Structure and optical properties of core-shell bimetallic Ag(n)Ni(n) clusters: Comparison with pure silver and nickel clusters.
We present the structural, electronic, and optical properties of bimetallic Ag(n)Ni(n) (n<or=7) clusters investigated in the framework of the density functional theory (DFT) (DFT and time-dependent DFT). The structure of Ag(n)Ni(n) clusters is found to be governed essentially by the formation of a Ni-core surrounded by silver atoms. The cohesive energies and the ionization potentials are calculated. The UV-visible absorption spectra of bimetallic clusters are compared to those of pure silver and nickel clusters. An interpretation of spectroscopic patterns in terms of contribution from s- and d-type excitations is also given. In particular the d electrons of nickel atoms are found to play a crucial role in the optical transitions in Ni-rich systems.
Harb
M
M
Université de Lyon, F-69622 Lyon, France.
Rabilloud
F
F
Simon
D
D