Fluorite Silicides Surface and Interface Structure

They are related by a 180°C rotation around the [111] axis. The type A sihdde has the same orientation as the siHcon substrate, while the type B sihdde shares the surface normal 111 axis with Si, but is rotated 180 °C about this axis with respect to the Si. Considering only tetrahedral coordination of ah Si at the interface, the interface metal atom can be either fivefold or sevenfold coordinated. 

Cherns et al. [53] found that only the sevenfold model was consistent with the displacements found, for both normal (A) and reversed (B) orientations of NiSi2. 

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