Magnetic excitation in a triangular lattice frustrated magnet NdMgAl11O19

Recently, powder samples of hexaaluminates REMgAl11O19 (RE = Pr, Nd) that have an ideal 2D triangular lattice of real earth ions have been synthesized. The evidence of significant antiferromagnetic interactions makes them a platform to investigate quantum spins on a triangular lattice. Nd3+ with Jeff =1/2 Kramer’s doublet ground state has been studied in many pyrochlore compounds but very few Nd-based triangular lattices. Therefore, it would interesting to study the magnetic properties of NdMgAl11O19, which has Nd3+ (4f3 4I9/2) ions and a perfect triangular lattice. It has less disorder than other triangular lattice QSL candidates like YbMgGaO4 and NaYbSe2. Our recent INS experiment on the isostructural CeMgAl11O19 shows a continuum of excitation around 0.1 meV at 0 field and spin waves around 1 meV under 4 T fields along the c-axis. A comparative INS experiment on NdMgAl11O19 could provide unique insights into the possibility of QSL physics on the triangular lattices.