Driving spin transition at interface: Role of adsorption configurations

作者：Zhang, Yachao^*

来源：Journal of Chemical Physics, 2018, 148(4): 044706.

DOI：10.1063/1.5007739

• DENSITY-FUNCTIONAL THEORY
• AUGMENTED-WAVE METHOD
• MOLECULAR SPINTRONICS
• CROSSOVER SYSTEMS
• STATE ENERGETICS
• 3D METALLOCENES
• MANGANOCENE
• GRAPHENE
• INSIGHTS
• SURFACE

A clear insight into the electrical manipulation of molecular spins at interface is crucial to the design of molecule-based spintronic devices. Here we report on the electrically driven spin transition in manganocene physisorbed on a metallic surface in two different adsorption configurations predicted by ab initio techniques, including a Hubbard-U correction at the manganese site and accounting for the long-range van der Waals interactions. We show that the application of an electric field at the interface induces a high-spin to low-spin transition in the flat-lying manganocene, while it could hardly alter the high-spin ground state of the standing-up molecule. This phenomenon cannot be explained by either the molecule-metal charge transfer or the local electron correlation effects. We demonstrate a linear dependence of the intra-molecular spin-state splitting on the energy difference between crystal-field splitting and on-site Coulomb repulsion. After considering the molecule-surface binding energy shifts upon spin transition, we reproduce the obtained spin-state energetics. We find that the configuration-dependent responses of the spin-transition originate from the binding energy shifts instead of the variation of the local ligand field. Through these analyses, we obtain an intuitive understanding of the effects of molecule-surface contact on spin-crossover under electrical bias. Published by AIP Publishing.

• 出版日期2018-1-28
• 单位贵州师范学院