Electronic and NLO characteristics of small neutral and singly charged iron-doped bismuth clusters

The electronic and optical properties of the iron-doped bismuth nanoclusters having less than 15 atoms are presented here. This doping is especially interesting since it enhances the stability and magnetic properties of the bismuth clusters, as shown here. The effect of singly charging the clusters on their stability and electronic properties is also investigated. Binding energy analysis shows that iron doping enhances the relative stability of the small bismuth clusters. An almost regular pattern is observed for the maximum Raman peak of the first five clusters and the succeeding nine clusters. An oscillating magnetic moment behavior is observed for the neighboring bismuth numbers from 5 to 11. Singly charged clusters also show similar magnetic characteristics. HOMO-LUMO energy gap also follows the expected pattern of the quantum confinement as larger clusters demonstrate the smaller difference between these two levels. Interestingly, this general downward trend falls in the range of visible light. The projected density of states (PDOS) also confirms the obtained results for the energy gap. The charge distribution behavior shows negative charge accumulation on iron atoms except for the case of FeBi.