Chemical and electrochemical synthesis of platinum black

We present electrochemical and chemical synthesis of platinum black at room temperature in aqueous and non-aqueous media. X-ray analysis established the purity and crystalline nature. The electron micrographs indicate that the nanostructures consist of platinum crystals that interconnect to form porous assemblies. Additionally, the electron micrographs of the platinum black thin layer, which was electrochemically deposited on different metallic and semiconductive substrates (aluminium, platinum, silver, gold, tin-cooper alloy, indium-tin-oxide, stainless steel, and copper), indicate that the substrate influences its porous features but not its absorbance characteristics. The platinum black exhibited a broad absorbance and low reflectance in the ultraviolet, visible, and infrared regions. These characteristics make this material suitable for use as a high-temperature resistant absorber layer for the fabrication of microelectronics

Hierarchically guided in situ nanolaminography for the visualisation of damage nucleation in alloy sheets

Hierarchical guidance is developed for three-dimensional (3D) nanoscale X-ray imaging, enabling identification, refinement, and tracking of regions of interest (ROIs) within specimens considerably exceeding the field of view. This opens up new possibilities for in situ investigations. Experimentally, the approach takes advantage of rapid multiscale measurements based on magnified projection microscopy featuring continuous zoom capabilities. Immediate and continuous feedback on the subsequent experimental progress is enabled by suitable on-the-fly data processing. For this, by theoretical justification and experimental validation, so-called quasi-particle phase-retrieval is generalised to conical-beam conditions, being key for sufficiently fast computation without significant loss of imaging quality and resolution compared to common approaches for holographic microscopy. Exploiting 3D laminography, particularly suited for imaging of ROIs in laterally extended plate-like samples, the potential of hierarchical guidance is demonstrated by the in situ investigation of damage nucleation inside alloy sheets under engineering-relevant boundary conditions, providing novel insight into the nanoscale morphological development of void and particle clusters under mechanical load. Combined with digital volume correlation, we study deformation kinematics with unprecedented spatial resolution. Correlation of mesoscale (i.e. strain fields) and nanoscale (i.e. particle cracking) evolution opens new routes for the understanding of damage nucleation within sheet materials with application-relevant dimensions

Optical Assets of In situ Electro-assembled Platinum Black Nanolayers

Abstract Optoelectronic technology has been increasingly driven towards miniaturization. In this regard, maintaining the optical properties of the bulk materials while reducing their size is a critical need. How thin must the film be to preserve the bulk material´s optical absorbance and reflectance characteristics? This is the central question for our study of the in situ electro-assembly broad band optical absorber films of platinum in non-aqueous solution of PtCl4. By reducing the in situ constructed film to sub-visible-wavelength thicknesses, the measured reflectance in the region from the ultraviolet to the infrared remained close to that exhibited by the micrometre-width films. These platinum black films broadly absorb electromagnetic waves at a sub-incident-wavelength thickness owing to their plasmonically increased absorbance cross-section. Simulation of various incident energy electron trajectories gives insights into the electron depth through the porous platinum black of ρ = 1.6 g/cm3 and previews the optical behaviour close to the atomic thickness

The MASCOT Radiometer MARA for the Hayabusa 2 Mission

The MASCOT radiometer MARA is a multi-spectral instrument which measures net radiative flux in six wavelength bands. MARA uses thermopile sensors as sensing elements, and the net flux between the instrument and the surface in the 18∘ field of view is determined by evaluating the thermoelectric potential between the sensors’ absorbing surface and the thermopile’s cold-junction. MARA houses 4 bandpass channels in the spectral range of 5.5–7, 8–9.5, 9.5–11.5, and 13.5–15.5 μm, as well as one long-pass channel, which is sensitive in the >3 μm range. In addition, one channel is similar to that used by the Hayabusa 2 orbiter thermal mapper, which uses a wavelength range of 8–12 μm. The primary science objective of the MARA instrument it the determination of the target asteroid’s surface brightness temperature, from which surface thermal inertia can be derived. In addition, the spectral bandpass channels will be used to estimate the spectral slope of the surface in the thermal infrared wavelength range. The instrument has been calibrated using a cavity blackbody, and the temperature uncertainty is 1 K in the long pass channel for target temperatures of >173 K. Measurement uncertainty in the spectral bandpasses is 1 K for target temperatures above 273 K

Toward high-throughput chip calorimetry by use of segmented-flow technology

•Chip calorimeters with sample transport in segmented flow.•Analysis of the signal dynamics under segmented-flow conditions.•Suppression of biofouling in the flow channel.•Heat production of spheroids.•Heat production of human hair follicles. The adaptation of segmented-flow technology to flow-through calorimetry was demonstrated by different kinds of newly designed chip calorimeters useful for liquids and suspensions as well as for solid samples. In segmented-flow technology, sample material is suspended in aqueous segments of nano- or microliter volume and transported by a water-immiscible carrier liquid. The analysis of the signal dynamics given by segmented samples in flow led to optimal settings of flow rate and sample volume for maximal throughput. For 12μL sample segments, a cycle time of 4min could be achieved. The protection of the measuring chamber of the calorimeters against biofouling caused by the water-immiscible carrier liquid was verified for segmented bacterial samples. The unique possibility to measure solid and aggregated samples in flow-through was demonstrated by the investigation of human hair follicles and fibroblast spheroids