Description
Inelastic neutron scattering (INS) is a powerful technique for investigating elementary excitations in condensed matter, including lattice dynamics, spin waves, and crystal electric fields. Traditionally, triple-axis spectrometers (TAS) are the premier instruments designed for these measurements. At the Australian Centre for Neutron Scattering (ACNS) within ANSTO, the thermal-neutron TAS Taipan and cold-neutron TAS Sika offer state-of-the-art capabilities, providing materials scientists with exceptional opportunities to probe advanced functional materials. These instruments have been instrumental in elucidating the underlying physical mechanisms of thermoelectric materials, quantum magnets, and multiferroics. Specifically, investigations on Taipan successfully deciphered the fundamental mechanism behind the ultralow thermal conductivity ($\kappa = 0.24\text{ W/m/K}$) in $\text{Cs}_3\text{Bi}_2\text{Br}_9$ single crystals, revealing a wave-like thermal transport contribution from optical phonons driven by phonon coherence effects. Meanwhile, Sika measurements provided compelling evidence that the Kitaev quantum spin liquid candidate $\text{Na}_3\text{Co}_2\text{SbO}_6$ hosts unexpectedly strong in-plane anisotropy and closely competing ferromagnetic/antiferromagnetic instabilities, shifting the traditional paradigm of the Kitaev model. Furthermore, complementary experiments on both Taipan and Sika disclosed distinct magnetoelectric coupling mechanisms in the multiferroic systems $\text{Co}_4\text{Nb}_2\text{O}_9$ and $\text{Mn}_4\text{Nb}_2\text{O}_9$ through detailed magnetic structure and spin dynamics analyses.
| I am the presenting author | Yes |
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