Define Curie temperature.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Ferromagnetism and Paramagnetism:**
- Ferromagnetic materials have a spontaneous magnetization due to the alignment of magnetic moments of atoms in the material.
- Paramagnetic materials, on the other hand, do not have a permanent magnetic moment and only exhibit magnetism in the presence of an external magnetic field.

2. **Defining Curie Temperature:**
- The Curie temperature (denoted as Tc) is the specific temperature at which a ferromagnetic material loses its ferromagnetic properties and becomes paramagnetic.
...