Characterization of pottery from the Republic of Macedonia I: Raman analyses of Byzantine glazed pottery excavated from Prilep and Skopje (12th–14th century)

In order to gain some understanding of and to characterize the materials used in Byzantine glazed ceramic finds in the Republic of Macedonia, as well as to obtain information on their manufacturing technology, micro‐Raman spectra of 15 representative glazed shards, all dated from 12th to 14th century, were recorded. The elemental composition of the body and glaze of selected shards was obtained by scanning electron microscopy‐energy dispersive X‐ray spectrometry (SEM‐EDXS). At least 17 different minerals in the ceramic body were identified from the Raman spectra, among which were a variety of feldspars (microcline, albite and sanidine) as well as andradite, apatite and forsterite. According to the identified minerals, locations of the used raw materials in the vicinity of the archaeological sites are proposed. There is a good correlation between the polymerization index derived from the Raman spectra and the lead content obtained from the SEM‐EDXS analyses, therefore the firing temperature of the analyzed glazes could be assessed. The SEM‐EDXS analyses showed the presence of different coloring agents (Cu, Co, Cr, Sb) as well as opacifying (Sb) and fluxing (Pb) agents in the glaze matrix. The content of P₂O₅ in the glaze of one of the shards is also discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Characterization of pottery from Republic of Macedonia II. Raman and infrared analyses of glazed pottery finds from Skopsko Kale

Byzantine and Ottoman pottery shards from Skopsko Kale, Republic of Macedonia (27 samples) were analyzed by infrared (IR) and micro‐Raman spectroscopies. IR spectroscopy provided data for assessing the firing temperature of the ceramic body as well as the basic mineralogical composition, while micro‐Raman spectroscopy was used for studying the glazes as well as for estimating the mineralogical composition of the ceramic body. The firing temperature of the Byzantine pottery was more uniform and ranged between 700 and 800 °C. In the case of the Ottoman pottery, a clear distinction between two different firing temperatures in the samples was made, thereby dividing them into two groups (700–800 and 800–900 °C). According to the previously established relationship between glaze composition and Raman parameters, the glazes in all analyzed samples were found to be lead‐based, with firing temperature below 700 °C. A total of 25 different mineral phases was identified in the body of the ceramics. Some pigments were also identified in the pottery glazes. Oleic acid (oil) and apatite residues (protein?) were identified in one sample. Copyright © 2009 John Wiley & Sons, Ltd.     

Micro‐Raman spectroscopy on analcime and pollucite in comparison to X‐ray diffraction

Natural and synthetic samples of analcime and pollucite (both zeolites belonging to the analcime group) were studied by means of micro‐Raman spectrometry, X‐ray fluorescence analysis (XFA) and X‐ray diffraction (XRD). On knowing the chemical and structural characteristics of each solid‐solution member, the observed shift in the spectral position of the Raman active modes can be explained and used for phase determination. As shown, the distinction between members of the analcime–pollucite solid‐solution series using Raman spectroscopy is significantly more conclusive than the corresponding XRD findings. Also, information about the structurally bound water inside the zeolite structure can be gained using Raman spectroscopy as long as a suitable exciting wavelength is selected. Copyright © 2008 John Wiley & Sons, Ltd.     

High‐throughput synchrotron X‐ray diffraction for combinatorial phase mapping

Discovery of new materials drives the deployment of new technologies. Complex technological requirements demand precisely tailored material functionalities, and materials scientists are driven to search for these new materials in compositionally complex and often non‐equilibrium spaces containing three, four or more elements. The phase behavior of these high‐order composition spaces is mostly unknown and unexplored. High‐throughput methods can offer strategies for efficiently searching complex and multi‐dimensional material genomes for these much needed new materials and can also suggest a processing pathway for synthesizing them. However, high‐throughput structural characterization is still relatively under‐developed for rapid material discovery. Here, a synchrotron X‐ray diffraction and fluorescence experiment for rapid measurement of both X‐ray powder patterns and compositions for an array of samples in a material library is presented. The experiment is capable of measuring more than 5000 samples per day, as demonstrated by the acquisition of high‐quality powder patterns in a bismuth–vanadium–iron oxide composition library. A detailed discussion of the scattering geometry and its ability to be tailored for different material systems is provided, with specific attention given to the characterization of fiber textured thin films. The described prototype facility is capable of meeting the structural characterization needs for the first generation of high‐throughput material genomic searches.     

Simultaneous X‐ray fluorescence and scanning X‐ray diffraction microscopy at the Australian Synchrotron XFM beamline

Owing to its extreme sensitivity, quantitative mapping of elemental distributions via X‐ray fluorescence microscopy (XFM) has become a key microanalytical technique. The recent realisation of scanning X‐ray diffraction microscopy (SXDM) meanwhile provides an avenue for quantitative super‐resolved ultra‐structural visualization. The similarity of their experimental geometries indicates excellent prospects for simultaneous acquisition. Here, in both step‐ and fly‐scanning modes, robust, simultaneous XFM‐SXDM is demonstrated.     

High‐resolution stress mapping of polycrystalline alumina compression using synchrotron X‐ray diffraction

The ability to achieve uniform stress in uniaxial compression tests of polycrystalline alumina is of significance for the calibration of piezospectroscopic coefficients as well as strength studies in ceramics. In this study high‐energy X‐rays were used to capture powder diffraction profiles over a half‐section of a polycrystalline alumina parallelepiped sample under an increasing uniaxial compressive load. The data were converted to strain and results were used for stress mapping of the sample. Stress maps from the study quantify the higher stresses at the sample–platen contact interface and reveal the evolution of the stress distribution in these specimens with load. For the geometry of the samples used, at the center section of the specimen the overall magnitudes of the compressive stresses were found to be 20% higher compared with the average expected theoretical stress based on the applied load and cross‐sectional area. The observed compressive stresses at the corners of the parallelepiped specimen were 62% higher and shear stresses were observed at the specimen interface to the load mechanism. The effects, seen at the interface, can lead to premature failure at these locations and can affect the accuracy of calibration of spectral peaks with stress as well as compression strength measurements. The results provide important information that can be used to establish guidelines on material and geometry considerations in developing compression tests on high‐strength ceramics.     

Identification and spectra–structure determination of soil minerals: Raman study supported by IR spectroscopy and X‐ray powder diffraction

Raman and IR spectroscopy were used for the characterization of several minerals in morphologically similar vertisol sequences from Kiževak (Serbia). It helped us to establish the surface layer transition going from calcic vertisols (containing gypsum and calcite) to calcimagnesic vertisols (containing aragonite, magnesium‐calcite and dolomite) derived from peridotite and serpentinite. The observed band positions are found to be solely characteristic for each carbonate mineral and are used to discuss the main structural features of carbonates and sulfates present in the studied soil. It was found that the dolomite, calcite and aragonite concretions are present in the deepest layer of the soil, whereas the gypsum is found in the topsoil. The identification was confirmed of the carbonates having calcite and aragonite structure, and the representative from the sulfate group (gypsum) was confirmed by X‐ray powder diffraction. Copyright © 2009 John Wiley & Sons, Ltd.     

Microfocus X‐ray scattering and micro‐Raman spectroscopy: Transcrystallinity in isotactic polypropylene

Microfocus X‐ray scattering and micro Raman spectroscopy have been applied to study the β‐transcrystalline morphology in isotactic polypropylene. The transformation from the α‐ to the β‐form through the so‐called bifurcation of growth mechanism has been investigated with high spatial resolution. We found that the mixed α–β region does not present spatial correlation along the shearing direction, implying that there is no cooperative crystallization from the different β‐nucleation centres. In addition, a strong change in the lamellar orientation of the α‐form thin layer that induces the growth of the β‐crystallites has been observed for the first time. Finally, changes in the relative intensities of some selected Raman bands allowed the observation of the α–β transformation process at the molecular level.

     

Object image correction using an X‐ray dynamical diffraction Fraunhofer hologram

Taking into account background correction and using Fourier analysis, a numerical method of an object image correction using an X‐ray dynamical diffraction Fraunhofer hologram is presented. An example of the image correction of a cylindrical beryllium wire is considered. A background correction of second‐order iteration leads to an almost precise reconstruction of the real part of the amplitude transmission coefficient and improves the imaginary part compared with that without a background correction. Using Fourier analysis of the reconstructed transmission coefficient, non‐physical oscillations can be avoided. This method can be applied for the determination of the complex amplitude transmission coefficient of amplitude as well as phase objects, and can be used in X‐ray microscopy.     

Pressure study of monoclinic ReO2 up to 1.2 GPa using X‐ray absorption spectroscopy and X‐ray diffraction

The crystal and local atomic structure of monoclinic ReO₂ (α‐ReO₂) under hydrostatic pressure up to 1.2 GPa was investigated for the first time using both X‐ray absorption spectroscopy and high‐resolution synchrotron X‐ray powder diffraction and a home‐built B₄C anvil pressure cell developed for this purpose. Extended X‐ray absorption fine‐structure (EXAFS) data analysis at pressures from ambient up to 1.2 GPa indicates that there are two distinct Re—Re distances and a distorted ReO₆ octahedron in the α‐ReO₂ structure. X‐ray diffraction analysis at ambient pressure revealed an unambiguous solution for the crystal structure of the α‐phase, demonstrating a modulation of the Re—Re distances. The relatively small portion of the diffraction pattern accessed in the pressure‐dependent measurements does not allow for a detailed study of the crystal structure of α‐ReO₂ under pressure. Nonetheless, a shift and reduction in the (011) Bragg peak intensity between 0.4 and 1.2 GPa is observed, with correlation to a decrease in Re—Re distance modulation, as confirmed by EXAFS analysis in the same pressure range. This behavior reveals that α‐ReO₂ is a possible inner pressure gauge for future experiments up to 1.2 GPa.     

Della Robbia blue glaze: micro‐Raman temperature study and X‐ray fluorescence spectroscopy characterization

Micro‐Raman temperature study and X‐ray fluorescence (XRF) spectroscopy were used for characterization of the blue glaze on Saint John the Baptist—majolica terracotta relief attributed to Andrea Della Robbia and Saint John the Baptist with Cross—majolica terracotta statue attributed to Giovanni Della Robbia. Both objects are on permanent exhibition in the John and Mable Ringling Museum of Art in Sarasota, FL. This study proves that the detection of the 548 cm⁻¹ Raman band alone cannot serve as evidence for presence of lazurite crystallites in the pigment in the glaze. It was established that the famous Della Robbia blue is due to the combined effect of Co Ni Cu Zn atoms and S₃⁻ ions embedded in a lead silicate matrix. It is proposed that the Della Robbia family used Co‐containing sulfide ores as a source for manufacturing their blue pigments. Copyright © 2009 John Wiley & Sons, Ltd.     

An assessment study of tiles from Topkapı Palace Museum with energy‐dispersive X‐ray and Raman spectrometers

A limited number of studies concerning Ottoman ceramic technology have been performed using the scanning electron microscopy‐energy dispersive X‐ray spectrometry and micro‐Raman spectroscopy techniques. The discovery of the ceramics, which were described as ‘Iznik’, at excavation sites outside of the city of Iznik, caused disagreements over the exact origin of Iznik products. In this study, bodies, glazes, and pigments of 46 tile/ceramic shards of unknown origin, which were supplied from the vaults of Topkapı Palace Museum, and two reference tile fragments, known as Kütahya products, supplied from the demolished Surp Krikor Lusavoriç church and, additionally, two Iznik reference tiles were examined using the scanning electron microscopy‐energy dispersive X‐ray spectrometry and micro‐Raman spectroscopy techniques. Results of both techniques were evaluated together for the first time to determine the power of nondestructive Raman spectroscopy technique in differentiation of Ottoman tiles. In this work, bodies of the Kütahya tiles were found to be different than Iznik and Tekfur stone‐paste bodies, which are rich in clay rather than quartz. Two different lead‐alkali glaze compositions were found for Kütahya tiles; one was rich in PbO (over 35%) and the other one was rich in alkali (PbO less than 25%). Barite inclusions were detected in the bodies and in the glazes of some Ottoman tiles, which could be the fingerprint for the Kütahya products. It was found that the under glaze red decoration is essentially a mixture of hematite and quartz in different proportions. Shades of red decoration mainly depend on the amount of hematite in the mixture. Sixteenth century tomato red decoration contains more quartz compared with 17th century dark red decoration. This study showed that a similar technology was also applied at Kütahya in the 16th century. A linear correlation was found between the position of the Raman intense stretching peak Q₃ and lead oxide content of lead‐alkali glazes, which could allow for the differentiation of Ottoman tiles based on the nondestructive Raman analysis. This study provides an important additional reference data and discussion for the Ottoman tiles. Copyright © 2011 John Wiley & Sons, Ltd.     

Combined measurement of X‐ray photon correlation spectroscopy and diffracted X‐ray tracking using pink beam X‐rays

Combined X‐ray photon correlation spectroscopy (XPCS) and diffracted X‐ray tracking (DXT) measurements of carbon‐black nanocrystals embedded in styrene–butadiene rubber were performed. From the intensity fluctuation of speckle patterns in a small‐angle scattering region (XPCS), dynamical information relating to the translational motion can be obtained, and the rotational motion is observed through the changes in the positions of DXT diffraction spots. Graphitized carbon‐black nanocrystals in unvulcanized styrene–butadiene rubber showed an apparent discrepancy between their translational and rotational motions; this result seems to support a stress‐relaxation model for the origin of super‐diffusive particle motion that is widely observed in nanocolloidal systems. Combined measurements using these two techniques will give new insights into nanoscopic dynamics, and will be useful as a microrheology technique.     

In situ X‐ray diffraction study on the growth kinetics of NiO nanoparticles

The growth kinetics of NiO nanoparticles have been studied by in situ X‐ray diffraction using two detection systems (conventional and imaging plate). NiO nanoparticles were formed by thermal decomposition after heating of an amorphous compound formed by the coprecipitation method. It was found that the detection method using an imaging plate is more efficient than the conventional detection mode for observing changes in the crystallite growth of nanocrystalline materials. Studies have been carried out to investigate the effects of the heating rates on the particles growth. The results suggest that the growth process of the particles is accelerated when the samples are treated at low heating rates. The evolution of particles size and the diffusion coefficient obtained from X‐ray powder diffraction patterns are discussed in terms of the thermal conditions for the two types of detection.     

Application of a pnCCD in X‐ray diffraction: a three‐dimensional X‐ray detector

The first application of a pnCCD detector for X‐ray scattering experiments using white synchrotron radiation at BESSY II is presented. A Cd arachidate multilayer was investigated in reflection geometry within the energy range 7 keV < E < 35 keV. At fixed angle of incidence the two‐dimensional diffraction pattern containing several multilayer Bragg peaks and respective diffuse‐resonant Bragg sheets were observed. Since every pixel of the detector is able to determine the energy of every incoming photon with a resolution ΔE/E? 10^?2, a three‐dimensional dataset is finally obtained. In order to achieve this energy resolution the detector was operated in the so‐called single‐photon‐counting mode. A full dataset was evaluated taking into account all photons recorded within 10⁵ detector frames at a readout rate of 200 Hz. By representing the data in reciprocal‐space coordinates, it becomes obvious that this experiment with the pnCCD detector provides the same information as that obtained by combining a large number of monochromatic scattering experiments using conventional area detectors.     

White‐beam X‐ray radioscopy and tomography with simultaneous diffraction at the EDDI beamline

A set‐up for simultaneous imaging and diffraction that yields radiograms with up to 200 frames per second and 5.6 µm effective pixel size is presented. Tomograms and diffractograms are acquired together in 10 s. Two examples illustrate the attractiveness of combining these methods at the EDDI beamline for in situ studies.     

Single‐crystal X‐ray diffraction and resonant X‐ray magnetic scattering at helium‐3 temperatures in high magnetic fields at beamline P09 at PETRA III

The resonant scattering and diffraction beamline P09 at PETRA III at DESY is equipped with a 14 T vertical field split‐pair magnet. A helium‐3 refrigerator is available that can be fitted inside the magnet's variable‐temperature insert. Here the results of a series of experiments aimed at determining the beam conditions permitting operations with the He‐3 insert are presented. By measuring the tetragonal‐to‐orthorhombic phase transition occurring at 2.1 K in the Jahn–Teller compound TmVO₄, it is found that the photon flux at P09 must be attenuated down to 1.5 × 10⁹ photons s^?1 for the sample to remain at temperatures below 800 mK. Despite such a reduction of the incident flux and the subsequent use of a Cu(111) analyzer, the resonant X‐ray magnetic scattering signal at the Tm L_III absorption edge associated with the spin‐density wave in TmNi₂B₂C below 1.5 K is intense enough to permit a complete study in magnetic field and at sub‐Kelvin temperatures to be carried out.     

A large‐solid‐angle X‐ray Raman scattering spectrometer at ID20 of the European Synchrotron Radiation Facility

An end‐station for X‐ray Raman scattering spectroscopy at beamline ID20 of the European Synchrotron Radiation Facility is described. This end‐station is dedicated to the study of shallow core electronic excitations using non‐resonant inelastic X‐ray scattering. The spectrometer has 72 spherically bent analyzer crystals arranged in six modular groups of 12 analyzer crystals each for a combined maximum flexibility and large solid angle of detection. Each of the six analyzer modules houses one pixelated area detector allowing for X‐ray Raman scattering based imaging and efficient separation of the desired signal from the sample and spurious scattering from the often used complicated sample environments. This new end‐station provides an unprecedented instrument for X‐ray Raman scattering, which is a spectroscopic tool of great interest for the study of low‐energy X‐ray absorption spectra in materials under in situ conditions, such as in operando batteries and fuel cells, in situ catalytic reactions, and extreme pressure and temperature conditions.