The growth in the number of satellites in Low Earth Orbit, coupled with the possibility of their catastrophic disruption, may lead to more orbital debris, which in turn has increased the risk of damage to spacecraft arising from impacts by small pieces of debris. There is thus an urgent need to monitor the small particle population in Low Earth Orbit, using a new generation of dust detectors. Various designs are in preparation, and several use the principle of observing particles via their impact penetration of thin films. Previously, most laboratory studies of penetration of thin films have used spherical impactors for ease. However, these are not representative of the shapes of orbital debris. Accordingly, here, impacts are reported at 5 km s -1 , by various shaped projectiles (sizes typically 0.5 – 2 mm) on thin (12.5 μm thick) Kapton films. The shapes used were spheres, rods, cubes and platelets, and represent a selection of the shapes present in the orbital debris population that arises from catastrophic disruption of spacecraft. The size and shape of the holes in the Kapton arising from the impacts, are shown to reflect the size and cross-sectional area of an impactor as it passes through the film; even the presence of angular corners in the impactors can be seen in the holes. However, due to the variable aspect of an individual impactor presented to the film during an impact, identification of the exact 3-dimensional shape cannot be obtained from the 2-dimensional hole. Nevertheless, with minor exceptions it is possible to separate more spherical (i.e., natural dust) impactors from the other shapes (i.e. variously shaped anthropogenic debris). • Cosmic dust impact detectors which use thin films are sensitive to impactor shape • It is shown that the angles at corners of impactors are preserved in the hole shape • In general, the impact hole shape in a thin film retains the impactor aspect at impact • But since the aspect at impact is unknown, the full 3D impactor shape cannot be found

Electron beam absorbed current (EBAC) microscopy can provide spatially resolved electrical information that conventional probe methods and local scanning probes often miss in nanoparticulate thin films. Here we present the development of a practical scanning electron microscopy (SEM)-based methodology to qualitatively assess conductivity uniformity and electrical continuity in thin films spanning two electrodes using TiO2 films as a model system. The approach combines a purpose-built insulating holder, readily made without clean-room and advanced lithography access, with embedded electrodes and a measurement configuration to visualize current pathways and identify electrically disconnected regions that may not be apparent from morphology alone. Line scans and 2D maps enable rapid screening of film quality, highlighting cracks, and poor particle connectivity. The workflow is designed for reproducibility and can be adapted to other semiconducting or weakly conducting thin films where microscale continuity is critical to device performance. Fabricate a biasable dual-electrode SEM holder by embedding bent copper plates in an insulating resin body and machining a defined deposition channel (drilled to expose copper + resin in one plane), enabling repeatable electrode gaps and robust external connections for EBAC measurements. Prepare thin films that reliably bridge the electrode gap by using a diluted, well-dispersed nanoparticle suspension (e.g., TiO2 in IPA) and controlled drop-casting into the channel; confirm continuous coverage using standard SEM imaging before electrical mapping. Map conductivity uniformity in situ using EBAC (line scans and 2D maps under applied voltage) to rapidly locate conductive pathways and diagnose electrically disconnected regions that may appear morphologically continuous, providing a reproducible screening workflow adaptable to other weakly conducting thin films.

Passive solid-state detectors based on lithium fluoride (LiF) crystals and TLD-100 pellets were irradiated in the range from 0.65 to 1000 Gy and LiF thin films from 20 to 1000 Gy at different dose-rates within the two dose ranges, with the 60 Co source of the Calliope irradiation facility at ENEA Casaccia, Italy. The 1 mm-thick LiF crystals and pellets were commercially available, while the LiF films were grown, by thermal evaporation on bare and Al coated Si(100) substrates, with nominal thickness of 0.5, 1 and 2 μm, at ENEA Frascati, Italy. The principle of operation of these radiation detectors is the optical reading of visible radiophotoluminescence (RPL) emitted by radiation-induced F 2 and F 3 + color centers (CCs). The RPL spectra of the LiF crystals and of the TLD-100 pellets were measured under continuous wave laser excitation at 445 nm, while for the LiF films the spectrally integrated RPL signal was measured by a fluorescence microscope equipped with a blue LED as pumping source. In pellets, the RPL signal intensity showed a linear behavior as a function of the irradiation dose, which is independent from the dose rate. Despite of the close similarity of the RPL spectra, a slightly supra-linear behavior was found for the LiF crystals. Due to the LiF films limited thickness and thus the low RPL signal, a linear RPL response was clearly measured only at the highest doses, for both kind of substrates and all the investigated thicknesses. On the basis of these results, further investigations are under way to understand the observed behaviors in order to exploit the RPL of these LiF-based detectors for dosimetry of gamma rays in a very wide dose range up to MGy. • LiF crystals, thin films and TLD-100 pellets were gamma irradiated up to 1 kGy • F 2 , F 3 + CCs RPL spectra measured under cw laser excitation in crystals and pellets • RPL showed linear response with dose and dose-rate independence in pellets • F 2 , F 3 + CCs RPL measured by a fluorescence microscope in LiF thin films • RPL showed linear response at the highest doses in films on Si and Al substrates

This work demonstrates the Langmuir–Blodgett (LB) assembly of liquid-phase exfoliated MoSe 2 and WSe 2 flakes into optically active thin films on SiO 2 substrates and correlates their structural, morphological, and optical responses. XRD, SEM, and TEM confirms the polycrystalline 2H phase of both transition metal dichalcogenides, with interplanar spacings consistent with the reported values. Atomic force microscopy reveals apparent thicknesses of ∼1.2 nm for MoSe 2 and ∼5 nm for WSe 2 , indicating laterally non-uniform films composed of few-layer regions and multilayer aggregates. Raman spectra show the characteristic (in-plane) and (out-of-plane) vibrational modes with layer-dependent peak separation. UV–Vis absorption spectra exhibit bandgap energy approximately at 1.62 eV and 1.6 eV for MoSe 2 and WSe 2 , respectively. Photoluminescence is dominated by emission from localized thinner regions within the LB films, underscoring the strong influence of thickness distribution and film morphology on excitonic behavior. These results highlight LB assembly as a scalable route to deposit non-uniform but optically active MoSe 2 and WSe 2 films. • Langmuir–Blodgett assembly of MoSe 2 and WSe 2 thin films demonstrated. • Structural and morphological properties confirmed by XRD, SEM, TEM, AFM. • Non-uniform films with few-layer and multilayer nanosheet regions observed. • Optical bandgaps ∼1.62 eV (MoSe 2 ) and ∼1.6 eV (WSe 2 ) extracted. • Photoluminescence dominated by excitonic emission from thinner regions.

Rapid and label-free detection of microalgae is increasingly required for environmental surveillance and bio-industrial process control, where decisions must be made from subtle interfacial changes rather than from bulk concentration alone. In this work, chromium (Cr) thin films (20-75 nm) were deposited by RF magnetron sputtering and evaluated by spectroscopic ellipsometry (SE) to develop a thickness-optimized optical transducer for microalgae biosensing. Thickness-dependent optical constants (n, k) were extracted using a Drude-Lorentz dispersion model incorporating an effective-medium roughness layer. The 75 nm film exhibited the most bulk-like and spectrally stable response with comparatively low effective loss across the visible range, while 20-30 nm films showed larger deviations attributable to microstructure- and interface-mediated scattering contributions in the ultra-thin regime. Biosensing was implemented by forming Cr/PVA and Cr/PVA+microalgae stacks and quantifying the differential phase response. The 75 nm Cr/PVA platform delivered the strongest microalgae-induced modulation, exhibiting a Δ phase shift of 40.6° within 2.65-3.20 eV, thereby identifying a high-contrast spectral window for detection. Machine learning was required because Ψ-Δ spectra are high-dimensional, nonlinear, and strongly correlated, and multilayer spectral blending (Cr/PVA/biological loading) limits reliable thresholding and linear separation. A multitask deep neural network was trained to learn the coupled Ψ-Δ response for rapid prediction, and support vector machines were used for supervised discrimination of film stacks. By converting dense SE signatures into decision-ready labels on a thickness-optimized substrate, the proposed SE-ML framework advances an intelligent, non-destructive route for rapid microalgae screening and environmental diagnostics.

The development of recombinant casein with precision fermentation creates an opportunity to use specific genetic variants of casein for the development of foams. Small differences in the amino acid sequence between variants will affect their interfacial, thin film, and foaming properties, allowing for a more targeted design of products. This study explores these effects in αs1-casein variant A and B (RCA and RCB), where RCA lacks amino-acid residues 14-26 compared to RCB, which results in a tail-train interfacial configuration after adsorption, whereas RCB assumes a train-loop-train configuration. Air-water interfaces stabilized with both variants were studied with large amplitude oscillatory dilatation and shear, and imaged with AFM. Films stabilized with RCA or RCB were also studied with a thin film balance combined with micro interferometry. Foam properties of both variants were determined using a FoamScan. In thin film balance experiments, low concentrations of RCB (0.05%) formed mobile interfaces that allowed for Gibbs-Marangoni flows and led to superior foam stability (t1/2: 1h). At increased concentrations of RCB the Gibbs-Marangoni flows were inhibited, and foam stability decreased. RCA formed a stiffer, less mobile interface (dilatation and shear) and therefore inhibited the Gibbs-Marangoni flows altogether, which led to low foam stability which improved with increasing concentration (t1/2: 8-20min). Clearly, the deletion of amino acids in caseins can greatly impact their interfacial and foaming behavior. These results highlight the potential for using different genetic variants of recombinant caseins for tuning its functionality.

Scalable formation of high dispersed-phase fraction (ϕ) emulsions without mechanical agitation is a critical challenge in colloid and interface science. Conventional high-energy routes rely on cavitation and shear induced breakup, leading to uncontrolled temperature rise and degradation of bioactives, whereas low-energy methods offer gentle operation but limited throughput. We hypothesize that vapor-phase condensation on surfactant solutions can bypass shear-driven breakup entirely, enabling thermally gentle, energy-efficient and continuous formation of dense emulsions by nucleating and stabilizing droplets at the interface before coalescence can occur. Building on earlier studies of Emulsions by Vapor Condensation (EVC) on deep stagnant pools, we developed a continuous Emulsions by Vapor Condensation on Thin Film (EVC-F) process incorporating a custom-designed Dispenser-Spreader-Sweeper (DSS) arm. The arm uniformly spreads a surfactant-laden oil film on a cooled substrate and cyclically sweeps away condensate formed emulsions, enabling continuous operation. Using food grade surfactants (polyglycerol polyricinoleate and soy lecithin), we systematically investigated how variations in film thickness, residence time (DSS rotation speed), and condensation rate modulate interfacial nucleation kinetics and droplet evolution, thereby controlling ϕ and emulsion stability, as supported by morphological and rheological analyses. The EVC-F process produced submicron droplets (100 to 800nm) with tunable ϕ up to about 25%, surpassing previous EVC systems that produced less than 1%. PGPR yielded highly stable emulsions with monomodal, narrow droplet size distributions and near-Newtonian like rheology, whereas lecithin produced larger and more polydisperse droplets. Mixed systems exhibited composition dependent stability, with PGPR rich blends remaining stable for more than 30days. The improved stability of EVC-F emulsions relative to ultrasonication suggests that condensation-driven interfacial nucleation mitigates coalescence and dispersed phase loss typically observed under shear-dominated, non-isothermal conditions. These results establish EVC-F as a thermally gentle, energy-efficient, and scalable route for producing dilute to dense food-grade emulsions relevant to soft-matter, colloidal, and interfacial science.

Microsecond pulsed glow discharge mass spectrometry stripping combined with three-dimensional crater profilometry - a new method for measuring the thickness of micro- and nano-films.

The planar hexagonal phase of ZnO, known as h-ZnO, g-ZnO, α-ZnO, the Bk structure, the 5-5 phase, the α-BN phase, etc., has P63/mmc symmetry and is implicated in ferroelectric switching mechanisms for wurtzite-ZnO. It is well known in thin films on substrates and can be stabilized by external pressure, but its possible existence is critical in high-purity nanocrystals under ambient conditions. Indeed, a crystal structure has been reported, but this work remains controversial as first-principles calculations predict very different structural properties. Herein, the original experimental data is re-refined, through phase-shift determination and Morlet wavelet transformation, that molecular dynamics simulations associate with a P63/mmc structure with unit-cell parameters at room temperature of a = 3.45±0.02 Å and c = 4.46±0.02 Å. These values are 0.35 Å and 0.80 Å, respectively, larger than those previously reported and in good agreement with computational predictions. This confirms that ZnO nanocrystals can form a metastable planar hexagonal phase. It provides key information pertaining to polarization switching in ZnO, its derivatives, and general wurtzite-structured materials.

Effect of annealing temperature on the structural, chemical, morphological, and optical properties of copper gallate (CuGa2O4) thin films under oxygen environment

We present a comparative study of three Monte Carlo simulation frameworks—SRIM, GEANT4, and PHITS—for modeling the transport, stopping, and atomic cascade of negative muons in micrometer-scale, multilayer systems relevant to Muon-Induced X-ray Emission (MIXE) experiments at the Paul Scherrer Institute (PSI). Using a lithium-ion battery as a benchmark target, simulated stopping depth profiles are compared with experimental data from the GIANT spectrometer. All three codes reproduce the overall muon depth distributions with good consistency, even across sharp density contrasts. SRIM provides reliable stopping depth estimates for compact geometries, whereas PHITS reproduces GEANT4 results with comparable accuracy and additionally generates muonic X-ray spectra. These spectra, however, exhibit a systematic energy offset in the K-line transitions of medium- and high-Z elements relative to theoretical and experimental values. Despite this bias, PHITS accurately captures relative intensities and spectral shapes, enabling element-specific line identification. The results demonstrate that SRIM and PHITS constitute practical tools for rapid estimation of muon stopping depth and stopping profiles, and that PHITS holds strong potential for predictive MIXE spectroscopy once its transition-energy bias is corrected. • Benchmarking of GEANT4, PHITS, and SRIM for Muon-Induced X-ray Emission (MIXE) simulations. • Consistent prediction of negative-muon implantation depths in multilayer materials. • Identification of systematic muonic K-line energy shifts in PHITS simulations. • Validation of relative muonic X-ray intensities against experimental battery data. • Practical guidance for simulation-assisted MIXE experiment design.

Cerium-doped yttrium aluminum garnet (Y 3 Al 5 O 12 :Ce, YAG:Ce) thin films were prepared by reactive co-sputtering from two separate elemental sources (Y 3 Al 5 alloy and pure cerium) using a dual hollow cathode plasma-jet system in an Ar/O 2 atmosphere. This plasma-based approach enabled spatial control of Ce incorporation through the geometric configuration of the sputtering sources and tailored power input. Film composition and structure were analyzed using LIBS, XRD, and optical methods, revealing a gradient in Ce content across the substrate array. Post-deposition annealing at 1000 °C was essential for crystallization and luminescence activation, resulting in the formation of single-phase YAG at low Ce concentrations and a gradual transition toward CeO 2 -rich films at high Ce loading. Photoluminescence and cathodoluminescence studies showed Ce 3+ emission at moderate doping levels, while higher Ce content led to phase segregation, Ce 4+ formation, and luminescence quenching. These results demonstrate that dual hollow cathode reactive sputtering provides a flexible approach for controlling the Ce distribution and for exploring the structural and optical behavior of YAG:Ce films under extreme Ce loading conditions. • Reactive sputtering of YAG:Ce thin films from metallic targets by two hollow cathodes • Ce concentration controlled by nozzle geometry and independent discharge powers • Post-annealed films show YAG:Ce crystallization and Ce 3+ luminescence activation • Demonstrated route for tunable luminescent garnet coatings for optical applications

Hard-axis collapse in Co thin films: Insights from remnant magnetoresistance and micromagnetic simulations

Effect of sputtering working pressure on InZnO and InZnMgO thin films and their application to solar cells

This work extends a previous investigation on plasmon enhanced optical gain in Nd 3+ doped TeO 2 -ZnO (TZ) pedestal waveguides incorporating gold nanoparticles (Au NPs) for applications at 1064 nm. The influence of Nd 3+ concentration and the role of a SiO 2 spacer layer on the plasmon assisted optical gain of Nd 3+ doped TZ were investigated. Thin films were deposited by RF magnetron sputtering, with the Nd 3+ concentration controlled by varying the number of Nd 2 O 3 pellets (1, 2, and 3). Pedestal waveguides with heights of ∼3.6 μm and widths ranging from 4 to 40 μm were characterized. Optical gain measurements at 1064 nm under 808 nm excitation showed that the lowest Nd 2 O 3 concentration achieved the highest relative gain (G R ) with enhancement of up to ∼80% due to Au NPs. Although higher Nd 3+ concentrations led to smaller improvements, attributed to self-absorption and non-radiative losses, the positive role of Au-NPs was observed. The introduction of SiO 2 spacer layers (25 or 100 nm) between the active core and Au NPs completely suppressed the plasmonic enhancement, confirming the importance of adequate distances between the rare-earth ions and the metallic NPs. These findings highlights the critical roles of dopant concentration and nanoscale Au NPs-core separation in maximizing plasmon assisted G R in Nd 3+ doped TZ based waveguides, providing guidance for the design of compact and efficient on-chip optical amplifiers. • Plasmon-assisted optical gain strongly depends on Nd 3+ concentration • Au nanoparticles deposited directly on the core: gain growth of up to ∼80% at 1064 nm • Optimal performance for the lowest Nd 3+ concentration: gain of up to 11 dB/cm • Au nanoparticles and the active core distance: relevance to promote plasmonic effects • Higher Nd 3+ concentrations reduce waveguide performance

In this work we study the depth profiles of oxidized metastable Zn 3 N 2 thin films using time-of-flight elastic recoil detection analysis (TOF-ERDA). The goal of the experiment is to test the reproducibility of the concentration and thickness quantification with two different ion beams: 18 MeV and 20 MeV . Our results show very good agreement between the depth profiles obtained with both beams, which confirm the top-down transformation of the layers. The elemental loss was evaluated in the samples, showing that N and H are sensitive to beam damage, while O and Zn remain stable. This loss needs to be considered to obtain more accurate quantification of the atomic content in the layers.

Comprehensive study on the impact of A-site cation engineering on crystallite growth, strain, and defect dynamics in lead bromide perovskite nanostructures and thin films

Making waves: The ecological risk illusion-chemical tools are not final arbiters.

First cluster of relapsing fever compatible with louse-borne transmission in southern Saudi Arabia: An eight-case series from Najran.

To assess how resin cement viscosity and thickness influence the static shear bond strength (s-SBS) of adhesively bonded lithium disilicate ceramic. Cylindrical lithium disilicate samples were prepared and randomly assigned to four experimental groups (n = 10), based on two factors: resin cement thickness (thin ≈50 µm or thick ≈150 µm) and viscosity (high or low). A tri-layer configuration (ceramic-resin cement-ceramic) was used, with standardized ceramic discs obtained from CAD/CAM blocks. The bonding ceramic surfaces were etched with hydrofluoric acid, silanized, and a defined bonding area (≈6 mm2) was delimited using adhesive tape. The resin cement thickness was controlled by applying either one (thin) or three (thick) overlapping layers of adhesive tape. Resin cement was applied, and assemblies were seated under a 100 g static load. After light-curing, specimens were subjected to static shear bond strength testing (s-SBS) using a universal testing machine (crosshead speed: 1 mm/min; load cell: 1 kN). Failure mode was classified under stereomicroscopy, and representative samples were analysed under SEM. Additional specimens were used to confirm cement layer thickness using a profilometer. For the thick resin cement layer (≈150 µm), viscosity significantly influenced bond strength, with high-viscosity cement showing higher mean values (27.36 MPa) compared to the low-viscosity cement (19.65 MPa). In contrast, resin cement viscosity did not affect the bond strength in the thin layer condition (≈50 µm). Most specimens exhibited adhesive failure at the ceramic-cement interface. Resin cement selection based on viscosity is particularly relevant when a thick cement layer is anticipated, whereas for ideal, thin cement films, viscosity is a less consequential factor for interfacial bond strength.