- Gaël Bastien: Tunning the Kitaev magnet alpha-RuCl3 with hydrostatic pressure and chemical substitution
- 20. 3. 2019, 14:10
- lecture room F2, first floor Ke Karlovu 5
- more information
Abstract:
The study of magnetic frustration in solid state physics lead to the discovery of various exotic phases of matter such as quantum spin liquids, spin glasses or spin ices. The Kitaev model on a honeycomb lattice is a recent case of frustrated magnetism, where the frustration arises from bound directional Ising interactions named Kitaev interactions. This exactly solvable model harbors a quantum spin liquid ground state. Such Kitaev interactions occur in 4d and 5d jeff=1/2 Mott insulators such as alpha-RuCl3 thanks to a strong spin-orbit coupling. In alpha-RuCl3 due to small additional magnetic interactions, a long range magnetic order occurs instead of the quantum spin liquid. However this long range order is suppressed under magnetic field and the occurrence of a field induced quantum spin liquid is elusive. In this study, we tune the magnetic properties of alpha-RuCl3 by the application of hydrostatic pressure and by the chemical substitution of the Ru3+ ions by lower spin-orbit coupling ions: Cr3+. We demonstrate, that hydrostatic pressure induces a structural transition toward a valence bond solid. On the other hand, upon Cr doping we report the destabilization of the magnetic order into a spin glass state and a change of the magnetic anisotropy.