Schottky defect is likely to be found in

Options

A. AgI
B. NaCI
C. ZnS
D. ZnO

Answer

**Step-by-Step Solution:**

1. **Understanding Schottky Defect**:
- A Schottky defect is a type of point defect in a crystal lattice where an equal number of cations and anions are missing from their lattice sites. This results in vacancies in the crystal structure.

2. **Characteristics of Schottky Defect**:
- It occurs in ionic solids where the sizes of cations and anions are similar.
- The presence of equal vacancies of cations and anions maintains the electrical neutrality of the crystal.

3. **Identifying Suitable Crystals**:
- To find materials that exhibit Schottky defects, we need to look for ionic compounds where the cation and anion sizes are comparable.
- Examples of ionic compounds include NaCl (Sodium Chloride), AgI (Silver Iodide), ZnS (Zinc Sulfide), and ZnO (Zinc Oxide).

4. **Analyzing the Options**:
- **NaCl**: Sodium ion (Na⁺) and Chloride ion (Cl⁻) have similar sizes, making NaCl a candidate for Schottky defects.
- **AgI**: The size difference between Ag⁺ and I⁻ is significant, making it less likely to exhibit Schottky defects.
- **ZnS**: The size difference between Zn²⁺ and S²⁻ is also significant, which makes it less likely to show Schottky defects.
- **ZnO**: Similar to ZnS, the size difference between Zn²⁺ and O²⁻ is too large for Schottky defects to occur.

5. **Conclusion**:
- Based on the analysis, NaCl is the only compound among the options provided that is likely to exhibit Schottky defects due to the comparable sizes of its cations and anions.

**Final Answer**: Schottky defect is likely to be found in NaCl.

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