Electronic structure and magnetic properties ofNi3nAlnclusters

Abstract

The equilibrium structure, electronic, and magnetic properties of Ni 3n Al n , ͑n =1, 8͒ clusters are investigated using ab initio total-energy calculations based on density functional theory. Asymmetric and amorphous structures are observed for n Ͼ 1 clusters, in contrast with the earlier work reported based on Gupta potentials; where, clusters with Ni 3 Al compositions were found to be symmetric. Magnetic moment per atom in these clusters is significantly enhanced with respect to the bulk. The distribution of magnetic charge on Ni and Al atoms is highly inhomogeneous and depends on their number of Al and Ni neighbors. The Al atoms quench the magnetic moments of Ni 3n Al n clusters when compared with the magnetic moments of pure Ni clusters. The analysis of the charge density shows a net transfer of charge from s-type orbital of Ni to p-type orbital of Al. The density of states exhibits features like Heusler alloys. The implications of this on the conductance in such clusters are discussed.

Density Functional Study on the Structural, Electronic, and Magnetic Properties of 3d Transition-Metal-Doped Au5Clusters

“…During the last few decades, the binary clusters have attracted considerable attention of a wide range of researchers. − Theoretical and experimental studies have demonstrated that the nature of the cluster can be altered significantly with the addition of a single impurity atom. , − Doping of gold clusters with an impurity atom has been actively sought to tailor the desired structural, electronic, catalytic, and magnetic properties for potential applications in nanotechnology, microelectronics, solid-state chemistry, and materials science. − For example, Zhang et al proved that doping with different 3p impurity atoms (Al, Si, P, S, and Cl) can strongly influence the structure, stability, electronic property, and growth pattern of gold clusters, which is very distinct from the case of 3d transition-metal-doped Au n clusters . Kumar et al carried out ab initio calculations on Gd-doped gold clusters and found a magic cage cluster Gd@Au 15 that has the attractive features of a large highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) gap and a great magnetic moment that could make it useful for both phototherapies of cancer cells as well as bioimaging .…”

Tailoring Electronic Structure Through Alloying: The AgnCu34–n (n = 0–34) Nanoparticle Family

“…Following up on them, increasing efforts have recently been devoted to revealing the effects beyond those of stoichiometry. A recent DFT study of the electronic and magnetic properties of Ni 3 n Al n NPs highlights the role of nanoscale on the magnetic properties by showing that the magnetic moment per atom is significantly higher for those NPs than for either species of atoms in the bulk and that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) gaps are affected by the size of these NPs. That study also shows that the distribution of magnetic charge is inhomogeneous, depending on the number of Al and Ni neighbors.…”