Elekiban magnets how do they work

Magnetism - how it works and types of magnets

Magnets: attractive objects

Magnets attract other objects, provided that certain materials are contained in an object. For example, iron, nickel and goblin are magnetic. The force that acts between a magnet and the metals mentioned is called magnetism.

Magnetizing substances consist of numerous atoms, in the nucleus of which the electrons are located. The movement creates magnetic fields - a magnet is formed. In principle, a large magnet can be imagined as follows: Many small magnets align themselves in the same direction and two different poles are created, the north and south poles. In fact, the largest magnet is our planet earth with the north pole and south pole.

Magnetism: A Glimpse into the Past

The phenomenon of magnetism was studied in more detail in the middle of the 19th century. Michael Faraday made a number of basic experiments and James Clerk Maxwell provided a theoretical description of the phenomenon in 1864, which he put in the Maxwell equation. His theory was that electricity and magnetism are inextricably linked and that both are different forms of the same effect. Quantum mechanics, which was scientifically explored in the first half of the 20th century, enabled a fundamental understanding of magnetism. Whether a material is magnetic is determined by its atomic structure and the elementary particles. It is possible to magnetize things that are not actually magnetic, namely by making the atoms electromagnetically charged.

Permanent magnets and non-permanent magnets

There are two different types of magnets. One type is not permanently magnetic, the other is permanently magnetic. They are also called permanent magnets. Magnetic force is extremely versatile.

Electromagnets

Non-permanent electromagnets are used, for example, in the automotive industry. Wherever an electric motor works, magnets of various shapes are used - be it to close the trunk, open the windows or operate the windshield wipers. The starter also works with magnetism. Electric cars also work with magnets. The attractive and repulsive forces of a magnet cause the motor to rotate and the car begins to roll. These magnets are not permanently magnetic.

Permanent magnets

A permanent magnet has constant magnetic forces. Permanent magnets are able to attract or repel ferromagnetic substances such as iron, nickel or goblin. In contrast to electromagnets, they do not need electricity to build up a magnetic field. A permanent magnet always consists of ferromagnetic materials, the individual atoms of which are aligned in parallel. This alignment happens, for example, when ferromagnetic rock cools down. The ancient Greeks found such stones in the area around Magnesia. Incidentally, it represents the historical root of the term magnetism.

Artificially manufacture permanent magnets

Permanent magnets can be produced artificially by making alloys strongly magnetized by external magnetic fields. Samarium cobalt, for example, is used for this purpose. How strongly a permanent magnet is magnetized depends on two factors. On the one hand, the material plays a role, on the other hand, the way in which the magnetization was carried out.

A high degree of magnetization is achieved when the so-called atomic spins are all aligned in parallel. Based on the Maxwell equation mentioned above, it follows that there are only magnetic fields that have a north and a south pole. The effective force of the permanent magnets can be explained by the charge movement of the individual atoms. The electrons move extremely fast, which is called electron spin. This results in the magnetic moment, the magnetic force that attracts metallic substances. How strong the magnetism of a permanent magnet is depends on the force of the magnetic moment and, as I said, on how completely the electrons are aligned in parallel. This is expressed by the so-called energy product, which is a quality mark for magnets. If a magnet has a high force, the quality or the grade is particularly high. Neodymium magnets are very strong, ferrite magnets and AINiCo magnets are less strong (Al = aluminum, Ni = nickel, Co = cobalt)

Neodymium magnets: the super power

Magnets made of neodymium are called super magnets and there are good reasons for this. Even with the smallest size, they have enormous powers. They belong to the category of the strongest permanent magnets in the world and are made of a neodymium-iron-boron alloy (NdFeB). Because of their extraordinary adhesive force, they are ideal for use in confined spaces. However, they do need a coating to prevent them from rusting. They are used, for example, in furniture construction, in lighting systems, in model construction and in the context of plastics technology.

Ferrite magnets

Ferrite magnets are ceramic permanent magnets. They are dark gray and can be easily identified by their color alone. When comparing ferrite magnets to neodymium magnets, the biggest difference is that they don't need a protective coating to keep corrosion off. Ferrite magnets are particularly cheap, but also much weaker than neodymium magnets. As a rule, strontium ferrite is used. Ferrite magnets can withstand cold down to -40 ° C and heat up to 250 ° C. They are inexpensive and perfect for outdoor use.

AlNiCo magnets

Ferrofluids, horseshoe magnets and bar magnets are well suited for training purposes. Ferrofluid is a magnetic liquid that works very well for illustrative experiments. Physics teachers can use steel balls made of aluminum, nickel or cobalt as well as iron filings to introduce students to the fascinating world of magnetism.

Magnets made from samarium-cobalt alloys

Like neodymium magnets, these magnets are so-called rare earth magnets. They are insensitive to temperatures and they do not rust. Compared to neodymium, however, they are more expensive because production is more complex and raw materials are scarce.

Conclusion: The right type of magnet for every application

Whether as a helpful gadget for attaching notes to the refrigerator, as a practical lock for cupboards, for driving motors or for moving suspension railways like the Transrapid in Japan - everyday life is inconceivable without magnetism. Depending on the area of ​​application, magnets are used with the right effective force and invisibly - almost as if by magic - ensure comfort, speed, security and movement.