Which of the following arrangements shows schematic alignment of magnetic moments of antiferromagnetic substances ?

Options

A.
B.
C.
D.

Explanation

To determine the schematic alignment of magnetic moments in antiferromagnetic substances, we can analyze the characteristics and arrangements of magnetic moments in different types of magnetic materials. Here’s a step-by-step solution:

### Step 1: Understand Antiferromagnetism
Antiferromagnetic substances are characterized by the arrangement of magnetic moments (spins) of adjacent atoms or ions that are aligned in opposite directions. This results in a net magnetic moment of zero, as the opposing moments cancel each other out.

**Hint:** Remember that in antiferromagnetic materials, adjacent spins are anti-aligned.

### Step 2: Analyze the Options
We need to evaluate the given options based on the alignment of magnetic moments:
- **Option 1:** Shows all magnetic moments aligned in the same direction (ferromagnetic).
- **Option 2:** Shows magnetic moments alternating in an up and down pattern (antiferromagnetic).
- **Option 3:** Shows random orientations of magnetic moments (paramagnetic).
- **Option 4:** Shows magnetic moments aligned in the same direction (ferromagnetic).

**Hint:** Look for the pattern where adjacent moments are in opposite directions.

### Step 3: Identify the Correct Arrangement
From the analysis:
- **Option 1** and **Option 4** represent ferromagnetic arrangements.
- **Option 3** represents a random arrangement typical of paramagnetic substances.
- **Option 2** shows the alternating up and down arrangement, which is characteristic of antiferromagnetic substances.

**Hint:** The correct answer will have a clear alternating pattern of magnetic moments.

### Conclusion
The correct arrangement that shows the schematic alignment of magnetic moments of antiferromagnetic substances is **Option 2**, which displays an alternating pattern of up and down magnetic moments.

**Final Answer:** Option 2 (up, down, up, down, ...).