Rare-earth magnet facts for kids

Ferrofluid on glass, with a rare-earth magnet underneath

Rare-earth magnets are super strong magnets that never lose their magnetism. They are made from special metal mixes called alloys, which include rare earth elements.

These amazing magnets were first created in the 1970s and 1980s. They are the strongest type of permanent magnets we know! Rare-earth magnets create much more powerful magnetic fields than other common magnets like ferrite or alnico magnets.

There are two main kinds of rare-earth magnets: neodymium magnets and samarium-cobalt magnets. Some special rare-earth magnets, like Terfenol-D, can even change shape slightly when a magnetic field is applied. These magnets are also used in things like speakers.

Rare-earth magnets can be quite fragile and can easily rust. Because of this, they are usually covered with a special coating or plated. This helps protect them from breaking, chipping, or turning into powder.

How Rare-Earth Magnets Are Used

Since the 1990s, neodymium magnets have become more affordable. This has allowed them to replace older, weaker magnets in many modern devices. Their incredible strength means that smaller and lighter magnets can be used for the same job.

Everyday Uses of Strong Magnets

Neodymium magnet balls

Rare-earth magnets are used in many things you might see every day:

• Computer hard drives store information using these magnets.
• Wind turbines use them to generate electricity.
• Your speakers and headphones use them to make sound.
• Bicycle dynamos use them to power lights.
• MRI scanners, which doctors use to see inside the body, rely on them.
• Fishing reels have them for smooth braking.
• Cordless tools use them in their powerful motors.
• High-performance motors in robots and machines use them.
• Hybrid and electric vehicles use them in their motors.
• Mechanically powered flashlights use them to create light when shaken or cranked.
• Industries use them to keep products clean and protect equipment.
• They can even catch tiny metal bits in engine oils to prevent wear.

Other Cool Uses

Rare-earth magnets have many other interesting uses:

• Linear motors, like those in maglev trains, use them to float and move.
• In stop-motion animation, they help hold figures in place.
• Scientists use them to study magnetic levitation and superconductors.
• They are found in special Electrodynamic bearings.
• Launched roller coasters use them to accelerate quickly.
• LED Throwies are small LEDs with a magnet, used for temporary art.
• Neodymium magnet toys are popular for building and playing.
• Electric guitar pickups use them to turn string vibrations into sound.
• They are popular for miniature figures in games, helping to attach parts.

Images for kids

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  Neodymium magnets (small cylinders) lifting steel balls. These magnets can lift thousands of times their own weight!

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  A neodymium magnet with most of its nickel plating removed.

See also

In Spanish: Imán de tierras raras para niños