Filtern
Dokumenttyp
Sprache
- Englisch (4)
Schlagworte
- EDX (2)
- Ionic liquids (2)
- Reference material (2)
- Auger electron spectroscopy (1)
- CRM (1)
- Crystallinity (1)
- Depth profiling (1)
- Fluorine (1)
- Line scan (1)
- Low energy (1)
Energy-dispersive X-ray spectrometry (EDX) is one of the most applied methods used for the analysis of the chemical composition of solids and thin films. Recent progress in EDS (Energy Dispersive X-ray Spectrometer) technology has increased the general performance also in the energy range < 1 keV addressing low Z elements. Suitable test materials to be employed especially to check the low-energy EDS performance – also in line with ISO 15632 - are rather limited and mainly based on C K and F K lines. In order to obtain valid results in laboratories accredited in compliance with ISO/IEC 17025 it is necessary to periodically check the instrument performance.
Ionic liquids (ILs) are proposed as simple and efficient test materials to evaluate the performance of energy dispersive X-ray spectrometers (EDS) in the low energy range below 1 keV. By only one measurement, C Kα, N Kα, O Kα, and F Kα X-ray lines can be excited. Additionally, the S Kα line at 2.3 keV and, particularly, the S L series at 149 eV complete the picture with X-ray lines offered by the selected ILs. The well-known (certifiable) elemental composition of the ILs selected in the present study can be used to check the accuracy of results produced with the available EDS quantification routines in the low energy range, simultaneously, for several low atomic number elements. A comparison with other reference materials in use for testing the performance of EDS in the low energy range is included.
Analytical routines for a comprehensive in-depth morphological, structural, and chemical characterization of functionalized TiO2 films by using different state-of-the-art analytical techniques are presented and discussed with the main objective to identify potential reference TiO2 coating parameters able to be certified at a later stage. TiO2 films fabricated by two different synthetic procedures as representative for two main large-scale applications were selected: (i) pulsed d.c. magnetron sputtering for photocatalytic applications and (ii) screen printing from preformed anatase nanoparticles. The screen-printed films were further loaded with a sensitizing dye for application as a dye-sensitized solar cell. Film properties such as microstructure and crystallographic texture of pulsed d.c. magnetron sputtering synthesized films were systematically studied by means of scanning nanobeam electron diffraction in a transmission electron microscope and the surface and inner morphology by scanning electron microscopy. The dye distribution over the depth of screen-printed TiO2 layers was analyzed before and after dye-loading by means of energy dispersive X-ray spectroscopy at scanning electronmicroscope, Auger electron spectroscopy and time-of-flight secondary ion mass spectrometry. The long-term goal of the present study is the improvement of quality of the TiO2 film parameters as measured by using different types of reference TiO2 coatings having specific parameters certified.
Hydrothermal synthesis of anatase TiO2 nanosheets with a high fraction of exposed {001} facets and related high photocatalytic activity - as an alternative to bipyramidal anatase TiO2 nanoparticles mainly exposing the {101} facets. The scope of the material preparation work is the thermal reduction of residual fluorides from HF (capping agent) induced during the synthesis of TiO2 nanosheets by calcination at 873K. The analytical task consists of detection and localization of fluorine present at the surface and/or in the bulk of TiO2 nanosheets before and after calcination by SEM/EDX, Auger electron spectroscopy and ToF-SIMS.