Abstract
A basic understanding of the driving forces of ion conduction in solids is critical to the development of new solid-state ion conductors. The physical understanding of ion conduction is limited due to strong deviations from harmonic vibrational dynamics in these systems that are difficult to characterize experimentally and theoretically. We overcome this challenge in superionic AgI by combining THz-frequency Raman polarization-orientation measurements and ab initio molecular dynamics computations. Our findings demonstrate clear signatures of strong coupling between the mobile ions and host lattice that are of importance to the diffusion process. We first derive a dynamic structural model from the Raman measurements that captures the simultaneous crystal-like and fluidlike properties of this fast ion conductor. Then we show and discuss the importance of anharmonic relaxational motion that arises from the iodine host lattice by demonstrating its strong impact on ion conduction in superionic AgI.
| Original language | English |
|---|---|
| Article number | 115402 |
| Number of pages | 7 |
| Journal | Physical Review Materials |
| Volume | 4 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Nov 2020 |
Funding
We would like to thank Ishay Feldman (WIS) for performing x-ray diffraction measurements, Lior Segev (WIS) for critical software development, and Claudio Cazorla (UNSW Sydney) and Brandon C. Wood (LLNL) for fruitful discussions. O.Y. acknowledges funding from the following: the Benoziyo Endowment Fund, the Ilse Katz Institute, the Henry Chanoch Krenter Institute, the Soref New Scientists Start Up Fund, Carolito Stiftung, the Abraham and Sonia Rochlin Foundation, and Erica A. Drake and Robert Drake. D.A.E. acknowledges funding from the following: the Alexander von Humboldt Foundation within the framework of the Sofja Kovalevskaja Award, endowed by the German Federal Ministry of Education and Research; the Technical University of Munich - Institute for Advanced Study, funded by the German Excellence Initiative and the European Union Seventh Framework Programme under Grant Agreement No. 291763; and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - EXC 2089/1–390776260.
All Science Journal Classification (ASJC) codes
- General Materials Science
- Physics and Astronomy (miscellaneous)