Development of powder diffraction apparatus for small-angle X-ray scattering measurements

A novel type of X-ray collimation system attached to commercial powder diffractometers makes the structural characterization of nanomaterials possible in a wide size range from <0.1 to 100 nm by combination of the small- and wide-angle X-ray scattering techniques. There is no dead interval in the detection between the small- and wide-angle regimes. This device can be attached to any existing 'θ/θ' powder diffractometer, providing a multi-functional small- and wide-angle X-ray scattering/diffraction (SWAXS) apparatus. After proper alignment and adjustment, the device can be removed and re-attached at any time to switch between normal and SWAXS functions. Copyright © International Union of Crystallography 2013

Rare Earths and the Balance Problem: How to Deal with Changing Markets?

The balance between the market demand and the natural abundance of the rare-earth elements (REEs) in ores, often referred to as the Balance Problem (or the Balancing Problem), is a major issue for REE suppliers. The ideal situation is a perfect match between the market demand for and the production of REEs, so that there are no surpluses of any of the REEs. This means that the rare-earth industry must find new uses for REEs that are available in excess and search for substitutes for REEs that have either limited availability or are high in demand. We present an overview of the trends in the applications for the different REEs and show that the demand for REEs for use in magnets, catalysts, and alloys is still increasing, while the application of REEs in polishing agents, glass, and ceramics are stable. On the other hand, the use of REEs in nickel–metal-hydride (NiMH) batteries and lamp phosphors is decreasing. These changes in the REE market have an influence on the Balance Problem, because the REEs that can be recycled from fluorescent lamps, cathode-ray tubes (CRTs), and NiMH batteries have to be at least partly reused in other applications. Magnesium and aluminum alloys offer an opportunity to mitigate the Balance Problem caused by these changes in the REE market. This is illustrated for REEs that can be recycled from fluorescent-lamp phosphor waste, CRT phosphors, and NiMH batteries. At present, five REEs (Nd, Eu, Tb, Dy, and Y) are being considered as very critical by Europe, the United States, and Japan, but we forecast that in the medium term, only neodymium will remain a critical REE. This paper discusses the relationship between criticality and the Balance Problem and shows how this relationship influences the market for specific REEs.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No 680629 (REMAGHIC: New Recovery Processes to produce Rare Earth-Magnesium Alloys of High Performance and Low Cost) (project website: http://www.remaghic-project. eu). KB and PTJ acknowledge funding from the European Community’s Seventh Framework Programme ([FP7/2007–2013]) under Grant Agreement No. 607411 (MC-ITN EREAN: European Rare Earth Magnet Recycling Network) (project website of EREAN: http:// www.erean.eu). Paul McGuiness (Sciencewriter.si, Slovenia) is acknowledged for the drawing of the figures

Sensing a Bacillis anthracis biomarker with well-known OLED emitter EuTta3Phen

Dipicolinic acid (DPA) is a distinctive biomarker for bacterial spores. Here, we present the successful demonstration of dramatic Switch-OFF sensing of DPA using an easily synthesised Eu(III) phosphor applied primarily in light-emitting devices. The sensor in the presence of water and phosphate is also demonstrated to be effective

Direct analysis of metal ions in solutions with high salt concentrations by total reflection x-ray fluorescence

Total reflection X-ray fluorescence (TXRF) is becoming more and more popular for elemental analysis in academia and industry. However, simplification of the procedures for analyzing samples with complex compositions and residual matrix effects is still needed. In this work, the effect of an inorganic (CaCl2) and an organic (tetraalkylphosphonium chloride) matrix on metals quantification by TXRF was investigated for liquid samples. The samples were spiked with up to 20 metals at concentrations ranging from 3 to 50 mg L^–1 per element, including elements with spectral peaks near the peaks of the matrix elements or near the Raleigh and Compton scattering peaks of the X-ray source (molybdenum anode). The recovery rate (RR) and the relative standard deviation (RSD) were calculated to express the accuracy and the precision of the measured element concentrations. In samples with no matrix effects, good RRs are obtained regardless of the internal standard selected. However, in samples with moderate matrix content, the use of an optimum internal standard (OIS) at a concentration close to that of the analyte significantly improved the quantitative analysis. In samples with high concentrations of inorganic ions, using a Triton X-100 aqueous solution to dilute the sample during the internal standardization resulted in better RRs and lower RSDs compared to using only water. In samples with a high concentration of organic material, pure ethanol gave slightly better results than when a Triton X-100–ethanol solution was used for dilution. Compared to previous methods reported in the literature, the new sample-preparation method gave better accuracy, precision, and sensitivity for the elements tested. Sample dilution with an OIS and the surfactant Triton X-100 (inorganic media) or ethanol (organic media) is recommended for fast routine elemental determination in matrix containing samples, as it does not require special equipment, experimentally derived case-dependent mathematical corrections, or physicochemical removal of interfering elements

Temperature dependence of the electrical conductivity of imidazolium ionic liquids.

The electrical conductivities of 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids and of 1-hexyl-3-methylimidazolium ionic liquids with different anions were determined in the temperature range between 123 and 393 K on the basis of dielectric measurements in the frequency range from 1 to 10^7 Hz. Most of the ionic liquids form a glass and the conductivity values obey the Vogel-Fulcher-Tammann equation. The glass transition temperatures are increasing with increasing length of the alkyl chain. The fragility is weakly dependent on the alkyl chain length but is highly sensitive to the structure of the anion.ionic liquids; molten salts;