Faculty of Physics and Center for Computational Materials Science, University of Vienna, Sensengasse 8/12, A-1090 Wien, Austria.
J Chem Phys. 2012 Jul 28;137(4):044710. doi: 10.1063/1.4737885.
Density-functional theory including spin-orbit coupling and corrections for dispersion forces has been used to investigate the structural and magnetic properties of Pt(3) and Pt(4) clusters deposited on a graphene layer supported on a Ni(111) substrate. It is shown that the strong interaction of the Pt atoms with the Ni-supported graphene stabilizes a flat triangular and a slightly bent rhombic structure of the clusters. Pt atoms are located nearly on top of the C atoms of the graphene layer, slightly shifted towards the bridge positions because the Pt-Pt distances are larger than the C-C distances of the graphene sheet lattice-matched to the Ni support. The strong interaction with the substrate leads to a substantial reduction of both the spin and orbital moments of the Pt atoms, not only compared to the clusters in the gas-phase, but also compared to those adsorbed on a freestanding graphene layer. The trends in the magnetic moments and in the magnetic anisotropy of the cluster/substrate complex have been analyzed and it is demonstrated that the anisotropy is dominated by the Ni support.
已使用包含自旋轨道耦合和色散力修正的密度泛函理论来研究沉积在 Ni(111) 衬底上的石墨烯层上的 Pt(3) 和 Pt(4) 团簇的结构和磁性。结果表明，Pt 原子与 Ni 支撑的石墨烯的强烈相互作用稳定了团簇的平坦三角形和略微弯曲的菱形结构。Pt 原子几乎位于石墨烯层的 C 原子的顶部，由于 Pt-Pt 距离大于与 Ni 支撑晶格匹配的石墨烯片的 C-C 距离，因此略微向桥位移动。与衬底的强烈相互作用导致 Pt 原子的自旋和轨道矩都大大降低，不仅与气相中的团簇相比，而且与吸附在独立石墨烯层上的团簇相比也是如此。分析了团簇/衬底复合物的磁矩和磁各向异性的趋势，并证明各向异性主要由 Ni 支撑决定。
