Magnetic Properties

Magnetic characteristics relate to a material’s reaction to a magnetic field. Magnetic fields have a unique influence on a wide range of materials.

The magnetic property, sometimes referred to as its magnetic response, responds to a magnetic field. The macroscopic magnetic aspects of a material are determined by the interaction of an external magnetic field with the magnetic dipole moments of the constituent atoms. Magnetic fields have a unique influence on a wide range of materials. One of the most well-known phenomena is the attraction of magnetic fields to ferromagnetic materials. 

Magnetism manifests itself in a multitude of ways.

The magnetic behaviour of materials in reaction to magnetic fields has been researched and classified into five fundamental magnetism categories based on their magnetic properties at different temperatures. From this vantage point, the following items are significant:

Diamagnetic material

A magnetic substance is referred to as a “diamagnetic material.” Diamagnetic materials are those that are incomprehensible to some but magnetic to others. Electromagnetic fields repel diamagnetic materials due to their resistance to one other. When a magnetic field is used upon them, they create an induced magnetic field directed in the opposite direction, producing a repelling force. 

Diamagnetic and paramagnetic

Diamagnetic and paramagnetic materials are nonmagnetic due to minute magnetizations that remain only as long as an applied field exists. In diamagnetic materials, magnetic susceptibility is negative (magnetic susceptibility). In this case, the induced magnetization in the material results in a decrease in the material’s magnetic field. Magnetic fields repel diamagnetic materials, which explains their name. Bismuth has the highest diamagnetic strength of any substance. Nonmagnetic materials are classed as paramagnetic or diamagnetic if they do not retain magnetization in the absence of an external magnetic field.

Magnetic materials are those that are magnetically resonant. Paramagnetic materials are made up of permanent atomic dipoles that may be manipulated independently and are orientated in an external field. Since diamagnetic and paramagnetic materials have minute magnetizations that endure only as long as a field is applied, they are categorised as nonmagnetic. 

Ferromagnetic

Ferromagnetic materials are magnetically resonant. Ferromagnetism is the underlying mechanism through which a substance (also called ferromagnetism) converts into a permanent magnet (i.e., materials that can be magnetised by an external magnetic field and remain magnetised after the external field is removed). Given that it is the most powerful kind of magnetism, it accounts for this ubiquitous occurrence. When a magnetic field is applied externally, ferromagnetism, ferrimagnetism, and antiferromagnetism maintain their magnetization indefinitely and exhibit no distinguishing zero-field susceptibility.

In addition to the spin moment’s contribution, one from the orbital magnetic moment is negligible compared to the spin moment’s contribution. Even in the absence of an external field, the magnetic moments of the electrons in the material line up parallel to one another, suggesting that the substance is magnetic. The temperature at which FERROMagnetic materials lose their ferromagnetic properties is the Curie temperature or Curie point.

The most common metal complexes include iron, cobalt, nickel, and most of their alloys and numerous rare earth metal complexes. The features of ferromagnetism are frequently used in business and modern technologies. Magnetically “soft” materials, such as annealed iron, may be magnetised but not typically retain their magnetism. In contrast, magnetically “hard” materials do.

Antiferromagnetic

Antiferromagnetic magnetically passive materials are nonmagnetic. Unlike in a ferromagnet, the magnetic moments of adjacent valence electrons tend to point in opposite directions when they are close together in an antiferromagnet. Antiferromagnetic refers to a material’s atoms being organised so that their neighbours are antiparallel to one another.

While antiferromagnetic order may exist at sufficiently low temperatures, it is usually considered to dissipate at and above the Néel temperature. At temperatures over the Néel temperature, a material’s magnetic characteristics often deteriorate because the thermal energy becomes large enough to disrupt the material’s microscopic magnetic ordering. MnO has a Néel temperature of around 116K.

Ferrimagnetic 

Ferrimagnetic materials are those that are attracted to one another magnetically. Ferromagnets and ferrimagnets have similar macroscopic magnetic characteristics; the distinction is in the source of each kind of magnet’s net magnetic moments. Ferrimagnetic materials, like antiferromagnetic materials, include populations of atoms with opposing magnetic moments; however, the opposing magnetic moments in ferromagnetic materials are uneven, resulting in the persistence of spontaneous magnetization.

When a magnetic field is applied externally, ferromagnetism, ferrimagnetism, and antiferromagnetism maintain their magnetization indefinitely and exhibit no distinguishing zero-field susceptibility. Ferrites are ferromagnetic ceramic compounds composed of iron oxides often used in everyday items like refrigerator magnets. Magnetite is an illustrative case (Fe3O4).

In nuclear power plants and power plants in general, the main generator, situated in a region with large magnetic fields, needs careful material selection. Typically, a primary generator consists of two components: one that spins and one that stays stationary:

• Stator: The stator is the fixed component of an electric generator that surrounds the rotor. The shifting field induces an electric current in the wire windings of the stator, which is utilised to produce energy.
• Rotor: The rotor is the revolving component of an electric generator that generates the magnetic field.

Magnetic susceptibility

Magnetic susceptibility is an electromagnetic characteristic of a material that indicates how strongly it is magnetised. When a magnetic field induces magnetization in a material, the magnetic susceptibility, a dimensionless proportionality factor that indicates the degree of magnetization, is measured. The magnitude of M is comparable to the applied field in the following statement:

Conclusion

This article explains the magnetic properties of solids. There are five types of material based on magnetic properties i.e. diamagnetic material, paramagnetic material, ferromagnetic material, anti-ferromagnetic material and ferrimagnetic material. Magnetic susceptibility is an electromagnetic characteristic of a material that indicates how strongly it is magnetised.