Studies of FemIrn nano clusters using Density Functional Theory Techniques

TL;DR

This study uses density functional theory to analyze the structure, magnetic properties, and electronic behavior of FemIrn clusters, revealing size-dependent binding energies, magnetic moments, and increased metallicity with alloying.

Contribution

It provides a comprehensive DFT-based analysis of FemIrn clusters, highlighting structural preferences, magnetic enhancements, and electronic property changes due to alloying.

Findings

Clusters are compact with maximized Fe-Ir pairs.

Binding energy increases with cluster size.

Ferromagnetic order persists after optimization.

Abstract

The structure, binding energy, magnetic moments and electronic structure of FemIrn clusters are investigated using state of the art density functional theory techniques. Fully unconstrained structural relaxations are undertaken by considering all possible non equivalent cluster structures. The optimized clusters are all compact, indicating a clear tendency to maximize the number of nearest neighbour Fe-Ir pairs. The binding energy shows an increment with cluster size. All the clusters preserve ferromagnetic order after optimization. The average magnetic moment generally shows an increase with Fe concentration. The spin polarized density of states is largely dominated by the contribution of d orbitals. An important enhancement of the local Fe moments in an Ir rich environment is observed due to the charge transfer between Fe and Ir. On the other hand, the Ir moments are already large in the pure Ir clusters and does not show significant enhancement with Fe doping. The HOMO-LUMO gaps show a general reduction with alloying, indicating more metallicity for the doped clusters than the pure ones.