An overview of the different types of magnets

Magnets are firmly integrated into our everyday lives. Types of magnets are introduced in elementary school - we learn how magnetism works and what we can use magnets for. A magnet creates a magnetic field that flows through it. This automatically creates two poles oriented to the south and north. The field enters the magnet at the south pole and exits at the north pole. Various materials such as iron or nickel are attracted or repelled by the magnetic effect, depending on the polarity.

But not every magnetic substance always has the same properties. There are different types of magnets that differ in materials, shapes, sizes, functions, forces, and areas of application.

What types of magnets are there?

Not every magnet works the same. A distinction is made between permanent and temporary magnets. So, there are types of magnets that are always magnetic and others that only have an attractive effect under certain circumstances.

Permanent magnets - Attraction around the clock

The so-called permanent magnets are well known to us from everyday life. You can find them on refrigerators, magnetic walls, jewelry, bags, and many other objects. Usually they are made of steel, nickel, or neodymium. In their basic state after production, they are not immediately magnetic. However, the substances have the potential to become magnetized. If you place the material in an existing magnetic field, it becomes permanently magnetized and retains this effect forever. From this point on, the permanent magnets exert an attraction on all ferromagnetic (e.g., iron, cobalt, nickel) and on all ferrimagnetic materials (ferrites). The different types of magnets are used both in everyday life and in industry. Typical examples are:

• Magnetic closures
• Speaker
• Office supplies
• Cargo cranes
• Electronics
• Mechanics

The different types of magnetism open a multitude of possible applications.

Not all types of magnets are permanent

It's a little different with the temporary magnets. They are only magnetic when they are in a second magnetic field. As soon as they are removed from the external magnetic field, they again lose the properties of magnetism. A practical example is paperclips held by a permanent magnet. The clamps attract each other until the external field is removed. After that, the paperclips no longer have any magnetic properties.

Electromagnets: Attracted at the push of a button

Even electromagnets are not permanently magnetic. They consist of a coil through which current flows. The physics of magnet types makes it possible for a magnetic field to be created. This is usually reinforced and distributed by an open iron core inside the coil. Since the special type of magnetism in this case is generated by electricity, electromagnets are very easy to control and regulate. This means that the magnetic effect can be switched on and off flexibly and the force of attraction can also be regulated using the current. This type of magnet is particularly popular in science and industry. A well-known example is cranes in scrapyards, which instead of a hook have an electromagnet that becomes magnetic at the touch of a button and attracts everything around it.

Ferrite or neodymium - Which type of magnet is stronger?

Magnets are not always made of the same material. As already described, there are ferromagnetic as well as ferrimagnetic materials. Alloyed iron or steel can be ferrite magnets. They differ from ferromagnetic materials in their heat resistance, for example. Ferrite can be heated up to 250 degrees Celsius without being damaged. Another special feature is that the material remains rust-free and is therefore perfect for outdoor use. Compared to ferromagnetic materials, however, the attractive force is much lower. However, the cost of such magnets is lower.

Neodymium magnets, on the other hand, are significantly more expensive. These belong to the ferromagnetic materials and can be referred to as strong or extra strong magnets. They are much more powerful than ferrite magnets and can therefore attract and hold heavier weights. To date, the properties of neodymium, which belongs to the rare earths, have been further improved. An alloy mixed with iron and boron (Nd2Fe14B) can generate the strongest magnetic field of a permanent magnet today. Because of their great attraction, they are also known as super magnets.

So, the different types of magnets – ferrite and neodymium – both offer advantages and disadvantages. Neodymium has a stronger adhesive force, but is less resistant to corrosion, for example. Ferrite magnets are less strong, but indestructible and finally inexpensive.

What are the strongest magnets in the world?

To clarify the question of which type of magnet is the strongest, a distinction is first made between permanent magnets and electromagnets. The strongest permanent magnet that can currently be produced is made of neodymium and can hold around 1,500 kg vertically.

World records, on the other hand, are set with electromagnets. The currently strongest controlled magnetic field of a man-made magnet is about 1,200 Tesla. To be able to classify this value better, you should imagine a normal refrigerator magnet with approx. 0.01 Tesla. This record value was reached at the University of Tokyo in 2018 and had far-reaching consequences. The researchers not only set a record, but also blew the laboratory door out of its anchorage because of the shock wave that occurred.

Russian researchers set a first record in 2001. They created a magnetic field with a strength of 2,800 Tesla that lasted only a few trillionths of a second before it finally exploded in the open air.