Quantum magnetic properties of the spin-1/2 triangular-lattice antiferromagnet Ba$_2$La$_2$CoTe$_2$O$_{12}$

TL;DR

This study characterizes the crystal structure and magnetic properties of Ba$_2$La$_2$CoTe$_2$O$_{12}$, revealing it as a quantum spin-1/2 triangular-lattice antiferromagnet with a characteristic 120-degree magnetic order and a one-third magnetization plateau.

Contribution

It provides the first detailed structural and magnetic analysis of Ba$_2$La$_2$CoTe$_2$O$_{12}$ as a quantum triangular-lattice antiferromagnet with easy-plane anisotropy.

Findings

Displays a magnetic transition at 3.26 K to a 120-degree ordered state.

Shows a one-third magnetization plateau characteristic of triangular-lattice quantum antiferromagnets.

Has an antiferromagnetic exchange interaction J/k_B = 22 K and anisotropic g-factors.

Abstract

We report the crystal structure of Ba$_2$La$_2$CoTe$_2$O$_{12}$ determined by Rietveld analysis using X-ray powder diffraction data. It was found from magnetic measurements that Ba$_2$La$_2$CoTe$_2$O$_{12}$ can be described as a spin-1\2 triangular-lattice antiferromagnet with easy-plane anisotropy at low temperatures. This compound undergoes a magnetic phase transition at $T_{\rm N}\,{=}\,3.26$ K to an ordered state with the $120^{\circ}$ 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 $J/k_{\rm B}\,{=}\,22$ K, $g_{\parallel}\,{=}\,3.5$ and $g_{\perp}\,{=}\,4.5$, respectively.