On the growth behavior, structures, energy, and magnetic properties of bimetallic $\hbox {M}_{{n}}\hbox {Pd}_{{n}}$ (M = Co, Ni; n = 1–10) clusters

Abstract

In this work, the growth behavior, structures, energetic and magnetic properties of $\hbox {Co}_{{n}}\hbox {Pd}_{{n}}$ and $\hbox {Ni}_{{n}}\hbox {Pd}_{{n}}$ (n = 1–10) clusters were investigated employing auxiliary density functional theory (ADFT). Initial geometries for successive optimization were extracted from Born–Oppenheimer molecular dynamics (BOMD) trajectories. It is demonstrated that when the cluster size increases, the Co and Ni atoms became shrouded by Pd atoms, leading to the initial formation of M@Pd (M = Co and Ni) core–shell structures. The spin multiplicities of the $\hbox {Co}_{{n}}\hbox {Pd}_{{n}}$ and $\hbox {Ni}_{{n}}\hbox {Pd}_{{n}}$ (n = 1–10) clusters increase with cluster size. The CoPd clusters exhibit higher spin multiplicity and are characterized by higher spin magnetic moments than the NiPd counterparts. This study reveals that the spin density distributions are located on the Co and Ni atoms in the respective clusters. As the cluster size increases both systems tend to donate more easily electrons and the binding energies per atom grows monotonically.