A combined laser-induced damage threshold (LIDT) measurement routine is presented specifically for optics, which are subject of further optimization to nanosecond fusion laser optics. By extending a raster scan method with an R(S)-on-1 routine that has a last intact spot damage criterion, not only the current LIDT limited by the most critical defect is measured but also up to the intrinsic LIDT of the coating. This demonstrates how existing routines can be combined to distinguish between a defect-driven and an intrinsic damage threshold. During coating optimization studies, this allows to correlate specific coating process parameters directly to their influence on both the defect-driven and the intrinsic LIDT of the coating. A high-quality in situ microscopic imaging during the measurement routine is essential for the precise LIDT evaluation, and combined with high-precision ex situ measurement techniques, it allows an even more detailed investigation of participating damage mechanisms. An exemplary cross-sectional microstructure damage analysis showed that observed changes in color can be linked to a local delamination of the coatings top layer and a change in reflectivity.

This study experimentally investigates electrical characteristics and degradation phenomena in polycrystalline zinc oxide thin-film transistors (ZnO-TFTs). ZnO-TFTs with Al2O3 gate dielectric, Al-doped ZnO (AZO) source-drain contacts, and AZO gate electrode are fabricated using remote plasma-enhanced atomic layer deposition at a maximum process temperature of 190 degrees C. We employ positive bias stress (PBS), negative bias stress (NBS), and endurance cycling measurements to evaluate the ZnO-TFT performance and examine carrier dynamics at the channel-dielectric interface and at grain boundaries in the polycrystalline channel. DC transfer measurements yield a threshold voltage of -5.95 V, a field-effect mobility of 53.5 cm(2)/(Vs), a subthreshold swing of 136 mV dec(-1), and an on-/off-current ratio above 10(9). PBS and NBS measurements, analysed using stretched-exponential fitting, reveal the dynamics of carrier trapping and de-trapping between the channel layer and the gate insulator. Carrier de-trapping time is 88 s under NBS at -15 V, compared to 1856 s trapping time under PBS at +15 V. Endurance tests across 10(9) cycles assess switching characteristics and temporal changes in ZnO-TFTs, focusing on threshold voltage and field-effect mobility. The threshold voltage shift observed during endurance cycling is similar to that of NBS due to the contrast in carrier trapping/de-trapping time. A measured mobility hysteresis of 19% between the forward and reverse measurement directions suggests grain boundary effects mediated by the applied gate bias. These findings underscore the electrical resilience of polycrystalline ZnO-TFTs and the aptitude for 3D heterogeneous integration applications.

Optical components for laser applications face increasing requirements on long-term and high-power stability. Understanding the root causes of damage is crucial for further improvements. The benefits of in-depth microstructure analysis are illustrated using selected results.

Electron-energy-loss spectroscopy (EELS) with an electron microscope and X-ray absorption spectroscopy (XAS) with a synchrotron are techniques for material characterization, both of which are based on exciting core electrons. Both techniques have a similar energy resolution, but while the spatial resolution of EELS can drop to atomic scales, the spatial resolution of XAS is typically limited to micrometer scales. Yet, XAS is commonly the preferred technique for analysis of the extended fine structure of ionization edges, mainly thanks to the excellent signal-to-noise ratio and the large range of ionization energies (from similar to 5 to similar to 40 keV) that can be probed at synchrotron end stations. In contrast, EELS is traditionally limited to ionization energies of less than or similar to 2 keV because electrons in the beam that lose more than 2 keV will be too distant from the operating energy of the electron microscope. Chromatic effects in the postsample lenses allow only some of such energy-loss electrons to reach the EELS detector, as the latter electrons will either suffer from being strongly defocused or will not make it to the detector at all. In this paper, we present results from our novel Iliad EELS spectrometer, which offers a greatly increased range of ionization energies up to 30 keV. We achieve this vast increase by carefully controlling the optics of our electron microscope and carefully matching the optics of our EELS spectrometer to it, such that all the chromatic effects are removed or compensated. We exemplify its performance by recording EELS nearedge fine structure (ELNES) of the Zr L-edges at 2.3 keV, extended fine structure EELS (EXELFS) of Cu K-edge at similar to 9 keV, and EELS of the Mo K-edge at 20 keV and Sb K-edge at similar to 30 keV. We benchmark our data against near-edge and extended fine structure X-ray absorption (XANES and EXAFS) data, and we quantitatively analyze the Cu K-edge EXELFS, demonstrating the capability to determine elementspecific bond lengths and to distinguish different oxidation states such as metallic Cu, Cu2O, or CuO on a submicrometer scale.

A combination of XRD, solid-state NMR and state-of-the-art imaging techniques were used to investigate how the calcium orthophosphate/calcium silicate ratio affects the crystallisation of bioactive glasses in the system SiO2-P2O5-CaO-CaF2. In the phosphate-free glass, xonotlite, wollastonite and cuspidine crystallised. From 2.4 mol% P2O5, fluorapatite also formed, while the amount of wollastonite decreased. Crystallisation tendency was low for low phosphate contents, while above 3 mol% P2O5 it increased. The phosphate-free glass showed a volume crystallisation mechanism with constant activation energy. By contrast, the glass with the largest phosphate to silicate ratio showed both volume and surface crystallisation, causing a pronounced decrease in activation energy with crystallisation degree. This work shows that by changing the phosphate/silicate ratio we can determine which crystal phases form, obtaining for example fluorapatite-free or wollastonite-free glass-ceramics, depending on the desired application and properties such as mechanical strength or activity in contact with physiological solutions.

We report on the source-drain contact improvement in zinc oxide thin-film transistors (ZnO-TFTs) using Al-doped ZnO (AZO) intermediary layers by a thermal atomic layer deposition (ALD) process. This plasma-free method enables optimization of the AZO atomic ratio (Al:Zn) to improve contact resistance. In this study, Al:Zn is modulated between 1.0-5.0% using ALD and confirmed by energy-dispersive X-ray spectroscopy. AZO intermediary contacts are measured electrically using both linear transfer-length method (TLM) structures and integrated at the source-drain regions of ZnO-TFTs. These measurements show that the 20 nm AZO intermediary contact reduces TLM contact resistance compared to direct contact between Al metal and ZnO. Al:Zn ratios between 1.5% and 3.0% yield TFTs with switching characteristics. ZnO-TFTs with a 2.5% AZO intermediary layer exhibit the most favorable electrical characteristics with a contact resistance of 140 Ω/μm, sub-threshold swing of 130 mV/dec, on/off-current ratio of 1.9×10 9 , a threshold voltage of -6.81 V, hysteresis of 10 mV, and field-effect mobility of 44.8 cm 2 /(V·s). These measurements suggest that 2.5% AZO is the most effective Al:Zn ratio for intermediary contact layers in ZnO-TFTs.

The influence of MgO content on the structural characteristics and performance of bimetallic Co–Ni catalyst was investigated for CO2 reforming of CH4. Three different catalysts with the same amount of active metals (Co and Ni) but different Mg loading in the Mg–Al support were prepared by co-precipitation method. The catalysts were subjected to different characterization techniques to obtain information about their bulk, structural, textural properties, site formation and performance for DRM. Results showed there was reduction in the surface area (N2 adsorption), a change from a single bulk phase spinel to dual-phase (XRD), and an increase in the degree of spinel inversion (Al-NMR) from 0.29 to 0.57, as the MgO loading changed from 25% to 65% in the support. There was also improved support basicity (CO2-TPD), metal support interaction changed (STEM EDX), the ease of metal reduction and site formation (Ni/Co K-edge XANES) became better as the MgO loading increased. Improved MgO loading facilitated the formation of inverse spinel and MgO - Ni/Co solid phase, which enhanced better reactants conversion and faster conversion of deposited carbon from the catalysts surface during DRM.

This publisher’s note reports corrections in Appl. Opt. 63, 1641 (2024)APOPAI0003-693510.1364/AO.515083.

A-Si/SiO 2 nanolaminates are deposited by magnetron sputtering and show a decreasing absorption when the a-Si single-layer thickness is reduced from 2.4nm to 0.7nm. Moreover, an increase of the Tauc band gap by 0.18eV is measured. Experimental Tauc band gaps are compared to calculated effective band gaps, utilizing a numerical Schrödinger solver. Further, it is demonstrated that the refractive index can be controlled by adjusting the a-Si and SiO 2 single-layer thicknesses in the nanolaminates. The nanolaminates are optically characterized by spectroscopic ellipsometry, transmittance, and reflectance measurements. Additionally, TEM images reveal uniform, well-separated layers, and EDX measurements show the silicon and oxygen distribution in the nanolaminates.

A glass with the composition 7.9 Li2O center dot 2.0 MgO center dot 1.4 ZnO center dot 10 Al2O3 center dot 2.7 B2O3 center dot 72.6 SiO2 center dot 0.9 ZrO2 center dot 2.1 TiO2 center dot 0.4 Sb2O3 was thermally treated at temperatures in the range from 650 to 750 degrees C. During thermal treatment, at first, nearly spherical Zr1-xTixO4 crystals with sizes of 5-20 nm were formed. On these nanocrystals, elongated particles consisting of TiO2 were observed to grow. Subsequently hexagonal beta-quartz solid solution was formed at temperatures >= 650 degrees C. In this beta-quartz solid solution, Zn as well as Mg and excess Al were incorporated. At temperatures >690 degrees C, the formation of tetragonal beta-spodumene solid solution was observed. In the microstructure of the formed glass-ceramics, a volume concentration of around 12% spherical aggregates with a diameter of 1.5-2 mu m composed of beta-spodumene solid solution and areas enriched in Al and Zn occur. These heterogenous structures were formed by the transformation of beta-quartz solid solutions to beta-spodumene solid solution. At the same time, Zn(Mg) and excess Al were expelled from the aluminosilicate phase and a cubic spinel type phase Zn(Mg)Al2O4 was formed. These aggregates did not contain a glassy phase. In-between these spherical aggregates, i.e. in around 88% of the volume, tiny Zr1-xTixO4 crystals, aluminosilicate crystals with diameters of around 200 nm, and a glass phase shoved away by these growing crystals consisting of oxides of Mg, Zn, Al, Si, and Sb happened to occur.

Glasses with the base composition 60 SiO2·37 B2O3·3 Na2O (in mol%) were doped with different concentrations of terbium oxide. These glasses show phase separation in borate-rich droplets surrounded by a silicate matrix. By means of scanning transmission electron microscopic analyses including energy dispersive X-ray spectroscopy, structural changes during phase separation are investigated, focusing mainly on the local sites of the luminescent ions. Moreover, phase separation structures of as cast and heat-treated glasses are characterized regarding droplet shape and size, as well as size distribution. The luminescence properties of the phase separated glasses are correlated with their nano- and microstructure. Already in the glass with the lowest Tb3+ concentration, the local environments in which the Tb3+ ions reside in could be identified. This early clustering of the luminescent ions remains undetected in fluorescence lifetime measurements. Only in the time-resolved fluorescence measurement of the glass with the highest Tb3+ concentration, which contains very large Tb-rich agglomerates, an indication of clustering is found. Since clustering of rare earth ions can be detrimental to the performance of an optical material, early detection is beneficial. The studies show that high-resolution transmission electron microscopy can assist with this concern.

The present work deals with the fabrication of Ti-6Al-4V in situ alloyed with 3.5 wt.% Cu (Ti-6Al-4V-3.5Cu), its microstructural evolution, and its related tensile properties. Specimens with a relative density of 99 +/- 0.1% presented a microstructure that differed from that of pure Ti-6Al-4V in LPBF, which usually exhibits a fully martensitic structure (alpha '). In Ti-6Al-4V-3.5Cu, apart from alpha-Ti, beta-Ti, and intermetallic Ti2Cu were also observed, generated by in situ martensite decomposition. Initially solidified large columnar beta-Ti grains underwent a martensitic transformation to alpha '. Cyclic reheating caused by layer-wise deposition during LPBF enabled the diffusion of Cu and V, allowing the transformation of alpha ' to stable alpha-Ti and the precipitation of beta-Ti and Ti2Cu. The alpha ' decomposition and formation of beta-Ti and Ti2Cu contributed to an UTS of 1362 +/- 14 MPa and an Rp0.2 of 1313 +/- 14 MPa in the horizontal specimen orientation in the as-built state. The elongation at fracture was 3.9 +/- 0.6%. In the vertical orientation, the specimens exhibited an UTS of 1305 +/- 19 MPa, an Rp0.2 of 1215 +/- 23 MPa, and an elongation at fracture of 5.4 +/- 1.5%. Stress-relief annealing reduced the UTS and Rp0.2 to 1099 +/- 6 MPa and 1014 +/- 5 MPa, respectively, with an increase in elongation at fracture to 6.7 +/- 0.4% in the horizontal specimen orientation. In the vertical specimen orientation, stress relief annealing resulted in an UTS of 1051 +/- 13 MPa and an Rp0.2 of 926 +/- 18 MPa. The elongation at fracture was increased to 11.3 +/- 1.3%.

The influence of MgO content on the characteristics and conduct of bimetal Co-Ni catalytic agent was investigated for Dry reforming reaction (DRM). Three different series of catalysts with same amount of active metals (Nickel and Cobalt), but different loading of Magnesium in the MgAl support was prepared using co-precipitation method. The catalysts were subjected to different characterization techniques to obtain information about their textural, bulk, surface properties, ease of metal reduction and site formation. Results showed a considerable variation in these properties of the catalysts as the MgO loading increases from 25% to 65% in the support. There was reduction in the surface area (N 2 adsorption), a change from a single bulk phase spinel to dual phase (XRD), and an increased in the degree of spinel inversion (Al-NMR) as the MgO loading changed. There was also improved support basicity (CO 2 -TPD), metal support interaction changed (STEM EDX), and the ease of metal reduction and site formation (Ni/Co K-edge XANES) became better as the MgO loading increased from 25% to 65%. All these results translated to different catalytic performance for DRM, including the ease of deposited carbon removal from the surface of the catalytic agent.

Noble metals such as Ag can be used as nucleation agents in glass ceramics. In glasses, it is incorporated predominantly as Ag I . At temperatures slightly above the glass transition temperature, T g , Ag I reacts with Sb III to Sb V and metallic Ag. Usually, face-centered cubic Ag particles are nearly spherical and get facetted during crystal growth. By contrast, in the case of BaO/SrO/ZnO/SiO 2 glasses, silver has, in comparison to other noble metals, another significant, yet different effect. It forms metallic particles (hexagonal phase) with plate-like morphology during thermal treatment at 675 °C. In the second step of thermal treatment at 760 °C, this phase most probably expels some metallic Sb, which is oxidized by Sb V (present in the surrounding glass phase) to Sb III . As a result, the plate-like morphology is maintained and a crystalline shell around the metallic core is formed, mainly consisting of ZnO with some SiO 2 and antimony oxide, as proved by scanning transmission electron microscopy combined with energy-dispersive X-ray spectroscopy. This shell triggers the volume crystallization of Ba 0.5 Sr 0.5 Zn 2 Si 2 O 7 , a phase with low thermal expansion. By comparison, alloying of Au with Sb does not occur according to the phase diagram. Instead, a thermal treatment at temperatures slightly above T g leads to nanocrystalline, spherical Au particles. Hence, alloying and subsequent decomposition of the alloy is a prerequisite for the formation of plate-like noble metal particles.

Nowadays, coating development and understanding of failure patterns on ophthalmic lens coatings requires state-of-the-art microstructure diagnostics. The potential of different methods (SEM-FIB, ToF-SIMS, HR-(S)TEM) is evaluated and illustrated using selected results.