Diffusion of sodium ions in amorphousNa2Si2O5: Quasielastic neutron scattering andab initiomolecular dynamics simulations
| Autor: | Srungarpu N. Achary, Sanghamitra Mukhopadhyay, Prabhatasree Goel, Samrath L. Chaplot, Rakesh Shukla, Ranjan Mittal, Sanjay Kumar Mishra, Avesh K. Tyagi, Baltej Singh, Mayanak K. Gupta |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Physics and Astronomy (miscellaneous) Relaxation (NMR) Ab initio 02 engineering and technology Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Amorphous solid Ion Crystallography Phase (matter) 0103 physical sciences Quasielastic neutron scattering General Materials Science Orthorhombic crystal system 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Review Materials. 4 |
| ISSN: | 2475-9953 |
| DOI: | 10.1103/physrevmaterials.4.045802 |
| Popis: | The dynamics of Na ions in amorphous $\mathrm{N}{\mathrm{a}}_{2}\mathrm{S}{\mathrm{i}}_{2}{\mathrm{O}}_{5}$, a potential solid electrolyte material for Na battery, have been investigated by employing. the quasielastic neutron scattering (QENS) technique in the temperature range 300 to 748 K. To understand the diffusion pathways and relaxation timescales of Na ionic diffusion, the experimental studies are complemented by ab initio and force-field molecular dynamics simulations. The QENS data are fairly well described by a jump-diffusion model with a mean jump length of about 3 \AA{} and residence time about 9 ps. Our molecular dynamics simulations have predicted that the diffusion of $\mathrm{N}{\mathrm{a}}^{+}$ ions occurs in the amorphous phase of $\mathrm{N}{\mathrm{a}}_{2}\mathrm{S}{\mathrm{i}}_{2}{\mathrm{O}}_{5}$ while absent in the crystalline orthorhombic phase even up to 1100 K. The molecular dynamics simulations have revealed that in the amorphous phase, due to different orientations of silicon polyhedral units, several accessible pathways are opened up for $\mathrm{N}{\mathrm{a}}^{+}$ diffusions. These pathways are not available in the crystalline phase of $\mathrm{N}{\mathrm{a}}_{2}\mathrm{S}{\mathrm{i}}_{2}{\mathrm{O}}_{5}$ due to rigid spatial arrangement of silicon polyhedral units. |
| Databáze: | OpenAIRE |
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