Breaking through the nitrogen ceiling Single-molecule magnets could prove useful in miniaturizing a wide variety of devices. However, their application has been severely hindered by the need to cool them to extremely low temperature using liquid helium. Guo et al. now report a dysprosium compound that manifests magnetic hysteresis at temperatures up to 80 kelvin. The principles applied to tuning the ligands in this complex could point the way toward future architectures with even higher temperature performance. Science, this issue p. 1400 Ligand tuning raises the upper temperature for hysteresis in a single-molecule magnet just above nitrogen’s boiling point. Single-molecule magnets (SMMs) containing only one metal center may represent the lower size limit for molecule-based magnetic information storage materials. Their current drawback is that all SMMs require liquid-helium cooling to show magnetic memory effects. We now report a chemical strategy to access the dysprosium metallocene cation [(CpiPr5)Dy(Cp*)]+ (CpiPr5, penta-iso-propylcyclopentadienyl; Cp*, pentamethylcyclopentadienyl), which displays magnetic hysteresis above liquid-nitrogen temperatures. An effective energy barrier to reversal of the magnetization of Ueff = 1541 wave number is also measured. The magnetic blocking temperature of TB = 80 kelvin for this cation overcomes an essential barrier toward the development of nanomagnet devices that function at practical temperatures.

中文翻译：

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镝茂金属单分子磁体的磁滞高达 80 开尔文

突破氮上限 单分子磁铁可证明可用于使各种设备小型化。然而，由于需要使用液氦将它们冷却到极低的温度，它们的应用受到了严重阻碍。郭等人。现在报告了一种镝化合物，它在高达 80 开尔文的温度下表现出磁滞。应用于调整该复合物中配体的原理可以为未来具有更高温度性能的架构指明方向。科学，这个问题 p。1400 配体调谐将单分子磁体中磁滞的上限温度提高到刚好高于氮沸点。仅包含一个金属中心的单分子磁体 (SMM) 可能代表基于分子的磁信息存储材料的尺寸下限。他们目前的缺点是所有 SMM 都需要液氦冷却来显示磁记忆效应。我们现在报告了一种化学策略来获取镝茂金属阳离子 [(CpiPr5)Dy(Cp*)]+（CpiPr5，五异丙基环戊二烯基；Cp*，五甲基环戊二烯基），它在液氮温度以上显示磁滞。还测量了 Ueff = 1541 波数的磁化反转的有效能垒。该阳离子的磁性阻挡温度 TB = 80 开尔文克服了开发在实际温度下起作用的纳米磁体器件的基本障碍。五甲基环戊二烯基），在液氮温度以上显示磁滞。还测量了 Ueff = 1541 波数的磁化反转的有效能垒。该阳离子的磁性阻挡温度 TB = 80 开尔文克服了开发在实际温度下起作用的纳米磁体器件的基本障碍。五甲基环戊二烯基），在液氮温度以上显示磁滞。还测量了 Ueff = 1541 波数的磁化反转的有效能垒。该阳离子的磁性阻挡温度 TB = 80 开尔文克服了开发在实际温度下起作用的纳米磁体器件的基本障碍。