Speaker
Description
We have Performed an inelastic neutron scattering (INS) investigation on the trimer ruthenate Ba$_5$Ru$_3$O$_{12}$, that undergoes long-range antiferromagnetic ordering at $T_\mathrm{N}$ = 60 K. The INS spectra suggest two distinct spin-wave excitations one at 5.6 meV, which is less intence and a broader intense excitation around 10-15 meV. Notably, these magnetic excitations persist well above $T_\mathrm{N}$, indicating short-range correlations in the trimer network. We have modelled this spectra using linear spin-wave theory (SpinW) in combination with machine-learning force-field (MLFF) calculations which suggest that Ba$_5$Ru$_3$O$_{12}$ hosts strong magnetic frustration arising from competing nearest and next-nearest-neighbor exchange interactions, exchange anisotropy, and strong spin–orbit coupling. These competing interactions stabilize a non-collinear magnetic structure which makes this compound different from all other compounds that belongs to the same ruthenate trimer family. Furthermore, our theoretical calculations of the isolated Ru$_3$O$_{12}$ trimer ground state are consistent with the experimentally observed excitation energies, providing a unified understanding of the magnetic dynamics in Ba$_5$Ru$_3$O$_{12}$.
| Session | Magnetism |
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