TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Rackwitz, Vanessa A1 - Reuter, Dirk T1 - X-ray scattering and its benefits for X-ray spectrometry at the SEM PY - 2009 DO - https://doi.org/10.1017/S1431927609094392 SN - 1431-9276 SN - 1435-8115 VL - 15 IS - Suppl. 2 SP - 1122 EP - 1123 PB - Cambridge University Press CY - New York, NY AN - OPUS4-19792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Salge, T. A1 - Terborg, R. A1 - Rackwitz, Vanessa T1 - Advanced elemental analysis with ED-EPMA, WD-EPMA and mu-XRF at a SEM N2 - It is a latent wish of any SEM/EDS (scanning electron microscope with an energy dispersive spectrometer) analyst to “see more” of the analyzed specimen, i.e. to improve the existing analytical figures of merit. One key issue are the relatively poor limits of detection (not below 0.1 mass-%) provided by energy dispersive X-ray spectrometry (EDX) with the conventional electron excitation (ED-EPMA). This is a consequence of relatively low peak-to-background ratios and reduced energy resolution when compared to wavelength dispersive spectrometry (WD-EPMA). Recent technological developments make possible to equip the SEM with a wavelength dispersive spectrometer (WDS), so that significantly better energy resolution can be attained. Also a relative new product that can be easily attached to a SEM/EDS system is a micro-focus X-ray source. Hence, it is possible to perform (micro-focus) X-ray fluorescence spectrometry (μ-XRF) and take advantage of the enhanced peak-to-background ratios (well suited for trace analysis). However, there are also some disadvantages: an increased measurement time and excitation with a high current in the 10s of nA range are usually required for WDS. μ-XRF provides more bulk information and poor limits of detection for light elements. By combining the advantages of these analytical techniques “seeing more” becomes possible. KW - ED-EPMA KW - WD-EPMA KW - (mu-)XRF KW - EDX PY - 2011 DO - https://doi.org/10.1017/S1431927611003874 SN - 1431-9276 SN - 1435-8115 VL - 17 IS - Suppl. 2 SP - 600 EP - 601 PB - Cambridge University Press CY - New York, NY AN - OPUS4-26751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rackwitz, Vanessa A1 - Hodoroaba, Vasile-Dan T1 - An attempt of exploiting the compton-to-rayleigh intensity ratio for improved analysis with muXRF at a SEM KW - X-ray scattering KW - Compton scattering KW - Rayleigh scattering KW - XRF PY - 2012 DO - https://doi.org/10.1017/S1431927612006678 SN - 1431-9276 SN - 1435-8115 VL - 18 IS - Suppl. 2 SP - 964 EP - 965 PB - Cambridge University Press CY - New York, NY AN - OPUS4-26753 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Rackwitz, Vanessa T1 - Prediction of detection limits of micro X-ray fluorescence (muXRF) KW - X-ray scattering KW - Limits of detection KW - Peak-to-background KW - Peak-to-noise KW - XRF KW - Modelling PY - 2012 DO - https://doi.org/10.1017/S1431927612006563 SN - 1431-9276 SN - 1435-8115 VL - 18 IS - Suppl. 2 SP - 942 EP - 943 PB - Cambridge University Press CY - New York, NY AN - OPUS4-26754 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rackwitz, Vanessa A1 - Procop, M. A1 - Hodoroaba, Vasile-Dan T1 - Characterization of polycapillary X-ray semilenses with SEM/EDX 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 - 2010 DO - https://doi.org/10.1017/S1431927610054280 SN - 1431-9276 SN - 1435-8115 VL - 16 IS - Suppl 2 SP - 932 EP - 933 PB - Cambridge University Press CY - New York, NY AN - OPUS4-27219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Rackwitz, Vanessa A1 - Reuter, Dirk T1 - Micro-focus X-ray fluorescence (mu-XRF) as an extension of the analytical SEM KW - mu-XRF KW - SEM KW - EDS PY - 2010 DO - https://doi.org/10.1017/S1431927610054115 SN - 1431-9276 SN - 1435-8115 VL - 16 IS - Suppl. 2 SP - 904 EP - 905 PB - Cambridge University Press CY - New York, NY AN - OPUS4-27220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rackwitz, Vanessa A1 - Warrikhoff, A. A1 - Hodoroaba, Vasile-Dan T1 - Accurate determination of small spot X-ray tube spectra by means of direct measurement in a calibrated instrumental setup N2 - A calibrated instrumental setup was specially developed for the purposes of accurate measurements of absolute X-ray spectra emitted by modern micro-focus, low-power X-ray tubes. By knowing all the instrumental parameters the spectra measured with the 16 m long setup are recalculated into emitted X-ray tube spectra in photons per eV per msr per nA per s. KW - X-ray tube KW - Calibration KW - Absolute X-ray spectrum KW - Setup PY - 2014 DO - https://doi.org/10.1039/c3ja50353d SN - 0267-9477 SN - 1364-5544 VL - 29 IS - 3 SP - 458 EP - 463 PB - Royal Society of Chemistry CY - London AN - OPUS4-30196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Procop, M. A1 - Rackwitz, Vanessa T1 - Check and specification of the performance of EDS systems attached to the SEM by means of a new test material EDS-TM002 and an updated evaluation software package EDS spectrometer test - Version 3.4. N2 - Four years ago BAM has made available via its webshop a test material, EDS-TM001, as well as an accompanying software package, "EDX spectrometer check", to be employed by both EDS (energy dispersive spectrometer) users and manufacturers to check and pecify, respectively, the performance of an EDS. KW - EDS detector KW - EDX KW - Test material KW - EDS-TM002 KW - EDS performance test KW - Software PY - 2013 DO - https://doi.org/10.1017/S1431927613008271 SN - 1431-9276 SN - 1435-8115 VL - 19 IS - Suppl. 2 SP - 1256 EP - 1257 PB - Cambridge University Press CY - New York, NY AN - OPUS4-29421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rackwitz, Vanessa A1 - Krumrey, M. A1 - Laubis, C. A1 - Scholze, F. A1 - Hodoroaba, Vasile-Dan T1 - New reference and test materials for the characterization of energy dispersive X-ray spectrometers at scanning electron microscopes N2 - Checking the performance of energy dispersive X-ray spectrometers as well as validation of the results obtained with energy dispersive X-ray spectrometry (EDX) at a scanning electron microscope (SEM) involve the use of (certified) reference and dedicated test materials. This paper gives an overview on the test materials mostly employed by SEM/EDX users and accredited laboratories as well as on those recommended in international standards. The new BAM reference material EDS-CRM, which is currently in the process of certification, is specifically designed for the characterization of EDS systems at a SEM through calibration of the spectrometer efficiency in analytical laboratories in a simple manner. The certification of the spectra by means of a reference EDS is described. The focus is on the traceability of EDS efficiency which is ensured by measurements of the absolute detection efficiency of silicon drift detectors (SDD) and Si(Li) detectors at the laboratory of the PTB using the electron storage ring BESSY II as a primary X-ray source standard. A new test material in development at BAM for testing the performance of an EDS in the energy range below 1 keV is also briefly presented. KW - EDX KW - EDS KW - Performance check KW - SEM KW - Test materials KW - Spectrometer efficiency PY - 2015 DO - https://doi.org/10.1007/s00216-014-8242-5 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 11 SP - 3045 EP - 3053 PB - Springer CY - Berlin AN - OPUS4-33025 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Rackwitz, Vanessa T1 - Gaining improved chemical composition by exploitation of compton-to-rayleigh intensity ratio in XRF analysis N2 - The high specificity of the coherent (Rayleigh), as well as incoherent (Compton) X-ray scattering to the mean atomic number of a specimen to be analyzed by X-ray fluorescence (XRF), is exploited to gain more information on the chemical composition. Concretely, the evaluation of the Compton-to-Rayleigh intensity ratio from XRF spectra and its relation to the average atomic number of reference materials via a calibration curve can reveal valuable information on the elemental composition complementary to that obtained from the reference-free XRF analysis. Particularly for matrices of lower mean atomic numbers, the sensitivity of the approach is so high that it can be easily distinguished between specimens of mean atomic numbers differing from each other by 0.1. Hence, the content of light elements which are “invisible” for XRF, particularly hydrogen, or of heavier impurities/additives in light materials can be calculated 'by difference' from the scattering calibration curve. The excellent agreement between such an experimental, empirical calibration curve and a synthetically generated one, on the basis of a reliable physical model for the X-ray scattering, is also demonstrated. Thus, the feasibility of the approach for given experimental conditions and particular analytical questions can be tested prior to experiments with reference materials. For the present work a microfocus X-ray source attached on an SEM/EDX (scanning electron microscopy/energy dispersive X-ray spectroscopy) system was used so that the Compton-to-Rayleigh intensity ratio could be acquired with EDX spectral data for improved analysis of the elemental composition. PY - 2014 DO - https://doi.org/10.1021/ac5000619 SN - 0003-2700 SN - 1520-6882 VL - 86 IS - 14 SP - 6858 EP - 6864 PB - American Chemical Society CY - Washington, DC AN - OPUS4-31179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -