Comparison of Ferromagnetic, Paramagnetic, and Diamagnetic Materials

Materials can be classified based on their response to a magnetic field. The three main types are ferromagnetic, paramagnetic, and diamagnetic materials. Here’s a detailed comparison:

1. Ferromagnetic Materials

• Properties:
  • Strongly attracted to magnets and can become magnetized.
  • They retain their magnetization even after the external magnetic field is removed.
  • Have high magnetic permeability.
• Examples: Iron, Nickel, Cobalt.
• Illustration: A bar magnet is a typical ferromagnetic material that can attract small pieces of metal and retain its magnetic properties for a long time.

2. Paramagnetic Materials

• Properties:
  • Weakly attracted to magnetic fields.
  • Their magnetization is temporary and only exists when exposed to an external magnetic field.
  • The alignment of magnetic dipoles is random, and it does not retain magnetization when the field is removed.
• Examples: Aluminum, Platinum, Magnesium.
• Illustration: Aluminum shows weak attraction to a magnet but does not stay magnetized once the external field is removed.

3. Diamagnetic Materials

• Properties:
  • Repelled by magnetic fields, but only weakly.
  • Do not retain any magnetization once the external field is removed.
  • Have negative magnetic susceptibility.
• Examples: Copper, Bismuth, Graphite.
• Illustration: Copper is a diamagnetic material that is weakly repelled by magnets and shows no permanent magnetic properties.

Summary

• Ferromagnetic materials are strongly attracted and can retain magnetization.
• Paramagnetic materials are weakly attracted but lose magnetization once the external field is removed.
• Diamagnetic materials are weakly repelled and have no lasting magnetization.