Paramagnetism


Introduction

Paramagnetism is demonstrated as the kind of ''magnetism'' through which components are weakly captivated by evidently applied ''magnetic fields''. It forms induced and internal magnetic fields in the administration of the applied field of magnetism. The magnetic phenomenon of an atom possessing more than one unpaired electron is termed Paramagnetism. Unpaired electrons in the magnetic field have a magnetic dipole moment and perform like tiny magnets.

What is Paramagnetism?

Paramagnetism is defined as a magnetism feature of materials type feebly captivated by powerful magnets. It was named and researched by Michael Faraday, a British scientist in 1845. It is determined that some of the compounds and most of the elements are paramagnetic. The paramagnetic materials have a permanent dipole moment that is magnetic because of the unfinished cancellation of orbital magnetic moment and electronic spin.

Dipole moments are aligned randomly in the invisibility of the field of the magnet. Hence, the material of Paramagnetism does not have net macroscopic magnetisation. Paramagnetic materials are demonstrated as the materials that are weakly fascinated by magnets. The substances incorporate gold, oxygen, aluminium and more. These atomic elements consist of electrons; among the many some spin in a similar direction. It is because the property provides the atoms with the same polarity.

Paramagnetic Liquid

Figure 1: Paramagnetic liquid of the material in paramagnetism

The alignment degree relies on the external field's strength and inversely on the specimen temperature. The orientation is again distracted by thermal vibration in paramagnetism and demagnetised when the materials of Paramagnetism are dissolved from the magnetic field.

This is the main reason why paramagnetic substances cannot be utilised as permanent magnets. For instance, if a glass filled with a small amount of paramagnetic liquid is kept over two dissimilar magnetic poles, the liquid reflects an elevation in the middle point.

Currie law

Currie's law was uncovered by Pierre Curie and the law particularised that magnetisation is paramagnetic material that differs directly with the application of a magnetic field. The power of this magnetisation differs inversely with the application of temperature to the material according to Curie's law. According to the law, it means that magnetisation in the substance is less if the temperature of paramagnetic material is more. The formula of Currie's law is represented as C=MT/B, where M denotes the magnetisation of the substance, C determines Currie's constant, B is the field of magnet solicitude to the material and T is the temperature represented in Kelvin. The physical essential constant of Currie relies on the efficient movement of ions which has an accurate average solid moment. It is the calculation of how powerfully a component can display magnetic orientation rather than passing through thermal fluctuations.

Paramagnetic materials and their susceptibility

Material 

Magnetic Susceptibility [10-5] (SI units)
Aluminium (Al) 2.2
Magnesium (Mg) 1.2
Sodium (Na) 0.72
Lithium (Li)1.4

Table 1: Magnetic susceptibility of Paramagnetic material

Paramagnetic materials are because of the presence of some electrons that are unpaired and create the electrons paths realignment that is caused by an external magnetic field.

Electric fields

Figure 2: Paramagnetic materials and electric fields

The above image represents alignment in paramagnetic materials when the electric field is removed and applied. Paramagnetic materials do not retain any sort of magnetisation in the non-appearance of the externally applied field of the magnet because the motion thermally randomises the spin alignment liable for magnetism.

Properties of Paramagnetic material

  • The atoms of paramagnetic substances have a permanent magnetic moment because of unpaired spin when the net "atomic dipole moment" represents zero. The paramagnetic field region shifts from a weak field to a strong field in the non-uniform external magnetic field.

  • The paramagnetic rod kept itself parallel to the field of magnetism because the field is powerful near the poles (Zhang et al. 2021). In Paramagnetism, paramagnetic liquid in the U-tube arose in the limb which is between magnetic poles.

  • Magnetisation intensity in Paramagnetism is positive, relatively small and is directly proportional to the field of magnetisation. The susceptibility of magnets in Paramagnetism is also positive and small.

  • The lines of the magnetic field become deeper inside the substances of Paramagnetism (Haskel et al. 2020). Permeability is moderately larger than 1 and magnetisation of paramagnetic materials is inversely proportional to the ultimate temperature.

  • Paramagnetic materials follow curie's law based on which susceptibility of the magnet is inversely proportional to the ultimate temperature.

Difference between Paramagnetism and diamagnetism

Paramagnetic substanceDiamagnetic substance
Paramagnetic substances in magnetism are frailly captivated by a magnetIn diamagnetism, the diamagnetic substances are debilitated and repulsed by a magnet.
The substances in paramagnetism have the tendency to get shifted from weaker to stronger parts in the external ''non-uniform'' field of magnet.The substances in diamagnetism have the tendency to get shifted from stronger to weaker parts in an external "non-uniform" field of magnet.
The magnetic susceptibility displayed in the materials of paramagnetic is small and positiveThe susceptibility of magnets in diamagnetic substances tends to be negative.
The paramagnetic gas spreads in the administration of the magnetic field if the gas is introduced between magnet pole pieces.The diamagnetic gas spreads at the right angle of the field of the magnet if the gas is introduced between magnet pole pieces.
Calcium, Lithium, Oxygen, Chromium, and Platinum are some of the instances of Paramagnetism.Mercury, gold, silver, nitrogen, and copper are some instances of diamagnetic substances.

Table 2: Difference between Paramagnetism and diamagnetism

Uses of paramagnetic material and its determining behaviour

Paramagnetic materials or pharmaceuticals are generally spread into particular organ systems or sites of diseases that are clinically helpful for contrast of tissue enhancement in the images of nuclear magnetic resonance (Thoughtco, 2022). In determining the behaviour of paramagnetic material in an external magnetic field, consider the instance of an Oxygen tank. In the first stage, the alignment of the external ''magnetic field'' is determined where the ''magnetic field'' of the earth points from South to North. In the last stage, the paramagnetic object's net dipole moment will be in similar supervision as the external field. The net dipole moment also points from South to North.

Conclusion

In Paramagnetism, the dipole moments do not line up with appropriate uniformity because the atomic motion randomly within the substance leads to atomic collisions. The atoms emerge out of orientation not permanently after such sorts of collision. In reality, it is demonstrated in Paramagnetism, that the net dipole moment of the substances of paramagnetic waves is less in comparison to the atomic interactions that are accounted for. It is obtained from the fact of Paramagnetism that the external field is parallel to the field.

FAQs

Q1. What is the difference between diamagnetic and paramagnetic materials?

Paramagnetic materials are feebly attracted by the field of a magnet whereas diamagnetic material is weakly repelled by a magnetic field.

Q2. What are the main types of magnets?

Diamagnetic, Paramagnetic and ferromagnetic are mentioned as the main types of magnets.

Q3. What is the definition of susceptibility of magnet?

Magnetic susceptibility is referred to as a calculation of the estimation a body is going to be magnetised in the applicable field of a magnet.

Q4. Where Currie's temperature application is found?

The temperature at which material transforms into a paramagnetic substance on heating is referred to as Currie's temperature. The change is basically employed in optical media storage for erasing old information.

Q5. What is a paramagnetic material?

It is a kind of material which is oriented to the available fields of a magnet.

References

Journals

Davidovich, M. V. (2018). Diamagnetism and paramagnetism of a metamaterial consisting of rings with a current. JETP Letters, 108(5), 279-286. Retrieved from: https://www.researchgate.net

Haskel, D., Fabbris, G., Kim, J. H., Veiga, L. S., Mardegan, J. R. L., Escanhoela Jr, C. A., ... & Kim, J. W. (2020). Possible quantum paramagnetism in compressed Sr 2 IrO 4. Physical review letters, 124(6), 067201. Retrieved from: https://arxiv.org/pdf/1911.09786

Zhang, J., Kosaka, W., Kitagawa, Y., & Miyasaka, H. (2021). A metal–organic framework that exhibits CO2-induced transitions between paramagnetism and ferrimagnetism. Nature Chemistry, 13(2), 191-199. Retrieved from: http://canli.dicp.ac.cn

Websites

Phys, 2022. About Applications of Magnetism. Retrieved from: https://phys.libretexts.org [Retrieved on: 7th June 2022]

Thoughtco, 2022. About Paramagnetism Definition and Examples. Retrieved from: https://www.thoughtco.com [Retrieved on: 7th June 2022]

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Updated on: 18-Aug-2023

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