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Diamagnetic Materials

Last updated date: 24th Jul 2024
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What are the Diamagnetic Materials?

In your childhood, you might have played with magnets but at that time you didn't know how those magnets attracted pieces of iron. At Vedantu, you will understand the whole mechanism behind the phenomena of magnetism. Here in this article, we are going to study the diamagnetic materials, their properties and their applications. 

Diamagnetism is a magnetic feature of matter in which electrons within a substance spin faster in response to an external magnetic field, generating magnetic forces that resist or repel the outside magnetic field. When put in a magnetic field, diamagnetic substances are normally repelled by the magnetic field or are freely magnetized in the opposite direction of the magnetic field.

Diamagnetism is a magnetic phenomenon in which the electrons inside a material reject the external magnetic field. Anton Brugmans discovered diamagnetism in 1778 as Bismuth was repelled by magnetic fields that he discovered. Faraday coined the term 'diamagnetic', which he eventually altered to diamagnetism. When a magnet or a magnetic field is introduced close to a diamagnetic substance, it repels it weakly. The magnetic intensity of these materials is very low or negative, and they are unaffected by temperature. Examples of diamagnetism include the bending of the water surface and the levitation of a frog.

Diamagnetic Materials' Properties

In Diamagnetic materials, there are no atomic dipoles since the resulting magnetic moment of each atom is zero, that is because of the paired electrons and these are repelled by a magnet. Because of this repulsion, the substances in it have a propensity to shift from a strong to a weak section of the external magnetic field in a non-uniform field.

Magnetization 'I', which is proportional to the field, has a very low intensity and is also negative. These have a low and negative magnetic susceptibility and the relative permeability is just under unity. Diamagnetic materials are temperature-insensitive as they don't obey Curie's law. Because the field is stronger at the poles, a rod of Diamagnetic material hangs in a homogenous magnetic field with its length perpendicular to the field direction. The magnetic dipole moment is tiny and polarised in the opposite direction as the magnetic field 'H'. If a Diamagnetic liquid is placed in a watch glass between two pole pieces that are very near to one another, liquid collects on the sides and depression appears in the center, where the field is greatest. When a liquid is put on a watch glass placed over two pole pieces that are sufficiently separated apart, the liquid accumulates in the middle, where the field is weakest. The source of diamagnetism is an induced dipole moment created by a shift in the orbital motion of electrons in atoms caused by the applied field.

Diamagnetism Materials or Diamagnetism Applications

Because diamagnetism is the outflow of magnetic fields within a material, big and powerful Diamagnetic materials can be levitated, or levitate magnets. In superconductors, the Diamagnetic response results in zero internal magnetic fields. In the presence of a strong permanent magnet, the Meissner effect illustrates how some materials may be readily levitated. High-temperature superconductors, on the other hand, are made from unique materials that require costly processing and cryogenic fluids to reach the superconducting state. Perfect diamagnets are superconductors that have a blue color and expel all of their external magnetic fields.

FAQs on Diamagnetic Materials

1. Is Water Diamagnetic in Nature? Why?

It is stated that water is diamagnetic. Diamagnetic molecules contain only electron pairs. However, water contains two bonding pairs of electrons between the hydrogen and oxygen atoms and two lone pairs of electrons which are present in the oxygen atom.

Paramagnetic molecules at least have one unpaired electron. This occurs when the molecule has an odd number of electrons (like in NO). It also occurs when there are even numbers of electrons (as in O2) in a few molecules.

We can notice that the water repels the magnet. This occurs because whenever we get any magnetic field near water, it creates its own magnetic field and thus repels the magnet, which is called diamagnetism.

2. How to Identify if a Molecule is Either Paramagnetic or Diamagnetic?

We can determine whether a material is either diamagnetic or paramagnetic by using a Gouy balance method. If we place material near a strong magnet, the paramagnetic materials are attracted to the magnet of the balance, where the diamagnetic materials are repelled.

It is also pointed out that all paramagnetic materials are also diamagnetic, but diamagnetic materials are not required to be paramagnetic. 

The force the Gouy balance method exerts on a paramagnetic material has both a paramagnetic component and a diamagnetic component. However, typically, the diamagnetic component is much weaker than that of the paramagnetic component.

3. What are the properties of diamagnetic materials?

Diamagnetic materials have a lot of properties. These materials do not obey curie's law and don't depend on temperature. They are always repelled by a magnet and when placed in a magnetic field, they tend to travel towards the weaker part of that magnetic field. Their relative permeability is slightly less than 1 and their magnetic susceptibility is small being negative. Diamagnetic materials' intensity of magnetization is proportional to the field. 

4. What are superconductors?

Superconductors can be described as those materials which show superconductivity i.e., they have no electrical resistance and are not affected by an external magnetic field. They can be termed as the perfect diamagnetic materials as they obey the perfect diamagnetic screening as they expel all magnetic fields. Although, at normal temperatures, superconductors can not be made because superconductivity can only be achieved at very low temperatures. 

5. How can I study the diamagnetic materials and their properties?

To study the diamagnetic materials, their types and their properties, you can refer to the article which is given above in the FAQ section. You will get detailed information related to all these topics. You can visit the website of Vedantu or can also download its app to get access to different kinds of study materials like video lessons, doubt-clearing sessions, notes, etc. All these resources will help you to learn all the concepts related to diamagnetic materials.