Ionic solids with Schottky defects contain in their structure

Options

A. Cation vacancies only
B. Cation vacancies and interstital cations
C. Equal number of cation and anion vacancies
D. Anion vacancies and interstitial anions

Answer

To solve the question regarding the structure of ionic solids with Schottky defects, we will analyze the characteristics of Schottky defects and the options provided.

### Step-by-Step Solution:

1. **Understanding Schottky Defects**:
- Schottky defects occur in ionic solids when an equal number of cations and anions are missing from the crystal lattice. This creates vacancies in the structure.
- The presence of these vacancies maintains the overall charge neutrality of the solid.

2. **Analyzing the Options**:
- **Option 1: Cation vacancies only** - This is incorrect because Schottky defects involve both cations and anions leaving the lattice.
- **Option 2: Cation vacancies and interstitial cations** - This is also incorrect as Schottky defects do not involve interstitial cations; they only involve vacancies.
- **Option 3: Equal number of cation and anion vacancies** - This is correct because Schottky defects specifically involve the removal of one cation and one anion, leading to equal vacancies.
- **Option 4: Anion vacancies and interstitial anions** - This is incorrect because, similar to option 2, Schottky defects do not involve interstitial ions.

3. **Conclusion**:
- Based on the analysis, the correct answer is **Option 3: Equal number of cation and anion vacancies**.

### Final Answer:
Ionic solids with Schottky defects contain in their structure **equal number of cation and anion vacancies**.

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