Open AccessPressure study of monoclinic ReO 2 up to 1.2 GPa using X‐ray absorption spectroscopy and X‐ray diffraction
Author(s) -
Ferreira Fabio Furlan,
Corrêa Hamilton P. S.,
Orlando Marcos T. D.,
Passamai José L.,
Orlando Cíntia G. P.,
Cavalcante Isabela P.,
Garcia Flávio,
Tamura Edilson,
Martinez Luis G.,
Rossi Jesualdo L.,
De Melo Francisco C. L.
Publication year - 2009
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049508036029
Subject(s) - extended x ray absorption fine structure , monoclinic crystal system , powder diffraction , absorption spectroscopy , synchrotron , diffraction , x ray crystallography , x ray absorption fine structure , crystal structure , hydrostatic pressure , absorption (acoustics) , rietveld refinement , crystal (programming language) , x ray absorption spectroscopy , chemistry , crystallography , ambient pressure , spectroscopy , analytical chemistry (journal) , materials science , optics , physics , programming language , quantum mechanics , computer science , composite material , thermodynamics , chromatography
The crystal and local atomic structure of monoclinic ReO 2 (α‐ReO 2 ) under hydrostatic pressure up to 1.2 GPa was investigated for the first time using both X‐ray absorption spectroscopy and high‐resolution synchrotron X‐ray powder diffraction and a home‐built B 4 C anvil pressure cell developed for this purpose. Extended X‐ray absorption fine‐structure (EXAFS) data analysis at pressures from ambient up to 1.2 GPa indicates that there are two distinct Re—Re distances and a distorted ReO 6 octahedron in the α‐ReO 2 structure. X‐ray diffraction analysis at ambient pressure revealed an unambiguous solution for the crystal structure of the α‐phase, demonstrating a modulation of the Re—Re distances. The relatively small portion of the diffraction pattern accessed in the pressure‐dependent measurements does not allow for a detailed study of the crystal structure of α‐ReO 2 under pressure. Nonetheless, a shift and reduction in the (011) Bragg peak intensity between 0.4 and 1.2 GPa is observed, with correlation to a decrease in Re—Re distance modulation, as confirmed by EXAFS analysis in the same pressure range. This behavior reveals that α‐ReO 2 is a possible inner pressure gauge for future experiments up to 1.2 GPa.