The physics of critical phenomena is well established in systems as diverse as molecular fluids, crystalline alloys and magnetic materials. As the critical point is approached, the susceptibility increases anomalously and fluctuations give rise to dramatic opalescence. Evidence has recently emerged for the existence of a second critical point in the liquid state at supercooled temperatures, below which polyamorphic phases coexist differing in density but sharing the same composition. Whilst much attention has been paid to supercooled water, polyamorphic phases have been observed in many elemental and oxide liquids potentially offering routes to low-entropy glasses. Our recent direct observation of a polyamorphic phase transition in levitated molten yttria–alumina offers the first opportunity to study the associated critical point in a real supercooled system. In situ small-angle X-ray scattering records sharp rises in the average correlation length of density fluctuations and in the compressibility as the transition is approached. Both increases approximate to the universal power-law relations predicted by the three-dimensional Ising model in common with all critical point phenomena. The observation brings the second critical point predicted in liquids into line with other critical phenomena.

Strain in silicon on insulator (SOI) and strained-silicon(s-Si)/silicon–germanium (SiGe)/Si-substrate crystals is analysed by means of synchrotron X-ray microbeam diffraction. It is found that strain features of the s-Si/SiGe/Si crystals are much different from those of SOI crystals from the lattice tilt and lattice parameter distribution points of view. The two-dimensional lattice tilt maps obtained by scanning the synchrotron X-ray microbeam of about 1 μm in size on the sample surface are useful to study local strain distribution in those materials.

Resonant elastic X-ray scattering (RXS) at the erbium absorption edge was investigated in the orbital-ordered compound ErVO3. An RXS signal resonating near the Er L3-edge was clearly observed at (1 0 0). Using this signal, we studied the relation between the anisotropy of the Er 5d orbital and the V 3d orbital ordering because the covalency between the Er 5d and V 3d orbitals is expected to stabilize the C-type orbital ordering of the V 3d electrons.

The depth profiles of the constituent in iron oxide scales were investigated by X-ray diffraction measurement with controlling X-ray penetration depth at SPring-8. We successfully observed the interface region of scales non-destructively using X-ray with energy of 28 keV. The results indicated that the volume fraction ratio of Fe3O4 to FeO around the surface of samples increased by isothermal heat treatment. This suggested that the transformation of FeO to Fe3O4 due to isothermal heat treatment proceeds from surface into the inside of scale.

Fourier transform infrared (FTIR) spectroscopy has gained significant attention among the forensic scientists because it shows high sensitivity and selectivity, and offers near-real-time detection. Application of the multivariate statistical techniques for the analysis of the spectra is necessary in order to enable feature extraction, proper evaluation and identification of obtained spectra. In this paper we show the development of a feasible procedure for the characterization of spectroscopic signatures of the explosive materials in the remnants after explosion. In our research especially designed and prepared sample catchers were used during the blasts of three various high explosives: C-4, TNT and PETN. Principal component analysis (PCA) was performed using broad spectral data range (600–4000 cm−1) for sample classification into separate classes. Most of the information contained in spectral data was compressed by PCA in few relevant principal components that explain most of the variance of spectral data. The results show that FTIR spectroscopy in combination with multivariate methods are well suited for identification and differentiation purposes even in very large data sets and could be employed by forensic laboratories for rapid screening analysis.

We present preliminary reflection extended X-ray absorption fine structure results on reactive magnetron sputtering molybdenum nitride (MoN) layered samples, with different compositions and surface layer thickness. The results obtained over a wide range of incidence angles show significant differences between two samples where the outer layer is either Mo metal or MoN.

Within the framework of a wide study of pieces of cultural heritage from the Andalusian baroque period, synchrotron radiation techniques were used to characterize the metallic parts of mirrors and musical organ pipes. By using X-ray fluorescence (XRF) and X-ray diffraction (XRD) with micrometre resolution information was obtained which was relevant either in the conservation or in the identification of these pieces. By monitoring with micro X-ray diffraction (μXRD) the degradation process of the amalgam of the mirrors, the evolution of the corrosion products could be followed. The identification and distribution of trace elements of tin and lead phases forming the organ metal pipes was carried out with the aid of micro X-ray fluorescence (μXRF). This technique allowed for the quantification of the elemental distributions in the major and minor components, knowledge useful to improve the manufacture of modern musical organs.

I13L is a 250 m long hard X-ray beamline (6–30 keV) currently under construction at the Diamond Light Source. The beamline comprises two independent experimental endstations: one for imaging in direct space using X-ray microscopy and one for imaging in reciprocal space using coherent diffraction-based imaging techniques. This paper will discuss the coherence branch, where well-defined coherence properties and preservation of the coherent flux are important. We will demonstrate the impact of optical components and stability onto the beamline performance, using phase-space-based ray-tracing techniques. The implications onto the beamline design will be demonstrated using our in-house build quadruple crystal monochromator as an example.

Kyushu University has installed the hard X-ray beamline, BL06, at bending magnet source of SAGA Light Source in Japan. It is designed for X-ray absorption fine structure (XAFS) spectroscopy and small-angle X-ray scattering (SAXS) experiments. The X-ray energy covered by the beamline ranges from 2.1 to 23 keV using a Si(111) flat double-crystal monochromator. Two bent cylindrical-type focusing mirrors are used, each with a different focal point. They are set in the optics section and can be used independently. One of the mirrors has a focal distance of 6 m, which corresponds to the sample stage for XAFS experiments, while the second mirror focuses at 10 m, corresponding to the detector for the SAXS experiments. The photon flux measured by the ion chamber at mirror focal point is 1010 phs/s. The experimental hutch houses the detection equipment for both XAFS and SAXS. For XAFS studies, a set of ion chambers for transmission mode and a Lytle detector and a Si drift detector for fluorescence yield mode are available. For SAXS studies, the camera pass length can be chosen from 0.5 to 2.5 m with 0.5 m increments in between, and an image plate is operated as signal detector. The beamline will be opened for user operation around summer 2010.

A new X-ray absorption cell dedicated to in situ and operando experiments in heterogeneous catalysis has been built and tested. It allows measurement of X-ray absorption spectroscopy (XAS) spectra in transmission mode under the flow of various gas mixtures at elevated temperatures (600°C) and pressures (50 bar). The working conditions are representative of phenomena that take place in fixed bed reactors.

Optically detected X-ray absorption spectroscopy (ODXAS) and X-ray excited optical luminescence (XEOL) have been applied in parallel to the study of local bonding in luminescent diamonds. Imaging ODXAS and XEOL reveal correlations between lateral variation in colour (transmitted light and luminescence) and local carbon bonding in selected samples showing strong optical absorption contrast. Dark regions of the crystals viewed in transmitted light correlate with a lower total luminescence yield when excited with soft X-rays of photon energy ~280 eV. ODXAS reveals a higher proportion of sp2-bonded carbon species in darker (less luminescent) regions associated with graphitic micro-inclusions.

Al3Ti, Al13Cr2 and Al13Fe4 are important intermetallics in a number of Al alloy systems including complex ultra-high-strength systems with excellent elevated-temperature performance. A full knowledge of their properties and crystallographic structures is a key factor for the understanding of these complex alloys. In the present study samples of the three pure intermetallics were prepared and regions of interest identified in a billet of Al93Fe3Cr2Ti2 alloys and 20 × 10 × 2 µm samples extracted utilizing a Focussed Ion Beam Transmission Electron Microscopy (FIB TEM) sample preparation technique. Using the microfocus spectroscopy beamline I18 at Diamond Light Source we were able to examine 5 µm sections of the samples using X-ray Diffraction (μ-XRD) and Extended X-ray Absorption Fine Structure (μ-EXAFS) in an attempt to describe the local structure of the second-phase particles and characterized the microstructure of the FIBed samples to selectively illuminate the different phases.

We present a study of a complex ultra-high-strength Al alloy containing ~40 volume per cent of second-phase particles, ranging in size from nanometres to a few microns. The microstructure has been investigated using scanning electron microscopy and high-resolution synchrotron X-ray diffraction using the I11 beam line at the Diamond Light Source, UK. Powder diffraction was carried out to (i) determine phases present, (ii) quantify the weight per cent of each phase and (iii) quantify size and strain effects in the Al matrix. The high beam quality (i.e. low divergence and wavelength purity) and multi-analysing crystal detectors makes this an ideal instrument to resolve the high peak density and determine the contribution of sample broadening in the complex alloy. Using Pawley and Rietveld full pattern fitting, the intermetallic phases present were determined to be Al3Ti, Al13Cr2 and Al13Fe4. The weight fraction of each phase was calculated from the Rietveld refinements and correlated well with thermodynamic calculations assuming an equilibrium microstructure. Size and strain in the Al matrix was measured from peak broadening using a Double Voigt analysis and showed significant physical broadening due to both size and strain.

Containerless techniques (levitation) completely eliminate contact with the sample. This unique sample environment allows deep supercooling of many liquids and avoids contamination of high-temperature melts. Recent experiments at the Advanced Photon Source (APS) high-energy beamline 11 ID-C used aerodynamic levitation with laser beam heating and acoustic levitation with cryogenic cooling. By using these two methods, liquids were studied over much of the temperature range from −40 to +2500°C. This paper briefly describes the instrumentation and its use and is illustrated with examples of measurements on molten oxides and low-temperature liquids.

This paper will describe the results of in situ high-energy X-ray measurements performed on stable and supercooled oxide liquids using containerless techniques. As will be discussed in the companion paper (Weber et al.), the use of an aerodynamic levitator furnace with laser heating allows the structures of refractory oxide liquids to be probed. Because of the contactless nature of this sample environment liquids can be deeply supercooled, and this provides opportunities to study the metastable structures of supercooled liquids. Of particular interest are the so-called fragile liquids that depart from Arrhenius-law viscosity behaviour and that, by definition, have temperature-dependent structures. The focus of this paper is the study of two oxide systems, MgO–SiO2 and Al2O3–SiO2. These two liquids have highly disordered stable liquid structures that differ substantially from the structures of the equivalent glasses. We present data showing how these structures change when supercooled and demonstrate dramatic changes in short-range (coordination number) and intermediate-range order during vitrification. These data have been collected by isothermal measurement and also fast quenching methods using the recently developed method of rapid acquisition using a Perkin Elmer amorphous silicon flat panel detector; this gives a large Q coverage for incident energies of >115 keV. The rapid data acquisition enables the vitrification process to be observed directly.

We demonstrated high-resolution element-specific diffraction microscopy using a hard X-ray beam focused by Kirkpatrick–Baez mirrors. Coherent diffraction patterns of an Au/Ag nanoparticle were measured at incident X-ray energies around the Au LIII absorption edge. By calculating the difference between the intensities of reconstructed images obtained at different energies, an image of the Au element could be derived. From the difference image, it was suggested that the replacement reaction progresses from the corners of Ag cubic particle.

The electronic structure of Co (100 Å)/Cu (50 Å) bilayer film on Si(100) has been investigated using valence band photoemission at 50 eV. The aim is to understand the Co/Cu interface and the nature of intermixing in Co and Cu layers. The valence band of Co/Cu interface shows three features at −0.3, −1.17 and −1.9 eV binding energy. The experimental observations are explained with the help of calculations based on projected augmented wave pseudopotential method using density functional theory. The origin of −0.3 eV feature is mainly due to the Co 3d minority spin states while the features at −1.17 and −1.9 eV are due to the formation of Co and Co–Cu mixed nanoclusters at the interface.

The electronic structure of CeAg2Ge2 single crystal has been investigated by using resonant valence band photoemission and angle-resolved photoemission spectroscopy at different photon energies. Resonant photoemission has been observed near the 4d threshold of Ce at 121 eV. The constant initial state spectra show two photoemission features having 4f character near the Fermi level that exhibits Fano-like sharp resonance profile. Experimental energy bands have been mapped from the normal-emission photoelectron spectra of CeAg2Ge2 (001) surface along the Γ–Z direction. Four photoemission features are observed to show the dispersion related to the Ce 4f states and the hybridized Ag 4d with Ge 4p states. The experimental spectra have been interpreted with the help of calculations based on full potential linear augmented plane wave method using density functional theory.

We investigate the interfacial electronic structures of the heterojunction Fe/pentacene/Fe on Cu(100) substrate, using synchrotron-based photoemission spectroscopy. No chemical reaction is observed at either Fe/pentacene or pentacene/Fe interface. The hole injection barrier was estimated to be about 0.95 eV between pentacene and under the Fe thin film. C K-edge NEXAFS revealed that the long axis of pentacene molecule was almost perpendicular to the surface plane. With increasing Fe thickness deposited on pentacene film, the pentacene's HOMO shifts to higher binding energy whereas the C 1s binding energy showed an interesting unusual behaviour due to the initial band bending gradually suppressed by the increasing core-hole screening effect.

In the past few years, we have witnessed the appearance of exotic magnetism of atoms in nano-scaled systems associated with compounds that are non-magnetic in their bulk form. Different models ranging from orbital magnetism delocalized over the whole molecule to localized one associated to the modification of the electronic structure have been proposed. Hence, one of the main challenges is to determine the mechanism that induces both the magnetic moment and the exchange interactions, leading to the ferromagnetic-like behaviour in these nanostructures. Aimed at obtaining a deeper insight into the induction of magnetic moments on nominally non-magnetic atoms, we have performed an XMCD study on rare-earth–iron Laves phase compounds containing Ga or Ge. XMCD probes the magnetic polarization of both Ga and Ge in these compounds. Our results show that when the rare-earth (R) is non-magnetic this polarization is uniquely due to the hybridization with the Fe neighbours, while it is enhanced when R is magnetic due to the Fe–R hybridization. As a consequence, the magnetic polarization of both Ge and Ga atoms differs as this hybridization does.