Abstract
Pyrochlore magnets have attracted interest as systems for realizing critical phenomena, rich magnetic structures, associated topological band structures, and nontrivial quantum phases. Na3Co(CO3)2Cl is a pseudospin-1/2 antiferromagnet in which the Co2+ ions form a pyrochlore network. Its structural and magnetic properties were investigated using magnetization, heat capacity, ESR, single-crystal x-ray diffraction, powder neutron diffraction and powder inelastic neutron scattering. Magnetization and heat capacity measurements indicated a ground-state doublet, which is regarded as pseudospin 1/2, dominated the magnetic properties at low temperatures, with a magnetic exchange of 9.6 K. As the temperature decreases, a magnetic transition is observed at 1.6 K, which is confirmed to be an all-in-all-out magnetic order. The crystal field excitations observed by inelastic neutron scattering experiments indicated the Ising nature of the ground-state doublet. This thorough study revealed that Na3Co(CO3)2Cl can be regarded as a pseudospin-1/2 pyrochlore lattice antiferromagnet with dominant Ising-type interactions.
| Original language | English |
|---|---|
| Article number | 495801 |
| Journal | Journal of Physics Condensed Matter |
| Volume | 36 |
| Issue number | 49 |
| DOIs | |
| State | Published - Dec 11 2024 |
Funding
This work was partly supported by Grants-in-Aid for Scientific Research (Grant Nos. 19KK0069, 19H05824, 20K14395, 22H00101, 23KK0051, and 23K03296) from MEXT of Japan and the Research Program for the CORE lab of \u2018Dynamic Alliance for Open Innovation Bridging Human, Environment, and Materials\u2019 in the \u2018Network Joint Research Center for Materials and Devices.\u2019 The high-field magnetization and the heat capacity measurements were carried out under the GIMRT Program of the Institute for Materials Research, Tohoku University, and the Visiting Researcher\u2019s Program of the Institute for Solid-State Physics, University of Tokyo. Synchrotron x-ray diffraction and inelastic neutron scattering experiments were performed using resources from the Photon Factory (No. 2016G143) and J-PARC (No. 2019A0163), respectively. Powder neutron diffraction experiments were performed at the High Flux Isotope Reactor (HFIR) of the Oak Ridge National Laboratory (ORNL) and Japan Research Reactor 3 (JRR-3). The travel expenses for the experiment on HB-2A at ORNL were sponsored by the General User Program of ISSP-NSL and the U.S.-Japan Collaborative Program on Neutron Scattering. The data supporting this study are available from the authors upon request. The authors declare no conflicts of interest associated with this manuscript.
Keywords
- Ising-type anisotropy
- all-in-all-out magnetic order
- pyrochlore antiferromagnet