71 research outputs found
Experimental determination of ruthenium L-shell fluorescence yields and Coster-Kronig transition probabilities
The L-shell fluorescence yields and the Coster-Kronig factors of ruthenium
(and the corresponding uncertainty) were determined for the first time
experimentally by applying radiometrically calibrated instrumentation of the
Physikalisch-Technische Bundesanstalt. The resulting fluorescence yields
(, ,
) and the Coster-Kronig factors (,
, ) agree reasonable well with parts of the
data from the literature
qualifying label components for effective biosensing using advanced high throughput seira methodology
The multiplexed SEIRA analysis of antibody-functionalized NP biolabels that can be exploited for specific assay platforms in view of high-performance readout
Grazing incidence X-ray fluorescence of periodic structures – a comparison between X-ray standing waves and geometrical optics calculations
Grazing incidence X-ray fluorescence spectra of nano-scaled periodic line structures were recorded at the four crystal monochromator beamline in the laboratory of the Physikalisch-Technische Bundesanstalt at the synchrotron radiation facility BESSY II. For different tilt angles between the lines and the plane of incidence of the monochromatic synchrotron radiation, spectral features are observed which can be understood and explained with calculations of the emerging X-ray standing wave (XSW) field. On the other hand, there are structures, i.e., pronounced modulations above the substrate's critical angle of external total reflection, which are not included in the XSW concept. Novel geometrical optics calculations can reproduce these structures taking the sample's specific geometric conditions into account
Characterization of sub-monolayer coatings as novel calibration samples for X-ray spectroscopy
With the advent of both modern X-ray fluorescence (XRF) methods and improved
analytical reliability requirements the demand for suitable reference samples
has increased. Especially in nanotechnology with the very low areal mass
depositions, quantification becomes considerably more difficult. However, the
availability of suited reference samples is drastically lower than the demand.
Physical vapor deposition (PVD) techniques have been enhanced significantly in
the last decade driven by the need for extremely precise film parameters in
multilayer production. We have applied those techniques for the development of
layer-like reference samples with mass depositions in the ng-range and well
below. Several types of reference samples were fabricated: multi-elemental
layer and extremely low (sub-monolayer) samples for various applications in XRF
and total-reflection XRF (TXRF) analysis. Those samples were characterized and
compared at three different synchrotron radiation beamlines at the BESSY II
electron storage ring employing the reference-free XRF approach based on
physically calibrated instrumentation. In addition, the homogeneity of the
multi-elemental coatings was checked at the P04 beamline at DESY. The
measurements demonstrate the high precision achieved in the manufacturing
process as well as the versatility of application fields for the presented
reference samples
Comprehensive Comparison of Various Techniques for the Analysis of Elemental Distributions in Thin Films: Additional Techniques
In a recent publication by Abou-Ras et al., various techniques for the analysis of elemental distribution in thin films were compared, using the example of a 2-µm thick Cu(In,Ga)Se2 thin film applied as an absorber material in a solar cell. The authors of this work found that similar relative Ga distributions perpendicular to the substrate across the Cu(In,Ga)Se2 thin film were determined by 18 different techniques, applied on samples from the same identical deposition run. Their spatial and depth resolutions, their measuring speeds, their availabilities, as well as their detection limits were discussed. The present work adds two further techniques to this comparison: laser-induced breakdown spectroscopy and grazing-incidence X-ray fluorescence analysisThe work was supported in part by National Research Foundation of Korea (NRF) grant funded by Korea government (MEST, No. 2013- 064113), by the Spanish MINECO within the Ramón y Cajal programme (RYC-2011- 08521), and by the European Metrology Research Program (EMRP) within the projects IND07 Thin Films and ENG53 ThinErg
Accurate experimental determination of gallium K- and L3-shell XRF fundamental parameters
The fluorescence yield of the K- and L3-shell of gallium was determined using
the radiometrically calibrated (reference-free) X-ray fluorescence
instrumentation at the BESSY II synchrotron radiation facility. Simultaneous
transmission and fluorescence signals from GaSe foils were obtained, resulting
in K- and L3-shell fluorescence yield values consistent with existing database
values(omega_Ga_K=0.515 +- 0.019, omega_Ga_L3=0.013 +- 0.001). For the first
time, these standard combined uncertainties are obtained from a properly
constructed Uncertainty Budget. These K-shell fluorescence yield values support
Bambynek's semi-empirical compilation from 1972: these and other measurements
yield a combined recommended value of omega_Ga_K=0.514 +- 0.010. Using the
measured fluorescence yields together with production yields from reference
Ga-implanted samples where the quantity of implanted Ga was determined at 1.3%
traceable accuracy by Rutherford backscattering spectrometry, the K-shell and
L3-subshell photoionization cross sections at selected incident photon energies
were also determined and compared critically with the standard databases.Comment: 17 pages, 6 figure
Titanium and titanium oxides at the K- and L-edges: validating theoretical calculations of X-ray absorption and X-ray emission spectra with measurements
Using well-calibrated experimental data we validate theoretical X-ray
absorption spectroscopy (XAS) as well as X-ray emission spectroscopy (XES)
calculations for titanium (Ti), titanium oxide (TiO), and titanium dioxide
(TiO) at the Ti K- and L-edges as well as O K-edge. XAS and XES in
combination with a multi-edge approach offer a detailed insight into the
electronic structure of materials since both the occupied and unoccupied
states, are probed. The experimental results are compared with ab initio
calculations from the OCEAN package which uses the Bethe-Salpeter equation
(BSE) approach. Using the same set of input parameters for each compound for
calculations at different edges, the transferability of the OCEAN calculations
across different spectroscopy methods and energy ranges is validated. Thus, the
broad applicability for analysing and interpreting the electronic structure of
materials with the OCEAN package is shown
Complementary methodologies for thin film characterization in one tool – a novel instrument for 450 mm wafers
- …