas obtained for deconvolution of positron mean lifetime results in the sequential etching technique for detecting defect depth profiles are presented. In this experiment, only the conventional positron lifetime measurement with radioisotope-based positrons is used. The important role of the positron implantation profile is discussed. These formulas were successfully used to describe the depth profile of defects formed in sliding contact in pure vanadium. Two different layers were detected below the surface. [ABSTRACT FROM AUTHOR]

An efficient new thermal-wave inverse-problem approach based on an integral-equation boundary-value method coupled with an imperialist competitive algorithm was developed. The methodology was successfully applied to simultaneously reconstruct density and thermal conductivity depth profiles in a sintered powder metallurgy sample from an industrial automotive manufacturer with a surface layer of higher density than the bulk. The density and thermal conductivity depth profiles were validated independently using the manufacturer's data and in-house temperature and porosity measurements. The present non-destructive inverse problem approach represents a generalized formalism to thermal-wave reconstruction of dual depth profiles using frequency scan data measured from the interrogated surface. From a fundamental viewpoint, the method adds significant insights into the relationship between thermal conductivity and density distributions in inhomogeneous solids. [ABSTRACT FROM AUTHOR]

Rhincodon typus, or the whale shark, is the largest extant fish in the world and is classified as endangered on the IUCN's Red List. Due to their enormous size and conservation status, whale sharks are rarely housed in aquaria. Here we present a behavioral analysis culminating from a large effort by 89 observers from 2008-2012 to study four R. typus (ID codes: AL, TA, TR, YU) longitudinally in an aquarium setting. We found that relatively simple behavioral metrics such as swim speed, depth occupation, swimming direction, and lead-follow interactions demonstrated R. typus individual variation and responses to habitat changes. All sharks displayed increased swim speeds 30-minutes before regimented feed times, when there was scent of food being fed to other animals in the habitat. Consistently in the habitat, one male shark (YU) was recorded swimming more at depth, faster, almost exclusively clockwise, and engaged in fewer close proximity interactions with others than expected by chance. In contrast, a larger female shark (AL) was observed swimming the slowest, at the surface more than others, led other sharks more than she followed, and had strong lead-follow interactions with another shark of the opposite sex (TA). TA and TR did not differ from each other in depth profiles or speed, but did differ in their proclivity to lead or follow. Depth preferences and lead-follow interactions suggest some partitioning of the habitat and the possibility of social hierarchy in this species. These results represent the first longitudinal behavioral analysis of aquarium R. typus, offering meaningful similarities and contrasts to field observations. [ABSTRACT FROM AUTHOR]