Abstract
Rare-earth triangular lattice materials have been proposed as a good platform for the investigation of frustrated magnetic ground states. , with the delafossite structure, contains perfect two-dimensional triangular layers separated by potassium ions, realizing this ideal configuration and inviting study. Here we investigate the magnetism of at millikelvin temperatures by heat capacity and neutron powder diffraction. Heat capacity results reveal a magnetic transition at 0.2 K in zero applied field. This long-range order is suppressed by an applied magnetic field of 0.5 T below 0.08 K. Neutron powder diffraction suggests that the zero-field magnetic structure orders with in a stripe spin structure. Unexpectedly, Er is found to have a reduced moment of 3.06(1)/Er in the ordered state, and diffuse magnetic scattering, which originates at higher temperatures, is found to persist in the ordered state, potentially indicating magnetic fluctuations. Neutron diffraction collected under an applied field shows a metamagnetic transition at T to ferromagnetic order with and two possible structures, which are likely dependent on the applied field direction. The zero-field stripe spin structure can be explained by the anisotropic interactions or the first-, second-, and third-neighbor couplings in the antiferromagnetic triangular lattice.
- Received 1 June 2020
- Revised 22 March 2021
- Accepted 22 March 2021
- Corrected 24 May 2021
DOI:https://doi.org/10.1103/PhysRevB.103.144413
©2021 American Physical Society
Physics Subject Headings (PhySH)
Corrections
24 May 2021
Correction: The omissions of a data availability statement and Acknowledgment section have been fixed.