Wu Wei
London Centre for Nanotechnology, University College London, Gower Street, London, WC1E 6BT, UK.
J Phys Condens Matter. 2014 Jul 23;26(29):296002. doi: 10.1088/0953-8984/26/29/296002. Epub 2014 Jul 3.
The magnetic properties of a theoretically designed molecular chain structure CuCoPc2, in which copper-phthalocyanine (CuPc) and cobalt-phthalocyanine (CoPc) alternate, have been investigated across a range of chain structures. The computed exchange interaction for the α-phase CuCoPc2 is ∼ 5 K (ferromagnetic), in strong contrast to the anti-ferromagnetic interaction recently observed in CuPc and CoPc. The computed exchange interactions are strongly dependent on the stacking angle but weakly on the sliding angle, and peak at 20 K (ferromagnetic). These ferromagnetic interactions are expected to arise from direct exchange with the strong suppression of super-exchange interaction. These first-principles calculations show that π-conjugated molecules, such as phthalocyanine, could be used as building blocks for the design of magnetic materials. This therefore extends the concept of quantum metamaterials further into magnetism. The resulting new magnetic materials could find applications in the studies such as organic spintronics.
对理论设计的分子链结构CuCoPc2的磁性进行了研究，其中铜酞菁（CuPc）和钴酞菁（CoPc）交替排列，研究范围涵盖了一系列链结构。计算得出α相CuCoPc2的交换相互作用约为5 K（铁磁性），这与最近在CuPc和CoPc中观察到的反铁磁相互作用形成强烈对比。计算得出的交换相互作用强烈依赖于堆积角，而对滑动角的依赖性较弱，并且在20 K（铁磁性）时达到峰值。这些铁磁相互作用预计源于直接交换，同时超交换相互作用受到强烈抑制。这些第一性原理计算表明，诸如酞菁之类的π共轭分子可作为磁性材料设计的构建单元。因此，这将量子超材料的概念进一步扩展到了磁性领域。由此产生的新型磁性材料可能在有机自旋电子学等研究中找到应用。
