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The structure of the Ga85.8In14.2 eutectic liquid alloy is investigated both under ambient conditions and at high pressure/high temperature using X‐ray absorption spectroscopy (XAS) and X‐ray diffraction (XRD) techniques. The local structure of the liquid alloy at ambient conditions is analyzed using double‐edge refinements of the XAS data. Solid–liquid phase transitions under high‐pressure and high‐temperature conditions are monitored by combined XAS and XRD measurements along several quasi‐isobaric heating runs, allowing to draw a melting line up to 10 GPa. The established melting line is found to be slightly below the one of pure gallium (Ga) and to follow its trend as expected from the eutectic nature of the compound. A series of Ga K‐edge X‐ray absorption fine structure (XAFS) spectra measured at different pressures indicates the absence of large structural modifications at local Ga sites in the liquid within the investigated pressure and temperature range. [ABSTRACT FROM AUTHOR]

In order to disentangle the physical effects at the origin of transition metal K‐edge X‐ray magnetic circular dichroism (XMCD) in coordination polymers and quantify small structural distortions from the intensity of these signals, a systematic investigation of Prussian blue analogs as model compounds is being conducted. Here the effects of the temperature and of the external magnetic field are tackled; none of these external parameters modify the shape of the XMCD signal but they both critically modify its intensity. The optimized experimental conditions, as well as a reliable and robust normalization procedure, could thus be determined for the study of the intrinsic parameters. Through an extended discussion on measurements on other XMCD‐dedicated beamlines and for other coordination compounds, we finally provide new transition metal K‐edge XMCD users with useful information to initiate and successfully carry out their projects. [ABSTRACT FROM AUTHOR]

X‐ray absorption spectroscopy is a powerful tool to probe in situ changes in the local structure of a material induced by pressure. In article no. 1800073 it was used by Kuzmin et al. to study the behavior of copper nitride (Cu3N) crystal lattice at high pressure (0–26.7 GPa). The analysis of the Cu K‐edge X‐ray absorption near‐edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS) suggests that at all pressures the local atomic environment around copper atoms remains close to that in cubic Pm‐3m phase. At the same time, a reduction of the lattice parameter of Cu3N by about 2% was found upon increasing pressure up to 26.7 GPa. These results indicate that the transition to the metal state in Cu3N above 5 GPa, observed previously using pressure‐dependent electrical resistance and optical absorption measurements, is due to the band gap collapse with a decrease of the unit cell volume. [ABSTRACT FROM AUTHOR]