TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Depth profilling of layered samples by Glow Discharge Optical Emission Spectroscopy (GD-OES) T2 - AIST-BAM Symposium on Material Surface Technology in TWIN Institute Programme; AIST Tsukuba Research Centre CY - Tsukuba, Japan DA - 2003-02-18 PY - 2003 AN - OPUS4-4325 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Survey on the Suitability of Coatings Containing Hydrogen as Lyared CRM for GDS T2 - Colloquium Spectroscopicum Internationale (CSI XXXIII) CY - Granada, Spain DA - 2003-09-07 PY - 2003 AN - OPUS4-5005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rackwitz, Vanessa A1 - Procop, M. A1 - Bjeoumikhova, S. A1 - Panne, Ulrich A1 - Hodoroaba, Vasile-Dan T1 - A routine procedure for the characterisation of polycapillary X-ray semi-lenses in prallelising mode with SEM/EDS N2 - The accurate knowledge of the properties of polycapillary X-ray semi-lenses has a significant influence on the quantitative results in a widespread field of applications involving microfocus X-ray beams. A routine procedure for the characterisation of a polycapillary X-ray semi-lens with a scanning electron microscope (SEM) having attached an energy dispersive spectrometer (EDS) is presented in this paper. A key issue of the procedure consists of fitting the semi-lens in front of the EDS for spectra acquisition. Relevant semi-lens parameters such as focal distance, full width at half maximum (FWHM) of the acceptance area, and transmission are determined in parallelising mode of the semi-lens. Special attention has been paid to the calculation of the transmission. KW - Polycapillary X-ray optics KW - Semi-lens KW - Parallelising mode KW - SEM KW - EDS KW - Acceptance area KW - FWHM KW - Transmission KW - Focal distance KW - XRF PY - 2011 DO - https://doi.org/10.1039/c0ja00135j SN - 0267-9477 SN - 1364-5544 VL - 26 IS - 3 SP - 499 EP - 504 PB - Royal Society of Chemistry CY - London AN - OPUS4-23555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rades, Steffi A1 - Hodoroaba, Vasile-Dan A1 - Ortel, Erik A1 - Wirth, Thomas A1 - Borghetti, P. A1 - Garcia, S. A1 - Gómez, E. A1 - Blanco, M. A1 - Alberto, Gabriele A1 - Martra, G. T1 - Organic surface modification and analysis of titania nanoparticles for self-assembly in multiple layers N2 - Parameters of TiO2 coatings can greatly influence their final performance in largescale applications such as photocatalytic measurements, orthopedic and/or dental prostheses, cell cultures, and dye-sensitized solar cells. From different film deposition procedures, self-assembly of TiO2 NPs in multiple layers was selected for systematic characterization. EDX, AES and ToF-SIMS analysis have been carried out in order to evaluate the functionalization of several types of TiO2 NPs differing in size, shape and surface area. KW - TiO2 KW - Nanoparticles KW - Surface modification KW - Functionalization PY - 2017 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/organic-surface-modification-and-analysis-of-titania-nanoparticles-for-selfassembly-in-multiple-layers/66776A4CA7FD059CE39041A99A922D90 DO - https://doi.org/10.1017/S1431927617010029 SN - 1431-9276 SN - 1435-8115 VL - 23 IS - S1 (July) SP - 1872 EP - 1873 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-42457 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan A1 - Bjeoumikhov, A. A1 - Wedell, R. A1 - Warrikhoff, A. T1 - Improvements of the low-energy performance of a micro-focus x-ray source for XRF analysis with the SEM N2 - X-ray Fluorescence (XRF) with a scanning electron microscope (SEM) is a valuable completion of the analytical capabilities of SEMs. Small and compact micro-focus x-ray sources are mounted to the microscope chamber, and the x-ray spectra are monitored with conventional EDS systems. Up to now the x-ray tubes used for the micro-focus x-ray sources are equipped with beryllium windows about 100 µm thick. The poly-capillary x-ray lenses have their transmission maximum at photon energies around 10 keV. It drops down in both low- and high-energy ranges. Hence, L-radiation from an Mo or Rh target will be strongly attenuated, and the excitation of fluorescence in the soft x-ray range becomes very ineffective. A new micro-focus x-ray source was developed. It is characterised by a lower self-absorption in the tube target, thin beryllium windows and an x-ray optics having a large distance between its foci and the maximum of transmission at about 5 keV. Thus K line fluorescence of light elements becomes effectively excited by the L-radiation from Mo or Rh tube targets. The detection limit for sodium oxide in glass was found to be below 1 mass%. KW - Micro-focus-XRF KW - X-ray tube KW - X-ray optics KW - SEM PY - 2009 DO - https://doi.org/10.1002/xrs.1159 SN - 0049-8246 VL - 38 IS - 4 SP - 308 EP - 311 PB - Wiley CY - Chichester AN - OPUS4-19583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terborg, R. A1 - Hodoroaba, Vasile-Dan A1 - Falke, M. A1 - Käppel, A. T1 - On the characterization of the geometrical collection efficiency of modern EDS systems N2 - To compare the performance of different energy dispersive X-ray spectrometers (EDS), it is important to define characteristic spectrometer parameters. The ISO 15632 standard defines parameters like energy resolution as FWHM for the Kα lines of carbon, fluorine and manganese. The quantum efficiency, which is the ratio of the detected photons divided by the number of incoming photons for different energies, is another significant spectrometer property. It is important for the light element and low energy line detection sensitivity as well as for higher photon energies above 10 keV. A striking EDS feature, provided and marketed by many manufactures, is the active area of the detector, although actually, the solid angle available for photon collection is the more relevant geometrical parameter. It is defined as: Ω = A /r2 with A being the active area of a spherical detector and r being the distance between the point of the radiation origin and the center of the surface of the active detector chip. A more accurate calculation should be used for large flat detector areas. One should note that the solid angle Ω is not an intrinsic spectrometer property. It can only be defined for a specific detector in combination with a specific system (e.g. SEM, EPMA or TEM). Thus, the minimal possible distance r is determined by the particular geometry e.g. a possible interference with the pole piece or other detectors/components in the chamber of a microscope. New EDS technologies use e.g. integrated SDD chips or inclined chips in thinner detector fingers which can be placed closer to the sample with the final result of larger real solid angles. Therefore, the knowledge of the real solid angle is one of the crucial parameters of an EDS microscope combination. A straightforward way to estimate the real solid angle is to simply determine A and r. If respective data are not provided by the manufacturer, this approach can be difficult. KW - EDS KW - EDX KW - Geometrical collection efficiency KW - Solid angle PY - 2014 DO - https://doi.org/10.1017/S1431927614007454 SN - 1431-9276 SN - 1435-8115 VL - 20 IS - Suppl. S 3 SP - 1144 EP - 1145 PB - Cambridge University Press CY - New York, NY AN - OPUS4-31388 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Uncertainties in Secondary Fluorescence Correction in EPMA N2 - Secondary fluorescence is an inevitable effect that has to be taken into account in any algorithm for quantitative electron probe microanalysis (EPMA) as an additional correction. Moreover, secondary fluorescence worsens spatial resolution of EPMA, as discussed once more in two recent papers. Secondary fluorescence is excited both by characteristic radiation and by the X-ray continuum. In most cases the correction is small. There are, however, cases, e.g. the determination of low heavy metal concentration in a light matrix, where the contribution of secondary fluorescence exceeds 10% of the measured X-ray line intensity. For secondary fluorescence correction the measured X-ray line intensity has to be divided by the correction factor (1+I_flchar/I_p +I_flcont/I_p )≈(1+I_flchar/I_p )(1+I_flcont/I_p ) in order to get those intensity I_p, which is excited only by the primary electrons and enables the determination of specimen composition. I_flchar and I_flcont mean the calculated characteristic and continuums fluorescence intensities. In order to get the intensity of fluorescence radiation, the absorption of the exciting radiation in the specimen, the photoionization probability and the self-absorption of the emitted line must be calculated. This can be performed in a straightforward way. The critical quantity is the X-ray yield of the exciting atoms in case of fluorescence by characteristic radiation and the bremsstrahlung yield of the specimen in case of continuum fluorescence. In the former case it is reasonable to apply the same physical model to calculate I_flchar and I_p. T2 - Microscopy & Microanalysis 2019 CY - Portland, OR, USA DA - 03.08.2019 KW - EPMA KW - Secondary fluorescence KW - Uncertainties KW - X-ray spectrometry KW - Fluorescence correction PY - 2019 AN - OPUS4-48673 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - New reference material candidates for traceable size measurement of non-spherical nanoparticles N2 - New model nanoparticles with well-controlled shape were synthesized within the EMPIR project nPSize - Improved traceability chain of nanoparticle size measurements. Their systematic characterization takes place by the traceable methods scanning/transmission electron microscopy, atomic force microscopy and small angle X-ray scattering. Following reference nanoparticle candidates are under investigation with respect to their homogeneity and stability: titania nanoplatelets (10-15 nm x 50-100 nm), titania bipyramides (~60 nm x 40 nm), titania acicular particles (100 nm x 15-20 nm; aspect ratio 5.5/6), gold nanorods (~10 nm x 30 nm), and gold nanocubes (~55 nm x 55 nm x 55 nm). T2 - HyMET Workshop on optical surface analysis methods for nanostructured layers CY - Berlin, Germany DA - 10.10.2019 KW - Nanoparticles KW - Reference materials KW - Traceability KW - Particle size distribution PY - 2019 AN - OPUS4-49285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Hoffmann, V. A1 - Steers, E.B.M. A1 - Griepentrog, Michael A1 - Dück, Alexander A1 - Beck, Uwe T1 - Round Robin exercise: Coated materials for glow discharge spectroscopy N2 - A Round Robin (RR) exercise on selected coated materials has been carried out with the aim of finding the optimal conditions for the analysis of nitride layers with GD-OES. Such pre-normative work is necessary for the evaluation of parallel development of the production of nitride layers as certified reference materials (CRMs). Two types of samples, Ti–N layer and V–N layer, respectively, with chemical compositions close to stoichiometry and a thickness of ~3 µm, deposited on a steel substrate, have been provided to the RR participants. Additionally, another type of sample, a (100 nm CrNi/100 nm Cu) multilayer (ML) stack deposited on silicon wafer has also been included in the RR. This sample can be used as a CRM for checking GD spectrometer conditions and it has been proved helpful in further development of GDS instrumentation and methodology. The RR exercise has been performed in the frame of the EC Thematic Network on Glow Discharge Spectroscopy for Spectrochemical Analysis (‘GDS-Net’). KW - Coated/Layered Reference Materials KW - Nitrides KW - Multilayer KW - GDS KW - Round Robin PY - 2006 DO - https://doi.org/10.1039/B513426A SN - 0267-9477 SN - 1364-5544 VL - 21 IS - 1 SP - 74 EP - 81 PB - Royal Society of Chemistry CY - London AN - OPUS4-11762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shimizu, K. A1 - Habaki, H. A1 - Wirth, Thomas A1 - Hodoroaba, Vasile-Dan T1 - New Development of Surface Analysis from a Standpoint of Users (1)DS"rf-GDOES" responding to needs for short time, high accuracy, diversified regions, and low cost KW - Atomic beam spectroscopy KW - Emission analysis KW - Cathode sputtering KW - Emission spectroscopy PY - 2004 SN - 0452-2834 VL - 52 IS - 8 SP - 72 EP - 75 PB - Nikkan kogyo shinbunsha CY - Tokyo AN - OPUS4-14523 LA - jpn AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Characterization of nanoparticles by means of high-resolution SEM/EDS T2 - EMAS 2015 - 14th European Workshop on Modern Developments and applications in microbeam analysis CY - Portoroz, Slovenia DA - 2015-05-03 PY - 2015 AN - OPUS4-33250 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -