Optimized flux single-crystal growth of the quantum spin liquid candidate ▫$NdTa_7O_{19}$▫ and other rare-earth heptatantalates, ▫$ErTa_7O_{19}$▫ and ▫$GdTa_7O_{19}$▫Šibav, Lia (Avtor) Lozinšek, Matic (Avtor) Jagličić, Zvonko (Avtor) Arh, Tina (Avtor) Khuntia, Panchanana (Avtor) Zorko, Andrej (Avtor) Dragomir, Mirela (Avtor) quantum spin liquidsingle-crystal growthmagnetic propertiesfluxrare-earth tantalatesSingle crystals are essential for characterizing a wide range of magnetic states, including exotic ones such as quantum spin liquids. This study reports a flux method for growing single crystals of NdTa7O19, the first quantum spin liquid candidate on a triangular spin-lattice with dominant Ising-like spin correlations. Purple NdTa7O19 single crystals with hexagonal morphology were successfully grown by using a K2Mo3O10–B2O3 flux. With lateral sizes up to 3.5 mm and a thickness up to 2 mm, these are the largest dimensions reported to date. The chemical composition was confirmed by powder and single-crystal X-ray diffraction along with scanning electron microscopy with energy dispersive X-ray spectroscopy. Aiming for an accurate determination of the magnetic anisotropy and its effect on the magnetic properties, NdTa7O19 crystals were additionally analyzed by magnetic susceptibility, revealing a substantial anisotropy without long-range magnetic ordering down to 2 K. Single crystals of two novel rare-earth heptatantalates, ErTa7O19 and GdTa7O19, were also grown, and their magnetic properties investigated. The magnetic anisotropy of ErTa7O19 closely resembles that of isostructural NdTa7O19, indicating the possibility of a similar exotic magnetic ground state. In contrast, GdTa7O19 shows paramagnetic behavior, consistent with previous results obtained for polycrystalline samples.American Chemical Society20252025-07-14 11:00:57Neznano22972UDK: 546ISSN pri članku: 1528-7505DOI: 10.1021/acs.cgd.5c00624COBISS_ID: 238455811ZDAsl© 2025 The Authors.