Superconductivity

What is Superconductivity? What are the applications and what are the challenges associated with them? Read further to know.

Superconductivity is a fascinating phenomenon that occurs in certain materials when they are cooled below a certain temperature, resulting in the complete absence of electrical resistance.

This article provides an introduction to the concept of superconductivity, its history, and its applications.

History of Superconductivity

The history of superconductivity dates back to 1911 when Dutch physicist Heike Kamerlingh Onnes discovered that mercury’s electrical resistance disappears when cooled to very low temperatures. He found that mercury’s resistance fell sharply at 4.2 Kelvin (−268.95 °C), a temperature that is only slightly above absolute zero. This discovery marked the birth of the field of superconductivity.

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Types of Superconductors

Superconductors can be classified into two main types:

1. Type I superconductors: These superconductors have a single critical magnetic field (Hc), above which they cease to be superconducting. They exhibit perfect diamagnetism below the critical field and show a sudden loss of superconductivity when the field is exceeded. Examples of Type I superconductors include Mercury (Hg), Lead (Pb), and Tin (Sn).
2. Type II superconductors: These superconductors have two critical magnetic fields: Hc1 and Hc2. They can exist in two different states, a mixed state and a Meissner state. The mixed state is characterized by a flux lattice, in which the superconductivity coexists with magnetic flux lines. In contrast, the Meissner state is a pure diamagnetic state in which the magnetic field is completely expelled from the material. Type II superconductors are more technologically significant than Type I because they can carry a much larger current density. Examples of Type II superconductors include Niobium-titanium (NbTi), Niobium-tin (Nb3Sn), and Yttrium-barium-copper-oxide (YBCO).

Superconductivity Applications

Superconductivity is a phenomenon where certain materials exhibit zero electrical resistance and the expulsion of magnetic fields when cooled below a critical temperature. This unique property of superconductors has opened up a plethora of opportunities for their use in various fields. Here are some of the major applications of superconductivity:

1. MRI machines: Superconducting magnets are an essential component of MRI machines, which use strong magnetic fields and radio waves to produce detailed images of the inside of the human body. Superconducting magnets are capable of producing higher magnetic fields than traditional magnets, resulting in clearer and more accurate images.
2. Particle Accelerators: Superconducting magnets are also used in particle accelerators, which are used to study the behavior of subatomic particles. The magnetic fields produced by superconducting magnets help to guide and focus the particles as they travel through the accelerator, enabling scientists to study their properties and interactions.
3. Power Transmission Cables: Superconducting materials can be used to create power transmission cables that have almost no electrical resistance. This means that electricity can be transmitted over longer distances with less energy loss, resulting in more efficient and cost-effective power transmission.
4. Electric Motors and Generators: Superconducting materials can be used to create more efficient electric motors and generators, which are essential components of many machines and devices. Superconducting motors and generators can operate with the greater power density and efficiency than traditional motors and generators, resulting in less energy consumption and lower operating costs.
5. Superconducting Quantum Computers: Superconducting materials are also being used to develop quantum computers, which have the potential to revolutionize computing by performing complex calculations much faster than traditional computers. Superconducting quantum computers use superconducting circuits to manipulate and store quantum information, which could lead to advances in fields such as cryptography, drug discovery, and materials science.
6. Fusion Energy: Superconductors are being investigated as a potential solution for producing sustainable fusion energy, which involves merging atomic nuclei to release energy. Superconductors are being used to create powerful magnetic fields that can confine and control the plasma used in fusion reactors, enabling the production of large amounts of energy.
7. High-Speed Transportation Systems: Superconductors are being explored as a potential solution for creating high-speed transportation systems, such as Maglev trains. Maglev trains use superconducting magnets to levitate and propel the train, resulting in faster and more efficient transportation.
8. Improved Energy Efficiency: Superconductivity can be used to create more efficient power transmission cables, motors, and generators, resulting in less energy loss and lower operating costs.
9. Faster Computing: Superconducting materials are being used to develop quantum computers that can perform complex calculations much faster than traditional computers. This could lead to advances in fields such as cryptography, drug discovery, and materials science.
10. Sustainable Energy: Superconductors are being investigated as a potential solution for producing sustainable fusion energy, which involves merging atomic nuclei to release energy. Superconductors can create powerful magnetic fields that can confine and control the plasma used in fusion reactors, enabling the production of large amounts of energy.

Challenges Associated with Superconductivity

Despite its vast potential, there are still several challenges that need to be overcome before superconductivity can be widely adopted.

1. High Cost: Superconducting materials are expensive to produce and require special manufacturing processes that add to their cost. This can make it challenging to adopt superconducting technology on a large scale.
2. Low Critical Temperatures: Superconducting materials typically require extremely low temperatures to exhibit their properties. This can be challenging to achieve and maintain, and can also limit the practical applications of superconductivity.
3. Sensitivity to Magnetic Fields: Superconducting materials are sensitive to magnetic fields, which can disrupt their properties. This can limit their use in applications that involve high magnetic fields, such as particle accelerators.
4. Mechanical Fragility: Some superconducting materials are mechanically fragile, which can make them challenging to work with and limit their use in applications that require mechanical strength.

Superconductivity-Indian Scenario

India has a long history of research in superconductivity, with notable contributions from institutions such as the Tata Institute of Fundamental Research (TIFR) and the Indian Institute of Technology (IIT) Bombay. This section provides an overview of the state of superconductivity research in India, including ongoing initiatives like the National Superconductivity Mission, which aims to promote the development of superconducting materials and their applications in various sectors.

National Superconductivity Mission

The National Superconductivity Mission (NSM) is an initiative launched by the Government of India in 2017 to promote research and development in the field of superconductivity. The mission aims to develop indigenous technology for superconductors and their applications in various industries, including healthcare, energy, and transportation.

The NSM is being implemented by the Department of Science and Technology (DST) in collaboration with the Department of Atomic Energy (DAE) and the Council of Scientific and Industrial Research (CSIR). The mission has a budget of INR 750 crores (approximately USD 105 million) for a period of five years.

Aims and Objectives

The NSM aims to develop indigenous technology for high-temperature superconductors and their applications in various industries, including energy, transportation, and healthcare. Superconducting cables, for example, can be used to transmit electricity with minimal losses, which can significantly increase the efficiency of the power grid.

The NSM also aims to establish test and characterization facilities for superconductors and superconducting devices. These facilities will enable researchers to study the properties of superconductors and develop new applications for them.

Another objective of the NSM is the development of superconducting devices and systems. Superconducting magnets, for example, can be used in medical imaging machines such as MRI scanners, and superconducting generators can be used in wind turbines to increase their efficiency.

Future Prospects

The future of superconductivity is full of promise, with new discoveries and applications on the horizon. This section explores some of the potential future developments in superconductivity, such as the use of superconductors in fusion energy, space exploration, and high-speed transportation systems. The section also discusses the challenges and opportunities that lie ahead for superconductivity research and development.

Conclusion

Superconductivity offers exciting opportunities for various fields, but there are still challenges that need to be overcome before it can be widely adopted. With ongoing research and development, it is possible that many of these challenges will be overcome, and superconductivity will become an essential component of modern technology. The potential for improved energy efficiency, faster computing, medical imaging, high-speed transportation, and sustainable energy make superconductivity an area of great interest and promise.

Article Written By: Priti Raj