Spin liquid ground state in the frustrated J1-J2 zigzag chain system BaTb2O4

We have investigated polycrystalline samples of the zigzag chain system BaTb${}_2$O${}_4$ with a combination of magnetic susceptibility, heat capacity, neutron powder diffraction, and muon spin relaxation measurements. Despite the onset of Tb${}^{3+}$ short-range antiferromagnetic correlations at $\mathrm{\mid }{\theta }_{CW}\mathrm{\mid }$ $=$ 18.5 K and a very large effective moment, our combined measurements indicate that BaTb${}_2$O${}_4$ remains paramagnetic down to 0.095 K. The magnetic properties of this material show striking similarities to the pyrochlore antiferromagnet Tb${}_2$Ti${}_2$O${}_7$, and therefore we propose that BaTb${}_2$O${}_4$ is a new large moment spin liquid candidate.