How do small atoms interact in interstitial solid solutions?

Small atoms interact in interstitial solid solutions primarily by fitting into the empty spaces between the larger host atoms in a crystal lattice. These interstitial sites are typically formed by the arrangement of the host atoms, which create spaces that smaller atoms can occupy without significantly disrupting the overall structure of the material.

When a small atom, such as carbon in iron, is introduced into the lattice, it occupies these interstitial positions, leading to various beneficial effects such as increased strength or altered electronic properties. The ability of small atoms to occupy interstitial sites is crucial for the formation of solid solutions, and the effectiveness of this process depends on the size and nature of both the small and host atoms.

In contrast, interactions involving electron transfer, repulsion of surrounding atoms, or the formation of ionic structures do not accurately describe the mechanism of small atom behavior within an interstitial solid solution.