Numerical study of the structural and vibrational properties of amorphous Ta{sub 2}O{sub 5} and TiO{sub 2}-doped Ta{sub 2}O{sub 5}
- Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne (France)
- Laboratoire de Mécanique des Contacts et des Structures, UMR 5259 Institut National des Sciences Appliquées de Lyon-CNRS, F-69621 Villeurbanne (France)
Using classical molecular dynamics simulations, we synthesized amorphous Ta{sub 2}O{sub 5} and amorphous TiO{sub 2}-doped Ta{sub 2}O{sub 5}. We show that Ta{sub 2}O{sub 5} is composed primarily of six-folded Ta atoms forming octahedra that are either organized in chain-like structures or share edges or faces. When Ta{sub 2}O{sub 5} is doped with TiO{sub 2}, Ti atoms form equally five- and six-folded polyhedra that perturb but do not break the network structure of the glass. Performing a vibrational eigenmode analysis and projecting the eigenmodes on the rocking, stretching, and bending motions of the Ta-2O and Ta-3O bonds, we provide an atomic-scale analysis that substantiates the interpretations of Raman spectra of amorphous Ta{sub 2}O{sub 5}. This eigenmode analysis also reveals the key role played by Ti atoms in the 5 to 12 THz range.
- OSTI ID:
- 22596945
- Journal Information:
- Journal of Applied Physics, Vol. 119, Issue 17; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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