Pressure-induced structural and magnetic transitions in honeycomb ruthenate Ag3LiRu2O6

Honeycomb ruthenates (Ru4+, 4d4) with strong spin-orbit coupling are expected to host unconventional magnetic ground state owing to a spin-orbital-entangled Jeff = 0 state. The hitherto-known honeycomb ruthenate Li2RuO3 is, however, known to display a spin-singlet dimerization where spin-orbit coupling is inactive. By using soft-chemical reaction, we obtained an Ag-intercalated Ag3LiRu2O6 which does not show dimerization of Ru atoms. Ag3LiRu2O6 shows a Van-Vleck-like paramagnetic susceptibility as expected for Jeff = 0 states. By applying pressure of ~0.5 GPa, Ag3LiRu2O6 shows a change of magnetic ground state likely associated with modified RuO6 distortion. Furthermore, signatures of pressure-induced dimerization have been seen at a higher pressure in NMR and XRD. To reveal the pressure-induced phase transitions, we propose high-pressure neutron diffraction on Ag3LiRu2O6 on PEARL.