Why a magnet lose magnetism when heated?
A magnet loses its magnetism when heated because heat causes the atoms inside the magnet to vibrate more energetically. This increased vibration disrupts the alignment of the magnetic domains within the magnet.
To understand why this happens, we need to understand a bit about the structure of a magnet. A magnet is made up of tiny regions called magnetic domains. Each domain consists of a large number of atoms, with their magnetic moments aligned in the same direction. These aligned magnetic moments create the overall magnetic field of the magnet.
When the magnet is heated, the atoms within it start to gain thermal energy. This energy makes the atoms vibrate more vigorously. As the temperature increases, the atomic vibrations become stronger, and the atoms move from their original positions. These random movements of the atoms cause the alignment of the magnetic domains to become disorderly.
As a result, the magnetism of the magnet weakens or disappears altogether. The loss of alignment between the magnetic domains leads to a reduction in the overall magnetic field strength. This is why a magnet loses its magnetism when heated.
If you want to experimentally observe this phenomenon, you can take a small magnet and heat it using a source of heat, such as a flame or a hot plate. As the temperature rises, you can use another magnet or a compass to check the magnetic strength of the heated magnet. You will find that the heated magnet becomes weaker or may not attract other magnetic materials at all.
It's important to note that the loss of magnetism due to heating is not necessarily permanent. Once the heated magnet cools down, the atoms regain their original positions and the magnetic domains can realign, restoring the magnet's magnetic properties.