We have designed and synthesized a novel magnetic cluster containing low-spin (S = 1/2) Fe³⁺ and spin-1/2 Cu²⁺ ions, which incorporates competing ferromagnetic Fe–Cu interactions and antiferromagnetic Fe–Fe and Cu–Cu interactions. This is achieved with the help of a cyanido-bridged hexanuclear iron-copper cluster [{Fe(Tp)(CN)₃}₄{Cu(MePz)₂}₂] following the building block approach. All experiments were carried out using the stable compound, [{Fe(Tp)(CN)₃}₄{Cu(MePz)₂}₂], after removing the solvent molecules at 110°C for 2 h. Unusual magnetic interactions in this compound are revealed by the temperature- and field-dependent dc magnetic measurements. These magnetic measurements indicate the existence of ferromagnetic interactions between the low-spin Fe³⁺ and Cu²⁺ ions via cyanide bridge dominating magnetic properties over a wide temperature range below ~15 K. At a still lower temperature, magnetic properties appear to be controlled by an effective antiferromagnetic interaction, possibly arising from inter-cluster couplings. Frequency-dependent ac susceptibility measurements establish a possible glassy state emerging below 4 K.

我们设计并合成了一种包含低自旋 (S = 1/2) Fe ³⁺和自旋-1/2 Cu ²⁺离子的新型磁性团簇，其中结合了竞争性铁磁 Fe-Cu 相互作用和反铁磁 Fe-Fe 和 Cu-铜相互作用。这是在氰基桥连六核铁铜簇 [{Fe(Tp)(CN) ₃ } ₄ {Cu(MePz) ₂ } ₂ ] 的帮助下实现的，遵循积木方法。所有实验均使用稳定化合物 [{Fe(Tp)(CN) ₃ } ₄ {Cu(MePz) ₂ } ₂]，在 110°C 下去除溶剂分子 2 小时后。温度和场相关的直流磁测量揭示了该化合物中不寻常的磁相互作用。这些磁性测量表明低自旋 Fe ³⁺和 Cu ²⁺离子之间存在铁磁相互作用，通过氰化物桥在低于 ~15 K 的宽温度范围内支配磁性。在更低的温度下，磁性似乎受到控制通过有效的反铁磁相互作用，可能由簇间耦合引起。频率相关的交流磁化率测量建立了一种可能出现在 4 K 以下的玻璃态。