What type of defect occurs when an impurity atom occupies a space in the crystal lattice?

An interstitial defect occurs when an impurity atom occupies a space within the crystal lattice that is normally occupied by the host atoms. This means that the impurity atom fits into the gaps between the regular lattice structure instead of taking the place of one of the atoms in the lattice. This type of defect alters the local structure of the material and can affect properties such as conductivity, diffusion rates, and mechanical strength.

The uniqueness of interstitial defects lies in the fact that they involve atoms that are smaller or compatible enough to fit into the existing spaces, resulting in a more complex arrangement of atoms within the lattice. Understanding interstitial defects is critical in materials science, especially regarding how materials behave under various conditions, such as applications in semiconductors or alloys.

The other types of defects, while relevant to the study of crystal structures, do not specifically describe the situation where an impurity atom takes up a space in the lattice. For instance, a vacant site defect refers to an absence of an atom in the lattice, while a substitute defect involves an impurity atom replacing a host atom in the lattice structure. Lattice distortion defects involve changes in the local arrangement of atoms without specifying the presence of impurity atoms. Thus, the interstitial defect is the most