Abstract
We report thermodynamic, neutron diffraction, and inelastic neutron scattering measurements on Cs2RuO4, a member of the celebrated family of frustrated magnets Cs2MX4 (M = Cu, Co, X = Br, Cl). Unlike the previously studied members, it is based on 4d transition metal ions with S = 1. Mapping out the H-T magnetic phase diagram reveals an unusual continuous spin-flop-like phase transition associated with a quantum critical point within the antiferromagnetically ordered phase. A quantitative analysis of the complex magnetic excitation spectrum measured in zero field allows us to derive a model magnetic Hamiltonian for this compound. Its main feature is a frustration of magnetic anisotropy on a level that is much higher than in any of the previously studied species. This frustration naturally explains the peculiar phase transition observed.
| Original language | English |
|---|---|
| Pages (from-to) | 1344361-13443612 |
| Number of pages | 12099252 |
| Journal | Physical Review B |
| Volume | 112 |
| Issue number | 13 |
| DOIs | |
| State | Published - Oct 21 2025 |
Funding
This work is supported by a MINT grant of the Swiss National Science Foundation. We acknowledge the beam time allocation at CAMEA, PSI (ID: 20240901), as well as the support of the HLD at HZDR, member of the European Magnetic Field Laboratory (EMFL), and the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter - ct.qmat (EXC 2147, Project No. 390858490). A portion of this research used resources at the High Flux Isotope Reactor (HFIR), a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The beam This work is supported by a MINT grant of the Swiss National Science Foundation.We acknowledge the beam time allocation at CAMEA, PSI (ID: 20240901), as well as the support of the HLD at HZDR, member of the European Magnetic Field Laboratory (EMFL), and the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter - ct.qmat (EXC 2147, Project No. 390858490). A portion of this research used resources at the High Flux Isotope Reactor (HFIR), a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The beam time was allocated to the DEMAND instrument (Proposal No. IPTS-33733.1).