Persistent Spin Dynamics in the Ising Triangular-lattice Antiferromagnet Ba${}_6$Nd${}_2$Ti${}_4$O${}_{17}$

Abstract

We report results of magnetic susceptibility, specific heat, and muon spin relaxation ($\hat{I}¼$SR) measurements on the polycrystalline Ba${}_6$Nd${}_2$Ti${}_4$O${}_{17}$, a disorder-free triangular-lattice antiferromagnet. The absence of long-range magnetic order or spin freezing is confirmed down to 30~mK, much less than the Curie-Weiss temperature -1.8~K. The magnetic and specific heat measurements reveal the effective-1/2 spins are Ising-like. The persistent spin dynamics is determined down to 37~mK. Our study present a remarkable example of Ising spins on the triangular lattice, which remains magnetically disordered at low temperatures and potentially hosts a quantum spin liquid ground state.