Local magnetism and spin dynamics of the frustrated honeycomb rhodate

Journal article

We report magnetization, heat capacity, 7Li nuclear magnetic resonance (NMR) and muon-spin rotation (μSR) measurements on the honeycomb 4d^5 spin liquid candidate Li2RhO3. The magnetization in small magnetic fields provides evidence for a partial spin freezing of a small fraction of Rh^4+ moments at 6 K whereas the Curie-Weiss behavior above 100 K suggests a pseudo-spin–1/2 paramagnet with a moment of about 2.2 μB. The magnetic specific heat (Cm) exhibits no field dependence and demonstrates the absence of long range magnetic order down to 0.35 K. Cm/T passes through a broad maximum at about 10 K and Cm ∝ T^2 at low temperature. Measurements of the spin-lattice relaxation rate (1/T1) reveal a gapless slowing down of spin fluctuations on cooling with 1/T1 ∼ T^2.2. The results from NMR and μSR are consistent with a scenario in which a minority of Rh4+ moments are in a short-range correlated frozen state and coexist with a majority of moments in a liquid-like state that continue to fluctuate at low temperature.

Authors: Khuntia, P; Manni, S; Foronda, F; Lancaster, T; Blundell, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review B
• Volume: 96
• Issue: 9
• Pages: 094432
• Publication date: 2017-09-25
• Acceptance date: 2017-09-06
• DOI: 10.1103/PhysRevB.96.094432
• EISSN: 2469-9969
• ISSN: 2469-9950
• Keywords: quantum spin liquid; μSR; spin orbit interaction; NMR; specific heat; magnetization