It was noted that the self-interstitial in Ge could assume multiple configurations; depending upon the temperature and charge state. Here, a first-principles density functional method was used to investigate the diffusion mechanisms of this defect. The energy barriers associated with the transformation between different structures were determined by using the climbing nudged elastic band method, as a function of the charge state. The relationship between the thermodynamic properties of the self-interstitial and the temperature evolution of electron radiation damage in Ge was considered.

First-Principles Study of the Diffusion Mechanisms of the Self-Interstitial in Germanium. A.Carvalho, R.Jones, J.P.Goss, C.Janke, S.Öberg, P.R.Briddon: Journal of Physics - Condensed Matter, 2008, 20[13], 135220 (5pp)