Strong exchange and magnetic blocking in N23--radical-bridged lanthanide complexes
Strong exchange and magnetic blocking in N23--radical-bridged lanthanide complexes
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DOI：
10.1038/nchem.1063
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发表时间：
2011-07-01
期刊：
影响因子：
21.8
通讯作者：
Long, Jeffrey R.
中科院分区：
文献类型：
--
作者：
Rinehart, Jeffrey D.;Fang, Ming;Long, Jeffrey R.
单分子磁体接近自旋设备的极限尺寸。这些配合物可以在低温下长时间保持自旋信息，这表明它们可能在高密度信息存储、量子计算和自旋电子学中应用。值得注意的是，大多数此类应用的成功取决于提高分子固有的自旋反转势垒。虽然最近的进展表明，含镧的络合物在产生大的势垒方面是可行的，但弱的或不存在的磁交换耦合允许快速的驰豫路径，从而减轻这些物种的全部潜力。在这里，我们证明了N-2(3-)自由基桥的扩散自旋可以导致双核Ln(II)(Ln=Gd，Dy)配合物中极强的磁交换。Gd(III)同系物对Gd(III)离子表现出迄今所观察到的最强的磁耦合，而高各向异性Dy(III)离子的掺入产生了一个在0.08T S(-1)扫描速度下的记录磁阻塞温度8.3K的分子。
Single-molecule magnets approach the ultimate size limit for spin-based devices. These complexes can retain spin information over long periods of time at low temperature, suggesting possible applications in high-density information storage, quantum computing and spintronics. Notably, the success of most such applications hinges upon raising the inherent molecular spin-inversion barrier. Although recent advances have shown the viability of lanthanide-containing complexes in generating large barriers, weak or non-existent magnetic exchange coupling allows fast relaxation pathways that mitigate the full potential of these species. Here, we show that the diffuse spin of an N-2(3-) radical bridge can lead to exceptionally strong magnetic exchange in dinuclear Ln(II) (Ln = Gd, Dy) complexes. The Gd(III) congener exhibits the strongest magnetic coupling yet observed for that ion, while incorporation of the high-anisotropy Dy(III) ion gives rise to a molecule with a record magnetic blocking temperature of 8.3 K at a sweep rate of 0.08 T s(-1).