Room temperature superconductivity

Context

Recently, two South Korean researchers proposed papers, claiming that a ‘lead-based compound’ developed by them had shown superconducting properties at room temperature, under normal pressure conditions.

• The discovery has the potential to revolutionize the technology space, and be one of the most impactful scientific discoveries of this century.

The first material to have been discovered to show super conductive properties was Mercury, which becomes a superconductor at close to 270 degree Celsius below zero.

 What is Superconductivity?

• Superconductivity refers to a state in which a material offers zero, or near-zero, resistance to electric current.
• A current is nothing but the movement of charged particles, electrons in most cases, in a particular direction. When the electrons move, they collide, and interact, with other atoms in the material.
• The current flowing encounters resistance which is an essential property in electrical conductivity.
• Resistance involves a loss of energy, mostly in the form of heat. This is the reason why electrical appliances get heated is this resistance.

What are Superconducting materials?

• Most of the other materials commonly used as superconductors are Lead, Aluminum, Tin, Niobium, and several others –at comparable temperatures, called critical temperature.
• There are several elements that show superconductivity at higher temperatures like up to 150 degrees.
• Scientists are looking for a material that can display superconductivity at room temperature (usually considered to be between 20 and 25 degree Celsius) and under normal pressure conditions.

How Superconductivity helps?

• Elimination of the electric resistance can result in super-efficient electrical appliances like removal of transmission losses in power cables, and massive gains in energy.
• Also, Superconducting materials show very interesting behaviour under magnetic field which allows the functioning of systems like the MRI scan machine and the superfast Maglev trains that float above the tracks.
• Superconductors have very critical uses in a wide variety of other scenarios as well.

What are the existing issues faced to induce superconductivity?

• As of now, superconductivity can be achieved only at very low temperatures, more than 250 degree Celsius below zero, very close to absolute zero which is – 273 degree Celsius.
• Additionally, some compounds are difficult to be produced; they are brittle and chemically unstable.
• The need of low temperatures for the materials to become superconductive, close to the absolute zero, which results in high operating costs.

Why the discovery of Room temperature conductivity significant?

• It has applications in magnetic resonance imaging (MRI) machines, low-loss power lines, and ultra-powerful superconducting magnets to mobile-phone towers.
• Researchers are also experimenting with them in high-performance generators for wind turbines.

Other researches related to superconducting materials:

• Recently, the researchers have created a material that is superconducting at room temperature, however, it only works at a pressure of 267 Gigapascals (GPa), which is equivalent to about three-quarters of pressure at the centre of Earth (360 GPa).
• Material Used: A mixture of carbon, hydrogen and sulfur was put in a microscopic niche carved between the tips of two diamonds (diamond anvil) and laser light was used on them to trigger chemical reactions.

India’s steps in similar direction: Various Indian research groups work on developing novel superconducting materials, and also strive to bring upon significant improvements in the functioning of already existing diverse superconductors ranging from the commonly used metallic A-15 compounds to cuprates, boro-carbides, borides, iron pnictides and chalcogenides to the more recent topological ones. Some of the recent developments are: topological insulators superconductivity; superconductivity at interface of insulator ultra-thin films; Size effects in Nano structured superconductors along with superconducting junctions, circuits and qubits.