The antiferro electric solid among these is:

Options

A. `KH_(2)PO_(4)`
B. `MnO_(2)`
C. `BaTiO_(3)`
D. `PbZrO_(3)`

Answer

To solve the question regarding which of the given options is an antiferroelectric solid, we can follow these steps:

### Step 1: Understand the Definition of Antiferroelectric Solids
Antiferroelectric solids are materials that exhibit a specific type of electrical polarization. In these materials, there are equal numbers of domains that are aligned in opposite directions, resulting in a net polarization of zero. This is similar to antiferromagnetic materials, where magnetic moments cancel each other out.

**Hint:** Remember that in antiferroelectric materials, the arrangement of dipoles is such that they cancel each other out.

### Step 2: Analyze the Given Options
We have four options to consider:
1. KH2PO4 (Potassium dihydrogen phosphate)
2. MnO2 (Manganese dioxide)
3. BaTiO3 (Barium titanate)
4. PbZrO3 (Lead zirconate)

**Hint:** Look for known properties of these compounds regarding their electrical behavior.

### Step 3: Identify the Antiferroelectric Solid
- **KH2PO4**: This compound is known for its ferroelectric properties but does not exhibit antiferroelectric behavior.
- **MnO2**: This compound is primarily known for its use as a semiconductor and does not show antiferroelectric characteristics.
- **BaTiO3**: This is a well-known ferroelectric material, not antiferroelectric.
- **PbZrO3**: This compound is recognized as an antiferroelectric material due to its unique domain structure that allows for the cancellation of polarization.

**Hint:** Recall that PbZrO3 is often cited in literature as a classic example of an antiferroelectric material.

### Step 4: Conclusion
Based on the analysis of the options, the antiferroelectric solid among the given choices is **PbZrO3** (option 4).

**Final Answer:** The antiferroelectric solid among these is **option 4: PbZrO3**.