REZnAl11O19 (RE = Pr, Nd, Sm–Tb): a new family of ideal 2D triangular lattice frustrated magnets

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 7; no. 32; pp. 10073 - 10081
• Main Authors: Ashtar, M, Marwat, M A, Gao, Y X, Zhang, Z T, L Pi, Yuan, S L, Tian, Z M
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2019
• Subjects: Antiferromagnetism; Electron spin; Frustration; Lattices; Magnetic properties; Magnetic transitions; Magnets; Praseodymium; Rare earth elements; Spin liquid; Structural analysis
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c9tc02643f

We report the synthesis, structure and magnetic properties of a new family of rare-earth (RE) based magnetoplumbite-type REZnAl11O19 (RE = Pr–Tb) compounds with space-group P63/mmc. The structural analysis reveals that magnetic RE ions form layers of ideal 2D triangular-lattices in the ab-plane well separated by several nonmagnetic polyhedra layers along the c-axis. The magnetic susceptibilities reveal that the compounds display dominant antiferromagnetic (AFM) exchange interactions and there is no magnetic transition down to 2 K. As a representative, PrZnAl11O19 exhibits large magnetic frustration with frustration index f = |θCW/TN| > 23 and absence of magnetic order down to 0.43 K, serving as a promising quantum spin liquid candidate. The magnetizations combined with electron spin resonances indicate the distinct anisotropic magnetic behaviors for compounds with different RE ions. These series of compounds provide a modeling system for exploring the novel magnetic phases of RE ions on ideal 2D triangular lattices.