Speaker
Description
The family of A2BB’O6 5d1 double perovskite materials has recently attracted attention due to their potential for multipolar ordering and the interplay of spin, orbital, lattice, and electronic degrees of freedom. In particular, the A2MgReO6 (A= Ba, Sr, Ca) family has recently been demonstrated to have a spin-orbit-lattice entangled ground state [1], prompting deeper exploration of the phonons. We used the temperature-dependent Raman spectrum of tetragonal Sr2MgReO6 to investigate its phonon spectrum and potential interactions with magnetic and multipolar orders. We report several new features appearing below the Néel temperature which suggest more change in symmetry than just an antiferromagnetic phase transition, two soft modes that may indicate a high-temperature cubic phase, and a series of high-energy electronic excitations corresponding on the scale of the spin-orbit coupling.
[1] Frontini, Felix I., et al. Physical Review Letters 133.3 (2024): 036501.
| Keyword-1 | Raman |
|---|---|
| Keyword-2 | Spin-orbit coupling |
| Keyword-3 | Double perovskite |