Structural, electronic and magnetic properties of small bimetallic zirconium–palladium clusters: Ab initio study

Abstract

Structural, electronic and magnetic properties of small bimetallic zirconium–palladium clusters, ZrnPdm (n+m⩽5), have been investigated using density functional theory with considering generalized gradient approximation and PBE functional. We have determined the ground state conformations of the bimetallic zirconium–palladium clusters by substitution of Zr and Pd atoms in the optimized lowest energy structures of pure zirconium and palladium clusters. Results reveal that binding energies of the pure Zrn clusters are significantly higher than Pdn clusters with the same number of atoms. Also it is found that binding energy of the Zrn and Pdn clusters increase with growth of the number of consisting atoms in the clusters. Results indicate that, for both Zrn and Pdn clusters the binding energy of planar forms is lower than three-dimensional structures. We have also found that the binding energy of the Pdn clusters increase with substituting one or more Zr atoms in these clusters. We have also studied the HOMO–LUMO energy gap and magnetic moment of the pure and combined Zr and Pd clusters. The energy gap analysis of the pure and combined Pd and Zr clusters show that in generally the HOMO–LUMO gap of the bimetallic ZrnPdm clusters increase in comparison with their corresponding pure clusters with the same number of atoms. According to the spin polarization DFT calculations all of the ZrnPdm (n+m⩽5) have net magnetic moments as instance the Zr2, Pd2 and ZrPd clusters show a total magnetic moment value of 2μB. Some more discussions around charge population and density of states of considered clusters as well as their structural properties have been discussed in the context.