Tuning the Magnetic Anisotropy of Single Molecules
Tuning the Magnetic Anisotropy of Single Molecules
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DOI：
10.1021/acs.nanolett.5b00987
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发表时间：
2015-06-01
期刊：
影响因子：
10.8
通讯作者：
Franke, Katharina J.
中科院分区：
文献类型：
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作者：
Heinrich, Benjamin W.;Braun, Lukas;Franke, Katharina J.
单个原子和分子的磁性是由原子尺度的环境决定的。一般来说，周围对称性的降低使d态分裂，使磁矩沿某些有利的方向排列。在这里，我们表明，我们可以通过操纵扫描隧道显微镜尖端吸附在Pb（111）上的单个铁（II）卟啉分子的环境来可逆地改变磁晶各向异性：当我们减少尖端分子距离时，我们首先观察到分子的轴向各向异性小幅增加，然后呈指数下降。这与之前观察到的具有额外轴向Cl配体的相同分子的单调增加形成对比（Nat. Phys. 2013, 9,705）：我们将两种物质各向异性的变化归因于分子在尖端吸引力存在下的变形，这导致了d级排列的变化。这些实验证明了通过机械控制精确调谐单个分子磁各向异性的可行性。
The magnetism, of single atoms and molecules is governed by the atomic scale environment. In general, the reduced symmetry of the surrounding splits the d states and aligns the magnetic moment along certain favorable directions. Here, we show that we can reversibly modify the magneto-crystalline anisotropy by Manipulating the environment of single iron(II) porphyrin molecules adsorbed on Pb(111) with the tip of a scanning tunneling microscope: When we decrease the tip molecule distance, we first observe a small increase followed by an exponential decrease of the axial anisotropy on the molecules. This is in contrast to the monotonous in-crease observed earlier for the same molecule with an additional axial Cl ligand (Nat. Phys. 2013, 9,705): We ascribe the changes in the anisotropy of both species to a deformation of the molecules in the presence of the attractive force of the tip, which leads to a change in the d level alignment. These experiments demonstrate the feasibility of a precise tuning of the magnetic anisotropy of an individual molecule by mechanical control.