0000000000435137
AUTHOR
Sakura Pascarelli
High-pressure x-ray-absorption study of GaSe
The III-VI layered semiconductor InSe has been studied by high-pressure single crystal x-ray absorption spectroscopy up to a maximum pressure of 14 GPa. The In-Se distance has been measured in both the low- pressure layered phase and the high-pressure NaCl phase. The bond compressibility in the layered phase is lower than the ``a'' crystallographic parameter compressibility, which implies an increase of the angle between the In-Se bond and the layer plane. Under plausible hypothesis, a description of the evolution of the whole structure with pressure is given. In particular, the intralayer distance is observed to increase with increasing pressure. A plausible precursor defect and a simple m…
Local electronic structure rearrangements and strong anharmonicity in YH3 under pressures up to 180 GPa
The authors acknowledge the ESRF program committee (Grenoble, France) for the opportunity to perform XAFS and XRD measurements. We are grateful to Prof. Dr Marek Tkacz from the Institute of Physical Chemistry, PAS Kasprzaka 44/52, 01-224 Warsaw, Poland, for high quality YH3 samples and to Dr. José A. Flores-Livas for a fruitful discussion. A.P.M. and A.A.I. acknowledge the Russian Foundation for the Basic Research (grant No 18-02-40001_mega) for financial support. J.P., A.K., and I.P. would like to thank the support of the Latvian Council of Science project No. lzp-2018/2-0353. ISSP UL acknowledge the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-20l 6-2017-TeamingPh…
Phase stability and electronic structure of iridium metal at the megabar range
[EN] The 5d transition metals have attracted specific interest for high-pressure studies due to their extraordinary stability and intriguing electronic properties. In particular, iridium metal has been proposed to exhibit a recently discovered pressure-induced electronic transition, the so-called core-level crossing transition at the lowest pressure among all the 5d transition metals. Here, we report an experimental structural characterization of iridium by x-ray probes sensitive to both long- and short-range order in matter. Synchrotron-based powder x-ray diffraction results highlight a large stability range (up to 1.4 Mbar) of the low-pressure phase. The compressibility behaviour was char…