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Bioimaging mass spectrometric techniques allow direct mapping of metal and biomolecule distributions with high spatial resolution in biological tissue. In this study laser ablation inductively coupled plasma mass spectrometly (IA-ICPMS) was used for imaging of transition metals (Fe, Cu, Zn, Mn, and Ti), alkali and alkaline-earth metals (Na, K, Mg, and Ca, respectively), and selected nomnetals (such as C, P, and S) in native ciyosections of mouse heart. The metal and nonmetal images clearly illustrated the shape and the anatomy of the samples. Zinc and copper were inhomogeneously distributed with average concentrations of 26 and 11 pg g-1, respectively. Titanium and manganese were detected at concentrations reaching 1 and 2 μg g-1, respectively. The highest regional metal concentration of 360 μg g-1 was observed for iron in blood present in the lumen of the aorta. Secondary ion mass spectrometzy (SIMS) as an elemental and biomolecular mass spectrometric technique was employed for imaging of Na, K, and selected biomolecules (e.g., phosphocholine, choline, cholesterol) in adjacent sections. Here, two different bioimaging techniques, LA-ICPMS and SIMS, were combined for the first time, yielding novel information on both elemental and biomolecular distributions. [ABSTRACT FROM AUTHOR]

Polysilicon (poly-Si) passivating contacts have enabled some of the highest lab-scale crystalline silicon (c-Si) solar cell conversion efficiencies, largely due to their excellent surface passivation quality, which can be aided by means of hydrogenation treatments. One frequently applied method is to use hydrogen-rich capping layers, such as Al2O3 or SiNx, which can provide hydrogen to the poly-Si/SiOx/Si interface upon annealing. In this work, the effect of the deposition conditions of the Al2O3 layers, fabricated by various types of atomic layer deposition (ALD), on the hydrogenation of p+ poly-Si is investigated, and it is compared to the direct passivation of c-Si by the same Al2O3 layers. It is found that excellent hydrogenation of the p+ poly-Si by Al2O3 could be reached by a wide range of ALD conditions, but higher annealing temperatures were required as compared to passivation of c-Si. The different ALD conditions result in Al2O3 layers with varying refractive indices, O/Al ratios, and hydrogen content, although these material properties become highly similar upon annealing. Furthermore, the p+ poly-Si layer appears to act as a reservoir for hydrogen, which alters the hydrogen effusion profiles of the Al2O3 layers. The results show that a wide range of Al2O3 layers are highly suitable for hydrogenation of p+ poly-Si and provide more insight into the hydrogenation process of poly-Si passivating contacts. [ABSTRACT FROM AUTHOR]

The thermal stability of thick (≈4 μm) plasma‐grown hydrogenated amorphous silicon (a‐Si:H) layers on glass upon application of a rather rapid annealing step is investigated. Such films are of interest as precursor layers for laser liquid‐phase crystallized silicon solar cells. However, at least half‐day annealing at T ≈550 °C is considered to be necessary so far to reduce the hydrogen (H) content and thus avoid blistering and peeling during the crystallization process due to H. By varying the deposition conditions of a‐Si:H, layers of rather different thermal stability are fabricated. Changes in the surface morphology of these a‐Si:H layers are investigated using scanning electron microscopy and profilometry measurements. Hydrogen effusion, secondary‐ion mass spectrometry (SIMS) depth profiling, and Raman spectroscopy measurements are also carried out. In summary, amorphous silicon precursor layers are fabricated that can be heated within 30 min to a temperature of 550 °C without peeling and major surface morphological changes. Successful laser liquid‐phase crystallization of such material is demonstrated. The physical nature of a‐Si:H material stability/instability upon application of rapid heating is studied. [ABSTRACT FROM AUTHOR]

Electroforming effects on the composition, structure, and electrical resistance of Pt/TiO2/Pt switching cells are investigated. The correlation between the electroforming procedure and the resulting bipolar switching behavior is discussed. The dependence of electroforming behavior on atmosphere is also identified, from which we define symmetric or asymmetric electroforming. The symmetry of electroforming is a key factor determining the resulting bipolar switching characteristics. From the experimental results we suggest a possible mechanism for electroforming in Pt/TiO2/Pt in terms of the formation of oxygen gas and vacancies in the vicinity of the anode. [ABSTRACT FROM AUTHOR]

Double layers of deuterated and hydrogenated amorphous silicon (a‐Si:H) on glass are heated in the ambient by scanning with a green (532 nm) continuous wave laser. The hydrogen diffusion length in the laser spot is obtained from the deuterium (D)–hydrogen (H) interdiffusion measured by secondary ion mass spectrometry (SIMS), the temperature in the laser spot is obtained by calculation. Under certain conditions, detachment of the deuterated layer from the hydrogenated layer is observed in the SIMS depth profiles, visible by rising oxygen and carbon signals at the D/H interface attributed to in‐diffusion of atmospheric gas species like water vapor, oxygen, and carbon oxide. Stacks involving both undoped and boron‐doped a‐Si:H films show disintegration. The results suggest that the parameters leading to the disintegration effects are the presence of a plane of reduced material cohesion at the D/H interface, a sizeable H diffusion length and a rather high heating rate. Herein, it is likely considered that the observed layer disintegration process is involved in the peeling of a‐Si:H films upon fast heating. Furthermore, the results show that rapid laser heating can be used to detect planes of reduced material cohesion which may compromise the electronic properties of a‐Si:H‐based stacks. [ABSTRACT FROM AUTHOR]

Rapid thermal annealing by, e.g., laser scanning of hydrogenated amorphous silicon (a-Si:H) films is of interest for device improvement and for development of new device structures for solar cell and large area display application. For well controlled annealing of such multilayers, precise knowledge of temperature and/or hydrogen diffusion length in the heated material is required but unavailable so far. In this study, we explore the use of deuterium (D) and hydrogen (H) interdiffusion during laser scanning (employing a continuous wave laser at 532 nm wavelength) to characterize both quantities. The evaluation of temperature from hydrogen diffusion data requires knowledge of the high temperature (T > 500 °C) deuterium-hydrogen (D-H) interdiffusion Arrhenius parameters for which, however, no experimental data exist. Using data based on recent model considerations, we find for laser scanning of single films on glass substrates a broad scale agreement with experimental temperature data obtained by measuring the silicon melting point and with calculated data using a physical model as well as published work. Since D-H interdiffusion measures hydrogen diffusion length and temperature within the silicon films by a memory effect, the method is capable of determining both quantities precisely also in multilayer structures, as is demonstrated for films underneath metal contacts. Several applications are discussed. Employing literature data of laser-induced temperature rise, laser scanning is used to measure the H diffusion coefficient at T > 500 °C in a-Si:H. The model-based high temperature hydrogen diffusion parameters are confirmed with important implications for the understanding of hydrogen diffusion in the amorphous silicon material. [ABSTRACT FROM AUTHOR]

Due to the increasing number of applications for ceramic components in reactive etching processes, the interest in the specific erosion behavior of highly etch‐resistant materials like yttrium oxide (Y2O3) has increased in the past years. Despite the large number of investigations already existing in this field, a more general understanding of the erosion mechanisms still lacks due to the limited comparability of these investigations. The huge difference in the kind of etching setups, processing parameters (bias voltage and plasma gas composition), and sample microstructures prevented consistent conclusions so far. To achieve a more general understanding, this study investigates the erosion behavior Y2O3 under a broad spectrum of plasma etching parameters. Therefore, the bias voltage is increased from 50 to 300 V and the plasma gas composition is gradually changed from Ar‐rich to CF4‐rich compositions. This systematic approach allows to directly correlate the morphology changes caused by plasma erosion with the related plasma etching parameters and enables to better understand their influence on the depth of physical and chemical interactions, surface damage, and etching rate. We discovered three distinct erosion regimes, which exhibit specific erosion characteristics. Using these observations, a schematic processing map for Y2O3 was developed, which could help to estimate the severity of the erosion attack dependent on the processing parameters. [ABSTRACT FROM AUTHOR]

A combined macroscopic and microanalytical approach was applied on two distinct barite samples from Ra uptake batch experiments using time of flight-secondary ion mass spectrometry (ToF-SIMS) and detailed scanning electron microscopy (SEM) investigations. The experiments were set up at near to equilibrium conditions to distinguish between two possible scenarios for the uptake of Ra by already existent barite: (1) formation of a Ba1-xRaxSO4 solid solution surface layer on the barite or (2) a complete recrystallization, leading to homogeneous Ba1-xRaxSO4 crystals. It could be clearly shown that Ra uptake in all barite particles analyzed within this study is not limited to the surface but extends to the entire solid. For most grains a homogeneous distribution of Ra could be determined, indicating a complete recrystallization of barite into a Ba1-xRaxSO4 solid solution. The maxima of the Ra/Ba intensity ratio distribution histograms calculated from ToF-SIMS are identical with the expected Ra/Ba ratios calculated from mass balance assuming a complete recrystallization. In addition, the role of Ra during the recrystallization of barite was examined via detailed SEM investigations. Depending on the type of barite used, an additional coarsening effect or a strong formation of oriented aggregates was observed compared to blank samples without Ra. In conclusion, the addition of Ra to a barite at close to equilibrium conditions has a major impact on the system leading to a fast re-equilibration of the solid to a Ba1-x Rax SO4 solid solution and visible effects on the particle size distribution, even at room temperature. [ABSTRACT FROM AUTHOR]

Lateral exchange of water and nutrients between xylem and surrounding tissues helps to de-couple uptake from utilization in all parts of a plant. We studied the dynamics of these exchanges, using stable isotope tracers for water (H218O), magnesium (26Mg), potassium (41K) and calcium (44Ca) delivered via a cut stem for various periods to the transpiration stream of bean shoots ( Phaseolus vulgaris cv. Fardenlosa Shiny). Tracers were subsequently mapped in stem cross-sections with cryo-secondary ion mass spectrometry. The water tracer equilibrated within minutes across the entire cross-section. In contrast, the nutrient tracers showed a very heterogeneous exchange between xylem vessels and the different stem tissues, even after 4 h. Dynamics of nutrients in the tissues revealed a fast and extensive exchange of nutrients in the xylem parenchyma, with, for example, calcium being completely replaced by tracer in less than 5 min. Dilution of potassium tracer during its 30 s transit in xylem sap through the stem showed that potassium concentration was up-regulated over many hours, to the extent that some of it was probably supplied by phloem recirculation from the shoot. [ABSTRACT FROM AUTHOR]

Fluxes of mineral nutrients in the xylem are strongly influenced by interactions with the surrounding stem tissues and are probably regulated by them. Toward a mechanistic understanding of these interactions, we applied stable isotope tracers of magnesium, potassium, and calcium continuously to the transpiration stream of cut bean (Phaseolus vulgaris) shoots to study their radial exchange at the cell and tissue level with stem tissues between pith and phloem. For isotope localization, we combined sample preparation with secondary ion mass spectrometry in a completely cryogenic workflow. After 20 mm of application, tracers were readily detectable to various degrees in all tissues. The xylem parenchyma near the vessels exchanged freely with the vessels, its nutrient elements reaching a steady state of strong exchange with elements in the vessels within 20 mm, mainly via apoplastic pathways. A slow exchange between vessels and cambium and phloem suggested that they are separated from the xylem, parenchyma, and pith, possibly by an apoplastic barrier to diffusion for nutrients (as for carbohydrates). There was little difference in these distributions when tracers were applied directly to intact xylem via a microcapillary, suggesting that xylem tension had little effect on radial exchange of these nutrients and that their movement was mainly diffusive. [ABSTRACT FROM AUTHOR]

Abstract: GaInPSb bulk and superlattice layers have been grown by metal organic vapour phase epitaxy (MOVPE) at low growth temperatures on exact and misorientated InP substrates. Optical and structural studies of the properties of the material reveal that phase separation plays an important role in the growth of this alloy, which is indicated by very broad linewidths in low-temperature photoluminescence (PL) measurements. To explain this behaviour simple miscibility gap calculations for the materials GaInPSb, GaInAsSb and GaInAsP have been performed using the regular solution model. A comparative growth analysis of GaInAsP, GaInPSb bulk and InPSb, GaInAsSb and GaAsSb superlattice structures showed that just the phosphorus- and antimony-containing alloys exhibited the broad low temperature (4K) PL linewidths (FWHM) of about 50–100meV. So it can be assumed that due to the large difference in binding energies phosphorus-containing antimonides require much more effort for good crystal quality than equal arsenical alloys. [Copyright &y& Elsevier]

A new approach to trace the transport routes of macronutrients in plants at the level of cells and tissues and to measure their elemental distributions, was developed for investigating the dynamics and structure-function relationships of transport processes. Stem samples from Phaseolus vulgaris were used as a test system. Shock freezing and cryo-preparation were combined in a cryogenic chain with cryo-time-of-flight secondary ion mass spectrometry (cryo-T0F-SIMS) for element and isotope-specific imaging. Cryo-scanning electron microscopy (cryo-SEM) was integrated into the cryogenic workflow to assess the quality of structural preservation. We evaluated the capability of these techniques to monitor transport pathways and processes in xylem and associated tissues using supplementary sodium (Na) and tracers for potassium (K), rubidium (Rb), and 41K added to the transpiration stream. Cryo-T0F-SIMS imaging produced detailed mappings of water, K, calcium, magnesium, the K tracers, and Na without quantification. Lateral resolutions ranged from 10 μm in survey mappings and at high mass resolution to approximately 1 μm in high lateral resolution imaging in reduced areas and at lower mass resolution. The tracers Rb and 41K, as well as Na, were imaged with high sensitivity in xylem vessels and surrounding tissues. The isotope signature of the stable isotope tracer was utilized for relative quantification of the 41K tracer as a fraction of total K at the single pixel level. Cryo-SEM confirmed that tissue structures had been preserved with subcellular detail throughout all procedures. Overlays of cryo-ToF-SIMS images onto the corresponding SEM images allowed detailed correlation of nutrient images with subcellular structures. [ABSTRACT FROM AUTHOR]

We compared the resistive switching performance of barium strontium titanate (BST) thin films with tungsten (W) and platinum (Pt) top electrodes, respectively. The yield, endurance, and reliability were strongly improved for the samples with W top electrode. Whereas the samples with Pt top electrode show a fast drop in the resistance for both high and low resistance states, the devices with W top electrode can be switched for 104 times without any obvious degradation. We attribute the improved switching performance to a reversible oxidation and reduction in a WOx layer at the W-BST interface, which was detected by time-of-flight secondary-ion-mass spectroscopy measurements. [ABSTRACT FROM AUTHOR]

• We demonstrate epitaxy of GeSn and SiGeSn alloys for optical applications. • Both semiconductors are combined to form direct bandgap group IV heterostructures. • Multi quantum wells show highest PL efficiency and lowest lasing thresholds. • Wavelength-tunable electroluminescence is demonstrated at room temperature. The recent rise of GeSn-based optically pumped lasers have multiplied the efforts to fabricate a fully CMOS compatible and group IV-based light emitter. Their integration with Si-based electronics may yield heavily reduced power consumption in integrated circuits and pave the way towards new sensing or medical applications. Here, we discuss the epitaxy of group IV GeSn and SiGeSn semiconductors and show their suitability for light emitting applications. Double and multi quantum well heterostructures are evaluated, whereby the latter enables an inherently easier control over the formation of deleterious misfit defects. Consequently, microdisk lasers fabricated from those show greatly enhanced light emission and reduced lasing thresholds. The use of in-situ p-i-n doping schemes allow the formation of light emitting diodes, resulting in electrically-enabled light emission already at room temperature. [ABSTRACT FROM AUTHOR]

Passivation of semiconductor surfaces is crucial to reduce carrier recombination losses and thereby enhance the device performance of solar cells and other semiconductor devices. Thin-film stacks of phosphorus oxide (PO x) and aluminum oxide (Al 2 O 3) have recently been shown to provide excellent passivation of semiconductor surfaces, including crystalline silicon and indium phosphide, and can also be highly interesting for passivation of other semiconductor materials such as Ge and III-V semiconductors. On silicon, the excellent passivation is attributed to the combination of a high positive fixed charge and a very low interface defect density. On InP nanowires, application of the PO x /Al 2 O 3 stacks improves charge carrier lifetime threefold as compared to unpassivated nanowires. In this work, we review and summarize recent results obtained on PO x /Al 2 O 3 stacks for semiconductor surface passivation. Several topics are discussed, including the passivation performance on various semiconductor surfaces, the processing of the PO x and Al 2 O 3 layers, the role of the capping layer, and aspects related to device integration. The PO x /Al 2 O 3 stacks feature some unique properties, including an unusually high positive fixed charge density, a low interface defect density, and can be prepared over a wide deposition temperature range. These unique properties arise in part from the mixing process that occurs between the PO x and Al 2 O 3 layers, which upon post-deposition annealing leads to the formation of AlPO 4. The surface passivation provided by PO x /Al 2 O 3 stacks is highly stable and the stack can be used to conformally coat high-aspect-ratio structures such as nanowires, showing their promise for use in semiconductor devices. [Display omitted] • PO x /Al 2 O 3 stacks provide excellent surface passivation on Si and InP. • PO x /Al 2 O 3 has a unique high positive fixed charge density (1012-1013 cm−2) on Si. • PO x /Al 2 O 3 has low interface defect density down to 1010-1011 eV−1 cm−2 on Si. • The Al 2 O 3 layer mixes with PO x during deposition, leading to AlPO 4 upon annealing. • The surface passivation quality provided by PO x /Al 2 O 3 is stable for over 1000 days. [ABSTRACT FROM AUTHOR]

For the first time a barite sample was investigated by applying electron microscopy and atom probe tomography in a complementary approach to characterize its inner microstructure. Pores covering the size range from a few nanometers to a few micrometers were identified inside particles of a commercially available high purity barite. The barite matrix appeared to be a single crystal. A particular feature of the observed porous structure is a system of layers containing a high number of homogeneously distributed nano-scale pores, alternating with layers containing a limited number of larger pores. High-resolution chemical analyses indicate that the pores contain a solution of water and sodium chloride. The filling of these nano-scale inclusions was interpreted as residua of the initial supersaturated solution used for particle growth by precipitation. These findings explain the high reactivity observed in previous Ra uptake studies on the same type of barite and provide further implications for the interpretation of these results. Our results offer a new analytical approach and necessary reference data for future investigations on changes of the internal barite structure during these Ra uptake experiments. [ABSTRACT FROM AUTHOR]

Homogeneous nickel germanosilicide layers with low sheet resistance have been achieved on highly strained SiGe layers. The layer homogeneity improves with decreasing Ni thickness. Ultrathin Ni layers of 3 nm thermally treated at 400 °C yield to homogeneous germanosilicide layers with a preferential {0 1 0} growth plane and sharp interfaces to the SiGe layer. This is assumed to be energetically driven by lower surface and interface energies due to the increased surface/volume ratio with decreasing layer thickness. The strain in the remaining SiGe layers can be conserved at lower temperatures. However, at higher temperatures, germanosilicidation enhances the strain relaxation. [ABSTRACT FROM AUTHOR]

Si/SiO x multilayer structures with ultra-thin silicon-suboxide layers are fabricated with molecular beam epitaxy. The silicon surface is oxidized during growth interruptions at an oxygen pressure between 1.0×10−7 mbar and 8.0×10−7 mbar. Overgrowth with Si of the oxidized surface is possible for coverages of a few monolayers of O and improves with increasing substrate temperature. X-ray diffraction shows that the silicon layers are single crystalline. Transmission electron microscopy measurements show that the suboxide layers are thick, pseudomorph, and exhibit crystalline order throughout the layer. In addition, transmission electron microscopy shows that the oxygen concentration is laterally inhomogeneous. The multilayer structures are thermally very stable, as rapid thermal annealing up to 1000°C shows no influence on the X-ray diffraction patterns. [ABSTRACT FROM AUTHOR]

Epitaxial Sr1 − xCa xRuO3 thin films were grown on SrTiO3 and LaAlO3 substrates with use of high pressure dc-sputtering. A number of complementary methods: X-ray diffraction (XRD), Rutherford backscattering (RBS), high resolution transmission electron microscopy (HRTEM), time-of-flight secondary ion mass spectrometry (ToF-SIMS), atomic force microscopy (AFM), and X-ray photoemission spectroscopy (XPS) was used to characterize both in-depth and lateral structure features. Fully strained thin films were obtained with a tetragonal lattice cell pronouncedly elongated in an out-of-plane direction, independent on details of deposition conditions. Growth types varied from a single layer-by-layer two-dimensional (2D) mode to three-dimensional (3D) spiral precipitations of different size. Interface layer between the substrate and the thin film as well as its surface suffer from considerable deviations from nominal stoichiometry, basically resulting from Ru deficiency. Samples stored under normal conditions undergo further compositional change of the surface region. The process of aging, extended over several days, involves incorporation of water and carbon dioxide present in an ambient atmosphere and a subsequent surface reconstruction. For samples deposited on SrTiO3 the valence band is indicative of a metallic character of the sample interior regardless of Ca content. The heterogeneous in-depth profile of the thin films is extremely important in fabrication of nanodevices, especially those based on ultrathin layers. [ABSTRACT FROM AUTHOR]

Abstract: In this work we report for the first time on the creation of thermal acceptors after laser irradiation of a phosphorous doped p-type silicon substrate in ambient atmosphere. The concentration of these defects up to 1020 cm−3 is leading to a conductivity change from n- to p-type just beneath the surface. Electrochemical capacitance voltage (ECV) measurements followed by resistivity measurements confirm this conversion of conductivity. Secondary ion mass spectrometry (SIMS) measurements show significant oxygen incorporation after laser irradiation. The comparison of saturation current density and lock-in thermography measurements of processed wafers in ambient and in nitrogen atmosphere reveal that these defects are electrically active recombination centres that disappear in absence of oxygen. In simulations of the temperature profile during laser processing a correlation between the pulse energy density (E P ) and the appearance of thermal acceptors has been observed. The influence of these laser induced acceptor defects on solar cell parameters has been finally investigated. An efficiency loss of 1.3% absolute pertinent to pulse energies usually applied in laser doping process under ambient atmosphere could be avoided by laser processing in nitrogen atmosphere. [Copyright &y& Elsevier]

SiC/SiO x hetero-superlattices as well as single layers of SiC and SiO x were fabricated and annealed at various annealing temperatures to investigate the evolution of annealing induced defects in these materials. We show that in SiC and SiO x materials and in SiC/SiO x multilayer system, crystallization, atomic diffusion, structural reconstruction, and hydrogen effusion take place upon annealing with different characteristic temperature dependences. The dependence of the spin densities on annealing temperature is explained as an overlap of the temperature dependence of the creation of additional dangling bonds due to hydrogen effusion and of the healing of dangling bonds due to element motion during the structural reconstruction. The stronger increase of spin density upon annealing in SiC as compared to SiO1.2 is ascribed to the effusion of a higher amount of hydrogen and the less efficient atomic diffusion up to the annealing temperature of 1050 °C. [ABSTRACT FROM AUTHOR]

Abstract: The SiC/SiOx hetero-superlattice (HSL) consisting of alternating near-stoichiometric SiC barrier layers for the electrical transport and silicon rich SiOx matrix layers for the quantum dot formation is a promising approach to the realization of silicon quantum dot (Si–QD) absorbers for 3rd generation solar cells. However, additional defect states are generated during post deposition annealing needed for the Si–QD formation causing an increase in sub-band gap absorption and a decrease in PL intensity. Proper passivation of excess defects is of major importance for both the optical and electrical properties of the SiC/SiOx HSL Si–QD absorber. In this work, we investigate the effectiveness of the hydrogen reincorporation achieved with hydrogen plasma in a plasma-enhanced chemical vapor deposition (PECVD) reactor, hydrogen dissociation catalysis in hot-wire chemical vapor deposition (HWCVD) reactor and annealing in forming gas atmosphere (FGA). Both the HSL samples and single layer reference samples are tested. The passivation quality of the hydrogen reincorporation was examined by comparing electrical and optical properties measured after deposition, after annealing and after passivation. In addition, the formation of Si–QDs in SiC/SiOx HSL was evaluated using high resolution transmission electron microscopy. We demonstrated that hydrogen can be successfully reincorporated into the annealed HSL sample and its single layer reference samples. FGA passivation is most effective for SiO1.2 single layers and HSL samples. Passivation with PECVD appeared to be only effective for SiC single layers. [Copyright &y& Elsevier]

Abstract: Experiments have been performed to determine the effect of deuterium plasma exposure on mirrors fabricated from Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy (Vitraloy 1, V1) in both the amorphous and crystallized state. It was found that for deuterium ion fluences above ∼2.6×1024 ions/m2, cracks and chips appeared on the surface of the crystallized mirrors. At a factor of two higher fluence, 5.2×1024 ions/m2 of 60eV ions, one specimen disintegrated into many fragments. The mirror specimens kept in the amorphous state, however, were not observed to have experienced any visual changes even after exposure to ion fluences as high as 1.5×1025 ions/m2. The difference in behaviour is explained as being due to hydrogen embrittlement, and differences in hydrogen transport between the two alloy states. [Copyright &y& Elsevier]

• Electrochemical doping of TiO 2 is prone to reductive deposition of contaminations. • Contaminations arise from counter electrode corrosion. • Traces from iridium mixed metal oxide counter electrode likely affect TiO x doping. • TiO x prepared with BDD counter electrode result in superior charge transfer. Defect-engineered or substoichiometric TiO x is of interest for use in photo- and electrocatalytic processes both as active material and catalyst support. Electrochemical doping of TiO 2 via cathodic polarization is an appealing preparation method and frequently employed. Here, we explored the electrochemical preparation of TiO x in an undivided cell using iridium-based (iridium mixed-metal-oxide) and boron doped diamond (BDD) counter electrodes. Cyclic voltammetry and impedance spectroscopy revealed superior charge transfer properties of crystalline TiO x electrodes prepared with BDD (TiO x -BDD). It is shown that the electrochemical properties correlate well with intensities of the H-signals determined using Time of Flight - Secondary Ion Mass Spectrometry (ToF-SIMS). Thus, it is concluded that electrochemical preparation using BDD causes favourable H+ intercalation and/or H diffusion into the sub-surface layers of TiO x. Our extensive analysis using a combination of electrochemical and surface characterization (LEIS and XPS) techniques, additionally suggests that cathodic deposition of Ir, originating from the Ir-based counter electrode, present in sub-ppm concentrations only results in less-efficient doping. Instead in the presence of sub-ppm level Ir contamination hydrogen evolution is favoured during cathodic polarization. The results presented within this study highlight the necessity to use inherently stable counter electrodes for electrochemical preparation and reveal the pronounced influence of trace contamination in electrochemistry in general and the doping mechanism of TiO x electrodes in particular. [ABSTRACT FROM AUTHOR]

Ruthenates represent an attractive field of investigation both due to their physical properties (electric conductivity, superconductivity, magnetism – often unconventional) and for their possible technical applications. The heterogeneous in‐depth profile of the thin films is extremely important in the fabrication of nanodevices, especially those based on ultra‐thin layers. Młynarczyk et al. (pp. 239–254) systematically investigate structural features of epitaxial Sr1 − xCaxRuO3 thin films grown on SrTiO3 and LaAlO3 substrates with the use of high‐pressure dc‐sputtering. The series of samples were characterized with a number of complementary methods: X‐ray diffraction, Rutherford back‐scattering, high‐resolution transmission electron microscopy, time‐of‐flight secondary ion mass spectrometry, atomic force microscopy, and X‐ray photoemission spectroscopy were used to characterize both in‐depth and lateral structure features. Possible applications of Sr1 − xCaxRuO3 thin films are largely determined by their thermal and chemical instability. Excessive process of aging was observed for the samples prepared with high pressure dc‐sputtering stored under normal conditions. Progressive stoichiometry instability at the surface layer in a presence of adsorbates should be noted as it significantly limits potential applications of these thin films. [ABSTRACT FROM AUTHOR]