Magnetic memory of a single-molecule quantum magnet wired to a gold surface
Magnetic memory of a single-molecule quantum magnet wired to a gold surface
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DOI：
10.1038/nmat2374
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发表时间：
2009-03-01
期刊：
影响因子：
41.2
通讯作者：
Sessoli, Roberta
中科院分区：
文献类型：
--
作者：
Mannini, Matteo;Pineider, Francesco;Sessoli, Roberta
在分子自旋电子学领域(1)，将磁性分子用于信息技术是一个主要目标，而观察表面单个分子的磁滞是发展分子存储阵列的必要步骤。虽然简单的顺磁分子沉积在铁磁表面(2)上可以表现出表面诱导的磁有序和磁滞，但分子水平的信息存储需要表现出固有剩余磁化的分子，如所谓的单分子磁体(3)(SMM)。它们因其丰富的量子行为而被深入研究(4)，但到目前为止，还没有关于各种非磁性衬底上的SMM单层的磁滞现象的报道，最可能的原因是表面团簇的化学不稳定(5)。利用X射线吸收光谱和X射线磁性圆二色同步加速器技术，将灵敏度推至极限，并在亚开尔文温度下操作，我们现在发现，坚固的、量身定做的Fe-4络合物在金表面保持磁滞。我们的结果表明，孤立的SMM可以用于存储信息。这条道路现在是开放的，以解决连接到处于受阻磁化状态的导电表面(6，7)的单个分子，从而能够在分子尺度(8，9)上研究电子传输和磁性自由度之间的基本相互作用。
In the field of molecular spintronics(1), the use of magnetic molecules for information technology is a main target and the observation of magnetic hysteresis on individual molecules organized on surfaces is a necessary step to develop molecular memory arrays. Although simple paramagnetic molecules can show surface-induced magnetic ordering and hysteresis when deposited on ferromagnetic surfaces(2), information storage at the molecular level requires molecules exhibiting an intrinsic remnant magnetization, like the so-called single-molecule magnets(3) (SMMs). These have been intensively investigated for their rich quantum behaviour(4) but no magnetic hysteresis has been so far reported for monolayers of SMMs on various non-magnetic substrates, most probably owing to the chemical instability of clusters on surfaces(5). Using X-ray absorption spectroscopy and X-ray magnetic circular dichroism synchrotron-based techniques, pushed to the limits in sensitivity and operated at sub-kelvin temperatures, we have now found that robust, tailor-made Fe-4 complexes retain magnetic hysteresis at gold surfaces. Our results demonstrate that isolated SMMs can be used for storing information. The road is now open to address individual molecules wired to a conducting surface(6,7) in their blocked magnetization state, thereby enabling investigation of the elementary interactions between electron transport and magnetism degrees of freedom at the molecular scale(8,9).