Pressure-induced formation of rhodium zigzag chains in the honeycomb rhodate Li$_2$RhO$_3$
| Autor: | Hermann, V., Biswas, S., Ebad-Allah, J., Freund, F., Jesche, A., Tsirlin, A. A., Hanfland, M., Khomskii, D., Gegenwart, P., Valentí, R., Kuntscher, C. A. |
|---|---|
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 100, 064105 (2019) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.100.064105 |
| Popis: | We use powder x-ray diffraction to study the effect of pressure on the crystal structure of the honeycomb rhodate Li$_2$RhO$_3$. We observe low-pressure ($P$$<$$P_{c1}$ = 6.5 GPa) and high-pressure ($P$$>$$P_{c2}$ = 14 GPa) regions corresponding to the monoclinic $C2/m$ symmetry, while a phase mixture is observed at intermediate pressures. At $P$$>$$P_{c2}$, the honeycomb structure becomes distorted and features short Rh--Rh bonds forming zigzag chains stretched along the crystallographic $a$ direction. This is in contrast to dimerized patterns observed in triclinic high-pressure polymorphs of $\alpha$-Li$_2$IrO$_3$ and $\alpha$-RuCl$_3$. Density-functional theory calculations at various pressure conditions reveal that the observed rhodium zigzag-chain pattern is not expected under hydrostatic pressure but can be reproduced by assuming anisotropic pressure conditions. Comment: 11 pages, 11 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|