Synthesis, disorder and Ising anisotropy in a new spin liquid candidate PrMgAl11O19

Abstract

Here we report the successful synthesis of large single crystals of triangular frustrated PrMgAl11O19 using the optical floating zone technique. Single crystal Xray diffraction measurements unveiled the presence of quenched disorder within the mirror plane, specifically ∼7% of Pr ions deviating from the ideal 2d site towards the 6h site. Magnetic susceptibility measurements revealed an Ising anisotropy with the c-axis being the easy axis. Despite a large spin-spin interaction that develops below ∼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.