标题： 三聚体结构与磁性基态在Ba5Ru3O12中的相互作用通过中子和muSR技术探测 显示英文标题

标题： Interplay between trimer structure and magnetic ground state in Ba5Ru3O12 probed by Neutron and muSR techniques

摘要： 我们报告了对三聚体钌酸盐Ba5Ru3O12系统的详细非弹性中子散射（INS）和穆斯鲍尔谱（muSR）研究，该系统在TN = 60 K时发生长程反铁磁有序。INS显示在TN以下存在两种不同的自旋波激发：一种在5.6 meV附近，另一种在10至15 meV之间。 这种在低和高动量转移区域同时存在的激发被推测是由于钌的强电子关联和自旋-声子耦合。 通过使用SpinW软件基于线性自旋波理论的INS光谱，我们表明Ba5Ru3O12由于相邻和次邻近Ru-矩之间的竞争交换相互作用、交换各向异性和强自旋-轨道耦合而表现出自旋挫折，导致非共线自旋结构，这与其他该系列中的钌酸盐三聚体不同。 有趣的是，这些磁激发即使在高于TN的高温下也并未完全消失，证明了该三聚体系统中存在短程磁关联。 这进一步得到了muSR光谱的支持，该光谱在磁相变附近显示出初始不对称性的逐渐下降，并通过最大熵分析进一步验证。 muSR光谱的结果表明磁序具有动态特性，这是由于三聚体内的局部磁各向异性所致，这是局部结构畸变和不同杂化的结果，与倾斜的自旋结构一致。 我们通过理论计算预测了Ru3O12孤立三聚体的基态，其结果与实验观察到的自旋激发一致。 显示英文摘要

摘要： We report a detailed inelastic neutron scattering (INS) and muon spin relaxation (muSR) investigations of a trimer Ruthenate Ba5Ru3O12 system, which undergoes long-range antiferromagnetic ordering at TN = 60 K. The INS reveals two distinct spin-wave excitations below TN : one around 5.6 meV and the other at 10 to 15 meV. The coexistence of such excitations at both low and high momentum transfer regions is speculated to be strong electronic correlation and spin-phonon coupling of Ruthenium. By accompanying the INS spectra based on a linear spin wave theory using SpinW software, we show that Ba5Ru3O12 exhibits spin frustration due to competing exchange interactions between neighboring and next-neighboring Ru-moments, exchange anisotropy and strong spin-orbit coupling, which yields a non-collinear spin structure, in contrast to other ruthenate trimers in this series. Interestingly, these magnetic excitations does not completely vanish even at high temperatures above TN , evidencing short-range magnetic correlations in this trimer system. This is further supported by muSR spectroscopy, which exhibits a gradual drop in the initial asymmetry around the magnetic phase transition and is further verified through maximum entropy analysis. The results of muSR spectroscopy indicates a dynamic nature of magnetic order, attributed to local magnetic anisotropy within the trimer as a result of local structural distortion and different hybridization, consistent with canted spin-structure. We predict the ground state of Ru3O12-isolated trimer through theoretical calculations which agree with the experimentally observed spin excitation.