标题： 孤立的自旋梯结构在Ln$_2$Ti$_9$Sb$_{11}$（Ln：La-Nd）金属中 显示英文标题

标题： Isolated spin ladders in Ln$_2$Ti$_9$Sb$_{11}$ (Ln:La-Nd) metals

摘要： 此处我们介绍了系列抗锑化物 Ln$_2$Ti$_9$Sb$_{11}$ (Ln: La--Nd) 的发现和表征，这些物质表现出良好分离的$n=2$稀土自旋梯结构。 我们讨论了新化合物的结构，特别关注磁性 Ln 自旋梯结构。 Nd$_2$Ti$_9$Sb$_{11}$和 Ce$_2$Ti$_9$Sb$_{11}$展现反铁磁相互作用和一个定义明确的双态基态，而 Pr$_2$Ti$_9$Sb$_{11}$展现弱磁单态基态。 Nd$_2$Ti$_9$Sb$_{11}$是一种不良金属，在300K时电阻率为0.1m$\Omega$-cm，具有较弱的温度依赖性。 沿着梯子方向的热导率在40K时表现出显著的场依赖性，远高于磁序温度1.1K。 与含有过渡金属自旋梯的化合物相比，稀土元素赋予了更低的能量尺度，使得这些化合物对外部刺激（如磁场）高度可调。 稀土离子的多样磁性和RKKY相互作用进一步促进了丰富磁性基态的潜在可能性，使这些材料成为无机方形自旋梯平台的一个罕见例子。 显示英文摘要

摘要： Here we present the discovery and characterization of a series of antimonides Ln$_2$Ti$_9$Sb$_{11}$ (Ln: La--Nd) which exhibit well-isolated, $n=2$ rare-earth spin ladders. We discuss the structure of the new compounds, with a particular focus on the magnetic Ln spin ladders. Nd$_2$Ti$_9$Sb$_{11}$ and Ce$_2$Ti$_9$Sb$_{11}$ exhibit antiferromagnetic interactions and a well-defined doublet ground state, whereas Pr$_2$Ti$_9$Sb$_{11}$ exhibits a weakly magnetic singlet ground state. Nd$_2$Ti$_9$Sb$_{11}$ is a poor metal with an electrical resistivity of 0.1m$\Omega$-cm at 300K and weak temperature dependence. The thermal conductivity along the ladder exhibits significant field dependence even at 40K, considerably higher than the magnetic ordering temperature of 1.1K. Compared to compounds with transition metal spin ladders, the rare-earth elements impart much lower energy scales, making these compounds highly tunable with external stimuli like magnetic fields. The diverse magnetism of the rare-earth ions and RKKY interactions further contribute to the potential for a wide array of rich magnetic ground states, positioning these materials as a rare example of an inorganic square spin-ladder platform.