论文标题
磁性六聚体在（Na，k）$ _ 2 $ CU $ _3 $ O（SO $ _4）_3 $矿物
Magnetic hexamers interacting in layers in the (Na,K)$_2$Cu$_3$O(SO$_4)_3$ minerals
论文作者
论文摘要
合成A $ _2 $ CU $ _3 $ O（SO $ _4）_3 $ fedotovite（A = K）和Puninite（A = Na）矿物质的磁性属性和基础磁模型，以及混合的去核nakcu Nakcu $ _3 $ O（SO $ _4）_3 $报告。我们表明，所有这些化合物都包含磁性Cu $ _6 $六聚体单元，在低于100 K的温度下，它充当单个Spin-1实体。这些磁分子之间的弱相互作用导致低于$ t_n $ = 3.4 k（a = na），4.7 k（a = nak）和约3.0 k（a = k）的远距离顺序。从头算计算阐明了磁性顺序的形成，这些计算揭示了晶体学$ bc $ bl $ bc $ bc $ bc $ bc $ bc $的二维相互作用。该模型表明存在$ s = 1 $磁性的弱扭曲的正方形晶格，并挑战了A $ _2 $ CU $ _3 $ O（SO $ _4）_3 $矿物质的早期描述。
Magnetic properties and underlying magnetic models of the synthetic A$_2$Cu$_3$O(SO$_4)_3$ fedotovite (A = K) and puninite (A = Na) minerals, as well as the mixed euchlorine-type NaKCu$_3$O(SO$_4)_3$ are reported. We show that all these compounds contain magnetic Cu$_6$ hexamer units, which at temperatures below about 100 K act as single spin-1 entities. Weak interactions between these magnetic molecules lead to long-range order below $T_N$ = 3.4 K (A = Na), 4.7 K (A = NaK), and about 3.0 K (A = K). The formation of the magnetic order is elucidated by ab initio calculations that reveal two-dimensional inter-hexamer interactions within crystallographic $bc$ planes. This model indicates the presence of a weakly distorted square lattice of $S=1$ magnetic ions and challenges the earlier description of the A$_2$Cu$_3$O(SO$_4)_3$ minerals in terms of Haldane spin chains.
