Unravelling spin dynamics in a new triangular lattice antiferromagnet

Geometric frustration has been a hot topic in both experimental and theoretical condensed matter physic because of the possibility to realise novel magnetic ground states and exotic quantum excitations. It is well known that a triangular arrangement of magnetic moments with antiferromagnetic coupling is among the most representative models in frustrated magnetism. We have recently synthesised a new layered triangular lattice compound NdMgAl11O19 in which Nd3+ ions are arranged into a perfect triangular lattice in the ab plane. In order to unravel the unusual spin dynamics in NdMgAl11O19, we would like to propose a comprehensive muSR study of a large quantity powder sample (~5 g) in the temperature range of 0.05-20 K at the RIKEN-RAL muon instrument ARGUS or CHRONUS. We request 3 days of beamtime.

几何阻挫（Geometric Frustration）因有望实现新奇磁基态与奇异量子激发，已成为实验与理论凝聚态物理领域的研究热点。众所周知，具备反铁磁耦合的磁矩三角排布是阻挫磁学中最具代表性的模型之一。我们近期合成了一种新型层状三角晶格化合物NdMgAl11O19，其中Nd³⁺离子在ab晶面内构成完美的三角晶格阵列。为阐明NdMgAl11O19中非同寻常的自旋动力学特性，我们提议对约5克的粉末样品开展系统性μ子自旋共振（muSR）研究，实验温度区间为0.05~20 K，拟使用RIKEN-RAL实验室的μ子束线仪器ARGUS或CHRONUS。我们申请3天的束流时间。