Synthesis, disorder and Ising anisotropy in a new spin liquid candidate PrMgAl$_{11}$O$_{19}$

TL;DR

This study reports the synthesis of large single crystals of PrMgAl$_{11}$O$_{19}$, revealing Ising anisotropy and persistent spin liquid behavior despite disorder, providing a new platform for exploring frustrated magnetism.

Contribution

It introduces a new spin liquid candidate with large single crystals, detailed disorder analysis, and characterization of Ising anisotropy in PrMgAl$_{11}$O$_{19}$.

Findings

Large single crystals successfully synthesized.

Presence of quenched disorder in the crystal structure.

No magnetic order or freezing down to 50 mK.

Abstract

Here we report the successful synthesis of large single crystals of triangular frustrated PrMgAl$_{11}$O$_{19}$ using the optical floating zone technique. Single crystal X-ray diffraction measurements unveiled the presence of quenched disorder within the mirror plane, specifically $\sim$7\% of Pr ions deviating from the ideal 2\textit{d} site towards the 6\textit{h} site. Magnetic susceptibility measurements revealed an Ising anisotropy with the \textit{c}-axis being the easy axis. Despite a large spin-spin interaction that develops below $\sim$10~K and considerable site disorder, the spins do not order or freeze down to at least 50 mK. The availability of large single crystals offers a distinct opportunity to investigate the exotic magnetic state on a triangular lattice with an easy axis out of the plane.