Growth of Bi on Cu(111): Alloying and dealloying transitions

Stabilizing and Organizing Bi3Cu4 and Bi7Cu12 Nanoclusters in Two‐Dimensional Metal–Organic Networks

“…TheBiclusters formed atriangular array with alattice constant of 2.26 AE 0.05 nm, corresponding to a( 5 p 3 5 p 3)R308 8 supercell of the substrate Cu (111) lattice.T he occurrence ratio of Phase Ia nd II is around 7:3, indicating that Phase Ii sm ore favorable,a lthough the two phases always coexist. We performed density functional theory (DFT) calculations to understand the structures of the Bi clusters and the nature of the interaction between the clusters and the molecular linkers.W et ested three possible models of the Bi trimer in phase I: 1) three Bi adatoms,2 )three Bi atoms substitutionally alloyed in the topmost layer of the Cu substrate, [16] and 3) close packing of three Bi adatoms and four Cu adatoms.O nly the last model agreed well with experimental data (see Supporting Information). Therefore we propose that three Bi atoms and four Cu atoms form aBi 3 Cu 4 multinuclear heterometallic cluster sitting on the Cu substrate (Figure 2a).…”

Ordinary and supernumerary resonant scattering of low energy electrons from the BiCu2(111) surface alloy

“…Given the fact that the depth of the minimum at 7.7 eV is about 6 times 1.6 × 10 −3 , taking into account that 6 equivalent (−1, 0) directions are available simultaneously for resonant scattering we estimate the mean domain size in our experiment to be of the order of 10 nm. An STM image selected and published by Girard [34] indicates that indeed such domain sizes do occur. A consequence of these rather small domains is that domain boundaries suppress the diffraction of electrons from an image state back into the specular channel.…”

“…At the maximum coverage of one-third, all of the Bi atoms are contained in only a single sub-lattice, while the occupation of the two other sub-lattices is zero. On a local scale of a few nm, as studied by Girard et al [34], this may well be true but for more macroscopic surfaces this requires ordering to occur over macroscopic distances and this may be kinetically limited and take a prohibitively long time, especially close to the ideal Bi coverage of ⅓ in the √3-BiCu 2 surface alloy . So macroscopically, the surface is expected to be comprised of finite size domains of the √3-BiCu 2 structure for an extended period of time.…”

Temperature-dependent structure, elasticity, and entropic stability of Bi phases on Cu{111}

“…Any additional Bi that is deposited in excess of 1/3 ML is incorporated in an overlayer phase [6,[9][10][11]. The precise structure of the overlayer phase depends on coverage and temperature and has been described in detail elsewhere [12].…”