来源：ACS Publications
The search for rare-earth triangular-lattice antiferromagnets continues to attract considerable attention owing to their potential for hosting exotic magnetic ground states. Here, we report the synthesis, crystal structure, and magnetic properties of the tellurate series, K3RETe2O9 (RE = Pr, Nd, and Gd–Yb), which crystallizes in a hexagonal (P63/mmc) structure. In the structure, the RE3+ ions form a large triangular lattice in the ab plane, with nearest-neighbor RE–RE distances ranging from 6.0429 to 5.9082 Å. Magnetization measurements reveal dominant antiferromagnetic interactions for all members, with no evidence of long-range magnetic order or spin freezing down to 1.8 K. Ultralow-temperature heat capacity measurements revealed that the Gd compound (S = 7/2) undergoes long-range magnetic order at TN ≈ 0.20 K, consistent with its estimated dipolar interaction scale. Conversely, the Nd and Yb counterparts, characterized by effective Jeff = 1/2 moments, remain paramagnetic down to 0.1 K and retain significant magnetic entropy. This persistent entropy, together with strong low-temperature spin fluctuations, suggests either ordering at lower temperatures or the realization of a quantum-disordered ground state. Our results establish K3RETe2O9 as a versatile platform for exploring exotic magnetic states in spatially extended triangular lattices.