Pressure-induced amorphization mechanism in Eu2(MoO4)3
| Autor: | Denis Machon, O. Le Bacq, Alain Pasturel, Denis Testemale |
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| Rok vydání: | 2011 |
| Předmět: |
X-ray absorption spectroscopy
Materials science Absorption spectroscopy Coordination number 02 engineering and technology Molybdate 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Crystal symbols.namesake chemistry.chemical_compound Crystallography chemistry 0103 physical sciences symbols Coherent anti-Stokes Raman spectroscopy Isostructural 010306 general physics 0210 nano-technology Raman spectroscopy |
| Zdroj: | Physical Review B. 83 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.83.214101 |
| Popis: | We identify a mechanism responsible for amorphization of rare-earth molybdate isostructural compounds by means of x-ray absorption spectroscopy (XAS) and Raman spectroscopy as well as first-principles calculations. Our present Raman spectra show that both ${\ensuremath{\beta}}^{\ensuremath{'}}$ and $\ensuremath{\alpha}$-Eu${}_{2}$(MoO${}_{4}$)${}_{3}$ undergo a pressure-induced amorphization. Both first-principles calculations and XAS measurements explain the process of amorphization by a spatial self-reorganization of the oxygen clouds around the Mo and Eu subnetworks as the pressure is increased inducing a change in the coordination number of the Mo atoms. This latter transforms the ${e}_{g}$ crystal field of the tetrahedra into a series of stabilization-degenerated peaks, which energetically favors a disordered overlapping of the former MoO${}_{4}$ tetrahedra instead of a mere ordered compression and rotation of these fragments. |
| Databáze: | OpenAIRE |
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