Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide The interplay between quantum effects from magnetic frustration, low-dimensionality, spin–orbit coupling, and crystal electric field in rare-earth materials leads to nontrivial ground states with unusual magnetic excitations. Here, we investigate YbTaO 4, which hosts a buckled square net of Yb 3+ ions with J eff = 1/2 moments. The observed Curie–Weiss temperature is about −1 K, implying an antiferromagnetic coupling between the Yb 3+ moments. The heat capacity shows no long-range ordering down to 0.10 K, instead shows a field-dependent broad maximum indicative of short-range correlations. The magnetic entropy recovered and magnetization measurements confirm a spin–orbit driven J eff = 1/2 Kramers doublet ground state. Point charge calculations show that the Yb 3+ ions do not host the quintessential XY spin anisotropy observed in typical Yb-based quantum magnets like NaYbO 2, YbMgGaO 4, and pyrochlores but rather exhibit an almond-shaped anisotropy with an easy axis. Thus, YbTaO 4 can serve as a model system to study frustrated magnetism in a square lattice using the J 1 – J 2 Heisenberg model. This work also emphasizes the significance of small perturbations to the local crystal electric field that can alter the spin anisotropy and change the collective behavior of the system.
Source: Inorganic Chemistry
Institution: Georgia Institute of Technology
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4405838409