6533b85efe1ef96bd12c077d
RESEARCH PRODUCT
Bond length compressibility in hard ReB2 investigated by x-ray absorption under high pressure
Julio Pellicer-porresAlfonso MuñozAlfredo SeguraAlain PolianA Congedutisubject
Extended X-ray absorption fine structureChemistry02 engineering and technology021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesMolecular physicsBond lengthCrystallographyChemical bondCovalent bondAb initio quantum chemistry methods[PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]0103 physical sciencesX-ray crystallographyCompressibilityGeneral Materials Science010306 general physics0210 nano-technologyStructural rigiditydescription
International audience; This work describes x-ray absorption measurements under high pressure in ReB2 , complemented by ab initio calculations. The EXAFS analysis yields the average Re–B bond compressibility, which turns out to be χReB = 5.6(9) × 10− 4 GPa−1 . Combining this information with previous x-ray diffraction experiments we have characterized the network of covalent bonds responsible for the rigidity of the structure. The main conclusion is that the compression is anisotropic and nonhomogeneous, reflecting bonding differences between Re–B and B–B bonds and also between nonequivalent Re–B bonds. The layer defined by boron atoms tends to become flatter under high pressure. As a consequence, the structural rigidity, necessary to attain high hardness values, is compromised.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2010-01-01 |