the value of magnetic moment is zero in the case of antiferromagnetic substaence because the domains …….. .

Options

A. get oriented in the direction of the applied magnetic field
B. get oriented opposite to the direction of the direction of the applied magnetic field
C. are oppositely oriented with respect to each other without the application of magnetic field
D. cancel out each other's magnetic moment.

Answer

To solve the question regarding the magnetic moment in antiferromagnetic substances, we need to understand the behavior of magnetic domains in these materials. Here’s a step-by-step solution:

### Step 1: Understand Antiferromagnetism
Antiferromagnetic substances are materials where the magnetic moments of atoms or ions align in opposite directions. This means that for every magnetic moment pointing in one direction, there is another pointing in the opposite direction.

**Hint:** Think about how magnetic moments interact in antiferromagnetic materials compared to ferromagnetic materials.

### Step 2: Analyze Magnetic Domains
In antiferromagnetic materials, the magnetic domains are structured such that they are oppositely oriented with respect to each other. This means that the net magnetic moment of the entire material is zero because the opposing moments cancel each other out.

**Hint:** Consider how the arrangement of magnetic moments affects the overall magnetism of the material.

### Step 3: Evaluate the Options
Now, let’s evaluate the provided options based on our understanding:
1. **Option A:** Domains get oriented in the direction of the applied magnetic field. (This is characteristic of ferromagnetic materials, not antiferromagnetic.)
2. **Option B:** Domains get oriented opposite to the direction of the applied magnetic field. (This is also not true for antiferromagnetic substances.)
3. **Option C:** Domains are oppositely oriented with respect to each other without the application of a magnetic field. (This is true for antiferromagnetic materials.)
4. **Option D:** Domains cancel out each other’s magnetic moment. (This is also true for antiferromagnetic materials.)

**Hint:** Focus on how the orientation of magnetic moments leads to the cancellation of the overall magnetic moment.

### Step 4: Conclusion
Based on the analysis, the correct answers are **Option C** and **Option D**. In antiferromagnetic substances, the magnetic domains are oppositely oriented with respect to each other, leading to a net magnetic moment of zero.

**Final Answer:** The value of magnetic moment is zero in the case of antiferromagnetic substances because the domains are oppositely oriented with respect to each other and cancel out each other's magnetic moment.