Ferromagnetism facts for kids

A magnet made of alnico, a type of iron alloy, with its keeper. Ferromagnetism helps explain how materials become magnets.

Ferromagnetism is a super strong type of magnetism. It's what makes materials like iron act like powerful magnets. These materials are strongly pulled towards other magnets. Out of all the different kinds of magnetism, ferromagnetism is the strongest! We use it every day in many cool technologies, like televisions and credit cards.

What Makes Materials Ferromagnetic?

Ferromagnetic materials are special because they are magnetic all by themselves. Even if they are super cold (at absolute zero) and no other magnets are nearby, they still have their own magnetic power.

The Role of Electrons

This happens because of tiny particles inside materials called electrons. Electrons are always spinning, a bit like tiny tops. This spin creates a tiny magnetic field. In ferromagnetic materials, the electrons like to spin in the same direction. When many electrons spin the same way, their tiny magnetic fields add up. This creates a stronger, noticeable magnetic force.

Temperature and Magnetism

When a ferromagnetic material gets hotter, its magnetism usually gets weaker. This is because heat makes the electrons move around more. When they move more, their spins don't stay perfectly lined up anymore. This makes the overall magnetic strength go down.

The Curie Temperature

There's a special temperature called the Curie temperature. If a ferromagnetic material gets hotter than its Curie temperature, it completely loses its strong magnetism. It stops being ferromagnetic. Each material has its own specific Curie temperature.

Common Ferromagnetic Materials

Some of the most well-known materials that are ferromagnetic include:

• Iron
• Cobalt
• Nickel

Hematite is another material that can be ferromagnetic, but only when it's above a certain temperature.

Images for kids

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  Electromagnetic dynamic magnetic domain motion of grain-oriented electrical silicon steel

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  Kerr micrograph of metal surface showing magnetic domains, with red and green stripes denoting opposite magnetization directions

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  Moving domain walls in a grain of silicon steel caused by an increasing external magnetic field in the "downward" direction, observed in a Kerr microscope. White areas are domains with magnetization directed up, dark areas are domains with magnetization directed down.

See also

In Spanish: Ferromagnetismo para niños