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We performed spatially resolved synchrotron-induced x-ray fluorescence analyses (SY-XRF) of five silverpoint drawings from the famous `Karlsruhe sketchbook´ and a silverpoint, which is assumed to be an original one used by the Renaissance artist Hans Baldung Grien (1484-1545) himself. The silverpoint, one out of a very small number of ancient styli conserved nowadays, is fixed on the so-called `Karlsruhe sketchbook´. Measurements were executed at the FLUO-TOPO beamline at the electron storage ring ANKA. It has been shown, that SY-XRF at this beamline is nondestructive and sensitive enough for the analysis of minor and major elements in the silver strokes. This study provides new insights into this graphical technique and ancient drawing instruments: results are that three drawings have been created with a common type of silverpoint containing about (10.4 ± 0.7) wt% of Cu. In all the cases, Hg at a 10% level by weight was identified in the strokes. Presence of Hg is not due to the original silver alloy, but is a result of a general alteration phenomenon of silverpoint drawings. This fact is confirmed by the analysis of the original silverpoint, which contains only small traces of Hg. The result for the copper content of the silverpoint (10.4 ± 1.7) wt% is in good agreement with that of these three drawings. It is supposable that the silverpoint found attached today served for the creation of the corresponding drawings. Moreover, the graphical technique of Baldung is found to be continual over three decades. Only one very late drawing dated to 1543 was probably realized with another silverpoint, containing about 3 wt% of Cu. This difference in the chemical composition of drawings from the late period might be used as a more precise dating indicator of Baldung drawings that are not clearly attributed to a certain period.
The color X-ray camera SLcam® is a full-field, single photon detector providing scanning-free, energy and spatially resolved X-ray imaging. Spatial resolution is achieved with the use of polycapillary optics guiding X-ray photons from small regions on a sample to distinct energy dispersive pixels on a charged-coupled device detector. Applying sub-pixel resolution, signals from individual capillary channels can be distinguished. Therefore, the SLcam® spatial resolution, which is normally limited to the pixel size of the charge-coupled device, can be improved to the size of individual polycapillary channels. In this work a new approach to a sub-pixel resolution algorithm comprising photon events also from the pixel centers is proposed. The details of the employed numerical method and several sub-pixel resolution examples are presented and discussed.
In this study the microscopic homogeneity of the newly developed plastic reference materials BAM H001-BAM H010 was investigated. The materials consist of an acrylonitryle-butadien-styrene terpolymer, doped with different amounts of the elements Br, Cd, Cr, Hg and Pb. For the quantitative determination of the degree of homogeneity, a procedure proposed by Kempenaers et al. (Fresenius J. Anal. Chem., 2001, 369, 733-737) was used. On every sample an extensive number of different points were analyzed and standard deviation for every element mentioned above was used to calculate a minimal sampling mass that is necessary to reach a certain level of uncertainty caused by inhomogeneity (mmin,5%). The experiments were taken out with synchrotron µ-XRF (SR µ-XRF) at BESSYII in Berlin and by laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS). The calculated values for mmin,5% of both techniques showed comparable results for all elements. It could be shown that the materials are suitable for calibration of micro analytic techniques if at least 64 µg are used.
This paper is an overview of the work developed by our group in the investigations of museum objects and alluvial gold, reflected in a series of studies published between 2000–2011, supplemented with new results, unpublished up-to-date. The X-ray based spectrometric techniques employed range from various X-Ray Fluorescence (XRF) investigations to ion beam analysis, including synchrotron radiation XRF and micro-Particle Induced X-ray Emission. The gold objects discussed are mainly part of the Sarmizegetusa Dacian hoards—spiraled bracelets (armbands) and coins. After obtaining in 2011 the permission of the Romanian authorities to take very small (1–2 mg) samples from the most 'unimportant' areas of the Dacian bracelets and several Koson staters, to analyze them by micro-SR-XRF at BESSY, in February 2012, the investigation of several micro-areas of 17 stater and 28 bracelet samples revealed important micro-structural inhomogeneity, especially in Sn and Cu. The same inhomogeneous micro-structure has been seen in Transylvanian alluvial gold. The analyses revealed details on the fingerprint of geological gold deposits and also the main characteristics of ancient gold metallurgy procedures used by the Dacians: a relatively low temperature (lower than Au melting point) and hammering during heating to obtain an ingot through sintering. The use of the sintering procedure was proved for the spiraled bracelets and the Koson without monogram coins, a tradition starting in the Bronze Age in Transylvanian gold processing. The existence of micro-inclusions of Ta-minerals in alluvial gold was also detected, explaining Ta trace presence in the artifacts from the Pietroasa hoard.
This work presents a complex evaluation of a series of Geto-Thracian silver adornments found on Romanian territory, part of the 4th century BC Agighiol (Northern Dobruja) hoard and of an ingot from the 1st century BC Geto-Dacian Surcea (Transylvania) hoard, using Synchrotron Radiation X-Ray Fluorescence and micro- Proton Induced X-ray Emission analysis and mapping in order to investigate aspects related to the elemental composition of the metal and the metallurgy implied in their manufacture. One of the samples can be linked to Laurion as the source of metal, and several items contain silver probably originated in Macedonia. The set of silver items was found to be heteregenous as composition and microstructure, and corrosion-related elements could be also identified in the X-Ray maps.
BAM line is multipurpose high-energy beamline. To extend studies of multicomponent alloys using EXAFS we perform own research and user experiments requiring multiedge spectroscopy, high-temperature and chemically aggressive sample environments. Our study of multicomponent alloys and high-entropy alloys open new perspectives in understanding their reactivity, corrosion, phase transformations and local ordering.
Strahlenverfahren in Kombination - ein Werkzeug für Analyse und Zertifizierung von Feststoffen
(2002)
For quantitative SRXRF measurements the angle of incidence of the incoming X-ray beam is an important factor. When the sample is focused by a long-range-microscope, the determination of the angle can be automatized using a simple algorithm. This was developed to improve the orientation of especially round or ornate samples. As a side effect the three dimensional surface can be reconstructed, too.
Synchrotron radiation sources with their unique properties in terms of intensity, polarization and adjustability offer a wide range of possibilities in materials research. A basic introduction about the creation and special properties of synchrotron radiation will be given. Examples of current work at BAMline, the high-energy measuring facility of the Federal Institute for Materials Research and Testing at the synchrotron BESSY, are used to illustrate the possibilities and limitations of existing measuring methods.
Synchrotron-induced X-ray fluorescence (Sy-XRF) analysis was used to study the chemical composition of precious Renaissance silverpoint drawings. Drawings by famous artists such as Albrecht Dürer (14711528) and Jan van Eyck (approximately 13951441) must be investigated non-destructively. Moreover, extremely sensitive synchrotron- or accelerator-based techniques are needed since only small quantities of silver are deposited on the paper. New criteria for attributing these works to a particular artist could be established based on the analysis of the chemical composition of the metal points used. We illustrate how analysis can give new art historical information by means of two case studies. Two particular drawings, one of Albrecht Dürer, showing a profile portrait of his closest friend, Willibald Pirckheimer (1503), and a second one attributed to Jan van Eyck, showing a Portrait of an elderly man, often named Niccolò Albergati, are the object of intense art historical controversy. Both drawings show inscriptions next to the figures. Analyses by Sy-XRF could reveal the same kind of silverpoint for the Pirckheimer portrait and its mysterious Greek inscription, contrary to the drawing by Van Eyck where at least three different metal points were applied. Two different types of silver marks were found in this portrait. Silver containing gold marks were detected in the inscriptions and over-subscriptions. This is the first evidence of the use of gold points for metal point drawings in the Middle Ages.
New analyses of a series of very rare silverpoint drawings that were executed by Rembrandt Harmensz. van Rijn (16061669) which are kept today in the Kupferstichkabinett (Museum of Prints and Drawings) of the State Museums of Berlin are reported here. Analysis of these drawings requires particular attention because the study has to be fully non-destructive and extremely sensitive. The metal alloy on the paper does not exceed some hundreds of µg/cm². Therefore, synchrotron radiation induced X-ray fluorescence (SR-XRF) is together with external micro-proton-induced X-ray emission the only well-suited method for the analyses of metalpoint drawings. In some primary work, about 25 German and Flemish metalpoint drawings were investigated using spatially resolved SR-XRF analysis at the BAMline at BESSY. This study enlarges the existing FrenchGerman database of metalpoint drawings dating from the 15th and 16th centuries, as these Rembrandt drawings originate from the 17th century where this graphical technique was even rarer and already obsolete. It also illustrates how SR-XRF analysis can reinforce art historical assumptions on the dating of drawings and their connection.