A spin-selective approach for surface states at Co nanoislands
A spin-selective approach for surface states at Co nanoislands
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DOI：
10.1140/epjb/e2010-00054-1
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发表时间：
2010-05-01
影响因子：
1.6
通讯作者：
Bucher, J. P.
中科院分区：
文献类型：
--
作者：
Heinrich, B. W.;Iacovita, C.;Bucher, J. P.
近年来，人们对Cu（111）和Au（111）上生长的钴纳米岛的表面电子态进行了广泛的研究，并取得了令人着迷的结果。在磁性表面中，钴岛特别吸引人，因为它们在费米能量附近的自旋极化电子态，包括少数特征的局域d态，以及多数特征的自由s-p态。我们在这里表明，这些状态是对结构细节（如应变和堆叠）微小变化的敏感探针，因此构成了研究结构和自旋相关性质之间相互作用的理想场所。由于它们的大小，Cu（111）上的钴岛提供了额外的机会来容纳适合自旋极化扫描隧道显微镜和光谱（SP-STM和SP-STS）的单磁吸附。我们在这里建立了，在刚好低于费米能级的能量区间内，过渡金属原子的自旋极化是由与岛相相反的表面诱导态控制的，而酞菁分子的自旋极化是由分子态控制的。这为在纳米尺度上控制和设计自旋极化现象开辟了有趣的前景。
During recent years the surface electronic states of cobalt nanoislands grown on Cu(111) and Au(111) have been extensively studied and still yield fascinating results. Among magnetic surfaces, cobalt islands are particularly appealing because of their spin-polarized electronic states near the Fermi energy, involving localized d states of minority character, as well as free-like s-p states of majority character. We show here that these states are a sensitive probe to minute changes of structural details such as strain and stacking, and therefore constitute an ideal playground to study the interplay between structural and spin-related properties. Due to their size, cobalt islands on Cu(111) offer the additional opportunity to host single-magnetic adsorbates suitable for spin-polarized scanning tunneling microscopy and spectroscopy (SP-STM and SP-STS). We establish here that, in an energy interval just below the Fermi level, the spin-polarization of a transition-metal atom is governed by surface-induced states opposite in sign compared to the island, while the spin-polarization of Co-Phthalocyanine molecules is governed by molecular states. This opens up interesting perspectives for controlling and engineering spin-polarized phenomena at the nanoscale.