Question

What happens when ferrimagnetic Fe₃O₄ is heated at 850 K and why?

What happens when Fe₃O₄ is heated to 850 K?

Answer 1

1. When ferrimagnetic Fe₃O₄ (magnetite) is heated to 850 K, it loses its ferrimagnetic property and becomes paramagnetic. This temperature (850 K) is known as the Curie temperature for Fe₃O₄.
2. At this temperature, the thermal energy becomes high enough to disrupt the alignment of the magnetic moments of the Fe²⁺ and Fe³⁺ ions that are responsible for its ferrimagnetism.
3. As a result, the net magnetic moment becomes zero, and the substance can no longer exhibit spontaneous magnetism.