Tuning the Ferromagnetic Coupling of Fe Nanodots on Cu(111) via Dimensionality Variation of the Mediating Electrons
Tuning the Ferromagnetic Coupling of Fe Nanodots on Cu(111) via Dimensionality Variation of the Mediating Electrons
复制标题
通过介导电子的维度变化调节 Cu(111) 上 Fe 纳米点的铁磁耦合
DOI：
10.1103/physrevlett.104.167202
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发表时间：
2010-04-23
影响因子：
8.6
通讯作者：
Shen, Jian
中科院分区：
文献类型：
--
作者：
Yin, Lifeng;Xiao, Di;Shen, Jian
利用原位磁光克尔效应测量和唯象模型，研究了弯曲Cu（111）衬底上Fe纳米点在不同邻域内的磁化强度各向异性和磁耦合的可调谐性。我们观察到，随着平台宽度w减小，磁化各向异性单调增加，当w小于纳米点尺寸d时更快。相反，磁耦合强度也增加，直到w类似于d，之后它急剧下降。这些惊人的观察结果可以通过调用介导点间耦合的表面电子的违反直觉的维度变化来合理化：当w >= d时，电子被限制为一维（1D），但当w < d时，由于纳米点桥接的台阶上的增强的电子溢出，电子变成准2D。
Using in situ magneto-optical Kerr effect measurements and phenomenological modeling, we study the tunability in both the magnetization anisotropy and magnetic coupling of Fe nanodots on a curved Cu(111) substrate with varying vicinity. We observe that, as the terrace width w decreases, the magnetization anisotropy increases monotonically, faster when w is smaller than the nanodot size d. In contrast, the magnetic coupling strength also increases until w similar to d, after which it decreases steeply. These striking observations can be rationalized by invoking the counterintuitive dimensionality variation of the surface electrons mediating the interdot coupling: the electrons are confined to be one dimensional (1D) when w >= d, but become quasi-2D when w < d due to enhanced electron spillover across the steps bridged by the nanodots.