What is Magnetism

Magnetism is a class of physical qualities that are mediated by a magnetic field, and it refers to the ability to generate attractive and repulsive phenomena in other entities by the application of a magnetic field. Magnetic fields are created by electric currents and the magnetic moments of elementary particles, which operate on other electric currents and magnetic moments to produce a magnetic field. Magnetism is a component of the coupled phenomenon of electromagnetic, and it is one of its aspects. When magnetic fields attract ferromagnetic materials, the most well-known effects occur. Ferromagnetic materials are strongly attracted by magnetic fields and can be magnetized to become permanent magnets, which generate magnetic fields in their own right. Demagnetization of a magnet is another possibility. Only a small number of substances are ferromagnetic; the most frequent of them are iron, cobalt, nickel, and their alloys, among other elements. The rare-earth metals neodymium and samarium are two examples of less common rare-earth metals. The prefix ferro- alludes to iron since permanent magnetism was discovered for the first time in lodestone, a type of natural iron ore known as magnetite, Fe₃O₄, which is a form of iron oxide.

History

Magnetism was first discovered in the ancient world, when people noticed that lodestones, which are naturally magnetized pieces of the mineral magnetite, could attract iron. This was the beginning of the scientific discovery of magnetism.

It is believed that the word magnet derives from the Greek phrase o magnitis lithos, which means “the Magnesian stone, lodestone.” Ancient Greek philosopher Aristotle attributes the earliest instance of what may be called a scientific debate of magnetism to the philosopher Thales of Miletus, who lived about 625 BC to approximately 545 BC and was born in Miletus, Greece. Magnetite is described in the ancient Indian medical classic Sushruta Samhita as being used to remove arrows that have been embedded in a person’s flesh.

Magnetism can be classified into several types.

Diamagnetism

Diamagnetism can be found in all materials and is defined as a material’s tendency to oppose an applied magnetic field and, as a result, to be repelled by a magnetic field. Diamagnetism can be found in all materials and is defined as However, in a material with paramagnetic qualities (that is, a tendency to increase the strength of an external magnetic field), the paramagnetic behavior takes precedence over the magnetic behavior. As a result, despite the fact that it occurs everywhere, diamagnetic behavior is only observable in materials that are entirely diamagnetic. Because there are no unpaired electrons in a diamagnetic material, the inherent electron magnetic moments are unable to induce a bulk effect in the material. In these instances, the magnetization is caused by the orbital motions of the electrons, which can be explained classically as follows:

The electrons surrounding the nucleus of a material exposed to a magnetic field will experience a Lorentz force from the magnetic field in addition to their Coulomb attraction to the nucleus when exposed to a magnetic field. Because of this force, depending on which direction the electron is circling, it may increase the centripetal force on the electrons, pulling them closer to the nucleus, or it may reduce the force, dragging them further away from the nucleus. According to Lenz’s law, this effect progressively increases the orbital magnetic moments that were aligned in the opposite direction of the field and lowers the ones that were aligned in the same direction as the field. As a result, a small bulk magnetic moment is produced, which is directed in the opposite direction of the applied field.

Paramagnetism

It is possible to find unpaired electrons in a paramagnetic substance; that is, atomic or molecular orbitals with exactly one electron in each of them. While the Pauli exclusion principle requires that paired electrons have their intrinsic (‘spin’) magnetic moments pointing in opposing directions, causing their magnetic fields to cancel out, an unpaired electron is free to align its magnetic moment in whatever direction it chooses. The application of an external magnetic field will cause these magnetic moments to tend to align themselves in the same direction as the applied field, so reinforcing the applied field.

Ferromagnetism

A ferromagnet, like a paramagnetic material, has electrons that are not coupled. However, in addition to the inherent magnetic moment of electrons having a tendency to be parallel to an applied field, there is also a tendency for these magnetic moments to orient parallel to one another in these materials in order to preserve a lower-energy state. So that the magnetic moments of the electrons in the material spontaneously line up parallel to one another, even in the absence of an applied field, the material is magnetic.

In each ferromagnetic substance exists a unique temperature range, known as the Curie temperature or Curie point, above which the substance’s ferromagnetic qualities are no longer present (i.e. it loses its ferromagnetic properties). This is owing to the fact that the thermal inclination to disorder outweighs the energy-lowering effect of ferromagnetic order in most cases.

Ferromagnetism is found in only a few substances; the most common of these are iron, nickel, cobalt, and their alloys, as well as several rare-earth metal alloys.

What exactly are the characteristics of magnetism

The following characteristics are exhibited by magnets:

• All magnets have two poles, which are referred to as the North Pole and the South Pole.
• Magnetic materials such as iron, nickel, and cobalt are drawn to magnets by their ferromagnetic properties.
• The magnetic force exerted by a magnet is greater in its poles than it is in its centre.
• A magnet that is freely hanging always points in the direction of North-South.
• Permanent magnets and temporary magnets are the two types of magnets available. Permanent magnets retain their magnetism even when they are not exposed to an external magnetic field, as demonstrated by experiments. Temporary magnets, on the other hand, lose their magnetism when they are separated from an external magnetic field, such as a magnet made of iron.

Causes of magnetism 

Magnetism is caused by a variety of factors.

Magnetism can manifest itself in other ways. According to HyperPhysics, diamagnetism is created by the orbital motion of electrons, which results in the creation of tiny current loops, which produce weak magnetic fields. This alignment of current loops occurs when an external magnetic field is applied to a material, with the result that the applied field is opposed by the current loops.

Conclusion 

Magnetism is the ability to induce attracted and repulsive phenomena in other entities by applying a magnetic field. Electric currents and magnetic moments of elementary particles form magnetic fields by interacting with other electric currents and magnetic moments. Magnetism is an aspect of the linked phenomenon of electromagnetic. The effects of magnetic fields on ferromagnetic materials are well-known. Magnetic fields attract ferromagnetic materials, which can be magnetized to produce permanent magnets that generate magnetic fields. A magnet can also be demagnetized. Iron, cobalt, nickel, and their alloys are among the most common ferromagnetic compounds. The rare-earth elements neodymium and samarium are two examples.