Spatially Resolved Magnetic Anisotropy of Cobalt Nanostructures on the Au(111) Surface
Spatially Resolved Magnetic Anisotropy of Cobalt Nanostructures on the Au(111) Surface
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Au(111) 表面钴纳米结构的空间分辨磁各向异性
DOI：
10.1021/acs.nanolett.7b03114
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发表时间：
2017
期刊：
影响因子：
10.8
通讯作者：
T. Komeda
中科院分区：
文献类型：
--
作者：
P. Mishra;Z. K. Qi;H. Oka;K. Nakamura;T. Komeda
了解表面支撑纳米团簇中垂直磁各向异性的起源对于基础研究和数据存储应用至关重要。在这里，我们使用 4.6 K 下的自旋偏振扫描隧道显微镜和第一原理理论计算研究了 Au(111) 基板上双层钴岛的垂直磁各向异性能量 (MAE)。 Au(111) 基底是研究成核位点和堆积顺序对 MAE 影响的优秀模型系统。我们的测量表明，双层岛的 MAE 很大程度上取决于两个 Co 层的晶体堆叠和第三层的成核。此外，Au(111) 上 Co 原子的 MAE 比 Cu(111) 上报道的 MAE 提高了 1.75 倍。我们的第一性原理计算将这种增强归因于金原子的大自旋轨道耦合。我们的结果强调了 Co 岛纳米级结构变化对 MAE 的强烈影响，并强调了空间分辨测量对于表面支撑纳米结构磁性表征的重要性。
Understanding the origin of perpendicular magnetic anisotropy in surface-supported nanoclusters is crucial for fundamental research as well as data storage applications. Here, we investigate the perpendicular magnetic anisotropy energy (MAE) of bilayer cobalt islands on Au(111) substrate using spin-polarized scanning tunneling microscopy at 4.6 K and first-principles theoretical calculations. Au(111) substrate serves as an excellent model system to study the effect of nucleation site and stacking sequence on MAE. Our measurements reveal that the MAE of bilayer islands depends strongly on the crystallographic stacking of the two Co layers and nucleation of the third layer. Moreover, the MAE of Co atoms on Au(111) is enhanced by a factor of 1.75 as compared to that reported on Cu(111). Our first-principles calculations attribute this enhancement to the large spin–orbit coupling of the Au atoms. Our results highlight the strong impact of nanometer-scale structural changes in Co islands on MAE and emphasize the importance of spatially resolved measurements for the magnetic characterization of surface-supported nanostructures.