Abstract
The interplay between itinerant electrons and local magnetic moments in quantum materials brings about rich and fascinating phenomena and stimulates various developments in the theoretical framework. In this work, thermodynamic, electric transport, and neutron diffraction measurements were performed on a newly synthesized honeycomb lattice magnet . Based on the experimental data, a magnetic-field–temperature phase diagram was constructed, exhibiting three essentially different magnetic regions. Below , moments order antiferromagnetically in zero field. We found that the ions form a pseudodoublet ground state with the Ising-like moments lying normal to the two-dimensional honeycomb layers. Application of a magnetic field along the easy axis gradually suppresses the antiferromagnetic order in favor of an induced ferromagnetic state above the critical field . In the vicinity of , a strong enhancement of the quantum spin fluctuations was observed. The quantum Ising nature of the local moments and the coupling to itinerant electrons are discussed.
2 More- Received 20 December 2021
- Revised 24 May 2022
- Accepted 19 August 2022
DOI:https://doi.org/10.1103/PhysRevB.106.054434
©2022 American Physical Society