Dresden 2011 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 101: Particles and clusters II

O 101.3: Vortrag

Freitag, 18. März 2011, 11:45–12:00, WIL C107

Stabilization mechanism for cage-like Si₁₆M⁺ clusters: From global structure optimization to understanding — •Dennis Palagin¹, Matthias Gramzow², and Karsten Reuter^1,2 — ¹Technische Universität München — ²Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin

Doping with endohedral metal atoms appears as a remarkable avenue to tailor the intrinsic properties of silicon clusters, as well as to stabilize cage-like geometries as suitable building blocks for novel engineered materials. A prevalent concept to rationalize this stabilization is that injection of metal electrons into the Si electron gas leads to electronic shell closure. A prominent example is Si₁₆V⁺, which with 68 valence electrons corresponds to a closed-shell configuration. Intriguingly, Si₁₆Ti⁺ and Si₁₆Cr⁺ with 67 and 69 electrons, respectively, are equally believed to stabilize in cage-like geometries [1]. Aiming to further clarify the stabilization mechanism we first use density-functional theory based basin-hopping to ascertain that the cage-like geometry indeed represents the ground-state structure for all three dopant atoms. From this basis we proceed to a detailed analysis of the obtained charge distributions to identify the nature of the bond and the stabilization mechanism in this dopant sequence. [1] J.T. Lau et al., Phys. Rev. A 79, 053201 (2009).