Mapping the spin correlations in the single crystal of a novel triangular lattice antiferromagnet ErTa7O19

Rare-earth (RE) based geometrically frustrated magnets represent a promising avenue in the search of enigmatic quantum spin liquids (QSLs). Our previous study has identified a novel family of RE heptatantalates RETa7O19, where in the Nd case strong Ising anisotropy on the triangular lattice leads to a QSL state. As the nature of the RE ions can strongly influence the magnetic anisotropy we initiated a study of isostructural ErTa7O19 with twice stronger magnetic interactions. Recent neutron diffraction measurements done on the WISH instrument revealed sizable magnetic diffuse scattering as a signature of short-range spin correlations. Here we propose a single crystal neutron diffraction study on the WISH instrument to map and compare the in-plane and out-of-plane spin correlations in the reciprocal space.

基于稀土（Rare-earth, RE）的几何阻挫磁体，是探寻神秘量子自旋液体（Quantum Spin Liquids, QSLs）的极具潜力的研究方向。我们此前的研究已发现一类新型稀土七钽酸盐RETa7O19家族，其中钕（Nd）基体系在三角晶格上呈现出强伊辛各向异性，进而催生了量子自旋液体态。鉴于稀土离子的固有属性可显著调控磁各向异性，我们启动了对磁相互作用强度翻倍的同构体系ErTa7O19的研究。近期在WISH谱仪上开展的中子衍射测量结果显示，存在显著的磁漫散射信号，这正是短程自旋关联的特征。在此，我们提议利用WISH谱仪开展单晶体中子衍射实验，以测绘并对比倒易空间内的面内与面外自旋关联特性。