The functionality of surfaces is dependent on two characteristic properties: surface topography and chemical composition. For instance, the secondary electron yield (SEY) of metal surfaces can be adjusted by surface nanostructures or by altering the surface composition. In this study, the two concepts are combined in a one-step process. Reactive Laser ablation based nanostructuring of copper surfaces in a carbon-containing atmosphere was performed, which results in the formation of a metal-particle carbon composite layer. Copper was irradiated with IR ps laser radiation (lambda = 1030 nm, Delta tp = 10 ps, frep = 100 kHz, Phi acc = 2300 J/cm2) in an acetylene atmosphere. The process results in the production of a nanostructured surface with a significant carbon content. The resultant maximum SEY (delta max) depends on the treatment parameters and on the storage time of the copper surface in air after the laser treatment process. The delta max of the laser treated copper surface was 1.2 after two weeks storage and increased to 1.4 after one year storage, while an electron conditioning (electron energy: 250 eV, electron dose: 3 & sdot;10-2C/mm2) after the one year allows delta max reduction down to 0.61. The results show that besides the topography the chemical composition plays an important role for the resulting SEY. In particular, the modification induced by electron conditioning results in a chemical reduction of the carbon-oxide bonds.

Masking of thin films and bulk materials is traditionally applied for the transfer of micron patterns into the functional material according to the requirements of the application. For optical purposes, lithographically produced micron patterns are transferred by plasma/ion etching, which is a traditional technology in microelectronics and other micron technologies. However, pattern transfer by atmospheric pressure plasma etching can help to save time and cost for a future sustainable production. Therefore, the pattern transfer of lithographic resist masks into fused silica using atmospheric pressure reactive plasma jets (APPJ) was studied as a new approach of micropatterning. First the etch rates of the potential masking materials, e.g. photoresists, as well as of fused silica as substrate are studied in dependence on the APPJ etching parameters, in particular on the gas composition (O-2/CF4) and the dwell time of the APPJ tool's footprint. Typical etch rates of the masking materials are in the range of 140 to 370 nms(-1) whereas the fused silica has a rate of 25 to 80 nms(-1). The surface morphology of masking materials changes during etching and features additional nanoscale roughness and waviness. The surface roughness of the etched masking materials and the fused silica are 2 to 5 nm rms and 1.5 nm rms for etch depths of similar to 3000 nm and similar to 600 nm, respectively. Finally, the pattern transfer by APPJ of a diffraction grating with a period of 15 mu m, depth of 230 nm and a roughness below 2 nm rms into fused silica was demonstrated.

Process stability and reproducibility are indispensable for the high-precision production of optical components using reactive ion beam etching. The influence of residual water on the etching mechanism of SiO2, Si and a photo resist has been investigated using the feed gas mixture of CHF3 and O2 with a radio-frequency broad beam ion source. Removal rates were determined for all materials at different water background pressures and etching yields were calculated using current density measurements of the ion beam. The composition of the reactive ion beam was investigated at three water background pressures using energy selective mass spectrometry. The composition of the near-surface was analyzed using two complementary techniques: time-of-flight mass spectrometry and X-ray photoelectron spectroscopy. A steady state oxygen-containing hydrocarbon and Si(OF) layer is found to form during reactive ion beam processing. A correlation is identified with the ion beam composition, whereby the composition and thickness of this layer is dependent on the water background pressure. Consequently, the etching yields and selectivities for the investigated materials are systematically altered. The technological consequences for reactive ion beam etching are discussed.

c -Axis oriented Sb 2 Te 3 thin films and GeTe–Sb 2 Te 3 superlattices by a fast pulsed laser deposition procedure at ≤150 °C involving an Sb 2 Te 3 seed layer.

Deposition of epitaxial oxide semiconductor films using physical vapor deposition methods requires a detailed understanding of the role of energetic particles to control and optimize the film properties. In the present study, Ga2O3 thin films are heteroepitaxially grown on Al2O3(0001) substrates using oxygen ion beam sputter deposition. The influence of the following relevant process parameters on the properties of the thin films is investigated: substrate temperature, oxygen background pressure, energy of primary ions, ion beam current, and sputtering geometry. The kinetic energy distributions of ions in the film-forming flux are measured using an energy-selective mass spectrometer, and the resulting films are characterized regarding crystalline structure, microstructure, surface roughness, mass density, and growth rate. The energetic impact of film-forming particles on the thin film structure is analyzed, and a noticeable decrease in crystalline quality is observed above the average energy of film-forming Ga+ ions around 40 eV for the films grown at a substrate temperature of 725 °C.

The 2-bit Lindqvist-type polyoxometalate (POM) [V6O13((OCH2)(3)CCH2N3)(2)](2-) with a diamagnetic {V6O19} core and azide termini shows six fully oxidized V-V centers in solution as well as the solid state, according to V-51 NMR spectroscopy. Under UV irradiation, it exhibits reversible switching between its ground S-0 state and the energetically higher lying states in acetonitrile and water solutions. TD-DFT calculations demonstrate that this process is mainly initialized by excitation from the S-0 to S-9 state. Pulse radiolysis transient absorption spectroscopy experiments with a solvated electron point out photochemically induced charge disproportionation of V-V into V-IV and electron communication between the POM molecules via their excited states. The existence of this unique POM-to-POM electron communication is also indicated by X-ray photoelectron spectroscopy (XPS) studies on gold-metalized silicon wafers (Au//SiO2//Si) under ambient conditions. The amount of reduced vanadium centers in the "confined" environment increases substantially after beam irradiation with soft X-rays compared to non-irradiated samples. The excited state of one POM anion seems to give rise to subsequent electron transfer from another POM anion. However, this reaction is prohibited as soon as the relaxed T-1 state of the POM is reached.

The nanostructuring on titanium surfaces is studied by low-energy argon ion irradiation. The surfaces are analysed by EBSD for grain orientation mapping, SEM for surface imaging, WLI and AFM for topography characterization, XPS and ToF-SIMS for chemical surface analysis. Under normal incidence specific nanoripple structures are formed, whereas the morphology is defined by the crystallographic conditions only. A characteristic relation between grain orientation and ripple size is elaborated. Experiments on co-deposition with Al, C, Cu, Fe, and Si indicate that Fe impurities influence nanostructuring. The effect of inclined ion incidence shows an overlay between orientation-dependent and process geometry-related structure formation.

The combined adjustment of the topography and of the chemical surface composition of stainless-steel surfaces allows the fabrication of super hydrophobic surfaces with manifold potential applications. However, the factual usability depends in many cases on the chemical stability of the modified surface. The chemical stability in correlation to Hydrogen peroxide (H2O2) of a two-step modified stainless steel surface was studied. For this purpose, the surface was nanostructured by means of ultrashort pulse lasers and then the laser-treated surface was chemically modified by means of a self-assembled monolayer (SAM). This approach enables the specification of nano/microstructure and chemical composition independent of each other. Various hierarchical micro- and nanostructures can be realized by laser texturing of stainless steel surfaces using infrared picosecond laser radiation. The modified surface with different surface topographies was then stored in 50 % H2O2-water solution and the contact angle was determined as a function of the exposure time. The H2O2 treatment results in a transition from a super hydrophobic to a super hydrophilic surface where the temporal stability of the super hydrophobic properties is dependent on laser-induced surface topography. Surfaces were produced which exhibited super hydrophobic properties for more than 14 days when stored in 50 % H2O2.

We demonstrate the formation of stable monolayers of polyoxometalates on a graphite substrate, which can be electronically multi-level switched and nanostructured without physical contact by the electric field of a scanning tunnelling microscope tip.

Optical elements made of aluminum with surface roughness in the sub-nanometer range are required for applications in the visible (VIS) and ultraviolet (UV) spectral range. Rapidly solidified aluminum (RSA) 501 is an interesting candidate to produce sufficiently smooth surfaces for these applications in an ultra-precision (UP) flycutting process. However, the polycrystalline grain structure and precipitates contained in the material limit the achievable surface roughness. In this research, a reactive ion beam finishing process of RSA 501 is investigated employing an electron cyclotron resonance (ECR)-driven ion source using CF4 and N2 gasses. Emphasis is placed on understanding the etching mechanisms that influence the topographic evolution to provide the basis for future production processes using the material for UV optics. Material composition characterization is applied to analyze the interaction between the reactive ion species and the RSA material. Surface modification transferring the native oxide top layer to an in situ forming and developing aluminum fluoride or -nitride etch front layer is found to prevent grain orientation-dependent etching. The effect of the ion incidence angle on the etch rates of precipitates and bulk material can be used to reduce the height of precipitates protruding from the surface after the UP-machining process. A surface roughness value of Sq = 0.9 nm +/- 0.1 nm (areal root mean square height) is achieved in the micro-roughness range when etching at 40 degrees and 80 degrees angle of incidence using collimated ion beams with CF4 process gas.

Interfacial bonding of three different semi-coherent bcc-Fe(110)/graphene interfaces is investigated using the plane-wave pseudopotential method within density functional theory. The analysis of bond lengths, charge densities, charge transfer, magnetic moments and densities of states shows that interfacial adhesion can be understood from the electronic structure. Graphene is considered on Fe(110) surfaces as well as embedded in (110) planes of bulk Fe. Moreover, the influence of single vacancies in graphene is studied in case of graphene on the Fe(110) surfaces. It is found that a single vacancy in graphene leads to a strong increase of interfacial adhesion. The most important contribution to the adhesion is covalent bonding with hybridization of Fe states and C states which is most pronounced for neighboring atoms of the vacancy.

Gallium oxide thin films were grown by ion beam sputter deposition (IBSD) at room temperature on Si substrates with systematically varied process parameters: primary ion energy, primary ion species (O2+ and Ar+), sputtering geometry (ion incidence angle α and polar emission angle β), and O2 background pressure. No substrate heating was applied because the goal of these experiments was to investigate the impact of the energetic film-forming species on thin film properties. The films were characterized with regard to film thickness, growth rate, crystallinity, surface roughness, mass density, elemental composition and its depth profiles, and optical properties. All films were found to be amorphous with a surface roughness of less than 1 nm. The stoichiometry of the films improved with an increase in the energy of film-forming species. The mass density and the optical properties, including the index of refraction, are correlated and show a dependency on the kinetic energy of the film-forming species. The ranges of IBSD parameters, which are most promising for further improvement of the film quality, are discussed.

Biomass is an alternative energy resource to fossil fuels because of its potential to reduce greenhouse gas emissions. However, ash-related problems are serious obstacles for this development, especially for the use in combustion plants. Thus, design and operation of biomass boilers require detailed understanding of ash transformation reactions during thermochemical conversion. To evaluate ash transformation in silica-rich biomass fuels, rice husk and rice straw were selected because of their abundance, limited utilization conflicts with the food sector, as well as their potential in both energy and material applications. This paper reveals ash transformation mechanisms relevant for the ash melting behaviour of silica-rich biomass fuels considering chemical and phase composition of the ashes. In this regard, several advanced spectroscopic methods and diffractometry were employed to characterize the materials. The ash transformation reactions and the viscosity were simulated using thermodynamic equilibrium calculations and a slag viscosity modeling toolbox. The results illustrate the impact of impurities on the atomic structure of the silica resulting in an altered ash melting behaviour and viscosity of the silica-rich ashes. Chemical water washing, acid leaching, and blending of rice straw with rice husk strongly influenced the chemical composition of the ashes and improved ash melting behaviour. The analysis also revealed the correlation between the crystalline fraction and the porosity in silica-rich biomass ashes, as well as a crystallinity threshold. These findings are highly relevant for future investigations in boiler designs and production of biogenic silica for material applications.

•LIPE enables low-defect machining compared to traditional laser ablation processes.•Little chemical as well as structural defects are formed due to LIP etching.•TEM characterization shows no crystal defects by the etching process.•Increase of reaction layer thickness with an increasing substrate temperature.

Ion beam finishing techniques of aluminium mirrors have a high potential to meet the increasing demands on applications of high-performance mirror devices for visible and ultraviolet spectral range. Reactively driven ion beam machining using oxygen and nitrogen gases enables the direct figure error correction up to 1 μm machining depth while preserving the initial roughness. However, the periodic turning mark structures, which result from preliminary device shaping by single-point diamond turning, often limit the applicability of mirror surfaces in the short-periodic spectral range. Ion beam planarization with the aid of a sacrificial layer is a promising process route for surface smoothing, resulting in successfully reduction of the turning mark structures. A combination with direct surface smoothing to perform a subsequent improvement of the microroughness is presented with a special focus on roughness evolution, chemical composition, and optical surface properties. As a result, an ion beam based process route is suggested, which allows almost to recover the reflective properties and an increased long-term stability of smoothed aluminium surfaces.

Indium tin oxide (ITO) thin films were grown by Ar ion beam sputter deposition under systematic variation of ion energy, geometrical parameters, and O2 background pressure and characterized with regard to the film thickness, growth rate, crystalline structure, surface roughness, mass density, composition, electrical, and optical properties. The growth rate shows an over-cosine, forward-tilted angular distribution with a maximum, which increases with increasing ion energy, increasing ion incidence angle, and decreasing O2 background pressure. ITO films were found to be amorphous with a surface roughness of less than 1 nm. Mass density and composition show only small changes with increasing scattering angle. The electrical resistivity behavior in dependence on the process parameters is complex. It is not only driven by the O2 background pressure but also very much by the scattering angle. The observed behavior can be understood only if competing processes are considered: (i) reduction of the number of oxygen vacancies due to the presence of O2 background gas and (ii) defect generation and preferential sputtering of oxygen at the surface of the growing films due to the impact of high-energy scattered particles. Even though absolute numbers differ, optical characterization suggests a similar systematics.

High-quality, ultra-precise processing of surfaces is of high importance for high-tech industry and requires a good depth control of processing, a low roughness of the machined surface and as little as possible surface and subsurface damage but cannot be realized by laser ablation processes. Contrary, electron/ion beam, plasma processes and dry etching are utilized in microelectronics, optics and photonics. Here, we have demonstrated a laser-induced plasma (LIP) etching of single crystalline germanium by an optically pumped reactive plasma, resulting in high quality etching. A Ti:Sapphire laser (λ = 775 nm, E Pulse/max. = 1 mJ, t = 150 fs, f rep. = 1 kHz) has been used, after focusing with a 60 mm lens, for igniting a temporary plasma in a CF 4 /O 2 gas at near atmospheric pressure. Typical etching rate of approximately ~ 100 nm / min and a surface roughness of less than 11 nm rms were found. The etching results were studied in dependence on laser pulse energy, etching time, and plasma – surface distance. The mechanism of the etching process is expected to be of chemical nature by the formation of volatile products from the chemical reaction of laser plasma activated species with the germanium surface. This proposed laser etching process can provide new processing capabilities of materials for ultra—high precision laser machining of semiconducting materials as can applied for infrared optics machining.

For fabrication of high-performance mirror devices, technical aluminum alloys Al6061 or Al905 are widely used. The surface error topography after manufacturing by single-point diamond turning is applicable in the infrared spectral range. For increasing demands on the optical surface quality in the shortwave visible and ultraviolet spectral range, further improvement of the surface roughness is required. Hence, a promising alternative process to attain the required surface quality is evaluated. Within the ion beam planarization technique, a photoresist layer is deposited by conventional spin coating or spray coating technologies exhibiting an ultrasmooth surface. When removing the resist by reactive ion beam etch (RIBE) processing using nitrogen process gas, the ultrasmooth surface topography of the resist is transferred into the substrate. We optimized the photoresist thermal pretreatment to realize roughness preservation and a steady-state material removal rate during RIBE machining The optimum preparation steps are explored based on roughness evaluation, chemical modification, and etch resistance of the negative photoresist. Reactive ion beam etching-based planarization is conducted on single-point diamond turned RSA Al905 and RSA Al6061 samples made of rapidly solidified aluminum (RSA) in a two-step process. The optimum process and the roughness evaluation are explored by topographic analysis applying a combination of white light interferometry and atomic force microscopy measurements. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License.

Ion beam finishing techniques are commonly used for improvement of surface error topography of optical devices. Optical aluminum surfaces after manufacturing by single-point diamond turning meet the requirements for applications in the infrared spectral range. However, optics used for applications in the short-wavelength visible and ultraviolet spectral range demand improved surface qualities. To overcome the limitations mainly caused by structural and compositional inhomogeneities of aluminum alloys, a reactive ion beam machining process using oxygen and nitrogen operating gas is applied. This technology enables direct surface machining while preserving the initial roughness up to a 1-mu m etching depth using low-energy ion beams. Moreover, the use of oxygen allows us to smooth the surface in the microroughness regime. Based on Monte-Carlo simulations and roughness evolution measured by atomic force microscopy, a more detailed discussion of the ion beam process is presented. Hence, a model scheme for direct smoothing of high-frequency surface features is suggested. (C) 2020 Society of Photo-Optical Instrumentation Engineers (SPIE)

Einrichtungsübergreifende elektronische Patientenakten (eEPA) stellen ein zentrales Element bei der Ausgestaltung von interoperablen medizinischen Versorgungsnetzwerken und Prozessketten dar. Die unterschiedlichen Anforderungen an verfügbare Dienste, Performanz und Qualitätssicherung bei der Kommunikation innerhalb der verschiedenen Sektoren des Gesundheitswesens erfordern für stationäre Leistungserbringer derzeit noch die Partizipation an verschiedenen sicheren Kommunikationsnetzen, die für eine sektorenübergreifende Kommunikation überbrückt werden müssen. Die einrichtungsübergreifenden telemedizinischen Versorgungspfade können dabei über automatisierte Prozessketten unter Nutzung des von der IHE (Integrating the Healthcare Enterprise) Initiative definierten Integrationsprofils CrossEnterprise Document Sharing (XDS) und assoziierter Integrationsprofile sowohl intrasektoral als auch sektorenübergreifend gut abgebildet werden. Die Bereitstellung von medizinischen Dokumenten in einer eEPA außerhalb von definierten Versorgungspfaden erfordert ein differenziertes Berechtigungsmanagement. Consent-Dokumente gemäß IHE APPC (Advanced Patient Privacy Consents)-Profil ermöglichen diesbezüglich die Dokumentation des Patienteneinverständnisses unter Einbeziehung von Informationen über geplante Zugriffsberechtigte, Dokumentenarten, Zeitraum und Art des erlaubten Dokumentenzugriffs. Die Steuerung des Zugriffs auf die medizinische Dokumentation durch den Patienten selbst ist dabei ein wesentlicher Bestandteil der geforderten Patientenzentrierung medizinischer Dienstleistungen. Neue, für den Einsatz auf mobilen Endgeräten optimierte Interoperabilitätsstandards wie FHIR (Fast Healthcare Interoperability Resources) ermöglichen in diesem Zusammenhang perspektivisch eine vereinfachte Bereitstellung von patientenzentrierten Gesundheitsakten und weiteren medizinischen Dienstleistungen auf mobilen Plattformen.