ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

Properties and chemistry of the Fe and Zn interfaces

For a systematic understanding of corrosion protection it is necessary to obtain a detailed atomistic understanding of the bonding mechanisms and energetics at interfaces and surfaces. The basis of this understanding is the tight binding (TB) parametrization of density functional theory (DFT). DFT is an accurate method for predicting materials properties but is limited with respect to the system size and number of configurations which can be investigated. To overcome this obstacle an efficient and transferable TB parameterization will be developed.

The methodological part of the project will concern the development of a TB parametrization of Zn and ZnO. This will augment the ICAMS TB library and will in conjunction with the TB parameterizations developed in AMS-01-05 and AMS-10-01 allow for the modelling of Fe-Zn interface properties.

The complex surface phase diagram of ZnO can be rationalized in terms of simple electron counting rules. As extended defects in oxides can act as electron donors and acceptors it is the first applied goal of this project to gain an understanding of how they can influence the surface chemistry of ZnO and hence macroscopic properties such as the isoelectronic point.

TB models will also be developed for selected organic molecules with interest as coupling agents and corrosion inhibitors. The parametrization should be able to treat dispersive interactions in addition to covalent and charge transfer interactions. It should furthermore form the link to the force-field methods used to treat polymers.

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