Optimized flux single-crystal growth of the quantum spin liquid candidate NdTa$_7$O$_{19}$ and other rare-earth heptatantalates, ErTa$_7$O$_{19}$ and GdTa$_7$O$_{19}$

Šibav, Lia (author), Lozinšek, Matic (author), Jagličić, Zvonko (author), Arh, Tina (author), Khuntia, Panchanana (author), Zorko, Andrej (author), Dragomir, Mirela (author)

Single 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 NdTa$_7$O$_{19}$, the first quantum spin liquid candidate on a triangular spin-lattice with dominant Ising-like spin correlations. Purple NdTa$_7$O$_{19}$ single crystals with hexagonal morphology were successfully grown by using a K$_2$Mo$_3$O$_{10}$−B$_2$O$_3$ 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, NdTa$_7$O$_{19}$ 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, ErTa$_7$O$_{19}$ and GdTa$_7$O$_{19}$, were also grown, and their magnetic properties investigated. The magnetic anisotropy of ErTa$_7$O$_{19}$ closely resembles that of isostructural NdTa$_7$O$_{19}$, indicating the possibility of a similar exotic magnetic ground state. In contrast, GdTa$_7$O$_{19}$ shows paramagnetic behavior, consistent with previous results obtained for polycrystalline samples.

• Language: English
• Keywords: quantum spin liquid, single-crystal growth, magnetic properties, flux, rare-earth tantalates, crystal structure, crystallization, crystals
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering; FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: Str. 4646-4654
• Numbering: Vol. 25, iss. 12
• PID: 20.500.12556/RUL-176548
• UDC: 546
• ISSN on article: 1528-7505
• DOI: 10.1021/acs.cgd.5c00624
• COBISS.SI-ID: 238455811
• Publication date in RUL: 03.12.2025

Record is a part of a journal

• Title: Crystal growth & design
• Shortened title: Cryst. growth des.
• Publisher: American Chemical Society
• ISSN: 1528-7505
• COBISS.SI-ID: 513575449

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: kvantna spinska tekočina, gojenje monokristalov, magnetne lastnosti, talilo, redkozemeljski tantalati, magnetizem, kristali, kovine redkih zemelj