论文标题
Spin-1 Trimer链中的激发化合物CANI3P4O14：与无间隙磁激发的分散式旋转
Excitations in the spin-1 trimer chain compound CaNi3P4O14: gapped dispersive spinwaves to gapless magnetic excitations
论文作者
论文摘要
已经通过非弹性中子中子散射研究了Spin-1 J1-J1-J2三聚体链CANI3P4O14的磁激发和自旋哈密顿量。实验数据表明，在3D远程有序的磁态（TC = 16 K）中，分散性旋转波激发和TC上方的无间隙磁激发。通过使用线性自旋波理论，模拟磁激发，用于耦合三聚体旋转链模型，可以很好地描述观察到的实验数据。该分析揭示了链内的铁磁J1和J2相互作用，以及链之间的抗铁磁互链相互作用J3。发现J1和J2的强度更近（J2/ J1〜0.81），并且J3被确定为弱（J3/ J1〜0.69），这与自旋链型晶体结构一致。还揭示了弱的单离子 - 肛门反相（d/j = 0.19）的存在。交换相互作用的优势和迹象解释了为什么在研究的Spin-1复合CANI3P4O14中不存在1/3磁化，而其S = 5/2基于MN的同一物质化合物。交换相互作用的迹象与从报告的DFT计算中获得的迹象一致，而发现它们的优势显着不同。 CANI3P4O14中J3的相对较强的值给出了TC以下的常规3D型磁顺序，但是，在TC上方保留其1D字符。本实验研究还表明，TC上单离子各向异性发生了急剧变化，表明CANI3P4O14中3D磁有序的稳定性归因于局部磁各向异性，除了链相互作用外。本研究泄露了对三聚体自旋链化合物中交换相互作用的全面知识的重要性，以了解其外来的磁性特性，例如1/3磁化高原。
Magnetic excitations and the spin Hamiltonian of the spin-1 J1-J1-J2 trimer chain compound CaNi3P4O14 have been investigated by inelastic neutron scattering. Experimental data reveal gapped dispersive spin wave excitations in the 3D long-range ordered magnetic state (TC = 16 K), and gapless magnetic excitations above the TC. Simulated magnetic excitations, by using the linear spin wave theory, for a model of coupled trimer spin-chains provide a good description of the observed experimental data. The analysis reveals both ferromagnetic J1 and J2 interactions within the chains, and an antiferromagnetic interchain interaction J3 between chains. The strengths of the J1 and J2 are found to be closer (J2/J1 ~ 0.81), and J3 is determined to be weaker (J3/ J1 ~ 0.69), which is consistent with the spin chain type crystal structure. Presence of a weak single-ion-anisotropy (D/J=0.19) is also revealed. The strengths and signs of exchange interactions explain why the 1/3 magnetization is absent in the studied spin-1 compound CaNi3P4O14 in contrast to its S= 5/2 counterpart Mn based isostructural compound. The signs of the exchange interactions are in agreement with that obtained from the reported DFT calculations, whereas, their strengths are found to be significantly different. The relatively strong value of the J3 in CaNi3P4O14 gives a conventional 3D type magnetic ordering below the TC, however, retains its 1D character above the TC. The present experimental study also reveals a sharp change of single-ion anisotropy across the TC indicating that the stability of the 3D magnetic ordering in CaNi3P4O14 is ascribed to the local magnetic anisotropy in addition to interchain interactions. The present study divulges the importance of full knowledge of the exchange interactions in trimer spin chain compounds to understand their exotic magnetic properties, such as 1/3 magnetization plateau.
