Cu12@Au30Ag12: a magnetic pentakis icosidodecahedron molecule with core-shell configuration

Abstract

A 54-atom trimetallic core-shell Cu₁₂@Au₃₀Ag₁₂ molecule has been identified by using first-principles calculations. This molecule with I_h symmetry consists of an icosahedral 12-atom Cu core (Cu₁₂) coated by a pentakis icosidodecahedral 42-atom Au-Ag shell (Au₃₀Ag₁₂) composed of an icosidodecahedral Au₃₀ and an icosahedral Ag₁₂. Both the molecular dynamics simulations and vibrational frequency analysis demonstrate the high stability of Cu₁₂@Au₃₀Ag₁₂. The analyses for electronic properties indicate that there exists spd hybridization which is crucial to maintain the geometrical configuration of Cu₁₂@Au₃₀Ag₁₂. Moreover, a total spin magnetic moment of Cu₁₂@Au₃₀Ag₁₂ is found to be 4 µ_B, which chiefly arises from the 6 s states of Au atoms. A new type of sugar gourd-like [Cu₁₂@Au₃₀Ag₁₁]_n nanowire is also proposed; the results demonstrate that the nanowire exhibits metallic and magnetic behaviors. The magnetic Cu₁₂@Au₃₀Ag₁₂ molecule and [Cu₁₂@Au₃₀Ag₁₁]_n nanowire can be promising candidates of novel magnetic nanomaterials and nanodevices.

Keywords: Core–shell configuration; Density functional theory; Electronic structure; Magnetic properties.