Quantum magnetic properties of the spin-1/2 triangular-lattice antiferromagnet Ba2La2CoTe2O12

Abstract

We report the crystal structure of Ba2La2CoTe2O12 determined by Rietveld analysis using x-ray powder-diffraction data. It was found from magnetic measurements that Ba2La2CoTe2O12 can be described as a spin-12 triangular-lattice antiferromagnet with easy-plane anisotropy at low temperatures. This compound undergoes a magnetic phase transition at TN=3.26K to an ordered state with the 120∘ structure. The magnetization curve exhibits the one-third plateau characteristic of triangular-lattice quantum antiferromagnets. The antiferromagnetic exchange interaction and the g factors parallel and perpendicular to the c axis were evaluated to be J/kB=22K,g∥=3.5, and g⊥=4.5, respectively. ©2018 American Physical Society