Synthesis, structure and magnetism of RTa7O19 (R = Pr, Sm, Eu, Gd, Dy, Ho) with perfect triangular lattice

We present the synthesis, structure and magnetic properties of a hitherto unstudied family of rare-earth based RTa7O19 (R = Pr, Sm, Eu, Gd, Dy, Ho) compounds with space groupP 6 over line 2 c. The structural analysis reveals that magnetic R ions form layers of ideal two-dimensional triangular lattices in the ab-plane separated by several nonmagnetic polyhedra layers along the c-axis. The magnetic susceptibility and magnetization measurements indicate the absence of long-range magnetic order and field-induced magnetic transitions in all the studied compounds. The details about the magnetism strongly depend on the type of R ions. The presence of geometrical frustration is discussed. Thus, RTa7O19 provides a new platform for exploring the frustrated magnetism.(c) 2022 Published by Elsevier B.V.

Automated summary

We present the synthesis, structure, and magnetic properties of a previously unexplored family of rare-earth based RTa7O19 compounds. Structural analysis reveals that magnetic R ions form ideal two-dimensional triangular lattice layers in the ab-plane, separated by nonmagnetic polyhedra layers along the c-axis. Magnetic susceptibility and magnetization measurements demonstrate the absence of long-range magnetic order and field-induced magnetic transitions in all studied compounds. The details of the magnetism strongly depend on the type of R ions. The presence of geometrical frustration is discussed. Thus, RTa7O19 offers a new platform for exploring frustrated magnetism.