Which of the following is ferroelectric compound?

Options

A. `BaTiO_3`
B. `K_4[Fe(CN)_6]`
C. `Pb_2O_3`
D. `PbZrO_3`

Explanation

To determine which of the given compounds is a ferroelectric compound, we need to understand the definition and characteristics of ferroelectric materials.

### Step-by-Step Solution:

1. **Understanding Ferroelectric Compounds**:
- Ferroelectric compounds are materials that exhibit spontaneous polarization that can be reversed by the application of an external electric field. This means they can maintain a permanent electric dipole moment even in the absence of an electric field.

2. **Identifying the Given Compounds**:
- The compounds provided in the question are:
- A) BaTiO3 (Barium Titanate)
- B) K4Fe(CN)6 (Potassium Ferrocyanide)
- C) Pb2O3 (Lead(III) Oxide)
- D) PbZrO3 (Lead Zirconate)

3. **Analyzing Each Compound**:
- **BaTiO3 (Barium Titanate)**: This compound is well-known for its ferroelectric properties. It has a perovskite structure and exhibits spontaneous polarization.
- **K4Fe(CN)6 (Potassium Ferrocyanide)**: This compound does not exhibit ferroelectric properties.
- **Pb2O3 (Lead(III) Oxide)**: This compound is not known for ferroelectric behavior.
- **PbZrO3 (Lead Zirconate)**: This compound is also known to exhibit ferroelectric properties, especially in its tetragonal phase.

4. **Conclusion**:
- Among the options, both **BaTiO3** and **PbZrO3** are ferroelectric compounds. However, the question asks for one, and BaTiO3 is the most commonly recognized ferroelectric material.
- Therefore, the answer is **A) BaTiO3**.

### Final Answer:
**A) BaTiO3 is a ferroelectric compound.**