Abstract
We report magnetic properties of a 3d9 (Cu2+) magnetic insulator Cu2OSO4 measured on both powder and single crystal. The magnetic atoms of this compound form layers whose geometry can be described either as a system of chains coupled through dimers or as a kagome lattice where every third spin is replaced by a dimer. Specific heat and DC susceptibility show a magnetic transition at 20 K, which is also confirmed by neutron scattering. Magnetic entropy extracted from the specific heat data is consistent with an S=1/2 degree of freedom per Cu2+, and so is the effective moment extracted from DC susceptibility. The ground state has been identified by means of neutron diffraction on both powder and single crystal and corresponds to an ∼120 spin structure in which ferromagnetic intradimer alignment results in a net ferrimagnetic moment. No evidence is found for a change in lattice symmetry down to 2 K. Our results suggest that Cu2OSO4 represents a type of model lattice with frustrated interactions where interplay between magnetic order, thermal and quantum fluctuations can be explored.
| Original language | English |
|---|---|
| Article number | 094422 |
| Journal | Physical Review B |
| Volume | 102 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 1 2020 |
Funding
V.Y.F. thanks P. Babkevich for his help with the refinement of diffraction data and F. Mila for stimulating discussions. We acknowledge the Paul Scherrer Institut, Villigen, Switzerland, for provision of synchrotron radiation beam time at beamline MS-X04SA of the SLS. This work is partially based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland, at the STFC ISIS Facility , and at the Institut Laue-Langevin . A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. This work was supported by the Swiss National Science Foundation (SNSF), Grant No. 188648.