Which of the following defects is also known as dislocation defect?

Options

A. Frenkel defect
B. Schottky defect
C. Non-stoichiometric defect
D. Simple interstitial defect

Explanation

To determine which of the defects listed is also known as a dislocation defect, we can analyze each option provided:

1. **Frenkel Defect**: In this type of defect, a cation leaves its original lattice site and occupies an interstitial site. This movement of the cation from its normal position to an interstitial site results in a dislocation within the crystal structure. Hence, the Frenkel defect is indeed known as a dislocation defect.

2. **Schottky Defect**: This defect occurs when equal numbers of cations and anions are missing from the lattice. Since there is no displacement of ions to interstitial sites, this defect does not qualify as a dislocation defect.

3. **Non-stoichiometric Defect**: This type of defect involves variations in the stoichiometry of the compound, but it does not specifically refer to dislocation of ions.

4. **Simple Interstitial Defect**: This defect involves the presence of extra ions in the interstitial sites, but it does not imply a dislocation from a regular lattice position.

Based on the analysis, the defect that is known as a dislocation defect is the **Frenkel defect**.

### Final Answer:
The defect that is also known as a dislocation defect is the **Frenkel defect**.

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