Combined experimental and theoretical study of hydrostatic He-gas pressure effects in α-RuCl3
| Autor: | B. Wolf, D. A. S. Kaib, A. Razpopov, S. Biswas, K. Riedl, S. M. Winter, R. Valentí, Y. Saito, S. Hartmann, E. Vinokurova, T. Doert, A. Isaeva, G. Bastien, A. U. B. Wolter, B. Büchner, M. Lang |
|---|---|
| Přispěvatelé: | IoP (FNWI), WZI (IoP, FNWI), Hard Condensed Matter (WZI, IoP, FNWI) |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Physical Review B, 106(13):134432. American Institute of Physics |
| ISSN: | 2469-9969 1098-0121 2469-9950 |
| Popis: | We report a detailed experimental and theoretical study on the effect of hydrostatic pressure on various structural and magnetic aspects of the layered honeycomb antiferromagent α-RuCl3. Through measurements of the magnetic susceptibility χ performed under almost ideal hydrostatic-pressure conditions by using helium as a pressure-transmitting medium, we find that the phase transition to zigzag-type antiferromagnetic order at TN = 7.3 K can be rapidly suppressed to about 6.1 K at a weak pressure of about 94 MPa. A further suppression of TN with increasing pressure is impeded, however, due to the occurrence of a pressure-induced structural transition at p≥ 104 MPa, accompanied by a strong dimerization of Ru-Ru bonds, which gives rise to a collapse of the magnetic susceptibility. Whereas the dimerization transition is strongly first order, the magnetic transition under varying pressure and magnetic field also reveals indications for a weakly first-order transition. We assign this observation to a strong magnetoelastic coupling in this system. Measurements of χ under varying pressure in the paramagnetic regime (T>TN) and before dimerization (p< 100 MPa) reveal a considerable increase of χ with pressure. These experimental observations are consistent with the results of ab initio density functional theory (DFT) calculations on the pressure-dependent structure of α-RuCl3 and the corresponding pressure-dependent magnetic model. We find that pressure strengthens the nearest-neighbor Heisenberg J and off-diagonal anisotropic Γ coupling and simultaneously weakens the Kitaev K and anisotropic Γ′ coupling. Comparative susceptibility measurements on a second crystal showing two consecutive magnetic transitions instead of one, indicating the influence of stacking faults, reveal that by the application of different temperature-pressure protocols the effect of these stacking faults can be temporarily overcome. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|