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Experimental STM images

We want to count, atom-by-atom, how the initial corrosion products develop. For this we have a range of surface science tools, including scanning tunneling microscopy (STM) and spectroscopy (STS) and electron spectroscopy of the core level and valence band (XPS, UPS) to develop a fundamental understanding of the oxidation process, as illustrated in the Figure above. STM allow for nanometer and often even atomic scale study of the surface structures of alloys and oxides, and STS yields information on the electronic structure, specifically the density of states (DOS) close to the Fermi energy with the same spatial resolution, information directly correlateable with density functional tools. For instance, oxide and metal-terminated surface regions can be distinguished by their geometric structure if atomic resolution is achieved, and their LDOS (local density of states), which leads to a change in image contrast even in the absence of atomic resolution and can be measured with scanning tunneling spectroscopy STS.

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