Department of Physics, The Ohio State University , Columbus, Ohio 43210, United States.
Nano Lett. 2014 Mar 12;14(3):1196-201. doi: 10.1021/nl404054v. Epub 2014 Feb 6.
The magnetic properties of molecular structures can be tailored by chemical synthesis or bottom-up assembly at the atomic scale. We used scanning tunneling microscopy to study charge and spin transfer in individual complexes of transition metals with the charge acceptor, tetracyanoethylene (TCNE). The complexes were formed on a thin insulator, Cu2N on Cu(100), by manipulation of individual atoms and molecules. The Cu2N layer decouples the complexes from Cu electron density, enabling direct imaging of the TCNE molecular orbitals as well as spin-flip inelastic electron tunneling spectroscopy. Results were obtained at low temperature down to 1 K and in magnetic fields up to 7 T in order to resolve splitting of spin states in the complexes. We also performed spin-polarized density functional theory calculations to compare with the experimental data. Our results indicate that charge transfer to TCNE leads to a change in spin magnitude, Kondo resonance, and magnetic anisotropy for the metal atoms.
通过化学合成或原子尺度的自下而上组装，可以调整分子结构的磁性。我们使用扫描隧道显微镜研究了单个过渡金属与电荷受体四氰乙烯（TCNE）复合物中的电荷和自旋转移。这些复合物是通过对单个原子和分子的操纵在薄绝缘体 Cu2N/Cu(100)上形成的。Cu2N 层将复合物与 Cu 电子密度隔离开来，从而能够直接成像 TCNE 分子轨道以及自旋翻转非弹性电子隧道谱。实验在低至 1 K 和高达 7 T 的磁场下进行，以分辨复合物中自旋态的分裂。我们还进行了自旋极化密度泛函理论计算，以便与实验数据进行比较。我们的结果表明，向 TCNE 的电荷转移导致金属原子的自旋大小、Kondo 共振和磁各向异性发生变化。
