Synthesis and properties of selenium trihydride at high pressures
Synthesis and properties of selenium trihydride at high pressures
复制标题
DOI：
10.1103/physrevb.97.064107
复制
发表时间：
2018-02
影响因子：
3.7
通讯作者：
Xiao Zhang;Wan Xu;Yu Wang;Shu-qing Jiang;F. Gorelli;E. Greenberg;V. Prakapenka;A. Goncharov
中科院分区：
文献类型：
--
作者：
Xiao Zhang;Wan Xu;Yu Wang;Shu-qing Jiang;F. Gorelli;E. Greenberg;V. Prakapenka;A. Goncharov
The chemical reaction products of molecular hydrogen (H 2 ) with selenium (Se) are studied by synchrotron x-ray diffraction (XRD) and Raman spectroscopy at high pressures. We find that a common H 2 Se is synthesized at 0.3 GPa using laser heating. Upon compression at 300 K, a crystal of the theoretically predicted Cccm H 3 Se has been grown at 4.6 GPa. At room temperature, H 3 Se shows a reversible phase decomposition after laser irradiation above 8.6 GPa, but remains stable up to 21 GPa. How-ever, at 170 K Cccm H 3 Se persists up to 39.5 GPa based on XRD measurements, while low-temperature Raman spectra weaken and broaden above 23.1 GPa. At these conditions, the sample is visually nontransparent and shiny suggesting that metallization occurred. Pressure was determined using the ruby fluorescence 34 and gold XRD 35 pressure markers with the appropriate temperature corrections. For the Raman experiments, a backscattering geometry was adopted for confocal measurements with incident laser wavelengths of 532 nm 36 . The Raman notch filters (three per each excitation wavelengths; additionally 488 and 660 nm laser lines were available) were of a very nar-row bandpass (Optigrate) allowing Raman measurements down to 10 cm -1 in the Stokes and AntiStokes. One of these notch filters is used as a beamsplitter to inject the laser into the optical path. The XRD experiments were collected at the synchrotron beam line sector 13 (GSECARS) of the Advanced Photon Source (APS) of the Ar-gonne National Laboratory with the wavelengths of 0.3344 Å. The initial data reduc-tion was performed using Dioptas software 37 . The lattice parameters were determined by a manual fitting of the observed XRD pattern to a simulated diffraction patterns using PowderCell software 38 . These results were further refined using UnitCell software 39 (where possible).
