Rollmann, Georg; Gruner, Markus Ernst; Hucht, Alfred; Meyer, Ralf; Entel, Peter; Tiago, Murilo L.; Chelikowsky, James R.:
Shellwise Mackay Transformation in Iron Nanoclusters
In: Physical Review Letters, Band 99 (2007), S. 083402
2007Artikel/Aufsatz in Zeitschrift
Shellwise Mackay Transformation in Iron Nanoclusters
Rollmann, Georg; Gruner, Markus ErnstLSF; Hucht, AlfredLSF; Meyer, RalfLSF; Entel, PeterLSF; Tiago, Murilo L.; Chelikowsky, James R.


Structure and magnetism of iron clusters with up to 641 atoms have been investigated by means of density functional theory calculations including full geometric optimizations. Body-centered cubic (bcc) isomers are found to be lowest in energy when the clusters contain more than about 100 atoms. In addition, another stable conformation has been identified for magic-number clusters, which lies well within the range of thermal energies as compared to the bcc isomers. Its structure is characterized by a close-packed particle core and an icosahedral surface, while intermediate shells are partially transformed along the Mackay path between icosahedral and cuboctahedral geometry. The gradual transformation results in a favorable bcc environment for the subsurface atoms. For Fe55, the shellwise Mackay-transformed morphology is a promising candidate for the ground state.