Abstract
Unusual successive order in NdB4 with the frustrated Shastry-Sutherland lattice was investigated by means of inelastic neutron scattering. We found that the pseudoquartet with |±5/2) and |±7/2) in the paramagnetic state splits into four levels in the magnetically ordered states. The observed spectra are in good agreement with the f-electron states obtained from the on-site Hamiltonian with the magnetic interaction (Jx)Jx, the coupling of Jx with quadrupole Ozx, and the crystalline electric field potential. The f-electron states reproduce the temperature dependences of the in-plane moment m⊥=(Jx), which is the primary order parameter, and a weakly induced mc=(Jz) as the secondary order parameter. The magnetic-quadrupole coupling emerges and plays an essential role under the geometrical frustration, where the Heisenberg interactions are canceled out.
| Original language | English |
|---|---|
| Article number | 104424 |
| Journal | Physical Review B |
| Volume | 111 |
| Issue number | 10 |
| DOIs | |
| State | Published - Mar 1 2025 |
Funding
This work was supported by JSPS KAKENHI Grant No. JP25390133. The neutron experiment at the Materials and Life Science Experimental Facility of the J-PARC was performed under a user program (Proposal No. 2019A0107). A portion of this research used resources at the High Flux Isotope Reactor, DOE Office of Science User Facilities operated by ORNL.